Assessment of fisheries habitat, Charlotte Harbor and Lake Worth, Florida final report for contract period 18 November 1981 through 30 November 1983

[From the U.S. Government Printing Office, www.gpo.gov]

I U. S. DEPARTMENT . '", ;'<F N0A-
COASTAL SERVICES :.'r ,
2234 SOUTH HOBSOr. . f,
CHARLESTON , SC ".'" - ''

ASSESSMENT OF FISHERIES HABITAT:

CHARLOTTE HARBOR AND LAKE WORTH, FLORIDA

Final Report

for contract period 18 November 1981 throuqh 30 November 1983

Barbara A. Harris, Kenneth D. Haddad, Karen A. Steidinger,

and James A. Huff

Florida Department of Natural Resources

Bureau of Marine Research

Marine Research Laboratories

St. Petersburg, FL

November 1983

I ~ ~ ~ ~ ~ ~ 3?Property of CSC Library

I a This project was supported by a grant from the Florida Office of Coastal

' rp-r- Management, Department of Environmental Requlation, with funds provided by

rem the United States Office of Ocean and Coastal Resource Management, NOAA,

under the Coastal Zone Management Act of 1972, as amended.

CONTENTS

Contents
Acknowledgements
I. Introduction and Rationale 1
II. Estuaries
A. Description 9
B. Importance of Estuaries as Nursery Grounds 13
C. Estuarine Habitat Components 15
1. Mangroves 16
2. Seagrass Beds 21
3. Salt Marshes 25
4. Mud Flats 29
5. Oyster Reefs 30
6. Unvegetated Subtidal Bottom Areas 32
7. Water Column 33
D. Estuarine Food Web 35
III. Adjacent Land Use and Habitat Alteration
A. Estuarine Limitations 39
B. Perturbations 43
IV. Restoration 51
A. Seagrass Restoration 52
B. Mangrove Restoration 57
C. Salt Marsh Restoration 61
D. Miscellaneous Restoration Techniques 64
V. Linking Juvenile Fish to Estuaries
A. Species Found in Estuaries 69
B. Diet Analyses 75
C. Stable Isotope Analyses 80
D. Correlations Between Fisheries Yield and
Habitat Type 83
E. Correlations Between Declines in Fisheries
Yield and Wetlands Destruction 85
1. Life History Studies
Red drum (Sciaenops ocellatus) 86
Spotted seatrout (Cynoscion nebulosus) 88
Black mullet (Mugil cephalisT 91
Blue crab (Callinectes sapidus) 92
Pink shrimp (Penaeus duorarum) 94
2. Fisheries Statistics: l950-1981 97
Charlotte Harbor 101
Lake Worth 106
VI. Land Use and Vegetation Maps of Charlotte Harbor and
Lake Worth: Historical and Recent 111
A. Background 111
B. Problems and Recommendations 112
C. Description of Map Products 115
D. Acreage Values - Charlotte Harbor
1. General Site Description 119
2. General Acreage Values 123

ACKNOWLEDGEMENTS

We express much gratitude to many people who provided assistance

during this project, particularly to those who helped formulate ideas on a

project to assess fisheries habitat loss during discussions as far back as

1980. We thank NASA Earth Resources Laboratory personnel for initial

training in ELAS and for answering the many questions concerning the

development of the Marine Resources Geobased Information System. We thank

Fred Calder and Dave Worley (DER) for providing valuable advice and support

in developing the successful grant application. Jim Stoutamire (DER) did

much to facilitate the completion of this report by providinq expeditious

contract guidance. Thanks also to Roy Williams and Mark Leiby for their

help with fisheries data; to Ann Marshall of Lee County's Marine Extension

Office, Roger Clark and William Sheftal of DNR Bureau of Land Manaqemnent,

Steve Travis of DNR Bureau of Parks and Recreation, and Stewart Bradow of

DER for their help in field sampling; to Mike Sprague for the use of SEAS'

boats; to Robin Lewis of Mangrove Systems, Inc. for use of his data in our

presentations; to Mark Moffler for his excellent drawings of seagrasses;

to David Crewz for his drafting and drawings of mangroves; to Warren Clary

of DOT for providing computer training; to Mary Krost and library staff

for providing much assistance; to Winnie Sue Moravec and Jeff Brown for

folding maps and binding the report, to DNR's Division of Recreation and

Parks for the use of their white printer; to Alonzo Felder for drafting

numerous graphs; and, finally, to Margie Myers for typing this report.

I I~~~~~~~~. INTRODUCTION AND RATIONALE

Estuaries are coastal embayments or lagoons where saltwater and

freshwater interact. They are among the most productive ecosystems on

I ~~~Earth because of this interaction and their relative shallowness compared

to open seas. Estuaries provide food and shelter for a multitude of living

resources such as fishes and crustaceans. Their fringing vegetation and

5 ~~~wetlands can absorb flood waters, recharge ground water, assimilate wastes

and excess nutrients and, therefore, they maintain water quality, recycle

5 ~~~nutrients, and control erosion. Estuaries also have a direct aesthetic,

recreational, and commercial value, exemplified by the location of urban

S ~~~centers and recreational and commercial enterprises. Protection and

5 ~~management of Florida estuaries to retain their natural functions and

benefits to man is tied to efficient growth management.

Nearly 70% of Florida's recreational and commercial fisheries species

are dependent on estuaries during at least part of their life span, usually

S ~~~in the juvenile stages prior to reaching harvest size. In Nakamura et

5 ~~~al.'s (1980) listing of recreational finfish stages found in estuaries, hle

stated "In each estuarine area, the number of species was lowest for eggs,

5 ~~second lowest for larvae, third lowest for adults, and highest for

juveniles .... Thus, additional credence is provided to the importance of

5 ~~~estuaries as nursery grounds for juvenile recreational fishes...." ShrirnD

and many species of juvenile fishes move out of the estuary to offshore

I ~~~areas to spawn or spend their adult life. They reenter the estuary as

5 ~~~eggs, larvae or juveniles. Some species, such as spotted seatrout, spend

their entire life within the estuary while others move out as juveniles and

come back to spawn near barrier islands or at the lower reaches of the

estuary.

Estuarine environments provide necessary food and protection from3

predators for these growing fishes. This dependency is one of inference

based on known repeated frequencies and abundance of juveniles in bays and
lagoons. Various experiments and field observations have also illustrated

that shallow bay bottoms and intertidal vegetated areas provide cover and

food items to a variety of animals. These estuarine and nearshore areas3

lend support and continuity to animal populations seeking refuge, but only

if the estuary, as a system of structural components and interactiveU

processes, maintains a healthy, dynamic state of diversity and

productivity.

Florida has extensive estuarine and marine coastal areas with emergent

vegetation such as marsh grasses and mangroves and submergent vegetation

such as seagrasses. About 430,000 acres of mangroves and an estimated3

502,000- acres of submerged vegetation exist in Florida. Sixty percent of

saltwater wetlands in the United States occur in Gulf Coast states and the

Gulf of Mexico supports two of the largest U.S. commercial fisheries:3

menhaden and shrimp. Amounts of emergent and submergent vegetation and

freshwater flow have been associated statistically with shrimp and fish3

yield in some areas.

The estuary is a multi-dimensional and multi-structured habitat forI

living resources such as fishes and crustaceans. Habitat represents where

an organism lives in time/space and includes bottom tyoe (e.g. vegetated),

water depth, water quality, salinity, and other parameters than can change1

daily, seasonally or geographically. Habitat has vertical and horizontal

vari abilIi ty. A specific species' habitat typically changes with age

whereby the animal moves from one area to another. The species is adapted

to such change; it is part of its life history. If the habitat is removed

I ~~or altered in a substantial .way, populations of that species may not

survive because of stress, lack of food, or increased competition or

predation. Many people interpret estuarine habitat by structural

component, e.g. mangrove stands, salt marshes, seagrass beds, oyster reefs,

mud flats, sand bars, or even man-made structures such as jetties. These

3 ~~~components represent shoreline and bottom type. Although certain species

or assemblages may be more prevalent in these areas, "habitat" per se is

I ~~~temporally and spatially multi-dimensional. It varies from one species to

3 ~~~another and is defined by a multitude of parameters. It is more than a

person can perceive visually from any one vantage point.

* ~~~~A variety of potential variables exist to determine relationships

between species and habitat. For example, the U.S. Fish and Wildlife

I ~~Service (USFWS) and others have identified availability of food items at

different ages, spawning season and area, age at spawning, transport of

eggs and larvae, larval recruitment and its area and timing, salinity and

3 ~~~temperature tolerances, substrate type, presence and abundance of

predators, water quality, available cover, and other habitat and species

3 ~~~variables. Resource partitioning among different species as juveniles or

adults can involve different temporal and spatial distributions by age and

I ~~~feeding habits. Differences in feeding apparatuses, digestive systems, and

3 ~~feeding habits can lessen direct competition for available resources and

allow species to co-exist. To develop Habitat Suitability Indices

3 ~~~(models), USFWS has used ranges and means of salinity, turbidity, depth,

* ~~~~~~~~~~~~~~~~~~3

dissolved oxygen, and temperature, water color, bottom type, sediments, and

diversity or amount of cover. The index is thought to have a relationship

to "habitat" carrying capacity, but values only suggest whether one area is

more or less suitable than another.

Since the 1950's, Florida's population has soared. With people came

development, agriculture, urbanization, and industrialization. Such3

development has destroyed or altered coastal habitats and wetlands. These

events have led to loss of productive vegetation and cover, loss of openI

bay areas, alteration of freshwater flow patterns, pollution of rivers and

estuaries, and other perturbations.

The direct loss of estuarine shoreline and bottom habitat componentsI

such as saltmarshes, mangroves, and seagrasses has been dramatic,

particularly adjacent to urban areas. Such direct loss has resulted from

dredging and filling, channelization, ditching, and mosquito impoundments.

For example, Lewis (1979) documented a 44% loss of mangroves on theI

southern shore of Hillsborough County and estimated an 81% loss of

seagrasses in Tampa Bay. Frayer et al. (1982) estimated that over one-

third of the United States losses in coastal wetlands due to urbanizationI

occurred in Florida. According to other projections, 215,000 additional

acres will be lost due to development during 1980-2000. Direct loss of

habitat components leads to loss of nursery habitat, increased suspended

loads, increased erosion, and decreased water quality. One of the most

dramatic examples of impact involves mosquito impoundments where salt

tolerant vegetation dies, poor water quality causes physiological stress,

and diverse fish assemblages are reduced to only a few tolerant speciesI

lower in the food chain (Harrington and Harrinqton, 1982). When one

impoundment was opened, it became revegetated and fish diversity increased

(Gilmore et al. 1982). This example points out that although habitat

components may be lost through removal or die offs, the habitat itself

merely changes; it has gone from a healthy environment with biotic

diversity and richness to one that supports fewer, less desirable species.

It then is the alteration of habitat that impedes the function and

efficiency of the system through shifts in species composition and loss of

certain populations.

Alteration of freshwater flow to coastal areas has severely impacted

estuarine systems. Alterations have occurred in timing, amount, quality,

and direction of freshwater discharge. Such alterations through water

retention areas, canalization, irrigation, and programmed releases can

increase or decrease estuarine salinity regimes and stress populations,

affect available dissolved oxygen, and affect the delivery and type of

nutrients and food particles. Modification of estuarine circulation

patterns through altered freshwater flow, channelization, dredge and fill,

bridges, and spoil banks can create poor flushing and exchange of water in

shallow areas and lead to a condition of excess nutrients and monospecific

algal blooms (eutrophication).

Other sources that can alter the quality and quantity of estuarine

habitats are point and nonpoint source pollutants, e.g. sewage, land

runoff, industrial wastes, pesticide spraying, mining, toxic chemical

spills, etc. Often these impacts are accumulative. Pollutants in the

water column may be barely detectable, yet they can be magnified in the

sediments through settling, adsorbtion, flocculation, and high residency.

They can, therefore, impact the system because the bottom and water are

coupled through biological, physical and chemical interactions. Even

though estuaries are dynamic systems adjusted to wide fluctuations, major3

acute or chronic stresses or impacts will alter the systems and the life it

supports.I

Amounts of emergent and submergent vegetation and freshwater flow have

been associated statistically with fisheries yield in some areas, yet mostU

perceived fisheries declines are based on user group observations and/or

reduced commercial landings, not on documented catch-per-unit effort

decreases. Sports fishermen and commercial fishermen have both complained

of reduced resource availability and have attributed it to a variety of

causes, but mainly to overfishinq and/or habitat alteration. However,3

without adequate fisheries statistics to determine total fishing mortality

and population dynamics, catch-per-unit effort and total populationI

abundance cannot be determined for such multispecies fisheries (>1001

species of interest in Florida marine waters). Correlation of fisheries

decline with habitat component loss is also difficult because of problems

with available fisheries statistics and lack of current quantification for

carrying capacity of different habitat components or ecosystems. CarryingI

capacity itself is difficult to define and characterize, much less

quantify, because it involves both benthic and pelagic environments, their

structure, quantity and quality. It represents how much biomass of a3

specific species or multiple species can be supported in a specified time-

space relationship. Carrying capacity can differ between salt-narshes, and

vegetated bay bottoms; it could vary between two seagrass beds in, two

different parts of the same estuary.

Florida is currently the second fastest growing state in the nation3

with 17.4 million residents projected for the year 2000. Over 60% of the

1000 new residents per day will locate along the coast; today, over 73% of3

Florida's residents already live in coastal counties. Decisions and

implementation of actions in the next few years will determine how

I ~~Florida's estuaries survive and in turn whether they will support living

resources as we know them now, and whether they will retain any aesthetic

and recreational appeal and value.

This is a critical period in Florida's history, one requiring

farsighted management and legislation. First we must understand what an

I ~~~estuary is, how it functions, and why it is necessary to maintain it as a

system. Only if we recognize and accept the values of individual estuaries

can we manage them properly.

The Department of Natural Resources, as well as many others,

recognizes that habitat alteration is a significant factor affecting

fisheries yield. Therefore, the Department has made a long term commitment

through various research projects and legislative requests to pursue

I ~~~documentation of such alterations, their effects on resource availability

and yield, the development of a more comprehensive fisheries statistics

program, restoration and enhancement techniques, and a program to purchase

sensitive lands. Concurrently with development of mitigation, restoration

and creation of estuarine habitat and the establishment of preserves and

I ~~~sanctuaries, we need to: 1) conduct long term multidisciplinary system

studies, 2) conduct trend analyses by inventorying estuarine resources and

changes therein over time, and 3) inform and educate the public on the
function and importance of estuaries. This Coastal Management oroject

entitled "Assessment of Fishery Habitat Loss, Use of a Coastal Geographic

Digital Data Base and Establishment of a Geobased Information System'

addressed trend analyses over time to correlate changes in habitat

I ~~~components, such as mangroves and seagrasses, with changes in fisheries

* ~~~~~~~~~~~~~~~~~~~~7

I
yield using aerial photography and commercial landings by individual
system, i.e. the Charlotte Harbor System and the Lake Worth System. The
continuance of the program in 1983-85 addresses trend analyses for U
additional systems and public education.

I
I
I
I
I
I
I
I
I
I
I
I
I
8

I
I
I
I
I
I ~Estuaries
I
I
Idacent Land Use and Habitat
I Alteration
I
I
I Restoration
I
I
I
I
I
I

I ~~~~~~~~~~~II. ESTUARIES

I II~~1 A. DESCRIPTION

U ~~~~Estuaries and lagoons constitute 80-90% of the Atlantic and Gulf

3 ~~~coasts of the continental United States (Lauff 1967). Pritchard (1967)

provided the most widely accepted defiinition of an estuary: "a semi-

3 ~~~enclosed coastal body of water which has a free connection with the open

sea and within which sea water is measurably diluted with fresh water

I ~~~derived from land dra inage." This fresh water is introduced as river flow,

3 ~~~stream flow, or overland sheet flow, with resulting estuarine waters known

as "brackish." Lankford (1977) described a coastal lagoon as "a coastal

3 ~~zone depression below MHHW (mean high high waves) having permanent or

ephemeral communications with the sea, but protected from the sea by some

I ~~type of barrier."

Estuaries are characteri zed by constant and variable changes. Tides

daily influence water depth, salinity regimes, and the presence or absence

of water in very shallow zones. Heavy rainfall introduces for short time

periods large amounts of fresh water. Dry spells cause estuarine waters to

3 ~~~become more saline. Wind mixes the water. Estuaries are capable of

withstanding these wide ranges in environmental parameters - conditions

I ~~~that normally would collapse other ecosystems. These variabilities are the

3 ~~~driving forces of estuaries. 'Without them, the system would not be an

estuary.

5 ~~~Day and Yanez-Arancibia (1982) describe the physical traits of

estuaries:

1 ~~~~~~~~~~~~~~~~~~9

I1. They are semi-enclosed yet connected to the sea. This partial

envelopment provides a buffer from oceanic effects.

2. They receive input from a freshwater source. The amount of fresh-

water varies from very low during periods of extreme drought to

high after storms or seasons of heavy rainfall. Dissolved andI

suspended materials and nutrients also enter the system via fresh-

water inflow.

3. Tides influence the circulation pattern of estuaries and are

important in physical, chemical, and biological interactions

Tidal action allows the mixing of fresh and salt water and plays a3

major role in exporting and importing material from and into the

estuary.

4. Estuaries are shallow. Surface turbulence, such as wind and3

waves, affects the bottom as well as the surface.

5. Estuaries have complex water circulation patterns, influenced by3

winds, tides, river currents, and the qeormorphology of the basin.

6. Relatively rapid geomnorphological changes occur in estuaries be-I

cause powerful physical energies resuspend and move sediments.

This characteristic is exemplified in Florida by the change in

shape and location of some barrier islands and the natural con-3

struction of new islands or channels during severe storms.

Whittaker (1975) found that estuaries, in comparison to several

other ecosystem types, are one of the most highly productive systems on
Earth (Table 1). Estuaries are characterized by high rates of primary and

secondary production because of their rich nutrient supplies, efficient

Table 1. NET PRIMARY PRODUCTION OF MAJOR ECOSYSTEMS
(After Whittaker 19/b5)

Ecosystem Net Primary Production
(g/m2/yr dry weight)

Normal range Mean

Lake and stream 100-1500 500

Swamp and marsh 800-4000 2000

Tropical forest 1000-5000 2000

Boreal forest 400-2000 800

Woodland and shrubland 200-1200 600

Savanna 200-2000 700

Temperate grassland 150-1500 500

Tundra and alpine 10-400 140

Desert scrub 10-250 70

Extreme desert, rock and ice 0-10 3

Agricultural land 100-4000 650

Open ocean 2-400 125

Continental shelf 200-600 350

Attached algae and estuaries 500-4000 2000

conservation, and the occurrence of several different types of primary

producers (Day and Yanez-Arancibia 1982). Estuaries are also ecologically

complex, not because of a high species diversity (species diversity is

actually quite low in estuaries), but because of the variety of environ-

mental factors, habitat types, and highly complex food webs.

Although estuaries are dynamic, transient, and variable, they are

remarkably stable as an ecosystem. Margalef (1968) explains that

ecological stability evolves in two different ways: (1) a system evolves

under constant conditions and develops a steady state and thus stability,

or (2) a system evolves under variable conditions and develops mechanisms

to adapt to the variability. Estuaries undoubtedly developed via the

second method. Estuarine biota have developed physiological and behavorial

patterns to adapt to their fluctuating environment (Day and Yanez-Arancibia

1982). Organisms that successfully dwell within the dynamic estuarine

system must be tolerant of change (Beal 1980).

Probably the single most renowned function of estuaries is their role

as nursery grounds for growing fish, shrimp, and shellfish. Because of

their high productivity, large food supply, diversity of cover, and

shallow, calm waters, estuaries serve as prime nurseries for many species.

This aspect will be discussed in detail in the next section.

High productivity of coastal offshore waters may result from the

existence of estuaries. Odum (1980) explained that most fertile coastal

zones receive nutrients either from deep water upwelling or from shallow

water outwelling with areas such as reefs, banks, seagrass beds, algal

mats, and salt marshes being the prime contributors. In Florida, mangroves

would also contribute nutrients. Odum (1980) stated that outwelling is

likely a periodic or seasonal occurrence, associated with high spring tides

and storms. Turner et al. (1979) found that offshore productivity and

densities of zooplankton, fish eggs, and fish larvae were strongly coupled

with the extent and productivities of local estuaries. They concluded that

the influence of estuaries on continental shelf ecology was extensive.

II B. IMPORTANCE OF ESTUARIES AS NURSERY GROUNDS

According to life history studies, very few marine species of

recreational and commercial value utilize the shallow coastal waters of

estuaries as spawning areas. However, estuaries are used extensively as

nursery grounds. Most finfishes and crustaceans migrate offshore to spawn.

The eggs are usually planktonic, developing into larvae that depend on

currents and tides to transport them toward shore. As post larvae, they

enter the estuary, and spend their juvenile existance in close association

with the estuarine system (Odum and Smith 1981). Some species grow within

the estuary for several years while others remain there for life. Numerous

authors such as Nakamura et al. (1980) and Odum and Smith (1981) have noted

the importance of estuaries as nursery grounds.

Joseph (1973) described nursery grounds as areas that (1) are physio-

logically suitable in terms of chemical and physical features, (2) provide

an abundant food supply, and (3) provide some degree of protection from

predators. Chemical and physical parameters include water depth, tempera-

ture, salinity, turbidity, and tidal and wave action. Climatic features

such as rainfall, cold spells, and wind coupled with tidal action may be

the most influencing factors on depth, temperature, and salinity,

irrespective of human influence. Because juveniles are more tolerant of

wide ranges in environmental variabilities than their adult counterparts,I

changes in depth, temperature, and salinity serve as protective mechanisms

for the juveniles by forcing out adults during periods of (for them)I

intolerable conditions. Seagrasses as well as mangrove roots and salt

marsh stalks mitigate predation by providing hiding places, as well as

baffles for waves and currents (Orth 1977). Beal (1980) summarized the

nursery aspect by stating that because the estuary is dynamic, species that

dwell there must be tolerant of change. This is certainly true for

juvenile fish and shrimp.

Margalef (1963) suggested that unpredictable environments character-I

ized by high abiotic stress maintain both a high resource standing crop and

low utilization by endemic species. Miller and Dunn (1980) applied this

concept to estuaries: an outside population whose early life stages are3

spent in estuaries to exploit the food source will profit by this

strategy.I

Miller and Dunn (1980) summarized the general features of feeding

relationships of estuarine juvenile fish assemblages:

1. Flexibility of feeding habits in time/space3

2. Omnivory

3. Sharing a common pool of resources among species5

4. Exploitation of food chains at different levels

by the same speciesI

5. Ontogenetic changes in diet with rapid growth5

6. Short food chains based on detritus/algal feeders.

The most important feeding characteristic is likely the first: the

ability to switch prey items in accordance with food availability, commonly

termed the generalist strategy. Miller and Dunn (1980) point out that

prey items undergo rapid and unpredictable changes in distribution and

abundance in response to abiotid stresses. For example, after a heavy

rain, the sudden presence of freshwater due to increased river flow,

terrestrial run-off, and the rain itself would probably produce a period of

hyposaline turbid conditions. This situation might present the juvenile

population with a new supply of food items. The generalist feeding

strategy then gives juvenile species a selective advantage over species

that have restricted diets.

II C. ESTUARINE HABITAT COMPONENTS

Florida estuaries are composed of six structural components or habitat

types: mangroves, seagrass beds, salt marshes, intertidal mudflats,

unvegetated subtidal bottoms, and oyster bars. Overlying all six is the

water column. In the intertidal zone, salt marshes and mangroves occur

high with mudflats and oyster bars found low. Seagrass beds grow in the

shallow subtidal zone. Unvegetated subtidal bottom occurs at depths below

the seagrass zone and within seagrass beds. The water column overlies all

the habitats during high tides and covers only the subtidal areas during

low tides. Sections II C1 through II C7 describe these seven areas in

greater detail.

II C 1. MANGROVES

Mangroves in Florida extend from the Keys to approximately 30�N

latitude on both coasts. Three species of mangroves are found in Florida

(Figure 1):

Red mangroves (Rhizophora mangle) are easily identified by their prop

roots. Reds generally grow nearest to the shoreline.

Black mangroves (Avicennia germinans) have characteristic small

verticle root offshoots, called pneumatophores, attached to the

underground roots and arising from the substrate. Blacks commonly

grow higher in the intertidal zone than reds.

White mangroves (Laguncularia racemosa) have a diffuse below-ground

root system with verticle, bulbous knee-like projections arising

from the roots. Whites generally occur much higher than reds or

blacks, out of the intertidal zone, in areas affected only by

extreme tides.

Odum et al. (1982) describe four factors that determine mangrove

distribution and extent of development:

1. Climate - since mangroves are a tropical species, they do not

tolerate temperatures below freezing for any length of time.

2. Saltwater - most mangroves are able to grow without difficulty in

pure freshwater habitats. However, they are faculative halo-

phytes; salinity acts as a competitive excluder to other vascular

plants.

3. Tidal fluctuation - tides serve as subsidies to mangrove systems

(a) The constant alternation of standing water and then no water

BLACK
MANGROVE

WHITE
MANGROVE
RED
MANGROVE

- -I HIGH TIDE

LOW TIDE

Figure 1. A stylized view of Florida mangroves.

and fluctuations in salinity reduces competition from other

vascular plants. (b) In some areas, tides carry salt water high

into the estuary against the outgoing flow of freshwater, allowingI

the establishment of mangroves well inland. Tides also transport

nutrients into mangroves, and export organic carbon, reducedI

sulphur compounds, propagules (seeds), and detritus.

4. Substrate and wave energy - the most productive mangrove systems

develop on substrates of anaerobic fine-grained muds composed of

silt, clay, and a large percentage of organic matter, with very

little wave energy.I

Lugo and Snedeker (1974) described six major mangrove forest communi-

ties (Figure 2): the overwash mangrove forest, fringe mangrove forest,

riverine mangrove forest, basin mangrove forest, hammock forest, and scrubI

or dwarf forest. Each type embodies its own characteristic variables,

ranges, and differences such as soil type, soil depth, flushing rates,

primary production, rate of litter decomposition, and nutrient recycling

rates.I

Mangroves are considered one of the Earth's most productive systems

(Odum et a]. 1982; see Table 2). Productivity of the three snecies vary

(Odum et a]. 1982); red mangrove has the highest net productivity, black

has intermediate values, and white retains the lowest, assuming the plant

inhabit the zones for which they are best adapted and that these areas ar

devoid of strong limiting factors. Odum et a] (1982) additionally noted

that reds experience a decreasing gross productivity with increasing

salinity while the productivity for blacks and whites increases to a

certain extent with increasing salinity.

(I) OVERWASH FOREST (2) FRINGE FOREST

(3) RIVERINE FOREST (4) BASIN FOREST

(5) HAMMOCK FOREST (6) SCRUB FOREST

Figure 2. The six mangrove communities (redrawn from
Odum et al. 1982, after Lugo and Snedaker
1974).

Table 2. NET PRIMARY PRODUCTION OF HABITAT COMPONENTS

Average NP Range NoI
Habitat (gC/m /day) (gC/m2/day) Source

Mangroves (all species) 5.3 1.0 - 12.6 Odum et al. 1982

Seagrasses (Syringodium, 1.0 - 4.0 0.5 - 16.0 Zieman 1982
Halodule, and
Thalassia)

Salt marsh 4.2 0.8 - 8.2 Durako et al. 1983

Mud flat 0.5 - Pomeroy 1959

Water column (phytoplankton) 0.9 --- Thayer and Ustach 1981

The estuarine system can benefit by the presence of mangroves. The

aerial root system, especially the red mangrove prop roots, provides a

substrate for algae attachment and serves as a protected habitat for

nursery-stage fish, crustaceans, and shellfish. These intricate root

systems also play an important part in substrate stabilization; their

presence retards erosion. Litter fall also can be important, forming the

basis of a mangrove-detritus food web, providing a supply of food to many

organisms.

Mangroves cleanse inflowing water and aid in nutrient cycling.

Nitrogen, phosphorus, heavy metals, and more are removed from the water by

the combined activities of prop roots, prop root algae, associated sedi-

ments, and the multitude of invertebrates and microorganisms present in the

system (Odum et al. 1982). Nutrient import, originating mostly from

upland and terrestrial sources, is either reduced by faunal species and

exported, or it becomes mangrove or algal biomass. Low nutrient import

results in low storage, low biomass, low productivity and small export,

whereas the outcome of high nutrient import is high storage, high biomass,

high productivity, and moderate export (Odum et al. 1982).

II C 2. SEAGRASS BEDS

Seven species of seagrasses inhabit Florida waters (Figure 3). Turtle

grass (Thalassia testudinum) is the most abundant of the seagrasses with

ribbon-like leaves from 2 to 35 cm in length and 2 to 12 mm in width. The

tips of the leaves are rounded. Thalassia is capable of forming extensive

beds. Shoal grass (Halodule wrightii) is generally accepted as the most

tolerant of all the seagrasses to temperature and salinity changes (cf.

Zieman, 1982). Leaves are flat and are from 10 to 20 cm long and 3 mm

wide. Leaf tips have 2 to 3 points. Shoal qrass, too, is capable of

forming extensive beds. Manatee grass (Syringodium filiforme) is usually

found amongst other species, or in small dense patches. Leaves are

cylindrical from 1.0 to 1.5 mm in diameter; length is variable. Three

species of Halophila are sparsely distributed (Zieman 1982). Leaves are

ovate from 10 to 30 mm long. Halophila engelmannii has 4 to 8 leaves on

the end of a stem 2 to 4 cm long. Halophila decipens and H. johnsonii have

paired leaves arising from a single rhizome node. Halophila decipens

differs from H. johnsonii in that the latter lacks root hairs, and veins

emerge from the midrib at 45� angles rather than 60� angles of the former.

Widgeon grass (Ruppia maritima) occurs in both fresh and salt water

environments. In saline systems, Ruppia is found primarily in areas of

reduced salinity (Zieman 1982), but it also inhabits and reproduces

4~~~~~
2~~~~~

I. Thalassia testudinum
2. Syringodium filiforme
3. Halodule wrightii

6 i ~ ~~~~~~~~~~~4. Halophila engelmannii
5. Halophila johnsonii
7 ~~~6. Ruppia maritima
a~~~ i~~~~ A ~~~7. Halophila deci pi ens

Figure 3. Seagrasses of Florida.

sexually in sites with salinities as high as 380/oo (M. Moffler,

personal communication).

Seagrasses perform many significant functions in estuarine systems.

(1) Since leaf growth is generally >5mm per day, and the typical lifetime

of a single Thalassia leaf is 30-60 days, seagrasses provide a tremendous

food source to herbivores, such as sea turtles and manatees, and detriti-

vores (Zieman 1982). In addition, exportation of living and detrital

material provides energy to areas quite remote from the source grass beds

(Zieman 1981). (2) In addition to their abundant food supply, seagrass

beds provide shelter, i.e. places to hide for young stages of numerous

fish, crustaceans and shellfish. The presence of seaqrasses is essential

to the occurrence and growth of many species of marine life (Zieman 1982).

Seagrasses also provide a surface for attachment for sessile epiphytes.

(3) Seagrass systems stabilize sediments; the leaves provide a baffle for

waves and currents and roots and rhizomes bind the sediments, thereby

retarding erosion (Zieman 1982). (4) Seagrasses aid in the cycling of

nitrogen by transporting it from the sediments into their leaf structure,

then into the environment via herbivory or as detritus (Zieman 1982).

In viewing seagrass systems with a holistic approach, they may be

classified as ecosystems of high diversity. Seagrass meadows provide a

habitat for numerous organisms. Kikuchi and Peres (1977) described the

biota that inhabit seagrass beds:

1. Species living on or near the leaves, including epiphytes, micro

and meiofauna, sessile fauna, mobile creeping and walking fauna,

and swimming epifauna.

2. Species attached to stems and rhizomes.

3. Mobile species living under the leaf canopy (permanent residents,

seasonal residents, visitors, and occasional migrants).

4. Infaunal species (found in unvegetated parts as well).

Added to this list are nektonic species living within and above the blades.

Brooke (1978) found 38 to 80 species were represented within five Thalassia

meadows (blade density >3,000 blades/m2) in south Florida; abundance varied

from 292 to 10,644 individuals/m2.

Seagrass blades create a surface on which epiphytes can attach. After

a leaf emerges, it remains "clean" for a period of time (Zieman 1982). As

they grow, they become heavily colonized, more so at the tips than at the

bases. Harlin (1980) compiled a species list of the microalgae,

macroalgae, and animals that have utilized seagrasses for attachment.

Because the majority of seagrass consumers (turtles and manatees excluded)

do not possess a gut flora to digest structural cellulose, their nutrition

is derived from seagrass cell contents and attached epiphytes. Epiphytized

blades thus provide a more valuable food source to most consumers than

clean blades.

Seagrasses probably are more important to the food web as detritus

than as a source for direct herbivory. Physical breakdown of detritus

occurs through the activities of crabs, shrimp, and amphipods. During

decomposition, particles become smaller and provide a larger surface area

for colonizers such as bacteria, fungi, and other microorganisms. Detritus

is an important food source for deposit feeders, providing polychaetes,

amphipods, isopods, ophiuroids, some gastropods, and mullet with much of

their nutrition (Zieman 1982). Detritivores assimilate plant compounds

with <5% efficiency as opposed to 50-100% efficiency at assimilatinq

associated microflora (Zieman 1982).

II C 3. SALT MARSHES

Salt marshes are herbaceous plant communities in northern Florida

intertidal zones that are periodically tidally flooded by salt or brackish

water. They predominate over mangroves (39% more acreage) as the most

abundant plant community of Florida's intertidal zone (Coastal Coordinating

Council 1973). They are replaced by mangroves as the dominate vegetation

south of Cape Kennedy and Tarpon Springs (Odum et al. 1982); marshes in

this southern region generally serve as a transitional zone between the

mangroves and fresh water marshes (McNulty et al. 1972).

Smooth cordgrass (Spartina alterniflora) dominates Florida's east

coast marsh vegetation (Durako et al. 1983). Along the southeast tip of

Florida, black needle rush, (Juncus roemarianus) exists in large marsh

areas in association with mangroves (Eleuterius 1976). Juncus also occurs

in large stands from Tarpon Springs to Apalachicola Bay. The Florida

panhandle has very little salt marsh.

Juncus produces plant biomass continuously whereas Spartina grows in

the spring with a general dieback in the winter (Turner 1976). No two

marshes are alike and variations in productivity (Table 2) reflect complex

interactions between light energy, temperature, tidal subsidy, nutrient

availability and other factors. Kruczynski et al. (1978) reported that net

aerial primary production of Juncus was highest in the low marsh decreasing

landward to about 30% of the low marsh value in the high marsh. They also

found the same to be true for Spartina; production decreased landward to

less than 20% in the high marsh of the original value in the low marsh.

Detrital material is the end result of 90% of the net production of

salt marshes (de la Cruz 1973). The export of detritus has historically

been believed to be the most important contribution of salt marshes to the

estuarine system. Studies have provided evidence that energy was being

exported because production values were consistently higher than the sum of

the losses due to respiration, grazing, and the accumulation of organic

sediments within the marsh (Durako et al. 1983). Studies that measure

amounts of carbon or organic matter entering and departing salt marshes

showed both a net export to the estuary and a net import. Other studies

however, demonstrated that salt marshes may retain and utilize their own

production (Durako et al. 1983).

Animal production is high in salt marsh systems. Subrahmanyam et al.

(1976) found densities of marsh invertebrates to be 540 individuals/m2 for

a Juncus low marsh and 381 individuals/m2 for the high marsh. Proximity of

the marsh to tidal waters or frequency of tidal inundation may be the

determining factor of organism density in salt marshes (Day et al. 1973).

Day et al. (1973) also reported that animal diversity within the marsh is

lower than values of adjacent open water areas, however, he found that

animal biomass was higher. Zimmerman (in prep.) found shrimp densities of

11 shrimp/m2 within a Spartina marsh as opposed to 1.5 shrimp/m2 in non-

vegetated sites.

Like seagrass and mangrove systems, salt marshes provide a concentra-

tion of high quality food for estuarine animals in addition to a conducive

environment for early life stages. Park and Batie (1979) describe four

additional functions for salt marshes: 1) tertiary sewage treatment,

2) fundamental part of nutrient cycles, 3) long-term accumulators of non-

point source pollution, and 4) short term pollutant buffers.

Releasing primary treated sewage into marshes introduces large amounts

of organic matter into a system already high in organic detritus and can

I ~~~reduce the oxygen content. of the water to unfavorable levels.

Eutrophication can easily result. On the other hand, marshes are capable

of assimilating secondary-treated sewage into their biological systems

without added stress. Secondary treatment of sewage wastes is a relatively

inexpensive process when done by sewage treatment plants. Tertiary

I ~~~treatment, however, is quite costly. By introducing secondary-treated

sewage into marshes, marshes can then become a site of free tertiary treat-

ment (Gosselink et a]. 1974).

* ~~~~Salt marshes share in the nitrogen and phosphorus cycle; salt marsh

systems break down particulate organic nitrogen and phosphorus, exporting

them in dissolved forms (Park and Batie 1979). This reaction increases

estuarine productivity since estuarine biota are better able to assimilate

I ~~~dissolved -organics.

As runoff, with its various types of associated non-point source

pollution, moves through salt marshes, its velocity is reduced. This

* ~~~causes suspended particles to settle out and become part of the sediment.

If these particles remain permanently deposited, the following may result

I ~~~(Park and Batie 1979):

1. reduction in turbidity.

I ~~~~2. reduction of sediment in main part of the estuary.

3. reduction of eutrophication due to adsorption of nutrients to

sedi ments.

* ~~~~4. reduction of toxic materials due to adsorption of pesticides and

heavy metals to sediments. In addition, the toxins may become

buried or decomposed. I
Salt marshes are capable of acting as short-term pollution buffers by
stretching out the time frame of pollutant loading during periods of heavy I
rainfall. Without wetlands, run-off would enter the estuary directly, I
however, by first flowing through the marsh, the length of time for
estuaries to receive run-off increases (Figure 4). This may not decrease
the total amount of pollution entering the estuary, but it would decrease
the amount per unit of time. I

<t< without wetlands|
I

0
_j ~ I

~~~~-withou wetlands

~~~~TIME

Figure 4. Rate of pollution loading to the receiving
water body (after Park and Batie 1979).
_J

z~~~~~~~~~~~~~
o2 '
0

To T, 2
TIME

Figure 4. Rate of pollution loading to the receiving
waterbody (after Park and Batie 1979).I

I
28I

I I C 4. MUD FLATS

Petersen (1981) defines mud flats as "any unvegetated shoreline of a

sound, lagoon, estuary, or river mouth that becomes exposed by lower

tides." Because of their barren appearance, at least in contrast to sea-

grasses and salt marshes, they are perceived to be insignificant in their

contribution to the gross primary production of the estuary. They

function, however, to produce not macrophytes, but rather microscopic

benthic algae.

Diatoms, dinoflagellates, filamentous green algae, and blue-green

algae compose the primary producers of mud flats, and are observed as a

discoloration of the sediment. Turnover is rapid, but productivity rates

are less than half that of salt marsh and seagrass systems (Table 2),

however, the crop is in a form readily useable by consumers. Many

herbivores and deposit feeding invertebrates consume the benthic algae of

mud flats.

Benthic infauna are the primary inhabitants of mud flats during low

tide when the flats are exposed. Numerous species of birds extensively

utilize this habitat as feeding grounds during daylight hours. However,

during high tides and especially at night, crabs, shrimp, and fish become

the major consumers. Summerson (1980; cited by Petersen 1981) found that

crabs and bottom-feeding fishes are more evenly distributed over vegetated

and unvegetated bottoms during the night. During daylight, however,

seagrass beds contain far higher numbers of fishes, crabs, and shrimp

(Petersen 1981).

In addition to their value as a food producer, mud flats also serve as

a site for detrital breakdown. Currents and tides carry plant debris from

the source habitat to the mud flat. During low tide, much debris is

available to fiddler crabs,, amphipods, and other detritivores that

physically break it down. Through these processes, a substantial amount of

production of other habitats is made available to mud flat consumers

(Petersen 1981).

II C 5. OYSTER REEFS1

Oyster reefs are defined as "the natural structures found between the

tide lines that are composed of oyster shell, live oysters, and other

organisms that are discreet, contiguous, and clearly distinguishable

(during ebb tide) from scattered oysters in marshes and mud flats, and from

wave-formed shell windrows." (Bahr and Lanier 1981).

Oyster reefs in Florida are composed of the American oyster

(Crassostrea virginica) that range from 20�N to 54�N latitude. The oyster

is a typical estuarine inhabitant, tolerating broad limits of salinity,

temperature, turbidity, and oxygen content. Because oysters are

gregarious, they tend to form mounds ranging in size from scattered clumps

to huge solid masses. The middle section of the intertidal zone affords

the best habitat for oyster reef development; the lower zone subjects

oysters to increased predation.

A typical reef is composed of three horizons. The upper layer (5-

10cm) dries out during low tide, hosts a film of algae, and is colored a

ISummarized from Bahr and Lanier (1981).

pale greenish grey. The mid layer remains moist and lacks an algal film.

A thin layer of detritus covers each shell and is colored reddish-brown.

The lower layer is composed' of non-living shells that are buried in

anerobic sediments. Of the upper and mid layers together, approximately

61% by volume consists of living oysters, 21% consists of dead shells, and

18% consists of silt, clay, and non-oyster macro-fauna.

In theory, oyster reefs benefit estuaries by influencing physical and

hydrological regimes. Oyster reefs dampen current velocities, undoubtedly

for small areas, perhaps influencing the entire estuary. A slower current

allows for settlement of particulate matter, thereby, decreasing turbidity.

Within natural systems, where hard substrate is rather limited, oysters

provide a much needed habitat for algae and animals that require hard

surfaces for attachment. In fact, every square meter of oyster reef

provides at least 50 square meters of available hard surface. The

irregular surface, filled with nooks and crannies, serves as shelter for

motile invertebrates and, during high tides, for small fish.

Oyster reef communities are composed primarily of suspension and

deposit-feeding macrofaunal species. The community consists of various mud

crabs, polychaetes, barnacles, other macrofauna, protozoa, metazoa, and

bacteria. Oysters themselves serve as food for various boring sponges and

the American oystercatcher, one of their major predators. Overall, this

macro-faunal community more importantly serves to assimilate carbon derived

from phytoplankton and detritus than it contributes to the food web.

Because many oyster reefs are intertidal or shallow subtidal, they

exist constantly at or near their stress tolerance threshold. Further

disturbance may destroy an entire reef community (Table 3).

Table 3. GENERAL EFFECTS OF MAN-INDUCED STRESS ON OYSTERS
(from Bahr and Lanier 1981)

Stress Detectable Effects

1) Sedimentation Burial and anoxia of adult oysters

2) Salinity increase over Increased predation and/or fouling
ambient concentrations

3) Oxygen depletion in Toxic effects of blue qreen algae
bottom water and other algae; excess particulate
(Eutrophication) organic carbon

4) Chemical Pollutants Sublethal effects, increased mor-
tality, reduced resistance to natural
stress, subtle changes in entire
community, reduced gametogenesis

5) Physical effects of Impairment of feeding mechanism
oil-type pollutants

6) Thermal loading Decreased community diversity,
increased respiratory cost

7) Overharvesting Depletion of breeding stock and culch
and decrease in bottom stability

8) Loss of wetlands Loss of wetland-water interface prime
reef habitat, decline of primary pro-
duction

II C 6. UNVEGETATED SUBTIDAL BOTTOM AREAS

Located below the photic zone or scattered throughout the estuary are

areas of unvegetated subtidal bottom. Large patches (>3m) of bare bottom

occur naturally in the photic zone due probably to high enerqy circulation

patterns. Large bar-type bare sites may serve to lessen wave surges and

current velocities, providing calmer areas behind the bar. Natural defoli-

ation may result from herbivore feeding behaviors such as those described

by Bjorndal (1980) for green turtles (Chelonia mydas) and by Packard (1981)

concerning West Indian manatees (Trichechus manatus). Reasons for the

natural existence of small patches of bare sand within expansive grass

flats remain questionable. Blowouts, or bare sites within beds that con-

sistently reject seagrass growth, may result because of high energy

patterns such as eddies that occur continuously at that particular location

(Durako, M., personal communication). Cryptic behavior of cownose rays

have caused total removal of Zostera communities (Orth 1977). Many areas

where underlying rock layers protrude through the bottom surface are

unsupportive of seagrasses and macro algal beds (personal observation).

Though reasons for their presence must exist, small sites of unvege-

tated subtidal bottom probably are not very productive. Orth (1977) de-

scribed sediment stability within these bare sites: storm activities pro-

duced sand ripples and erosion of <20cm in the bare areas whereas the

adjacent Zostera community indicated no evidence of instability. Orth

concludes that this instability accounts for the lack of species and

individuals in this habitat. Human-induced defoliations are numerous and

include activities such as motor boat propeller cuts, disposal of heated

effluent, turbidity, physical removal, and hiqh energy circulation

patterns; these are discussed in greater detail in section IVB.

3 I C 7. WATER COLUMN

Overlying parts or all of the six other estuarine habitats is the

water column. Several variables and, especially, the interactions between

the variables, cause the estuarine water column to exhibit differing

physiochemical characteristics. Depending on the time of year, time of

day, weather, tide and circulation patterns, the water column may be

extremely saline or fresh, clear or turbid, warm or cold, deep or shallow,

and calm or turbulent. Further, it is capable of existinq in any combina-

tion of these features. The water column is the medium through which most

marine fauna travel and feed. It is dynamic and organisms living within it

must be tolerant of change.

As the tide comes in, meroplanktonic stages entering the estuary can

rise to the top of the water column and profit by the free ride to safer

territory. High tide also creates a feeding habitat for larger predators

by deepening those areas that physically excluded them during low tide.

Receding tides, in a sense, "cleanse" the estuary by removing nutrients

that may eventually serve as a food source for offshore systems.

Phytoplankters are the primary producers of the water column. Compared

with seagrasses, mangroves, and salt marshes, productivity values for

phytoplankton are minimal (Table 2), however, phytoplankton productivity is

not limited to shallow areas (as are seagrasses) or shorelines (as are

marshes and mangroves). Instead, these organisms are capable of

reproducing in the photic zone over the total area of the system. Further,

phytoplankton exist in a state readily available to consumers. In other

words, phytoplankton need not pass through the many steps of the vascular

plant detrital food web before consumption by "higher" organisms. Although

the vascular plant detrital food chain may be most important in estuaries,

phytoplankters are essential components in the food chain supporting

zooplankton and larval fishes. Larval fish consume zooplankton, and

zooplankton can consume detritus, however, almost all detrital consumers

include at least 10 to 20% fresh algal cells in their diet (Odum 1970).

II D. ESTUARINE FOOD WEB

The trophic structure of estuaries features different sources of

primary production, numerous generalist feeders, and an intricate food web

(Day and Yanez-Arancibia 1982). Zieman (1982) listed the main sources of

primary production:

1. Macrophytes - seagrasses, mangroves, macroalgae, and marsh grasses

2. Benthic microalgae - benthic and epiphytic diatoms, dinoflagel-

lates, filamentous green and blue green algae

3. Phytoplankton

A diverse set of consumers contribute to the food web. An organism rarely

fits exclusively into one category or level due to changing food habits

resulting from age, time of year, and food availability (Odum and Heald

1972; Day and Yanez-Arancibia 1982). Juvenile fish, for example, switch

prey items as they grow. Following is a list of estuarine consumers (Day

and Yanez-Arancibia 1982):

1. First order consumers - pure herbivores, detritivores, and ominni-

vores; includes most zooplankton, filter feeders, fishes such as

mullets and menhaden, benthic deposit feeders, shrimps, crabs, and

most other fauna of wetlands.

2. Second order consumers - organisms that consume mostly first order

consumers and also small amounts of plant material and detritus;

fishes consuming zooplankton (anchovies and sardines, for ex-

ample), demersal fishes (such as croaker and catfish), other

crabs, and starfish.

3. Third order consumers - exclusively carnivorous organisms that

prey on first and second order consumers; many larger fishes and

birds.

Two basic food chains exist within the estuary: the grazing food

chain and the detrital food chain. Interactions between these two create

the complex food web of the estuary. The grazing food chain is basically:

primary producers -- herbivores -+ carnivores -> bacteria.

The detrital food chain is basically:

detritus - bacteria -> detritus feeders -> carnivores

bacteria.

The detrital chain is considered by many researchers to be the most

important of the two food chains (see Day and Yanez-Arancibia 1982). The

process is based, obviously, not on living primary production, but on dead

material. After a mangrove leaf, Juncus shoot, Spartina shoot, or seagrass

blade breaks off from its host plant, physical breakdown occurs

immediately. The material is shredded into smaller fragments by crabs and

amphipods and quickly becomes colonized by bacteria, fungi, and microalgae.

These decomposers are considered rich sources of vitamins and proteins,

greatly increasing the food value of the material. Heald and Odum (1970)

found that broken-down particles after 12 months contained 22% more protein

as compared to a protein content of 6% when they were still intact. Net

nutrient value is much higher for detritus materials than for the plant

material alone. In addition, this rich source of food decomposes slowly,

insuring a continuous production of food. Mann (1972; cited by Day and

Yanez-Arancibia 1982) states that the detrital colonizers are the actual

food source; the plant material passes through the gut systems of detrital

feeders almost unaltered.

Eighty to ninety percent of the nutrition of several species of

crustaceans, polychaetes, insect larvae, and small fishes is derived from

detritus (Robas 1970). Detritus feeders are consumed by over 60 species of

juvenile fishes that live in the estuary during at least parts of their

lives (Robas 1970). However, no estuarine food web is completely dependent

upon vascular plant detritus, in fact, according to Odum (1970), detritus

consumers appear unable to grow and successfully reproduce when consuming

solely detritus. He adds that at least 10 to 20% algal cells in the form

of diatoms or filamentous and blue-green algae are included in the diets of

almost all detrital consumers.

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
38
I

III. ADJACENT LAND USE AND HABITAT ALTERATION

III A. ESTUARINE LIMITATIONS

As discussed in Section II A, estuaries are extremely interactive,

highly dynamic ecosystems. However, even though estuarine biota are quite

capable of withstanding frequent environmental changes, they do have

limitations. In this section these boundaries will be described as well as

how they are exceeded and the resulting effects on estuarine habitats.

Odum and Copeland (1969) described three main energy types that

dominate estuarine systems:

1. Light energy activates the process of photosynthesis and is the

primary source of the estuarine food web.

2. Organic fuels constitute a second energy source. Incoming nutri-

ents flowing through the estuarine habitats "fertilize" the system

resulting in an increase in vascular plants and algae.

3. Mechanical energy, such as waves, wind, river and stream flow, and

tides serve as energy subsidies and are responsible for many

interactions that occur in the estuary.

A reduction in light energy, as might occur if estuarine waters became

turbid, would greatly affect the seagrass system. Copeland (1965) tested

the effect of light reductions by lowering the input of sunlight from 1500

to 200 foot candles on a simulated seagrass community. The community, pre-

viously dominated by Thalassia, soon became a blue-green algae community.

After stabilization, however, the productivity of the two community types

became equivalent. But, considering that blue-green algae is consumed

successfully by only a few species (Copeland 1965), as opposed to Thalassia

leaves and detritus that are consumed by numerous species, Thalassia

communities are much more useful, both as a food source and as a hiding

habi tat.

Lessening the amounts of incoming organic fuels (commonly derived from

freshwater sources such as rivers and terrestrial run-off) would decreaseI

the biomass of all the systems - mangroves, salt marshes, seagrasses, and

phytoplankton. However, an overabundance of nutrients precedes eutrophi-

cation. In response to increased nutrients, productivity increases

resulting in an increase in detrital material, but the amount of energy

required to breakdown this material has not changed. The system becomesI

eutrophicated and consists of sediments and a water column devoid of

oxygen. Vascular plants die and the system begins to cease functioning.

Mechanical energies within the estuary are numerous, and their

importance cannot be overemphasized. For example, tides and freshwater

inflows are responsible for the chemical properties of the water. If tidesI

were restricted from the estuary, freshwater would predominate and the

system would drastically change from a euryhaline system to a fresh system.I

Decrease in freshwater flows would cause an increase in salinity. The

numbers of molluscs, crustaceans, and fishes would rise, but the subtle

qualities of the estuary would be lost, especially its value as a

protective nursery ground.

Consistent high levels of dissolved oxygen do not occur in estuaries,I

due mostly to the large volume of organic matter in the surface sediments

and water column (Odum 1970). In fact, many estuaries possess a value wellI

below the standard of 4.0 mg 02 per liter water established for polluted

estuaries by the National Technical Advisory Committee in their 1968 report

on water quality criteria to the Secretary of the Interior (Odum 1970).

Odum (1970) theorized that since estuaries already exist in a borderline

I ~~condition, a decrease in dissolved oxygen content is capable of causing

mass mortalities. He further states that any process that suspends

oxidizable sediments also reduces the oxygen concentration of estuarine

water to a level unfit for normal biota. An example of this occurs

frequently in an unpolluted Everglades estuary during rainy season: l arge

I ~~volumes of cold rainwater sink to the bottom causing resuspension of

detrital materials. Oxygen is depleted and marine animal mortalities

U ~~~follow.

Although estuarine biota are capable of withstanding drastic tempera-

ture fluctuations, they cannot deal with continuous heat or cold. Severe

cold spells cause adult fish to migrate to offshore warmer waters, and

freezes destroy mangroves. Many resi dent speci es of tropi cal areas are

I ~~~surviving within a few degrees of their upper lethal limit (Lindall 1973).

Fishes rarely survive temperatures of 38'C, and waters typically exceeding

350C would probably not support a large or diverse fish population (Carr

and Giese] 1975). Effects of excessive heat from natural sources have not

been reported, but effects of heated effluent from power plants have been

we]lI documented. Roessler and Zieman (1969) found adverse effects from

effluent emerging from Turkey Point Power Plant in southern Biscayne. Bay;

I ~~~nearly all biota within 125 acres nearest the outfall were destroyed or

greatly reduced. By comparing two thermally-influenced creeks to an

ambient temperature creek, Carr and Giese] (1975) found a higher fish

density during summer months in the ambient creek. In addition, Juveniles

of species of commercial and recreational importance were 3 to 10 times

greater in biomass and numbers in the ambient creek than in the thermally

affected creeks.

Two extremely important, but not easily defined, parameters that

greatly influence the effects of various perturbations, are time and

multiple interactions. The estuary apparently can cope with literallyI

almost any major alterations, but for only relatively short periods of

time. For example, seagrasses will not be detrimentally affected by

turbidity if the condition exists for merely a week. But further periods

of inundation may result in reduction of photosynthesis and decreased

production.

Synergistic or multiple interactions are those perturbations that

occur coincidentally with others. It is often difficult to separate the

effects of single disturbances when another, or others, are present as

well. Using the seagrass community again as a hypothetical example,

turbidity, excessive freshwater, and above normal nutrient levels are

simultaneously introduced into the seagrasses due to heavy rains and river

flooding. Two months later, after the system returned to normalI

conditions, the seagrasses are thinner and less dense with fewer faunal

inhabitants. It would be difficult to pinpoint any single variable for the

results.

In summary, a reduction of light energy or a reduction or over-

abundance of organic fuels and mechanical energy, excessive changes in

chemical properties (oxygen and salinity) and temperature, or a combination

of any or all, since all variables are interrelated, may result in

decreased production. Lowered productivity is realized through the food

chain and the outcome is lower yields in fish stocks.

III B. PERTURBATIONS

Probably the greatest single disturbance that causes irreversible

I ~~damage in the shortest period of time is physical removal of parts or all

of the estuarine habitats. Destruction of this type often occurs on a

large-scale and includes activities such as channel dredging, dredge and

fill, shell-mining, and various sorts of shoreline modifications. Small

scale perturbations that directly and physically destroy habitat are

I ~~~produced from activities such as motorboat cuts and clam digging. Anything

that exceeds estuarine limitations, as discussed in the previous section,

H ~~either destroys habitat or reduces productivity; these disturbances may

include the introduction into the estuary of power plant effluent, storm

water run-off, industrial discharges, mosquito impoundments and vessel

discharges (gas and oil).

Channel Dredging

I ~~~~Because estuarine habitats are relatively shallow and typically link

the oceanic waters to the mainland, they pose transportation difficulties

to large vessels and even small boats. To alleviate this problem, channels

are cut into the sediment, providing deep areas for easy access through the

shallow zone. Odum (1970) explains that the dredging process would cause

* ~~~minimal damage if properly engineered; only the actual area containing the

navigation channel should be altered. However, Odum describes the continu-

al adverse effects resulting from the "hydraulic dredge cycle". Material

dredged from channels is typically dumped as nearby spoil banks. A~s the

spoil banks erode, dredged material is transported back into the channel,

necessitating re-dredging. Turbidity and destruction of circulation

patterns are often unavoidable by-products. Lindall and Saloman (1977)

I ~~~~~~~~~~~~~~43

reported outcomes of channel dredging that are significant to fishery

resources. Physical loss of aquatic habitat by creation of spoil islands,

segmentation and isolation of' parts of the estuary, alteration of tidal

exchange and circulation patterns, increased turbidity, and destruction of

submergent and emergent vegetation are some of these significant problems.
Mosquito Impoundments and Ditches

Mosquitoes, as adults, pose a threat to the health and sanity of

people and yet, as larvae, serve as food for juvenile fishes. Unfortu-.

nately, both mosquitoes and humans wish to occupy the same coastal areas --

humans, because of the aesthetic qualities, and mosquitoes because of theirU

need for moist, exposed soil on which to lay eggs. Higher intertidal salt

marsh and mangrove areas provide exceptional habitat on which mosquitoes

lay eggs. To help eradicate mosquitoes, a dike is built around the system

or channels are dug through it. Dikes serve to retain water within the

system while canals dry it out. They change an occasionally-flooded area

to one continuously flooded or to one persistently dry. Diking and

channelization remove the influence of tides and the inflow of terrestrial
freshwater and, therefore, a part of the nutrient import. Estuarine fauna

are no longer capable of moving into and out of the site, and its import-

ance as habitat for growing fishes and shellfish is destroyed. Harringtonj

and Harrington (1982) reported that during a few months following impound-

ment of a salt marsh community in Indian River County, nearly all theI

vegetation died and juvenile fish that originally used the site previous to

impoundment disappeared as well. Of 16 species found before impoundment,

only five remained after impoundment (Harrington and Harrington 1982,

1961.) GilImore et al . (1982) found a total of 12 species within the

44I

Harrington's impounded site as compared to 41 species in an impounded site

that was reopened to tidal influence via a single 80 cm culvert.

I ~~~Power Plants

To cool the operating system of electrical generating power plants,

water is essential. Placement of a power plant adjacent to an estuary

provides easy access to a direct source of required cooling water. After

the water is used, it is deposited back into the estuary. The foremost

I ~~perturbation the power plant provides to the estuary is the direct

I ~~~destruction of shoreline habitat, usually mangroves and marsh, to build the

plant. Three additional problems are as follows:

I ~~~~1. Impingement - organisms can get trapped on screens that filter the

intake water.

2. Entrainment - organisms of the intake water that pass through the

filter system can be killed or damaged by the turbulent and

I ~~~~~pressurized process of the cooling system.

3. Thermal effects - the impact of thermal pollution depends on

several variables - discharge volume, average and maximum tempera-

ture elevations, characteristics of plume dispersion, and hydro-

graphy of receiving waters. In addition to the reports discussed

in Part I of this section, another investigation found that

thermal effects from a coal-fired power plant destroyed 200 acres

of seagrasses and lowered the diversity of invertebrates to 40% of

3 ~~~~~their original value (Blake et a]. 1976).

Sewage Di sposal

3 ~~~~"The greatest direct threat to the clear productive waters of the

Charlotte Harbor area is inadequately treated and improperly disposed

* ~~~~~~~~~~~~~~45

domestic wastes" (U.S. Department of the Interior, Bureau of Land

Management, 1978). As described in Section III, estuaries provide an ideal

site for the disposal of secondary-treated sewage. However, the addition

of primary-treated sewage contains more nutrients than the system can

properly handle. A study of Hillsborough Bay found progressive eutrophi-

cation after years of receiving primary treatment (Federal Water Pollution

Control Administration, 1969). Water quality was lower as compared to all

other parts of Tampa Bay; measurements of dissolved oxygen were low, coli-

form bacteria surpassed safe levels, sediments became anoxic, and frequent

noxious algal fish kills and blooms occurred. In addition, diversity and

abundance of macroinvertebrates were lowered (Taylor et al. 1970).

Canals and Canal Developments

During the 1950's and 1960's, demand for waterfront property in the

southern half of Florida was immense. Developers met this need by

extensively exploiting the coastline. Available shoreline was limited, so

developers planned communities around networks of branching canals,

maximizing the amount of waterfront property to land configuration. Some

of these canal systems extend inland over thousands of acres. Morris

(1981) distinguishes three basic designs of waterfront canals:

1. Bay-fill or finger-fill canals: those constructed below mean low

tide by dredging and filling shallow bay bottoms.

2. Intertidal developments: those constructed by dredge-and-fill

between mean low and mean high water, typically in mangroves, salt

marshes, bays, estuaries, lakes, or other wetlands.

3. Inland or upland canals: those developed by excavating land above

mean high tide and connecting the canals to natural channels,

lakes, rivers, bays, or other natural or artificial waterways.

In the past, canal developments were usually constructed by dredging

I ~~out the channels, first, and depositing the dredged material behind

bulkheads, or seawalls, elevating the land surface to meet State criteria

for hurricane tide and flood protection (Morris 1981). During construc-

j ~~~tion, mangroves, seagrasses, and trees were removed from the dredge

location, and the fill material covered vegetation located in the landfill

sites, often destroying estuaring nursery sites over vast areas. Lindall

and Saloman (1977) determined that 23,521 acres of Florida estuaries have

U ~~~been filled, the majority for housing developments and industrial real

estate.

Three major deleterious effects of canal developments are apparent,

* ~~irrespective of less obvious concurrent impacts:

1. The immediate destruction of habitat at the construction site.

I ~~~~2. The presence of seawalls at the land/water interface, eliminating

critical habitat for the development of estuarine shoreline vege-

tation. This, in turn, eradicates nursery habitat, as well as a

* ~~~~~cleansing site for incoming water.

3.' The inability of circulation patterns to adequately flush the

waters and carry undesirable pollutants to the receiving water

body, and/or maintain a sufficient concentration of dissolved

oxygen throughout the water column of the entire canal network.

3 ~~~~Fortunately, the direct causes of water degradation within canal

systems were clear. The documentation of canal problems resulted in

restrictive legislation, causing a si gni f icant decrease- in canal

construction. However, canal developments continue to be permitted.

I ~~~~~~~~~~~~~~47

Perhaps these developers can follow the less negative approach to canal

design as devised by Morris (1981) and discussed in Section IV D. Of

course, the best approach is to completely ban the construction of

canals.

Stormwater Run-off

When rainfall occurs, much of the water perculates through the

ground. It is cleansed by the soil and lower rock layers and enters the

groundwater system. When rainwater falls on land it can enter the

estuary via rivers and streams as terrestrial run-off, relatively clean but

full of nutrients. The remainder enters the estuary via storm pipes asI

run-off from roads, lawns, parking lots, and agricultural cropland. This

run-off may contain pollutants such as pesticides, gasoline, oil, heavy

metals, and fine particles of rubber and asbestos. Odum (1970) termed the

influence of these pollutants "sub-lethal effects", and described it as a

poorly understood occurrence. Butler (1966) has shown that widespread

pesticide pollution significantly decreases the production of estuarine

fish and shellfish. Anderson and Peterson (1969) discovered that sublethal

concentrations of DOT prevented the establishment of a visual conditioned

avoidance response in some fish and also affected the thermal acclimation

mechanisin.

Industri al Di scharge

In Florida, phosphate is the prevalent mineral extracted from theI

ground. Phosphate plants, like power plants, require a cooling system that

utilizes water, therefore, Florida phosphate plants typically are found on

rivers or on estuarine shorelines. Upchurch et al. (1976) found that

effluent from a phosphate processing plant in Hillsborough Bay was heated

48I

to 18'C above ambient water temperatures, contained much fluoride, and was

a ci dic. The discharge caused the disappearance of all animals within 61

hectares, and diversity and abundance were low where organisms did occur.

Phosphate strip mining and processing plants established far upstream

affect the estuary. Though outflow water temperatures have probably cooled

by the time they reach the estuary, the chemical contaminants would no

doubt be sustained within the outflow.

I ~~~Miscellaneous Activities

Numerous additional activities that affect estuarine production

continuously occur. Vessels, whether they are large, small, commercial, or

recreational, release gas and oil into the water. Larger vessels are

capable of producing wakes that may disturb quiet areas and cause detri-

I ~~~mental affects such as stripping newly established vegetation from the

sediments. Motorboat scars within seagrass meadows persist for years

(Zieman 1976). The construction and placement of causeways and bridges

destroys habitat of the immediate site. After stabilization, however,

estuarine vegetation may sometimes return depending on boat activity, wave

action, turbidity, and other factors influencing reestablishment. Cause-

ways additionally alter circulation patterns that can severely affect some

I ~~~areas. Oil spills can cause extensive damage. Oyster shell dredging

* ~~~creates temporary turbid conditions within approximately 30 meters of the

site, in addition to a reduced organic content within the sediment, a 40%

loss in species, a 66% loss in abundance, and an 87% loss in biomass.

Within six to 12 months, however, these parameters can become naturally

restored to pre-dredge conditions (Conner and Simon 1979).

1 ~~~~~~~~~~~~~~49

Cumulative Effects

The health and well being of estuaries is based not on an impact of a

solitary activity, but rather on the accumulated effects of all activities,I

since the whole estuarine system is interrelated and interactive. Estevas

(1981) states:

"In Coastal Ecosystem Management, Clark (1977) names or dis-I
cusses nearly 100 activities with adverse estuarine impact. The
permutations of just those activities possibly relevant to south-
west Florida estuaries all profoundly numerous, and of inestimableI
impact due to the many variables involved. This does not mean,
however, that cumulative impacts cannot be anticipated, identified,
or managed. For all purposes, recent efforts to protect Charlotte
Harbor by its designation as a complex of aquatic preserves, and
possibly as an area of critical state concern, represents the
emergence of public concern for cumulative (additive and inter-

active) effects (CHPRMC, 1980)."

50~~~~~~~~

IV. RESTORATION

I ~~~~Estuarine shorelines and, nearby shallow waters provide the perfect

ecological environment for salt marshes, mangroves, and seagrasses,

however, this same shoreline aesthetically appeals to many humans as well.

Unfortunately, in many areas of Florida, humans who dwell along shorelines

do not want to coexist with native habitats. Instead, they live on

shoreline habitat restructured by developers. An anonymous author once

I~~~woe No thought has been given to the fact that the highly-
touted offshore fishing in this area of retirement homes
is directly related to the very mangrove swamps being
destroyed to make homes for the fishermen.
Present knowledge linking the estuarine system to such important

U ~~~entities as growth and survival of juvenile fish and shellfish, shoreline

stabilization, water quality, and food production has led scientists into

the complex realm of habitat restoration. Of course, the simplest and most

3 ~~~inexpensive "method" is preservation, in other words, absolutely no adverse

effects due to development shall occur. For areas already destroyed,

I ~~~preservation is of course, impossible; only future development can employ

this procedure. Next to preservation is conservation -- if a project must

be constructed at a specific location resulting in damage to natural

3 ~~systems, then the construction process should cause the least possible

deleterious effects. Mitigation is also a choice, but still results in

destruction of habitat in trade for preservation or re-establishment of

another site. This section addresses (1) post-development sites devoid of

I ~~~native vegetation, where vegetative restoration is indeed a possibility,

and (2) miscellaneous restorative and pre-development concerns such as

spoil island configuration, bulkhead alternatives, and rational canal

design. Various techniques of restoration are discussed, and those with

best results will be delineated. The reader should always keep in mind

that each restoration site is unique with different flow patterns and water

regimes, varying sediment compositions, and other parameters. Restorative

capacity is, therefore, peculiar to each site where restoration has or will

occur.

IV A. SEAGRASS RESTORATION

The major methods of reestablishing a seagrass population are seed

cultivation or transplantation of plugs, turfs, or sprigs, possibly apply-

ing hormone treatments executed at different times of the year. The dis-

cussion is limited to reports of seagrasses that occur in Florida waters.

Plugs: A plug of seagrass is composed of seagrass blades, roots, and

rhizomes with attached sediment. A plug is removed from the transplant

site with a shovel or post hole digger and transported intact to the

recipient site. A hole is dug into which the plug is placed; an anchor or

sediment cover holds it in place. Plugs are typically spaced one meter

apart. Disadvantages to this system are the damages it induces to the

donor site, the substantial time and labor requirements, and the slowness

of regrowth, especially of Thalassia (Godcharles 1971). Kelly et al.

(1971) was unsuccessful in applying this technique to Thalassia in Boca

Ciega Bay. Van Breedveld (1976), however, had 100% survival of Syringodium

in Tampa Bay by using a post hole digger and planting in rows in early

spring. Lewis and Phillips (1980) planted plugs in a small borrow area of

the Florida Keys that had silted in with fine calcareous sand and silt.

They had 35% survival for Syringodium and 37% for Thalassia; Halodule

plugs, however, failed.

Turfs: A turf is a large clump of sediment with seagrasses. A turf

is removed from the donor site and placed into a shallow trench at the

recipient site. Disadvantages are the same as described for plugs.

Phillips (1974) had no success with Thalassia in Tampa Bay, probably

because of erosion by currents, but Halodule exhibited some success. Van

Breedveld (1975) concluded that turf transplants are most preferable. He

suggested that the clumps be planted in rows, spaced 30 cm apart in

favorable substrates, and closer in unfavorable substrates with donor

sediment in between.

Sprigs: Sprigs are single "plants" composed of the blades, short

shoot, roots, and maybe the rhizomes, but no sediment. The donor site is

affected less deleteriously, but stress on the plant itself might be much

greater. Kelly et al. (1971) planted sprigs of Thalassia without rhizomes

in Boca Ciega Bay; 11 of 60 plants survived. Lewis and Phillips (1980)

reported a failure of nearly 100% of Thalassia, Halodule, and Syringodium

using springs in a borrow area of the Florida Keys.

Seeds: Thorhaug (1974) gathered Thalassia fruits from Caribbean beds

and immediately separated the seeds. The seeds were transported under

recirculating sea water and planted in the denuded Turkey Point Power Plant

discharge canal in Biscayne Bay. After 2.5 years, the transplant site was

moderately dense. After 4 years, blade density was 2000/rn2 as compared

with 2295/m2 at a control site. Lewis and Phillips (1980) reported nearly

100% failure of planting Thalassia seeds and seedlings in a silted-in

borrow area created by dredging.

Durako and Moffler (1981) reported 100% success in planting laboratory

seedlings in peat pellets (compressed dehydrated peat containing low grade

fertilizer); plants exhibited, healthy leaf growth after 3 months, and

maintained good health in situ for over 6 months. The transplant site

however, presented unsuitable growth parameters of high sedimentation and

turbidity, therefore, field results were inconclusive.

Durako and Moffler (1981) described several physiological variables

that must be considered when choosing seed stock for restoration projects:

When considering seed stock for mitigation projects, the
possibility of genetic fixing in local strains may be im-
portant (Odum, 1971). Geographically separated T. testudi-
num populations exhibit ecoplastic limits that are adaptive
To-local conditions (McMillan, 1978, 1979; McMillan and
Phillips, 1979). Response to the influence of habitat in-
clude variation in leaf length and width (Phillips, 1960;
Zieman, 1974) and variable reproductive patterns (Grey and
Moffler, 1978; Moffler and Durako, unpublished data). In
this regard, transplanting seeds or seedlings from remote
locations may result in failure or poor success since they
lack this factor compensation. The possibility of pathogen
introduction utilizing nonlocal seeds also suggests that
indigenous seed stock would be preferable for revegetation
projects.

An important consideration for seagrass restoration projects is the

feasibility for growth at the recipient site. Thorhaug (1980) planted

seedlings in 4 types of high stress environments in Biscayne Bay: areas of

submerged dredge spoil, bottoms damaged by sewage pollution, areas of high

tidal currents, and areas of shifting sand. Low survival occurred in areas

of strong tidal currents, those with wave action from boats, and the dredge

spoil site that was experiencing erosion and sediment shifting. Suitable

sites for seedling growth included areas of low energy with peaty bottoms

consisting of sandy, consolidated sediments.

Miscellaneous Techniques: Fonseca et al. (1979) removed Halodule (and

Zostera) from donor beds and rapidly transported them to a processing area.

Terminal shoots were separated'and woven into pre-cut biodegradable 20 x 20

cm mesh paper, with 15 shoots per O.04m2 mesh. The squares were placed 1 m

apart in a 6 x 6 m plot and attached to the substrate with sharp pins. The

logic behind this complex technique is a compromise between recovery time

and cost: revegetating only a small portion of the damaged area to an

advanced stage of succession. Though apparently successful, it is time

consuming, costly, and labor intensive.

Hormone treatments (mostly the use of Naphthalene Acetic Acid -NAA)

appear to exhibit no consistent results. In his work with pluq and sprig

transplants, Van Breedveld (1975, 1976) reported no advantages from using

hormone treatments. Thorhaug (1974), however, found that seeds soaked in

NAA solution appeared to increase root propagation. Kelly et al. (1971)

reported 100% success in transplanting sprigs without rhizomes that were

first dipped into NAA solution previous to planting. Whether the success-

ful attempts were due to hormone treatment or to other parameters such as

viability of the recipient site and the restoration technique itself

remains questionable.

The season in which restoration is attempted may play an important

role in successful projects. Saurs (1981) and Van Breedveld (1975) suggest

early spring as optimal for planting since seagrasses exist in a semi-

dormant state during this time. Saurs (1981) also emphasized that

historical changes must also be considered, i.e., if seagrasses are

disappearing within an area, restoration may prove useless. Disturbance to

the system is causing their demise and any restorative attempts may fail.

In summary, investigators must choose between several alternatives

before attempting restoration of a seagrass bed. Selection concerning

which restoration techniques to use, when to plant, the use or disuse of a

hormone treatment, cost considerations, and, most important, the

receptivity of the recipient site must all be considered. A final option

regards which species to place into the new site. Often, the system has

changed extensively and new growth of the original species may not be

feasible. Thorhaug (1980) noted that some investigators plant Halodule

because it grows faster, however, she argues against this reasoning because

Halodule might not support a faunal system as large or diverse as those

maintained by Thalassia beds, nor does it apparently function to stabilize

sediments as well. Lewis and Phillips (1980) suggest that Thalassia exists

as the climax species in an ecological succession with Halodule and

Syringodium; Halodule roots are shallow and it grows quickly, Syringodium

has deeper roots and grows slower than Halodule, and Thalassia has the

deepest roots and grows the slowest of all three. Reasons describing why

one site is better suited than another for a particular species are

multitudinous, and basically unknown (M. Durako, personal communication).

The reader is referred to Coastal Engineering Technical Aid No. 30-2

(Phillips, 1980) and a bibliography on seagrass planting and propagation

techniques (Knight et al. 1980) prepared for the U.S. Army, Corps of

Engineers, Coastal Engineering Research Center, for more information

regarding seagrass restoration.

IV B. MANGROVE RESTORATION

Lewis (1981) described some of the major reasons for the recent in-

creased interest in mangrove restoration: (1) the value of mangrove

forests has been realized and documented; (2) large-scale losses of

mangroves have occurred; and (3) legal authority has been granted to

regulatory agencies to control destruction of mangroves through develop-

ment and to establish fines, replanting requirements, and other mitigation

procedures.

Teas (1980) describes one goal for mangrove restoration: to develop a

functional, diverse ecosystem as rapidly as possible. He suggests (1981)

several short cuts that rapidly establish a mature system. Dense planting

and planting larger trees help accelerate development. Faster growth is

achieved with fertilizer treatments. Large block plantings as opposed to

scattered plantings are favored since larger forests harbor a more diverse

fauna. If the site is distant from other mangroves, introducing inverte-

brates, algae, and other fauna could accelerate development (Teas 1980).

Substrate stabilization appears to be one of the most important

functions of mangroves. Since black mangroves form dense root mats, they

may serve as better stabilizers than red mangroves (Savage 1972; Carlton

1974). White mangroves also grow dense root mats; they, too, can stabilize

substrate (Teas 1981). Lewis and Dunstan (1975) suggested achievement of

rapid stabilization by first planting Spartina alterniflora and then

planting mangroves within the Spartina. Pulver (1975) suggested plantinq

mangroves in greater densities, then allowing natural overcrowding and

competition or artificial thinning to occur.

Four basic methods of mangrove reestablishment have been applied:

planting of propagules, planting nursery-grown seedlings, transplanting

from field stocks, and air layering. These methods are herein described as

well as some common decisions and problems encountered in the field.

Planting propagules: This method simply involves collecting propa-

gules and placing them into the substrate at the restoration site.

Most restoration failures of planting seeds or seedlings appear to

occur due to high wave energy. This form of stress physically undermines

and removes plant material before it becomes established (Hoffman et al.,

in prep.). Natural high wave energy is caused by strong winds, but boat

wakes constitute an induced stress, especially in well-used recreation

areas. Teas et al. (1975) planted 178 young Rhizophora seedlings on a St.

Lucie River site that was subjected to waves from boat traffic; after 7

months, there were no survivors. However, a nearby low energy site had a

dense growth of mangroves after 5 years (Teas et al. 1975). After plant-

ing 60,000 Rhizophora propagules on a low energy site in Charlotte Harbor,

the same authors reported 85 to 90% survival after one year. Teas (1977)

reported 100% survival after 5 months of small pot-grown mangroves of all

species planted along a low energy canal. The establishment of a "rocky"

berm in areas prone to high wave energy in order to absorb destructive

water movements are sometimes used; this berm should be high enough to

inhibit waves, but porous enough to allow tidal infiltration.

If planted or growing too low in the tidal zone, mangroves are subject

"Sphaeroma disease." Sphaeroma terebrans is an isopod parasite that bores

into mangrove roots and stems, weakening them and making them more

vulnerable to adverse effects of wave stress. Hannan (1975) reported that

I ~~all mangroves planted 10 cm too low in the tidal zone were killed by

Sphaeroma, but trees planted above this level were not attacked.

Nursery-grown mangroves: -This method involves the growth of mangroves
in an artificial environment and transplanting them to restorative sites.

Evans et al. (1978) described how several methods of treatment affected

growth and survival of mangrove seeds. Mulched soils (50% grass

clippings/50% soil) enhanced growth rates of red and black mangroves, but

had no effect on survival of reds and an undetermined effect on survival of

blacks. Salt additions increased survival for both reds and blacks but was

ineffective on growth rate. Fertilizers showed no effect for red

I ~~~mangroves, but were detrimental to blacks. Various watering schedules did
not affect red mangroves, but blacks exhibited greater survival after one

I ~~~watering per week. These authors suggested that black mangrove seeds,

prior to planting, be soaked until their seed coats fall off and roots

start growing.

Transplanting mangroves: This method involves the removal of plants

from a donor site and replanting them at a recipient site. Pulver (1976)

1 ~~~developed guidelines for transplanting mangroves:
(1) The top and side branches should be pruned to approximately

2/3 of the original length.

(2) A root ball diameter about 112 the original tree height

should be retained.

(3) At the recipient site, when replacing soil in the hole,

the root ball should be watered and pushed down to insure

I ~~~~~a seal between it and the sides of the hole.

(4) The plant should be placed at about the same substrate

I ~~~~~~~~~~~~~~59

depth and the same tidal elevation as the original source

site.

(5) Plants should not be placed into unstable substrates.

Hoffman and Rogers (1980) successfully applied these methods but without

initial pruning. They reported 73.3% success after 13 months for

transplanting red and black mangroves on a dredge spoil island in Tampa

Bay on an area of low wave energy and proper elevation. Hannan (1975)

transplanted 4-year old root balled red mangroves at or above mid-tide

range in the Jensen Beach area; after 13 months, 85 to 100% survived. Teas

(1977) transplanted 14 black mangroves and white mangroves that were

previously root-pruned and top-pruned at the time of translocation; after 6

months, all were dead. Teas attributes these losses not to pruning, but to

improper handling.

Mangrove Air Layering: Air layering serves as an untried method of

restoration. Short sections of bark and phloem are stripped to the cambiam

and wrapped with Sphagnum moss and aluminum foil to retain moisture. Roots

soon emerge from the "layers". To form new trees, stems may be cut under-

neath the layers and planted at a new location. Carlton and Moffler (1978)

observed root growth 5 to 6 months following layering with 39% success for

red mangroves, 35% for white mangroves, and 6% for black mangroves.

Further investigations by the Department of Natural Resources (DNR) Bureau

of Marine Research indicate that root growth requires 4-6 months with

success rates of 87.5% for whites, 60.4% for reds, and 12.5% for black

mangroves (D. Crewz, personal communication). Investigators at DNR suggest

that air layering be performed just before the rainy season to take

advantage of higher humidities and temperatures, however, they warn that

too much water may lead to fungal/bacterial infection. Air layering

provides larger planting material without the labor-intensive costs of

I ~~~growing nursery plants or the-loss of plants from source sites associated

with transplanting. Addi ti onallIy, air layering allows for phenotypic

selection for specific traits (D. Crewz, personal communication).

In summary, restoration of mangrove stands and even the introduction

of mangroves into new sites is highly feasible. Planting in recipient

I ~~sites of low wave energy and fairly stable substrate appears to enhance

survival. Berms or another method of lowering wave stress can be placed at

sites of high wave energy. All four methods of restoration exhibit

successful results when guidelines are properly followed. Fehri ng et al .

(1979) stress the importance of community acceptance and assistance with

projects at or near developed areas. They further point out that most of

the habitat restoration projects are run by government agencies - these

U ~~~projects are assured of long-term commitments in most cases. Developers,

too should be responsible for long-term commitments, i.e., successful re-

establishment and not just initial plantings.

IV C. SALT MARSH RESTORATION

I ~~~~As with seagrasses and mangroves, the importance of marsh vegetation

is well-known and documented. Present salt marshes occupy calm waters

subject to tidal influences; restored marshes prefer the same habitat. In

planning for a restored site with the ultimate veqetative composition in

mind, Hunt (1979) suggested that investigators first observe the species

composition of nearby marshes (if any) occurring at the same elevations as

the site to be restored. Local species may be more likely to invade and

3 ~~~~~~~~~~~~~~61

colonize the area. Like mangroves, salt marsh revegetation has incorpo-

rated three methods: planting seeds and transplanting field and nursery

stock.

Seeds: If water levels maintain relatively shallow depths during the

time of seed germination and establishment or the site is located in the

upper portion of the tidal zone, revegetation by seeds may have positive

results; tidal action may otherwise dislodge seeds (Hunt 1979). Darovec

et al. (1975) recommended collecting cord grass seeds at least 3.Om from

the seaward edge of the marsh. Woodhouse et al. (1972) describe the proper

techniques of handling seeds and Darovec et al. (1975) summarized these

procedures: seeds should be stored in seawater between 1.7-3.3�C for two

to four months. Seeds planted in vivo require 6 to 25mm substrate over

them to prevent being washed away.

Transplants: Depending on the species, various harvest methods have

been suggested for different types of marsh vegetation. 15cm plugs of

Spartina alterniflora and S. patens should be removed from a mature marsh

in random locations, however, Juncus stock should be removed from one site

since the plant is easily destroyed by human traffic (Hoffman et al, in

prep.). Plugs of Spartina can be planted intact, or separated into

individual stalks, which reduces collection labor since one plug supplies

many stalks (Hoffman et al., in press). Removing the top 1/3 of Juncus

shoots reduces aerial transpiration and allows greater ease in handling

(Hoffman et al., in press). If high tide covers the cut top, survival is

reduced (Coultas, 1980). Some important techniques for transplanting are

described by Darovec et al. (1975):

1. "Transplants should be removed beyond 15 ft. from the

seaward edge of the marsh, taken in alternating square

yards in checkerboard array. Three to five plants should

remain in the center of each thinned square yard."

2. "Cordgrass and needlerush should be removed by shovel.

To minimize erosion, holes should be refilled with soil

rinsed from plant roots. Bare root plantings will work

satisfactorily if plants are kept moist and are not ex-

posed to direct sunlight. When transportation is involved,

roots can be kept in buckets of seawater or in wet burlap

sacks."

3. "Marsh transplanting should be done in winter and early

spring, preferably after the coastal storm season."

4. "Salt marsh plants should be planted in rows paralleling

the shoreline, cordgrass nearest the shoreline, plants

18-24 inches apart."

Coultas (1980) recommended that transplants with one or more buds be

used since these will produce more leaves and a greater height. He also

noted that "Rootone" (a commercial growth regulator) produces deleterious

effects.

Hoffman and Rogers (1980) performed an S. alterniflora restoration

project on dredge material in Hillsborough Bay. Plugs of S. alterniflora

were planted on a 1.64 ha. site of low wave energy and a favorable tide

regime. The 12cm plugs were placed one meter apart (center to center) in

rows two meters apart. After 14 months, 93.4% survived. Hunt (1979)

reported that sprigs of Spartina alterniflora grew well when planted 0.3,

0. 6, and O. 9m apart, but I1.8 and 2. 7m spaci ngs resul ted i n poor survi val.

Spartina patens, however, grew best at spacings of 1.8 and 2.7m (Hunt

1979) . Hunt additionally found that seeds grew with greater success than

spri gs.

IV D. MISCELLANEOUS RESTORATION TECHNIQUESI

Spoil Island Configuration: The initial formation and subsequent

maintenance of ship and boat channels requires huge amounts of sediments to

be dredged up. The sediments are typically dumped as random piles or spoilI

islands, adjacent to the channel sites, sometimes without regard to island

configuration in relation to current flow and ensuing erosion. Many times,

these islands quickly erode back into the channel necessitating further

dredging. In Tampa Bay, for example, three spoil islands were created in

1931. By 1957, two islands had completely eroded away. However, the

remaining island shifted continuously, and finally stabilized forming a

horseshoe shape with distinct arms. By 1966, one arm was shortened and

curved around forming a lagoon. A mixed mangrove habitat became

established and by 1979 the island served as a nesting site for 13 species

of birds.

Lewis and Dunstan (1974) suggested several methods to correctly

configure inevitable spoil islands. These suggestions were recommended forI

a proposed Tampa Bay harbor deepening project, but can also be applied to

other proposed channel sites as well. The overall shape of the new spoil

island should describe a three-to-one ratio of length to width. Stabili-

zation can be achieved more quickly through the establishment of oyster

U ~~~reefs and vegetation such as mangroves. An artificial reef composed of

surplus construction materials can be built to minimize wave action and

protect the shoreline.

Bulkhead Alternatives: Seawalls not only deprive the estuary of the

important shallow intertidal gradient between dry land and water, but they

also provide residents with an impersonal and false view of the natural

world. There are less obtrusive methods of changing or creating shoreline

I ~~~to allow man to live adjacent to water. One method is to leave the natural

vegetation and allow the mangroves and salt marsh to control erosion, a

task for which they were so well designed. Houses built on stilts elevate

* ~~their residents and provide not only a scenic view over the natural

shoreline vegetation, but also assurance against storm and hurricane tides.

I ~~The natural shoreline additionally provides habitat for numerous birds,

fish, and invertebrates. Depending -on the shoreline width, it may also

help cleanse water flowing through it.
A second method is to build a low wall of rip-rap. Rip-rap, with its

wealth of crevices, holes, and surface area, provides a habitat for algae

and invertebrates. It may also provide protection for inqrowing mangove

seedlings and other shoreline vegetation. It is relatively inexpensive and

I ~~~extremely strong and stable. Depending on the material used to create the

rip-rap wall, it can also be aesthetically appealing.

Rational Canal Design:

The early approach to canal designing was to maximize waterfront

property in relation to shoreline -space. Traditional desiqns provided

I ~~~little potential for effective flushing. This most always leads to water

quality and biological degradation. However, Morris (1981) states that on

I ~~~~~~~~~~~~~~65

a day to day basis, small amplitude tides, supplemented by periodic winds,

in most cases provides enough energy for flushing, if the canal was

designed properly. Obtaining the required energy, as Morris continues, canI

be accomplished by (1) eliminating unnecessary energy losses due to

mechanical reasons such as right-angle bends, deep holes, and culverts and

biological inbalances such as the absence of natural filtering action and

nutrient uptake provided by vegetation and aquatic organisms, and (2)

utilizing open channels to optimize mixing.

A good example of rational canal designing is demonstrated by a canal

network currently under construction along the intracoastal waterway south

of Jupiter, Florida. The site includes (Morris 1981):

meandering channels
large areas of intertidal channelsI
sloping, vegetated banks
elimination of dead ends
increased tidal prism
freshwater flow over salinity structuresI
more uniform change in section through tidal
entrances
natural preserves set aside along the water
The rational approach to canal design includes
common sense planning, in-depth data collection,
the correct application of physical chemical
biological and ecological principles, and the
use of judgement. The method cannot guarantee
that a given design will function as planned,I
but it will provide the kind of guidance needed
for environmentally compatible development.

Water Quality Improvements:

Indirect problems, in many cases, causes the disappearance ofI

estuarine vegetation, especially seagrasses. Poor water quality such as

high levels of organics and/or pollutants, high turbidity, and poor

.66

I ~~~circulation oftentimes is the cause. Restoring vegetative habitats,

especially seagrasses, in an area of poor water quality, would probably
I ~ ~result in a failed attempt., Several methods exist to improve water

I ~~~quality; these, of course, depend on the type of water quality perturbation

pasting at the site.
Improving sewage treatment and wastes released into the estuary would

lessen the amount of introduced nutrients, this reducing the process of

I ~~~eutrophi cati on. To induce better circulation in areas where circulation

has been moderated or terminated, one-way tidegates, cuts, and/or culverts

can be installed. Treatment of point and non-point sources of pollution,

especially stormwater run-off, would decrease the amount of chemicals and

toxins that are released into the estuary. These ideas represent only a

I ~~few options that exist to improve water quality of damaged estuaries.

I~~~~~~~~~~~~~~~6

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
68 I
I

I
I
I
II
I
I

* Linking Juvenile Fish to Estuaries

I
I
I
I
I
U

I
I
I11111 iith IAIIL~ II III�k~IA~r

V. LINKING JUVENILE FISHERIES SPECIES TO ESTUARIES

V A. SPECIES FOUND IN ESTUARIES

Many investigators have produced rather extensive juvenile species

lists for estuarine environments in Florida alone. Among them are Reid

(1954) and Kilby (1955) who listed species from Cedar Key; Harrington and

Harrington (1961) who recorded species from Indian River; Tabb and Manning

(1961) who listed species of Florida Bay; Springer and Woodburn (1960) and

Sykes and Finucane (1966) who listed fishes of Tampa Bay; and Odum and

Heald (1972) who recorded species from North River estuary.

While species lists represent single point-in-time presence of

juvenile fish in estuaries, studies of age and growth can document longer-

term presence. An example of this concept is a two year age and growth

project currently underway by DNR Bureau of Marine Research. The project

involves bimonthly collections of juvenile trout, drum, and related species

from various sites in the Tampa Bay estuary. Sites include seagrass beds,

sandy bottoms, and back water sites with generally turbid water and muddy

bottoms. Collections at these sites have yielded progressively larger

juvenile fish of the same species, indicating that these fish live and grow

within the estuarine system. In addition, this study will document growth

rates, site preference, and arrival time of new post-larvae that indirectly

indicates spawning times of adults.

Table 4 lists the recreational and commercial fishes of Florida.

Robins et al. (1980) provided the scientific and common names. Commercial

species are defined as those recorded in Florida Landings (Florida

Table 4. FLORIDA RECREATIONAL AND COMMERCIAL SPECIES

ESTUARINE-j RECREATIONAL COMMERCIAL
FAMILY/SPECIES DEPENDENT EAST WEST EAST WEST
Carcharhinidae - requiem sharks
(Carcharhinus spp.) + X X X X

Sphyrnidae - hammerhead sharks
Hammerheads, bonnethead (Sphyrna spp.) + X X X X

Acipenseridae - sturgeons
Atlantic sturgeon (Acipenser o. oxyrhynchus) X X
Gulf sturgeon (Acipenser oxyrhynchus desotoi) X X
Shortnose sturgeon (Acipenser brevirostrum) X X

Albulidae - bonefishes
Bonefish (Albula vulpes) + X X

Elopidae - tarpons
Ladyfish, Tenpounder (Elops saurus) + X X
Tarpon (Megalops atlantica-)a + X X

Clupeidae - herrings
Alabama shad (Alosa alabamae) + X
Alewife (Alosa pseudoharengus) + X X
American shad (Alosa sapidissima) + X X
Atlantic thread herring (Opisthonema oglinum) - X
Atlantic menhaden (Brevoortia tyrannus) + X
Gulf menhaden (Brevoortia patronus) + X
Spanish sardines (Sardinella aurita) X X

Ariidea - sea catfishes
Gafftopsail catfish (Bagre marinus) + X X X X
Sea catfish (Arius fel6s)- + X X X X

Exocoetidae - flying fishes
Ballyhoo (Hemiramphus brasiliensis) X X

Carangidae - jacks and pompanos
Blue runner (Caranx crysos) + X X X X
Cigarfish, scad (Decapterus spp.) X X
Crevalle jack (Caranx hippos) + X X X X
Florida pompano (Trachinotus carolinus) + X X X X
Greater amberjack (Seriola dumerili) - X X X X
Permit (Trachinotus falcatus) + X X X X

Centropomidae - snooks
Snook (Centropomus pectinatus) + X X

Coryphaenidae - dolphins
Dolphin (Coryphaena hippurus) X x X X X

Table 4. FLORIDA RECREATIONAL AND COMMERCIAL SPECIES (Continued)

IESIUARINE-I RECREATIONALI COMMERCIAL
I ~ ~FAMILY/SPECIES DEPENDENT EAST WEST EAST WEST
Ephippidae - spadefishes
Atlantic spadefish (Chaetodipterus faber) + X X

Gerreidae - mojarras
Spotfin mojarra (Eucinostomus argentus) + X X X X
I ~~Striped mojarra (Diapterus plumieri) + X X
Yellowfin mojarra-,-sa-nd-per-ch-,-go-atfish
(Gerres cinereus)X X
Silver jenny (Eucinosou ua + X X X X

Haemulidae - grunts
Pigfish (Orthopristis chrysoptera) + X X X X
Tomtate (Haemulon aurolineatum) + X X
White grunt (Haemulon plumieri)+X X X X

I Istiophoridae - billfishes
Blue marlin (Makaira nigricans) - X X X X
Sailfish (Istio-phorus platypterus) - X X
White marlin (letrapturus lbidT~u) - X x x x

Labridae - wrasses
Hogfish (Lachnolaimus maximus) X x X

I Lobotidae -trpeal
Tripletail (Lobotes surinamensis) + X X X X

E Lutjanidae - Snappers
Cubera snapper (Lutjanus cyanopterus) + X x x x
Lane snapper (Lutjanus synagris) + X X X X
Mangrove (Gray) npe7Ltau griseus) + X X X X
Mutton snapper (Lutjanus analis) + X X X X
Red snapper (Lutjanus campechanus) + X x X X
Vermillion snapper (RiomboplTTe-saurorubens) - X X X X
Yellowtail snapper (Ocyurus chrys~u-rus)-y~ X X X X
Mal acanthi dae - til1efi shes
3 ~~Ti lefish (Lopholatilus chamaeleonticeps) X X

Mugilidae - mullets
Black mullet (Mugil cephalus) + x x x x
Fantail mullet (Mugil trichodon) + X X
Silver, white muTT-ef(7u-g- I curema) + X x

I Percichthyidae - temperate basses
Striped bass (Morone saxatilis) + X X

I Pomacanthidae - angelfishes
Angelfish (H-olacanthus or Pomacanthus spp.) X X

* ~~~~~~~~~~~~~~~~71

Table 4. FLORIDA RECREATIONAL AND COMMERCIAL SPECIES (Continued)3

IESTUARINE-1 RECREATIONAL I COMMERCIALj I
FAMILY/SPECIES IDEPENDENT I EAST WEST I EAST WEST
Pomatomidae - bluefishes
Bluefish (Pomatomus saltatrix) + X X X X3

Rachycentridae - cobi asI
Cobia (Rachycentron canadum) x x x x

Sciaenidae - drums
Atlantic croaker (Micropogon undulatus) + X X X X
Black drum (Pagna rms + X X X X
Grey seatrouFi�inrgls + X XI
King whitingsotenkgfh (Menti ci rrhus
americanus) + X X X X
Red drum (Sciaenops ocellatus) I + X X X
Sand seatro-ut (Cyno scion arenarius) + x x x
Silver perch (Bairdiella chrysura) + X X
Spot (Leiostomus xanthuru~sT7 + x x x xI
Spotted seatrout (Cy~nosci~on nebulosus) + X X X X
White, silver seatrout Cynosc-ion n'othus)-X X X X

Scombridae - mackerels and tunasI
Bigeye tuna (Thunnus obesus) -x x
Blackfin tuna (Thunnus atlanticus) -X X
Bluefin tuna (Thu~nnus-thynnus)IIIII
Little tunny (Euthynnus alletteratus) x X X X
Skipjack tuna (Luthynnus pelarnis) - X X X X
Frigate mackerel-T(Auxi s th-azar-d) - X X X X
Ki ng mac kerelI ( Sco~mberomo-ru-sc cava]lla) + X X X X
Spanish mackerel (Scomberomorus maculatus) + X I X X

Serranidae - sea bassesI I II I
Bank sea bass (Centropristis ocyurus) 1 X I Ix
Black sea bass (Centropri sti s stri ata)-X X X
Gag grouper (Mycteroperca micr-o7e~p-1s7 +X X XX I I
Jewfish (Epinephelus itajara) + X X X X
Red grouper (Epi nephelus mono ) + X X X X
Rock sea bass (Centropr-is-t-i-s--piladelphica) + X X
Southern sea bass (Centropristis melana) x x
Warsaw (Epinephelus nigritus) - X X X X

Jparidae - porgiesI
Pinfish (Lagodon rhomboides) + X X
Scup (Stenotomus chrysops) X x X
Sheepshead (Archosarqus probatocephalus) + X X X X
White snapper, porgy (Calamus spp.) X X X x X

Table 4. FLORIDA RECREATIONAL AND COMMERCIAL SPECIES (Continued)

IESTUARINE-I RECREATIONALI COMMERCIAL
FAMILY/SPECIES DEPENDENT EAST WEST EAST WEST
Sphyraenidae - barracudas
Great barracuda (Sphyraena barracuda) + X X X X
Guaguanche (Sphyraena guaguancho) + X X X X

Xiphiidae - swordfishes
Swordfish (Xiphias gladius) X X X X

Bothidae - lefteye flounders
Gulf flounder (Paralichthys albigutta) + X X
Southern flounder (Paralichthys lethostigma) + X X X X
Summer flounder (Paralichthys dentatus) + X X

Balistidae - leatherjackets
Triggerfish (Balistes capriscus) + X X X X

Tetraodontidae - puffers
Southern puffer (Sphoeroides nephelus) + X X

CRUSTACEANS, SPONGES, AND MOLLUSKS

Spongiidae - sponges
Glove sponge (Spongia spp.) + X X
Grass sponge (Spongia graminea) + X X
Sheepswool sponge (Hippiospongia lachne) + X X
Yellow sponge (Spongia zimocca) + X X

Loliginidae: Squid (Loligo plei) - X X

Strombidae: Conch (Strombus gigas) + X X X X

Ostreidae: Oyster (Crassostrea virginica) + X X X X

Pectinidae: Scallops (Argopectin irradians) + X X X X

Veneridae: Clam (Mercenaria mercenaria) + X X X X

Penaeidae: Brown shrimp (Penaeus aztecus) + X X X X
Pink shrimp (Penaeus duorarum) + x X X X
White shrimp (Penaeus setiferus) + X X X X

Sicyoniidae: Rock shrimp (Sicyonia brevirostris) + X X X X

Palinuridae: Spiny lobster (Panulirus argus) + X X X X

Portunidae: Blue crab (Callinectes sapidus) + X X X X

Xanthidae: Stone crab (Menippe mercenaria) + X X X X

Department of Natural Resources, 1978). Considering that certain species

may or may not be regarded as recreational, dependi ng on the fi sherman,

recreational species are here defined as any fish caught and kept byI

saltwater anglers, all fish currently listed as a Florida record catch (a

co-sponsored DNR/IGFA project in developmental stages), and all species

pursued by sports fishermen. Species designated as non-food fishes

(typically bait fish) are included only as commercial species. Of 108 total

species, 89 are caught commercially (85 on the east coast, 83 on the west

coast), and 88 represent the recreational catch (84 on the east coast, 83

on the west coast).I

Table 4 also indicates which species reside in estuaries during someI

time in their lives. This information is based on literature citations

that indicate the presence within an estuary of any sub-adult stage of the

species listed. 71.9% (n=64) of the commercial species and 73.9% (n=65) of

the recreational species dwell in estuaries at least as pre-adults. Of theI

total commercial and recreational species, 68.5% (n=74) use estuaries as

nursery grounds. These amounts are significant, especially considering

the importance of fishing industries in Florida. Adding to this

information is the report by McHugh (1976) who estimated, using 1970

statistics, that 98% by weight of all Gulf of Mexico landings areI

estuari ne-dependent.

Unfortunately, the simple presence of young stages within an estuary

is not enough proof of the use of estuaries as nursery grounds. A link

must be established. Several methods exist to define this link. Direct

evidence can be attained by diet analyses and feeding studies. Indirect

741

evidence is provided by stable isotope analyses, correlations between

fisheries yield and habitat type, and correlations between declines in

fisheries yield and wetlands, destruction.

V B. DIET ANALYSES

Many researchers have examined gut contents to determine diet. Table

5 lists some recreational and commercial juvenile estuarine fishes along

with items found in their digestive tracts. An attempt was made to include

only fishes reported as less than or equal to 100mm in length, regardless

of species, to insure juvenile age class. Food items found most commonly

(composing over 50% of the gut content) are underlined.

Three obvious conclusions can be drawn from the table: (1) juvenile

fish utilize several food sources, (2) differing species share common food

sources, and (3) diets change as fish grow. These conclusions emphasize

four (#1, #3, #4 and #5) of Miller and Dunn's (1980) features of juvenile

fish feeding relationships as discussed in the previous section.

The most common food items found in digestive tracts of the majority

of species are copepods, shrimp, mysids, amphipods, fish, and polychaetes.

A subsequent food chain study would require a diet analysis of each of

these animal groups. However, within each group, no single feedinq

strategy exists, especially for those groups occupying the sub-tropical

shoreline waters of Florida. Within the polychaete group, for example,

omnivores, herbivores, deposit feeders, carnivores, and detritivores are

found, each consuming a wide variety of food items. Diet studies of these

groups are feasible and certainly important, but must be very specific.

Table 5. DIET ANALYSES OF SOME PRE-ADULT RECREATIONAL AND COMMERCIAL
ESTUARINE FISH

Species Size (mm) Code for Food1 Reference2

Ladyfish 19-38' 120,132 106

Atlantic thread herring 21-40 230 14
Juvenile 300 6
>40 120,140,131,230 14

Sea catfish small 620,160,100 90

Crevalle jack 79 600 61

Permit 15-20 140,135 14
15-44 160,420,221 38
26-35 610 14
>35 900 14
50-100 180,200 38

Silver jenny 11-15 120 14
16-39 120,911 14
19-70 160,120,400 102
>35 911 14

Striped mojarra 35-172 140,160,410 106

Pigfish 12-15 120,110,210 60
16-20 T2U 14
21-30 120,135 and/or 140,630 14
31-40 T357 and/or 140,911,120 14
40-100 160,135,133,200,911 60
41-55 911,135 and/or 140,160,120,630 14
56-80 T,911,134,630,210,120 14

White grunt 21-35 120,140 or 135,500 14
36-40 TT4 or 135,120 14

Black mullet Juvenile 500,510 61

Atlantic croaker 10-39 911,400,160,120 130
10-49 O-T,700,500,510 61
17-42 200,110,120,911,600 156
<39 120,100 133
40-49 121,120,141,100 133
40-89 TT1,400,160,120,500,140,135 130
50-59 100,141,120 133
50-124 510,500,300,700,600 61
60-79 121,141,120,100 133
80-99 120,100,911,141 133

1Code list located on page
2Numbers refer to references listed in Section X.

Table 5. DIET ANALYSES OF SOME PRE-ADULT RECREATIONAL AND COMMERCIAL
ESTUARINE FISH (continued)

Species Size (mm) Code for Food Reference

Grey seatrout 30-49 121,100,141 133
50-99 141,911,100 133

Red drum 0-19 120,140 4
20-39 140,120,160 4
40-49 T6O,140,600 4
50-69 60,160,911 4
70-99 176, 911,133,600,511,512

Sand seatrout 10-39 140,120,135,600 130
40-99 6TU,140,135,300 61,130

Silver perch 6-30 120,630,600,135 or 140,160, 14,60,90,
n1l =I70,140,911 106
23-63 130,140,410,160,610 90
25-50 140,135,133 60
25-99 135,120,160,200,911,600,100 122
30-39 1T2T -i 133
31-35 120,135 and/or 140 14
36-70 T37,120,160,100 14
40-69 T1T,121,100 133
50-80 140,135,161,911 60
60-82 140 156
70-99 141,100 133
Larval 120,630 102

Spot <25 120,110 60
Post-larval 120 70
15-100 500,200,910,100 60
20-69 911,500,120,920,140,220,400 130
40-99 700,500,510 61
50-99 120,121 133

Spotted seatrout 20-100 120,140,138 97
20-130 600,135 and/or 140,120,160 14
25-150 140,137 133
40-99 600,300,700,800,500,510 61
68-122 14-,160,410,138,610 102

Pinfish 10-30 120,160,135 and/or 140,1100,
-11,100 14
15-50 135,160,120 122
31-65 160,1100,911,135 and/or 140 14
39-61 222,140,160,223 106
40-99 700,500,800,600 61
51-100 120,135,510,160,200,133,600, 122
1400
66-90 135 and/or 140,1100,600,500 14
<76 1200,100,911,2000 53
Post-larval 120 70

Table 5. DIET ANALYSES OF SOME PRE-ADULT RECREATIONAL AND COMMERCIAL
tL5UAKINL Il5H (continued)

Species Size (mm) Code for Food Reference

Sheepshead <40 120,160,410,140,1300,200 106

Southern puffer 6-25 500,300,911,210,133,135 14

DIET CODE LIST

100 Crustaceans
110 Ostracods
120 Copepods
121 Pseudodiaptomus coronatus
130 Decapods
131 Megalops larvae
132 Crab zooae
133 Crabs
134 Xanthid crabs
135 Shrimp
136 Post larval shrimp
137 Penaeid shrimp
138 Cariddean shrimp
140 Mysids
141 Neomysis americana
150 Isopods
160 Amphipods
161 Gammarid amphipods
170 Cladocereans
180 Larger crustaceans
200 Mollusks
210 Gastropods
220 Bivalves
221 Donax variabilis
222 Brachidontes exustus
223 Congeria leucophaeta (now called Mytilopsis leucophaeta)
230 Veliger larvae
300 Zooplankton
400 Insect larvae
410 Chironomids
420 Larval and adult Dipteran insects
500 Detritus
510 Organic matter
511 Animal remains 300 Zooplankton: mostly cope-
512 Fecal pellets pods, mysids, larval
600 Fish penaeid shrimp
610 Small fish 700 Micro-invertebrates: small
620 Fish eggs bivalves, isopods,
630 Fish larvae amphipods, small
700 Micro-invertebrates crabs, chironomid
800 Larger invertebrates larvae
900 Benthic invertebrates 800 Larger invertebrates: mud
910 Annelids crabs, blue crabs,
911 Polychaetes shrimp spp.
920 Nematodes 500 Detritus: decaying marsh
1000 Vegetation grasses, phyto-
1100 Epiphytes plankton, zooplank-
1200 Diatoms ton, micro-benthic
1300 Algae animals
1400 Plant debris
2000 Chordates

Since most sources of Table 5 reported food items as groups, i.e. copepods

and polychaetes, without knowing the exact species serving as food items,

no conclusions can be drawn. However, using gut analyses to link

seagrasses and mangroves to juvenile fishes has potential, although

available knowledge about different trophic levels and their food items

does not provide enough information to concretely link juvenile species to

primary producers.

V C. STABLE ISOTOPE ANALYSES

Carbon, the element upon which all life is based, occurs on Earth in

three isotopic forms (12C, 13C, and 14C), and all prove useful in

scientific investigations. Radioactive 14C, due to its inherent instabil-

ity and, therefore, its rate of decay, provides an extremely valuable tool

for dating fossils.

12C and 13C occur as stable isotopes. Because the two isotopes react

at different rates during photosynthesis, every primary producer embodies a

certain ratio of the two isotopes, specific to the plant or plant group.

The ratio, known as the relative 13C content (613C ), is determined by the

equati on 12 1
C/ C sample - 1) 3
C standard

in which the standard refers to the PDB marine carbonate standard (Craig,

1953). 613C is typically measured in parts per million (0/00).

Because the standard has a higher ratio than almost all other carbon-based

materials, most materials have negative values. C3 plants (those that

convert carbon dioxide to a 3-carbon molecule) possess 613C values between

about -21 and -340/oo (Wong and Sacket 1978; Sacket, in press). C4

plants (those that convert carbon dioxide to a 4-carbon compound) maintain

values of approximately -6 to -19�/oo (Smith and Epstein 1971).

An interesting fact about 613C is that the ratio is maintained through

the food chain. In other words, whereas primary producers fix 13C/12C into

their biomass through photosynthesis, secondary consumers maintain the

ratios of plants they eat. Subsequently, tertiary consumers maintain the

ratio of their prey. The theory for the estuarine system follows that pre-

adult fishes, existing as top carnivores (irrespective of larger fish and

birds), should maintain 613C values identical to seagrasses and mangroves,

if these two primary producers do indeed serve as important food sources

for the estuarine system. Although the first measurements of 13C were made

in 1939 (Nier and Gulbransen 1939), the concept of ratio maintenance

through the food chain is relatively new, and very little work has been

done to date in this realm of research. A significant point is that 613C

is a function of an animal's history - it provides data of feeding

behaviors over time, averaging out seasonality and food availability. In

comparison, gut analyses provides data for only a single point in time.

Haines and Montague (1979) recognized two significant criteria for

using 13C/12C ratios to analyze food chains: (1) definite ratios must

exist for food sources alternate to those under investigation, and (2) the

ratio must be maintained through the food chain. Fry and Parker (1979)

noted that previous studies have indicated that animals possess a 13C

value very near the value of their diets, however, metabolism may affect

the value + 2% between individuals or species (Minson et al. 1975; DeNiro

and Epstein 1978).

No 613C studies for Lake Worth or Charlotte Harbor have been reported;

however, Fry and Parker (1979)and Fry et al. (1977) investigated the Upper

Laguna Madre seagrass ecosystem in Texas. The dominant seagrass at the

site was Halodule wrightii with smaller areas of Thalassia testudinum and

Halophila engelmanni. By comparing 613C values of fish, shrimp, and

invertebrates of the seagrass system to the same species offshore, they

found that benthic plants heavily influenced the carbon flow. Results from

another study by Fry et al. (1982) of a Caribbean seagrass bed and coral

reef suggested that benthic plants contribute 48-76% of the carbon in fish

generally greater than 40mm in length. Thayer et al. (unpublished) found

that deposit feeders and herbivorous invertebrates living on eelgrass

blades near Beaufort, N.C. obtained about 60% of their carbon from

seagrasses. In the same study, seagrasses provided omnivorous inverte-

brates and fishes 45% of their carbon.

Nitrogen and sulfur also are used as tracers in food web studies.

Both elements have two major stable isotopes: 15N and 14N, and 32S and

34S. Joseph Zieman (Department of Environmental Science, University of

Virginia, Charlottesville, VA) is currently analyzing juvenile shrimp of

south Florida estuaries using carbon, nitrogen, and sulphur. Other than

this study, little work has been done using tracer methods in Florida

estuaries, however, the papers reported here certainly support the use of

these methods as an effective tool in tracing estuarine food webs. Such

tracer studies could determine the significance of different vegetation

components within major estuarine systems, e.g. Charlotte Harbor and Tampa

Bay. These studies could partition out the contributions of manqrove

detritus, seagrasses, and phytoplankton in disturbed versus relatively

undisturbed systems.

V D. CORRELATIONS BETWEEN FISHERIES YIELD AND HABITAT TYPE

Amounts of emergent and submergent vegetation and freshwater flow have

been associated statistically with fisheries yield in some areas. For

example, Turner (1977) related shrimp yield to acreage of marsh and sub-

merged grassbeds as did Barrett and Gillespie (1973) who demonstrated a

positive correlation between brown shrimp landings in Louisiana and marsh

acreage with salinities above 100/oo. More recently, Zimmerman et al.

(1984) showed that juvenile brown shrimp in Texas were more abundant in

salt marsh areas than in nonvegetated areas.

The association between faunal abundance and marine vegetation is not

limited to shrimp. Macalaster (1982) showed that fish were more diverse

and abundant at vegetated sites than nonvegetated sites in the Chesapeake

Bay and that a decline in submerged grasses affected fisheries yield.

Weinstein and Brooks (1983) determined fish species and abundance differ-

ences between a tidal creek and an adjacent seagrass bed and although both

areas harbored wide ranging species, the seagrass area had hiqher diver-

sity. As Weinstein and Brooks pointed out, the specifics of habitat selec-

tion and utilization are not well documented, yet we accept the theory of

estuaries as nursery ground habitat based on occurrence, distribution,

abundance, and gut contents of those fisheries species studied.

Yokel (1975) reported that crustacean abundance was 3.9 times larger

within seagrass beds and algal mats than on nearby unvegetated bottoms.

Densities of fishes in south Florida estuaries and lagoons were found

generally higher within grass beds as opposed to adjacent non-vegetated

habitats (cf. Zieman 1982; Figure 5).

In addition to these reports, other studies have shown that in

Thalassia beds, areas of greater plant biomass contained both a higher

diversity and a greater abundance of epibenthic invertebrates than areas of

lesser biomass (Heck and Orth 1980). An extremely important point is that

the presence of seagrasses is critical to the presence of many other plant

and animal species living within the system. In other words, if all

seagrass blades were removed, much of the epibenthic faunal community would

probably vanish as well. Zieman (1982) notes that "there are few other

systems which are so dominated and controlled by a sinqle species...". In

summary, areas containing seagrasses are inhabited by a greater abundance

Fish

w' 75 Invertebrates

z 50-

I-.

HEAVY THIN SAND, MUD,
SEAGRASS SEAGRASS SHELL SAND,
Halodule 8 Thalassia Halodule SHELL

Figure 5. Relative abundance of some faunal communities within
seagrass beds and within adjacent non-vegetated sites.
(Redrawn from Zieman 1982, after Yokel 1975).

of organisms than unvegetated sites, and abundance appears to be directly

i ~~related to seagrass density.

I ~~~V E. CORRELATIONS BETWEEN DECLINES IN FISHERIES YIELD AND WETLANDS

DESTRUCTION

Since the literature well-documents the importance of estuaries as

I ~~nursery grounds, it is obvious that as estuarine habitat disappears, a

3 ~~~decline in associated fisheries also should occur. Lindall and Saloman

(1977) warned that "man's physical and chemical alterations of gulf

* ~~estuaries are threatening the continued production of its fisheries

resources." However, they could not quantify the impact.

3 ~~~~Two methods exist to quantify the relationship between fisheries

habitat alteration and associated fisheries decline. One method is to

I ~~~determine carry capacities of the various habitats. In theory, carrying

* ~~~capacity would describe the amount of fisheries species and individuals

that an area of habi tat can support. As fi sheri es habi tat is altered or

destroyed, the quantity of fisheries it supports can be predicted to be

destroyed as well. In practice, however, ways to determine carrying

.1 ~~~capacity *are basically unknown and are under investigation.

A second method i s to relate catch statistics of estuarine-dependent

species to declines in estuarine habitat over a period of time. Assuming

3 ~~~that catch effort has remained stable, that catch efforts occur at habitat

carrying capacity, and that all life history stages of a species is known,

3 ~~~this method should reflect a change in fisheries relative to changes and

alterations in habitat. To test this theory, five estuarine-dependent

1 ~~~~~~~~~~~~~~85

species were chosen as target groups: red drum (Sciaenops ocellatus),

spotted seatrout (Cynoscion nebulosus), black mullet (Mugil cephalus), blue

crab (Callinectes sapidus), and pink shrimp (Penaeus duorarum). Fisheries

statistics, though improper and inadequate as will be described in Section

V E 2, of these five species were obtained for the two study sites,

Charlotte Harbor and Lake Worth.

V E i. LIFE HISTORY STUDIES

RED DRUM (Sciaenops ocellatus)l

Red drum spends its juvenile and early subadult stages within

estuaries. Some adult populations live exclusively in the Gulf while

others live in estuaries. Red drum's range extends from Buzzards Bay,

Massachusetts to Key West, Florida on the Atlantic Coast and throughout the

Gulf of Mexico to at least as far south as Taxpan, Mexico on the Gulf

Coast.

Shrimp, crab and fish primarily comprise the diet of the adult red

drum. The literature also reports annelids, echinoderms, and bryozoans as

food items; these probably are ingested only incidentally. Florida red

drum spawn offshore in fall, reportedly near passes and channels.

Fecundity estimates for artificially conditioned and spawned red drum are 2

x 104 to 2 x 106 eggs per spawn. Fecundity of wild fish from Texas ranges

from 0.5 x 106 to 3.5 x 106 eggs per fish. Tidal currents carry larvae

through inlets and passes into estuarine areas where they settle out among

1Summarized from Perret et al. (1980)

the aquatic vegetation until they are strong enough to swim. In Florida,

the smallest larval fishes (5-7mm) were always found in shallow areas in or

I ~~~near the Gulf. In Mississippi- abundant juvenile red drum are found at the

I ~~~perimeter of marshes. In Florida, young fish are found in protected waters

with grassy or slightly muddy bottoms that are not affected by tides.

Following spawning, red drum appear to spend more time in offshore waters

and less time in estuaries.

I ~~~~Growth of the small fishes is rapid, and continues to be rapid during

the first year. A study of 106 juveniles collected from Everglades

National Park found growth rates of about 20mm per month. Results from

* ~~~tagging studies in Florida indicated that growth is not constant throughout

the year; fish exhibit a growth lag in spring, a rapid growth in summer and

a slight lag at the end of summer. Food density and larval stock density

influence growth as demonstrated in studies in mariculture systems.

I ~~~~For their first winter, many red drum ranging from 50 to 150mm move to

3 ~~~the deeper areas of estuaries. A gradual movement of fishes into the Gulf

during colder weather and a definite movement back into the estuary in

I ~~~early spring occurs after the first year. No apparent seasonal movement of
juveniles into the Gulf is known. As sub-adults, they move offshore prior

I ~~to maturation and spawning.

Red drum are euryhaline and eurythermal. Although they are found in

salinities from 0 to 500/00, they appear to prefer an optimum range of
3 ~~~30-350/oo. A direct relationship between size and salinity generally

occurs with smaller fish prefering low salinities and larger fish favoring

3 ~~~higher salinities. Red drum also have the ability to tolerate a wide range

of temperature. Although they are found in temperatures ranging from 2-

1 ~~~~~~~~~~~~~~87

31.8�C, red drum are sensitive to rapid and sustained lows in water

temperature.

In Florida, winter produces the greatest availability of red drum,

whereas in Texas, Louisiana, and Mississippi, the greatest numbers occur in

fall.

SPOTTED SEATROUT (Cynoscion nebulosus)l

The spotted seatrout is a species that spends all of its life within

the estuary. Primarily found in large areas of quiet brackish water with

extensive submerged vegetation, the species ranges from Cape Cod to Mexico.

Reflecting the mottled appearance of seagrasses, the spotted seatrout's

body is silvery with numerous dark spots on the sides and on the dorsal and

caudal fins. The world record catch was a 7.3kg fish taken in Virginia;

Florida's state record is a 7kg fish.

Feeding habits of the spotted seatrout change as the fish grows.

Postlarval seatrout feed on larval shrimp, copepods, small fish, and crabs.

They also prey on their own species. Copepods, mysids, penaeid shrimp, and

carridean shrimp comprise the diet of juveniles. Fish become an increas-

ingly important food item during the adult stage. Adult diets most often

consist of black mullet (Mugil cephalus), anchovies (Anchoa spp), pinfish

(Lagoden rhomboides), mojarras (Eucinostomus sp.), sheepshead minnows

(Cyprinodon variegatos), and penaeid shrimp (Penaeus sp.). It appears that

any preference for food items is more a function of food availability than

1Summarized from Lorio and Perret (1980)

of selectivity. This theory is exemplified by studies that found that

shrimp and fish were equally present in gut contents during May, June, and

July, when shrimp are most abundant in the area.

The spawning season of spotted seatrout in the Gulf is generally from

February through October. In Florida, spawning occurs from April through

September, peaking in late May/early June. Ripe fish occur all year in

Florida Bay, the southern limit of the species range, with a major peak

occurring in May and a lesser peak in September. Spawning takes place at

night and is believed to occur in the deeper channels and holes adjacent to

grassy bays and flats. Some spawning may also take place in the tidal

portions of estuaries and also outside the estuary. Fecundity estimates

range from 15,000 to 150,000 eggs per spawn.

Larval spotted seatrout grow from 1.5mm at hatching to about 4.5mm in

15 days. Rapid growth continues to about 13cm by the first winter and

about 24cm by the second winter. Growth lessens or ceases during winter

due probably to decreased metabolism and cessation of feeding activities

at lower temperatures. The most rapid growth occurs in July and August.

Longevity for spotted seatrout appears to be about 8 or 9 years.

Growth rates are density dependent, and may vary from one population

to another. Growth of spotted seatrout in five different estuaries along

the Florida coast occurred at different rates. Because seatrout popula-

tions from given estuaries exhibit differing growth characteristics, each

estuary and its population of spotted seatrout should be considered as a

separate stock.

Spotted seatrout are not considered a migratory species since they

seldom move more than 48.3km from their tagging site and very few leaving

their natal estuary. Movement patterns appear to be associated with

temperature, avoidance of fresh water, spawning, feeding, and protection.

Winter habitat throughout- the species' range extends farther offshore

and at greater depths. Optimum temperatures in Florida are 15 to 27�C.

Temperatures below 7 to 9�C force spotted seatrout to enter ocean inlets or

live offshore along the beach area for brief periods of time. However,

just as they move to deeper water to escape cold water, seatrout also

travel to deeper water to escape intolerable warm water.

Spotted seatrout is a euryhaline species sometimes found in fresh-

water and in hypersaline water of 750/o0. Normal salinity fluctuation

of 5 to 300/0o is important to all productive seatrout populations,

however, sudden changes in salinity may cause mass migration or mortali-

ties. Peak spawning occurs at 30 to 350/oo, but no spawning has been

reported to take place when salinity exceeded 450/00.

Spotted seatrout are found along their range within clear to very

turbid waters. The only documented negative effect of turbidity occurred

in Florida Bay following Hurricane Donna when turbulent water stirred up

the sandy bottom causing packing of the fishes' gill chambers and

mortality. Within the food web of the estuary, the spotted seatrout

represents a top carnivore, in fact in many estuaries the only carnivore

present in numbers. All other aquatic orqanisms, either directly or

indirectly, can serve as food. Because of this, the general health of the

estuary must be maintained to insure healthy populations of spotted

seatrout.

BLACK MULLET (Mugil cephalus)1

Black mullet represents a species that spends most of its life within

the estuary except during times of seasonal migration, annual spawning, and

during very young stages. Also known as striped mullet, black mullet are

found throughout in coastal waters and estuaries the tropics and

subtropics.

Adult and juvenile black mullet feed diurnally in bays and estuaries

during high tide. Mullet feed by sucking up surface layers of muddy

bottoms or by grazing on seagrasses, rocks, or other surfaces. Diatoms,

dinoflagellates, copepods, plant detritus (especially attached microflora),

and inorganic sediments commonly comprise their diet. When present, non-

toxic plankton provides the exclusive diet. Larvae and small juveniles

(2-35mm) feed on zooplankton.

1Summarized from Saltwater Fisheries Study and Advisory Council (1981) and

Futch (1976).

Spawning takes place in Florida from October through February, peaking

from November through January. Prior to spawning, mullet form large

schools and migrate from the estuary to offshore waters. Along the east

coast of Florida, spawning migrations move southward. The only distinct

migration pattern reported for the west coast occurs from Cedar Key to

Homosassa. Spawning usually occurs from 8 to 32km offshore in the Gulf of

Mexico.

Females produce from 1.2 - 2.7 million eggs in a single spawn,

releasing them directly into the water. Accompanying males fertilize the

floating, planktonic eggs. Depending on water temperature, hatching occurs

30 - 50 hours after fertilization. Hatched larvae measure 2 - 4mm, main-

taining an oceanic, planktonic existence for approximately 7 days. During

this time, they grow to 20-30mm and migrate inshore, passing through inlets

into the grassy parts of estuaries.

Growth rates directly correlate with water temperature and mullet from

Florida mature in 1-2 years, growing to a length of 230-350mm. Black

mullet live to 6-7 years and grow to about 750mm. Females typically live

longer and grow larger than males.

BLUE CRAB (Callinectes sapidus)l

The blue crab inhabits coasts from Nova Scotia to Argentina. It is

1Summarized from Saltwater Fisheries Study and Advisory Council (1981)

and Oesterling (1976).

I ~~~found from shore to approximately 90 meters in depth., but principally up to

35 meters.

I ~~~~The adult blue crab is characteristically omnivorous. Live and dead

fish, aquatic vegetation, clams, mussels, snails, amphipods, isopods,

insects and annelid worms comprise the diet of the adult blue crab. Food

j ~~~selection of larval crabs remains relatively unknown, however, laboratory

larvae have been raised successfully on dinoflagellates, brine shrimp, and

I ~~~sea urchin eggs. Crabs at the megalops stage feed on fish, shellfish, and

aquatic plants. Mating and spawning in Florida occur year-round, except in

northern Florida waters when the water temperatures drop below 15.6'C.

Female blue crabs mate only once per lifetime, during the molt from

juvenile to adult. Prior to this transition, the female will move to less

saline brackish waters, of 8-l80/oo salinity. She will then pair with

a male and will be carried, or cradled, underneath the male. While in this

cradled position, the female completes her final molt into the adult. At

I ~~~this time, while in the soft inter-molt stage, copulation (lasting several

hours) takes place. The male transfers his sperm to the female, of which

she stores in seminal receptacles within her body. The sperm are able to

live in this condition for about one year. After copulation, the male

I ~~still cradles the female beneath him until her new shell hardens, then he

* ~~~releases her.

After mating, females migrate to nearshore high salinity waters

3 ~~~(>250/o0) at the mouths of estuaries to spawn. Spawning typically

occurs I - 9 months subsequent to mating, with peak spawning in April and

June. Females spawn at least twice, each time laying 700,000 - 2 million

eggs. Classically, females follow a general latitudinal onshore/offshore

I ~~~~~~~~~~~~~~93

migration pattern. On Florida's Gulf coast, however, a tagging study

conducted by DNR Bureau of Marine Research found that females migrate

longitudinally, sometimes travelling over 640 km.

Females carry their eggs for 7-14 days in the offshore waters until

they hatch into a zoea larvae stage. Dependent upon temperature and

salinity, the seven zoea stages develop for 31-49 days, leading a

planktonic existence. The following megalops stage has both planktonic

and benthic features. By utilizing tidal currents, the megalops enter the

estuary and molt into the first crab stage. Grass beds and a variety of

shallow water areas provide habitats for growing crabs. Adult size

(>120mm) is achieved within 12-14 months and 18-20 molts. Movement to

deeper water occurs with increasing size. After reaching adult size, crabs

live about one more year.

PINK SHRIMP (Penaeus duorarum)l

Pink shrimp range from lower Chesapeake Bay to south Florida on the

Atlantic coast, throughout the Gulf of Mexico, and on the Bermuda coast.

The greatest abundance of pink shrimp occurs along coastlines characterized

by shallow bays and estuaries and where the continental shelf is broad and

shallow. Optimum habitat varies with age; shallow, quiet, clear water with

seagrass growth is preferred by young shrimp while adults live in the

1Summarized from Costello and Allen (1970) unless otherwise noted.

deeper offshore bottom areas with no seagrasses.

Pink shrimp spawn offshore and year round. Females release fertilized

microscopic eggs into the water; the eggs then sink to the bottom. After

hatching, the larvae are planktonic and are transported landward, apparent-

ly floating with currents. Three to five weeks are believed to pass before

the 8mm postlarvae enter the estuaries. Mortality rates for shrimp larvae

are estimated as 17% per day; extremely few make it to the estuaries. Post-

larvae enter the south Florida estuaries throughout the year but are least

abundant during the winter. When shrimp reach approximately 10mm, they

become benthic, concentrating within shallow seagrasses, and developino

into juveniles. Densities may exceed 32 individuals per m2 within the sub-

sequent two to four months. Shrimp grow rapidly, reaching commercially

acceptable size within a few months. As they grow and mature, most shrimp

gradually emigrate offshore into deeper, higher salinity water. Size at

emigration averages 90-100mm. A few, however, remain in the estuaries

after becoming adults. Eighty-three weeks is the estimated average maximum

age.

Most shrimp that develop within the estuarine waters of southwestern

Florida are captured either in the Dry Tortugas or Sanibel shrimping

grounds. However, most offshore waters adjacent to south Florida contain

maturing and adult pink shrimp, sometimes in depths to 110 meters. But

much of the bottom is too rough for conventional trawling gear; a rela-

tively smooth sandy bottom underlies the Sanbibel, Tortugas, and Hawk

Channel grounds where most large pink shrimp are taken commercially

(Costello and Allen 1966).

Spawning and distribution of shrimp populations may be determined by

temperature and salinity. On the Tortugas grounds, shrimp spawn in waters

of 19.6�-30.6�C, with highest activity coinciding with highest bottom

temperatures. A rising temperature may trigger spawning activity.

Preference for various salinity regimes vary with shrimp size and

geographic area. Young shrimp can survive for a short time at low

salinities. In the Florida Bay area, postlarvae were caught at salinities

from 12-43�/oo, juveniles at 0-470/oo, and adults at 25-

450/oo. The Tortugas grounds, have salinities of 36-380/oo.

Water that is mostly turbid generally harbors the largest concentra-

tions of young shrimp per unit area. Kutkuhn (1966) suggested that since

more detrital material is suspended, a greater food source and protective

cover is created.

Juvenile and estuarine-dwelling adult pink shrimp are omnivorous

bottom feeders, feeding primarily in shallow waters within seagrass beds.

Crustaceans and polychaetes comprise the main food source of juveniles in

south Florida, with no difference seasonally or with shrimp size. Stomach

contents from juvenile and adult shrimp from Tampa Bay, Florida indicated

indiscriminate feeding behaviors; diets consisted of sand, debris, algae,

diatoms, seagrass particles, dinoflagellates, foraminiferans, nematodes,

polychates, ostracods, copepods, mysids, isopods, amphipods, caridean

shrimp, caridean eggs, mollusks, and fish scales. Most feeding occurs at

night, though some takes place during daytime under turbid conditions.

V E 2. FISHERIES STATISTICS

I ~~~~Catch data for the five selected species were obtained from the annual

summaries of Florida Landings (Florida Department of Natural Resources,

1950-1978). National Marine Fisheries Service (Southeast Center, Miami)

provided information for 1979-1981 from their computer data base. All data

include only commercial catch information. Florida Landings lists commer-

I ~~~cial catch by county of landing (processing); study sites are, therefore,

defined by the counties surrounding them:

Charlotte Harbor =Charlotte and Lee Counties
* ~~~~~~~~Lake Worth = Palm Beach County

Catch data are graphically depicted in Figure 6 through Figure 14 for

Charlotte Harbor and Figure 15 through Figure 22 for Lake Worth. Each

I ~~figure with "LBS CATCH" on the y-axis shows a straight horizontal line

drawn through it; this line represents the 31-year average for that species

for that study site. Note, too, that the y-axis scale differs for each

figure. Since data for bait shrimp catch in Lake 'Worth are non-existent,

Lake Worth has no figure for bait shrimp.

There are five major problems associated with commercial catch data.

One of the most significant difficulties concerns the location where the

1 ~~~catch was made as opposed to the location where it was landed. Lake Worth

exemplifies this problem. The use of commercial nets except cast nets in

Lake Worth was banned in 1931 (Special Acts, 1931, Chapter 8796) and banned

in 1955 from any inlets and in waters surrounding the inlets of Palm Beach

County (Special Acts, 1955, Chapter 31137). However, Palm Beach County

1 ~~~~~~~~~~~~~~97

continuously contributes catch data, albeit low amounts, for estuary-

dwelling species to the landings' data base. Illegal commercial netting

supposedly occurs at night in Lake Worth; this may account for some of the

reported landings, since landing the catch in Palm Beach County is not

illegal. Theoretically, however, unless caught legally by hook or cast net

or illegally by commercial nets, landed catch in Palm Beach was harvested

outside the county. This problem of where the harvest was made is typical

throughout Florida's landing statistics.I

The second significant problem, most critical for this study, is the

absence of effort data. Catch per unit of effort would best reveal a riseI

or fall in catch rate for specific sites and species. For example, Figure

8, depicting the spotted seatrout catch of Charlotte Harbor, indicates a

general upward slope in landed poundage. Thi s increase may be due to the

presence of more seatrout or because of a rise in the number of fishermen.

Without effort data, increases and decreases in landed amounts remain un-

assessable.

A third consideration is that landings data exclude recreationalI

fisheries which, for certain species, exceed commercial efforts. Red drum.

and spotted seatrout, for example, are caught extensively by recreational

fishermen. This concern is compounded by the fact that effort in

recreational fishing has significantly increased in conjunction with the

rise in Florida's population and tourist industry.I

Fourth, si nce landings data are obtained from reports made by the

commercial dealers themselves, values are only as accurate as the dealers'

record; values are perhaps much higher. In addition, some commercial catch

is not reported at all (e.g. live catch of blue crabs sold to restaurants.

98I

Finally, landings data do not account for open and closed seasons or

local laws. For example, bait shrimp has the potential to serve as an

excellent indicator species of-estuarine health, since juvenile bait shrimp

grow and are captured within an estuary. However, in 1976, Charlotte

County, for example, banned the use of more than 1 trawl net at a time and

the trawl net must be under 25' in length (Special Acts, 1976 Chapter 76-

343 as amended by Chapter 77-525). In addition, Lee County banned the

practice of sweeping, dragging or hauling any nets except hand cast nets or

bait nets; bait nets must not exceed 100' in length, a depth greater than

6', nor a mesh size greater than 1 3/8" (Special Acts 1947, Chapter 23951,

as amended by Chapters 63-1560, 69-1236 and 69-1237). These laws must

certainly affect the distribution of landing statistics. Another example

concerns the local laws of Palm Beach County as described in the second

paragraph of this section - commercial netting, except cast netting, is

banned altogether in Lake Worth.

Existing problems in fisheries statistics can be resolved through

establishing a State program. A memorandum of understanding with National

Marine Fisheries (NMFS) has been signed by DNR to access aggregate

commercial landings. A cooperataive agreement between NMFS and DNR is

under consideration that will allow individual data access and eventually

the acquisition of the commercial statistics program. Additionally, DNR

has formulated a State marine fisheries statistics program that includes

both commercial and recreational fisheries statistics. The program was

designed to collect effort, area of catch, species composition and weight,

gear type used, and biological data. The acquisition of such data augments

historical data and will provide a more comprehensive data base necessary

for future management strategies and decisions. Until an improved fish-

eries statistics program is established, the use of present Landings' data
for comparing between site catch values and even trends over time may prove
erroneous. However, because no other data exists, Landing's values remain

as the only available information.

100~~~~~~~

700

500 i

400

300

200

900
IO 0 ~-

950 7955 960 965 1970 975 90

't40-
IY~~~ <~~~YEAR
Figure 6. Annual summaries of Florida Landings for red drum
landed in the Charlotte Harbor area. Horizontal line

indicates the 31 year average.

IO0 ~-

'90 -

o 80 -

I ~~~~~~~70-
0
195 60 1

10
'J 30 -
IL.

I ~~~~~~~20.+. - + -

I~~~~~~~~I

1950 1955 1960 1965 1970 1975 1980

Figure 7. Annual summaries of Florida Landings for red drum
landed in the Charlotte Harbor area over the amount
landed for the west coast of Florida.

I ~~~~~~~~~~~~~~~101

1500 --

1400 -

1300 --

1200 -

1100 -

o 900--

800

o 700 -

600 -

J 500

300 -

200 -

100 : : ; : : * : : : : : : : : : - I I I , I , , ,
1950 1955 1960 1965 1970 1975 1980
YEAR

Figure 8. Annual summaries of Florida Landings for spotted seatrout
landed in the Charlotte Harbor area. Horizontal line
indicates the 31 year average.

100 -

90 -

o 80 -

- 70 -

U60

o 40 --

U- 30
0
20 --

1950 1955 1960 1965 1970 1975 1980
YEAR

Figure 9. Annual summaries of Florida Landings for spotted seatrout
landed in the Charlotte Harbor area over the amount landed
for the west coast of Florida.

102

12000 -

I 1000 -

10000

9000-

8000-

7000 -XCZ) <

6000

5000

4000

3000 --

2 000
1950 1955 1960 1965 1970 1975 1980

YEAR

Figure 10. Annual summaries of Florida Landings for black mullet
landed in the Charlotte Harbor area. Horizontal line
indicates the 31 year average.

100 -

90-

80 --
so
0
70 7 -

o 60 -

40
o
50 --

LL
F'-

o 0 --

1950 1955 1960 1965 1970 1975 1980

YEAR

Figure 11. Annual summaries of Florida Landings for black mullet
landed in the Charlotte Harbor area over the amount landed
for the west coast of Florida.

103

3000 '

2500 --

1500

landed in the Charlotte Harbor area. Horizontal line
indicates the 30 year average.
U

100

90
50 -
1950 955 1960 YEA 70 1975 960

Figure 12. Annual summaries of Florida Landings for blue crab
landed in the Charlotte Harbor area. Horizontal line

indicates the 30 year average.

600 --

90
60--

U-U
p-

70 --
I.-

(2:
,. 50 --

4,0 ---.

o 30 - -
IA-

,o ,t /

I I I~~~~

1950 1955 1960 1965 1970 1975 1980
YEAR

Figure 13. Annual summaries of Florida Landings for blue crab
landed in the Charlotte Harbor area over the amount
landed for the west coast of Florida.

104

4000 -

3000

" 2000-

i 1000-

1950 1955 1960 1965 1970 1975 1980
YEAR

Figure 14. Annual summaries of Florida Landings for bait shrimp
landed in the Charlotte Harbor area. Horizontal line
indicates the 30 year average.

105

25146

20420

17098

6000

5000

4000

2000

I000 - !

1950 1955 1960 1965 19 70 1975 1980

Note change in scale. YEAR

Figure 15. Annual summaries of Florida Landings for red drum
landed in the Lake Worth area. Horizontal line
indicates the 31 year average.

100 -

90 -

u 80 -

U
70-
0

60
O 60 -,
in
. 50 -
0
40

-L 30 -

20 --

950- 955 90 41 0 *965 197 0 1975 1980 I
1950 1955 1960 1965 1970 1975 1980

YEAR

Figure 16. Annual summaries of Florida Landings for red drum
landed in the Lake Worth area over the amount landed
for the east coast of Florida.

106

218587 --

101465 --
o

50000 --

30000

20000

10000
20000 --

1 0000 -

1950 1955 1960 1965 1970 1975 1980
YEAR

Figure 17. Annual summaries of Florida Landings for spotted seatrout
landed in the Lake Worth area. Horizontal line indicates
the 31 year average.

100 --

90--

80--
U

70 -
U)

60--

< 50--
F-

20 --

4 0 --, - -

1950 1955 1960 1965 1970 1975 1980

YEAR

Figure 18. Annual summaries of Florida Landings for spotted seatrout
landed in the Lake Worth area over the amount landed
for the east coast of Florida.

107

900 --

700

600--

300
I- -
'~ 400 -- I

200 -

100 --

1950 1955 1960 1965. 1970 1975 !980
YEAR

Figure 19. Annual summaries of Florida Landings for black mullet
landed in the Lake Worth area. Horizontal line indicates
the 31 year average.

100 1

' 80 1

70
I
60 -
U)

<I
50--

� 40 -

30 --

950 955 960 o965 970 5 98--
1950 1955 1960 1965 1970 19 5 1980
YEAR

Figure 20. Annual summaries of Florida Landings for black mullet
landed in the Lake Worth area over the amount landed
for the east coast of Florida.

108

208900 --

6000 --

5000 --

: 4000--

WOO
u~~~~~~~~~~~~~~~~~

-J3000 --
_.I

2000 -'

1000 -'

1950 1955 1960 1965 1 970 1975 1980

Note change in scale YEAR

Figure 21. Annual summaries of Florida Landings for blue crab
landed in the Lake Worth area. Horizontal line
indicates the 30 year average.

100 --

I 80 -
70
C-,

70 --
p-

0 60 --

In
hi 50--
I w~~~~~~~~~~~~~~~~I

0
c 40-

0j 30--
-
LL
LL
� 20 --

I~~~~~~~~~~~O'
10 -

1950 1955 1960 1965 1970 1975 1980
YEAR

Figure 22. Annual summaries of Florida Landings for blue crab
landed in the Lake Worth area over the amount landed
for the east coast of Florida.

109

I
I
I
I

I
I
I
I
I
I
I
I
I
I
I
I
I
I
110 ~~~~I
I
I
l
i
I
l
I
I
I
l
110~~~~~~~
i

I
I
I
I
I
I
I
Land Use and Vegetation Maps of
Charlotte Harbor and Lake Worth:
Historical and Recent
I
I
I
I
I
I
I
I
1

VI. LAND USE AND VEGETATION MAPS OF CHARLOTTE HARBOR AND LAKE WORTH:

HISTORICAL AND RECENT

A primary objective of this project was to develop a digital data base

of coastal/estuarine habitat components and changes from 1940-50 to the

present in a quantitative and geographically specific manner.

VI A. BACKGROUND

I ~~~~The Florida Department of Transportation (DOT) Topographic Bureau was

I ~~~sub-contracted to provide the interpretation and mapping of historical and

current land use, vegetation, and drainage patterns of the Charlotte Harbor

and Lake Worth study sites. For the current interpretation of Charlotte

Harbor, controlled aerial photographs (flight altitude 12,000 ft, 2658 mn)

I ~~~were acquired in April, 1982 at a scale of 1:24,000 (I in = 2,000 ft; lcm=

0.24 kin) utilizing a specially outfitted Rockwell Aerocommander. Positive

false color infrared transparencies were produced for standard photo-

interpretation utilizing stereoscopic vision equipment. Current interpre-

tation for Lake Worth involved color aerials flown in 1975. Historical

* ~~~interpretation involved using black and white aerial photographs taken in

1940 for Lake Worth and 1946 and 1951 for Charlotte Harbor. Interpre-

I ~~tation and subsequent classification of surface features followed the

I ~~scheme of Kuyper et al. (1981).

Land use, vegetation, and drainage categories were then digitized into

the DOT computer graphics system. Digitized geographic data were placed in

a point-vector data format in this proprietary system (Friedly and Unger

1981). Output mapping products include ballpoint pen plots on drawing

paper and ink plats on mylar overlays for USGS 7.5 minute quadrangles

(quads) (1:24,000). Because the maps are digitized, adjacent 7.5 minute

quads may be merged to produce smaller scale maps typically at 1:48,000

scale (1"=4,000', 1.0 cm=O.48km). Other products that will be available to

users are maps depicting only selected land use or vegetation categories,

such as seagrass and mangroves, without other features and graphics

displayed. A combination of merging maps to any scale, and the selection

of one class to be displayed would result, for example, in a seagrass or

mangrove map of Charlotte Harbor.

VI B. PROBLEMS AND RECOMMENDATIONS

DOT encountered several major difficulties in the interpretation and

digitization of the aerial photographs. These problems resulted in a delay

in final map production.

The principal problem with interpretation of aerial photographs dealt

with seagrass delineations. The historical black and white photographs

presented an inherent lower quality for identifying seagrasses. In addi-

tion, the historical aerials were interpreted before the 1982 photographs.

Because historical interpretations could not be ground truthed, a problem

in the interpretation of seagrasses was not noticed until the 1982

photointerpretations were completed and comparative acreages computed.

Several historical photographs were reexamined and it became apparent that

general misinterpretations had occurred because of the unfamiliarity of the

photointerpreter with the photographic signatures of seagrasses. The

112

recent color infrared aerials presented no such problem as the quality was

exceptional for seagrass delineation. As a result of this finding, a time

consuming reanalysis and digitization of the historical seagrasses was

necessary.

A similar problem occurred in the analysis of mangroves versus tropi-

cal hammocks. The interpreters classified much of the exceptionally large

mangrove fringe as tropical hammock. This problem was again due to the in-

terpreter encountering new land cover signatures. Until the study site was

visited, this problem was not realized. Several valuable interpretive

methodologies were learned in this process:

1. Interpret the most recent aerials first. These are generally

of better quality and provide the photointerpreter with a

feel of the study site. This method may bias the historical

interpretation, however, the bias is far outweighed by the

increase in accuracy.

2. Visit the study site in the early stages of interpretation.

This will eliminate obvious classification errors because of

unfamiliarity with vegetation cover characteristics.

3. Complete all ground truthing effort prior to digitization.

Since most photointerpreters are unfamiliar with interpreting sea-

grasses, some general comments on seagrass interpretation and quantifi-

cation follow:

1. Color infrared photography provides excellent seagrass

mapping media in addition to the best delineation of all

other emerged habitats.

2. Low tide with clear waters (generally late October through

early June) provide the best imagery.

113

3. The relationship between the time of year the aerials were

flown to the seasonal densities of seagrasses is under

investigation (Section VIII 0). It may have some impact on

total acreages or perhaps on density descriptions.

4. The 1982 aerials for Charlotte Harbor were of sufficient

quality to develop a density classification system:

901 (sparse underwater vegetation) - This class was

characteri zed by approximately >70% exposed sand in the

actual meadow regardless of the patchiness observed within

the meadow and was considered minimal as habitat cover.

This category will most likely be the subject to

misinterpretation particularly if seasonal differences

exist.I

903 (moderate to dense underwater vegetation) - This class

encompassed all contiguous meadows with approximately <30%I

uniformally exposed sand. No attempt was made to develop a

separate class for moderate densities because of the

subjectiveness in interpretation at that level.

904 (Patchy underwater vegetation) - This category was

characterized by large unvegetated patches within areas of

>1m2 moderate to dense grass.

The historical aerials were simply classified as seagrass in oneI

category:

645(submerged aquatic vegetation)

Only one classification could be interpreted due to the quality of the

historical aerials and the absence of a method for ground truthing.

114

The major factor delaying map production was the digitization process.

This is a time-consuming job requiring an understanding of both the subject

matter and the complex digitization system. The bottleneck in the digiti-

zation process occurred for two related reasons. A system software upgrade

was implemented with the intent to streamline the digitization process and

provide the ability to compute acreages, to merge quads and to do other

needed data manipulations. The new software introduced a series of

deficiencies that required extensive time for correction. This was com-

pounded by a series of hardware failures. These delays created a severe

backlog in the digitization process. Considering that this project was

only one of many priorities for production, the order by which jobs were

completed was weighed by the contractor.

VI C. DESCRIPTION OF MAP PRODUCTS

The photointerpretation and ditgitizations were based on the U.S.

Geological Survey 7.5 minute by 7.5 minute quadrangle (quad) grids depicted

in Figure 23 for Charlotte Harbor and Figure 24 for Lake Worth. The quads

are individually named both numerically and with a common descriptor. The

common descriptor names have been used throuqhout this discussion.

Included in the map pockets of this report are several maps to pro-

vide examples and references of the map products available and used in the

report. They are as follows:

Map 1. Drainage Map - Historical (El Jobean)

Map 2. Drainage Map - Recent (El Jobean)

Map 3. Land Use and Vegetation Map - Historical (Matlacha)

W ~~~EL JOB A

> U N PUiA
PLACI + O
16~~~~~ I

PORT ond
BOCA M9 QQ*�4A i MOCHA
GRANDE \\4b

TIV;A ' i~iND MiI

WULFER +

Figure 23. Charlotte Harbor quadrangle names and locations.
116

Iz /it~ ~RIVIERA BEACH

6BI e Feron Bt

/ Okeec

Southen -PALM BEACH
Southern Blv - :
/ '~~~~~c

Uninterpreted area

I ~; /

-LAKE WORTH

_804

Figure 24. Lake Worth quadrangle names and locations.

117

Map 4. Land Use and Vegetation Map - Recent (Matlacha)

Map 5. Merged Land Use and Vegetation - Recent (El Jobean,

Punta Gorda)

Map 6. Merged Land Use and Vegetation - Recent (Placida, Port

Boca Grande)

Map 7. Merged Land Use and Vegetation - Recent (Punta Gorda SW,

Punta Gorda SE, Bokeelia, Matlacha)

Map 8. Merged Land Use and Vegetation - Recent (Captiva, Pine

Island Center, Wulfert, Sanibel)

Map 9. Merged Land Use and Vegetation - Recent (Fort Myers SW,

Fort Myers Beach, Estero)

Map 10. Land Use and Vegetation Map - Historical (Riviera Beach)

Map 11. Land Use and Vegetation Map - Recent (Riviera Beach)

The reader/user should note that the historical and recent maps often

are not directly comparable. Due to subjectivity in photo interpretation,

boundary lines are somewhat incongruous. The maps, therefore, should not

be overlayed to determine temporal changes in classification boundaries

except when making purely widescale, synoptic observations.

Drainage Maps: Historical and recent drainage maps have been produced and

are available for the Charlotte Harbor study area in quad or in merged

form. Examples of these are Maps 1 and 2, depicting the historical and

recent El Jobean quad. These maps provide a visual inventory for non-point

source drainage pattern changes that have occurred. Acreage of a drainage

system, linear miles of canals, and other drainage schematics potentially

can be quantified to assess the non-point source runoff into the estuary.

118

3 ~~~Land Use and Vegetation Inventory Maps: Maps 3, 4, 10, and 11 represent

the style of Land Use and Vegetation Inventory products produced for the

I ~~~Charlotte Harbor and Lake Worth study areas. Appendix A provides users of

3 ~~these products with the D.O.T. classification description associated with

the numerical classification codes. Maps 3 and 4 represent historical and

3 ~~recent interpretations of the Matlacha quad with corresponding acreage

values. Maps 10 and 11 provide the same format for the Riviera Beach (Lake

I ~~~Worth) quad. Because of the large number of individual quads (15 recent

and 15 historical for Charlotte Harbor and 3 recent and 3 historical for

I ~~~Lake Worth), the entire set of individual interpreted quad maps could not

3 ~~be included in this report.

3 ~~~Merged Maps: Maps 4-9 are examples of the map product created by merging

adjacent individual quad maps into a scale addressing a larger area.

I ~~Unfortunately, neither a classification key nor acreage values could be

3 ~~~incorporated into the merged maps. The user should refer to Appendix A

where numerical classifications can be identified.

VI D. CHARLOTTE HARBOR

VI Dl1. GENERAL SITE DESCRIPTION

3 ~~~~The Charlotte Harbor estuarine complex began to form approximately

5,000 years ago when a rise in sea level flooded the mouths of the Myakka

3 ~~~and Peace Rivers. Flooding caused sediments to be deposited in a series of

deltaic formations which began the in-filling of the present estuary.

119

This process also formed the present barrier island chain which began as a

spit of land north of the present Gasparilla Island. River sediments and

those of the littoral drift helped create the chain of barrier islands.

The resulting five major barrier islands of today (Gasparilla, Cayo Costa,

North Captiva, Captiva, and Sanibel) have joined, separated into additional

islands, and changed shapes continuously since their development (Herwitz

1977).

"Pine Island is believed to be a remnant of the original mainland,

that was isolated by a southerly shift in the river flow. Then, as sedi-

ments built up at the present location of Little Pine Island and the

evolving shape of Sanibel Island restricted water flow, the estuary broke

through the Gulf, creating a deep channel near the present Boca Grande

Pass. This pass eventually shifted to its present position (Herwitz 1977).

Other passes have been opened and closed by storm events and other natural

forces that are still acting on the system today. Both Cayo Costa and

North Captiva Island have had new cuts through them in the last year."

(Department of Natural Resources Bureau of Environmental Land Management

1983).

Charlotte Harbor today (Figure 25) is approximately 56km long

encompassing at least 71,680 ha of water area. Total shoreline includes

320km excluding the numerous mangrove islands. Shallow water up to M.8M

predominates the estuary with natural depressions and channel margins of

1.8 to 3.7m and 3.7m or greater within channels and anchorages (Taylor

1976).

Three major rivers flow into Charlotte Harbor. The Mayakka and Peace

Rivers, together draining a land area of approximately 76,800ha, flow into

120

I ~ ~~~~~~~~~~~~~ km

~~~~~~~~~~~~'Son

I Lemon Bay~~~~~~~~~~~L~-o

Gaspartifloa

~~~~~~~~~~~~~~~~~~~~~~~i Octtle Pine

North~~~~~~~~~~~~~~~e Co.iv

Coyo Costaj~~,'I 1-~~~ Matlsteo Pas

Figure 25. C halottlee Hror
121~~~sln

the northwest and northeast ends of Charlotte Harbor proper (Taylor 1976).

The Caloosahatchee River enters San Carlos Say, south of Charlotte Harbor

proper, draining about 307,200ha of land (Taylor 1976).

The watershed of all three rivers contain areas of pasture land,

citrus groves, and cultivated ground. In addition, the Peace River flowsI

through expansive sites of phosphate mines, while the Caloosahatchee

receivyes i ndustri al and domestic wastes from the urban areas surroundi ng

Fort Myers.

During periods of low tide and heavy rainfall, high river flow reduces

surface salinity throughout the estuary and also offshore to a distance ofI

several kilometers. During high tide and low river flow, a saline wedge of

bottom water has been documented to 38 miles upstream in the Caloosahatchee

and well upstream in the Myakka and Peace Rivers (Taylor 1976).

Aside from nutrient and waste inputs from the three river systems,

Charlotte Harbor has suffered very few detrimental impacts and remainsI

a relatively natural ecosystem. Beginning in 1977, the State of Florida

has purchased most of the land along Charlotte Harbor's shoreline, attempt-

ing to maintain a natural mangrove/marsh and, thereby, hopefully, a healthy

estuary. In addition, approximately 90% of the harbor itself exists as

fo ur aquatic preserves. However, behind some of this natural buffer area3

encroaches vast areas of development.

"The Charlotte Harbor area has been the site of enormous subdivisionI

development during the past thirty years. The General Development Corpo-

ration's Port Charlotte project covers almost 200 square miles inland from

Charlotte Harbor, between the Myakka and Peace Rivers. The projected

population of Charlotte County, if this and the other subdivisions

122

presently platted in the county were .occupied, would be nearly 1,000,000

people. The 1980 U.S. census population for Charlotte County was 58,460.

I ~~~"Cape Coral, Gulf American Corporation's subdivision north of the

Caloosahatchee River and east of Matlacha Pass, covers approximately 96

square miles. An estimated 400,000 people may one day inhabit that

j ~~presently incorporated city. The 1980 U.S. census population for Lee

County was 205,266. The Ft. Myers-(Cape Coral)-Lee County area has been

I ~~~identified in a number of reports as the fastest growing area in the United

States." (Department of Natural Resources Bureau of Environmental Land

U ~~~Management 1983).

I ~~~~Obviously, if wide-scale development continues with no consideration

for environmental impact, Charlotte Harbor could change radically. Wang and

Raney (1971) described Charlotte Harbor as one of the largest and least

contaminated estuarine complexes in all of Florida. Today, Charlotte

I ~~Harbor retains that image. Its unspoiled habitat houses over 40 endangered

and threatened species, including at least 15 active eagle nests.

In addition, the harbor's importance as a productive fisheries

5 ~~~environment, both in the past and today, is emphasized by Figures 6 through

14. Hopefully, the future will find Charlotte Harbor unchanged.

VI IJ 2. GENERAL ACREAGE VALUES

5 ~~~~Much change has occurred in Charlotte Harbor. Table 6 provides

acreage values for ei ght general categories. The ei ght categori es are

herein described. The number in parentheses following the category name is

the DOT numerical classification code. Appendix A provides a complete

I ~~~descri pti on.

123

Table 6. CHARLOTTE HARBOR ACREAGE VALUES

Level 1 Land Use name Urban Agriculture Rangeland Forestland
Level 2. Land Use code 100 200 300 400
Year 1945 1982 1945 1982 1945 1982 1945 1982
USGS Quadrangle Name I

El Jobean j 90 16657 1872 870 15222 2380 3586 1896

Punta Gorda SW 0 1093 0 0 6459 5128 737 2247

Placida 283 1915 0 249 3688 1464 647 1783

Bokeelia 162 1593 541 444 1477 1181 2655 1864

Port Boca Grande 299 300 0 0 360 458 229 292

Captiva 60 546 87 0 490 203 348 297

Wul fert 10 658 92 40 1045 329 461 875

Sani bel 113 3100 50 0 4456 668 494 1864

Punta Gorda 1270 16412 2336 1534 12319 1810 4106 1937

Punta Gorda SE 9 4249 454 1460 8237 1543 4341 6701

Matlacha 7 13561 1051 783 16155 866 4641 6348I

Pine Island Center 1 9120 490 954 10064 1482 4159 3786

Fort Myers Beach 320 2734 855 504 4321 982 908 2221

Fort Myers SW 1006 22556 5091 3288 16086 583 5341 3472

Estero 80 1611 I 218 157 I 5840 1627 I 1930 4908

TOTAL ACRES 3710 96105 I13137 10283 I106219 20704 I 34583 40491

% TOTAL ACRES 1% 16% 2% 2% t7% 3% 6% 7%/

Acreage Change +92395 I -2854 I -85515 +5908
Percent (%) Change + 2490% I - 22 I - 81% + 17%

124

Table 6. CHARLOTTE HARBOR ACREAGE VALUES
(Continued)

Transportati or
Level 1 Land Use name Water Wetlands Barrenland and Utilities
Level i Land Use code 500 600 700 800
Year 1945 1982 1945 1982 1945 1982 1945 1982

USGS Quadrangle Name

El Jobean 11231 12400 8772 6899 819 1176 178 287

Punta Gorda S.W. 17406 18191 18065 15762 2 148 21 34

Placida 33038 33711 4321 2979 447 319 170 207

Bokeelia 21126 21886 15861 15213 704 405 62 66

Port Boca Grande 41150 41354 421 98 131 77 58 49

Captiva 20426 30159 21008 11292 233 192 45 13

Wulfert 36428 37581 4311 3100 354 143 37 16

Sanibel 28795 29960 8548 6896 195 172 89 75

Punta Gorda 13876 14037 7197 3906 911 1564 531 1357

Punta Gorda S.E. 19347 19850 9456 7772 749 870 14 164

Matlacha 8462 9090 12230 10900 43 942 71 175

Pine Island Center 3598 5214 24122 21843 107 80 146 207

Fort Myers Beach 24786 25572 11371 9755 143 615 28 366

Fort Myers SW 7643 9847 6253 1844 1147 840 126 263

Estero 1487 3853 8290 5644 217 283 225 154

TOTAL ACRES 288799 312705 160226 123903 6202 7826 1801 3433

Acreage Change +23906 -36323 +1624 +1632
Percent (%) Change + 8% - 23% + 26% + 91%

125

Urban and Built Up (100)

In 1944-45, the Charlotte Harbor area had 3,710 acres classified as

urban. The Punta Gorda and Fort Myers SW quads comprised 61% of this

total. The 1982 inventory showed 96,105 acres (a 2490% increase). Fort

Myers SW experienced the greatest increase from 1,006 acres to 22,556U

acres (23% of the total).

Striking urban features in the Charlotte Harbor area are the massive

1960-1970's land boom development tracts where huge areas were cleared and

roads were built. Few, if any, have dwellings. Most of the tracts also

have canals for land drainage and harbor access. These urban tractsI

(classification 192) comprise 47,298 acres (49%) of the total urban area.

If these tracts alone are developed, assuming 4 dwellings/acre and 3

persons/dwelling, 567,576 new residents can impact the area with no

additional land development. This would cause a significant impact on the

Charlotte Harbor area if not properly planned.

Agriculture (200)I

As evidenced by the acreage values, agriculture is not a major

industry in the Charlotte Harbor study area. The historical acreages

(13,137 acres) decreased 22% to 10,283 acres at present. The bulk of this

acreage is pasture land or citrus crops.

Rangeland (300)

Rangeland decreased 81% from 106,219 acres to 20,704 acres. The

primary acreages in this category were shrub and brushland characterized by

scattered pines, palmetto and grasses. These vegetation types often

126

support cattle grazing, however, this is not quantified. It may be assumed

that most of the acreage loss (85,515 acres) transferred to urban gains

(92,395 acres). The shrub/brushland type areas supported the greatest

upland loss in the study area.

Forestland (400)

Forestland was the only Level I vegetation category to increase in

acreage (17%) from 34,583 to 40,491 acres. The majority of forestland

acreage is pine flatwoods. A large increase in exotic forestland (i.e.

Brazilian pepper, Melaluca, and Australian pine) was observed during this

time period. These species compete with natural rangelands, forestlands,

and wetland mangroves, accounting for the greatest forest habitat altera-

tion.

Water (500)

This category increased 8% from 288,799 acres to 312,705 acres. Most

of the increase may be attributed to canals and vegetated (seagrass) bottom

loss. Water comprised the major acreage of the study area.

Wetlands (600)

Wetlands experienced a 23% decrease in acreage from 162,226 acres to

123,903 acres. The major decrease in this category was seagrass (sub-

merged aquatic vegetation). Wetlands (fishery habitats) will be discussed

in detail in the following section.

127

Barrenland (700)

Barrenland increased 26% from 6,202 acres to 7,826 acres. Some

barrenland beach categories are important nesting habitat for terns,

skimmers, and other open-ground nesting birds.

Transporation (800)

A 91% increase from 1,801 acres to 3,433 acres was observed in the

study area. This directly reflects the increased development.

Special Category (900)

This category was used to record the 1982 seagrass densities and will

be discussed later in the following section. The historical seagrass

inventory was included under Wetlands (600) as code 645. For comparable

total wetlands acreages, the 1982 900 category has been added to the 1982

600 category in Table 6.

VI D 3. FISHERIES HABITAT COMPONENT ACREAGES

Fisheries habitat is considered the geoqraphical, physical, chemical

and biological environment in which a species can find food, cover, and re-

produce during the various stages of its life cycle. A fisheries habitat

component for this report is defined as a specific remotely-sensed and in-

terpretable submerged or emerged vegetated or non-vegetated class.

Different species at different ages can utilize many different habitat

components or can be monospecific as to habitat component. Although

different habitat components can be readily defined, a specific fish

128

habitat may only be determined through extensive sampling and research.

This report delineates some of the habitat components currently considered

important to fisheries production in general, but neglects many of the more

transient components such as salinity, temperature, turbidity, etc. Some

of these interpretable components include mangroves, seagrass beds, salt

marshes, non-vegetated tidal flats (mud flats), and oyster reefs. They

provide cover and an indirect food source for over 70% of Florida's

recreational and commercial fisheries species. Table 7 provides historical

* ~~~and recent acreage values for these fisheries habitat components.

Mangroves (612)

Section 11 C I provides a complete discussion of mangroves and can be

reviewed to familiarize the reader with the role of mangroves in estuaries.

Species delineation was not attempted within the mangrove category. A 10%

increase, 51,524 acres to 56,631 acres, was recorded for the study area.

These results are surprising because they do not follow the general

trend for wetland loss. State and local regulations protecting the man-

grove fringe surrounding Charlotte Harbor were enacted prior to any large-

scale destruction. Consequently, very few mangrove areas have been dredged

or filled and, in fact, area] coverage has increased by 5,107 acres. In-

creases can be explained by natural growth. It appears that much of the

mangrove increase could be related to the 8,158 acre loss of non-vegetated

tidal flat. Tidal flats provide suitable locations for mangrove seedlings

to take hold. If conditions are suitable for growth, new mangrove stands

can be propagated. Other factors such as rising sea level, spoil island

creation, marsh succession, and restoration can explain increases, but they

129

Table 7. CHARLOTTE HARBOR FISHERIES HABITAT COMPONENT ACREAGES

Non-Vegetated
Habitat Component Mangrove Tidal Flat Oyster Reef Saltmarsh Seagrass
Year 1945 1982 1945 1982 1945 1982 1945 1982 1945 1982

USGS Quadrangle Name

E1 Jobean 3433 4321 757 126 0 4 1762 1528 1632 894

Punta Gorda SW 6885 8251 2930 1079 173 28 436 169 6881 5760

Placida 1083 968 267 142 55 56 157 0 2610 1566

Bokeelia 3544 3731 52 31 0 38 29 24 12154 11367

Port Boca Grande 39 32 0 0 0 0 0 0 382 66

Captiva 1033 1121 57 0 0 2 0 7 19907 10162

Wulfert 1392 1426 0 0 0 0 0 0 2749 1674

Sanibel 3067 2943 148 3 8 10 22 0 5296 3940

Punta Gorda 4310 2799 858 95 4 5 550 140 892 772

Punta Gorda SE 2821 3502 1081 255 0 0 424 0 4246 3562

Matlacha 4243 5821 1268 51 0 8 462 0 5780 4940

Pine Island Center 8937 11291 2324 358 515 303 709 197 11462 9684

Fort Myers Beach 6032 5955 775 362 2 3 767 747 3586 2626

Fort Myers SW 1936 1190 378 53 0 0 1384 341 1465 189

Estero 2769 3280 311 168 49 31 549 394 3917 1293

TOTAL 51524 56631 11206 2723 806 488 7251 3547 82959 58495

Acreage Change +5107 -8483 -318 -3704 -24464
Percent (%) Change + 10% 76% - 39% - 51% - 29%
130

I ~~are most likely minor in this case.

The only quads showing mangrove losses were Placida, Port Boca Grande,

Sanibel, Punta Gorda, Ft. Myers Beach, and Ft. Myers SW. These areas lost

a total of 2,581 acres of which Punta Gorda comprised 1,511 acres or 59% of

the loss. Punta Gorda is one of the oldest developed areas within the

* ~~Charlotte Harbor study site and the mangrove loss can be attributed to the

early waterfront development that eliminated fringing mangroves.

The quads with the greatest increase in mangrove acreage were Punta
Gorda SW, Matlacha, and Pine Island Center (+5,298 acres). Pine Island

Center had the largest increase at 2,354 acres or 46% of the total

increase. These same quads had the largest decrease in non-vegetated tidal

flats (5,034 acres or 59% of the decrease). This further substantiates the

I ~~hypothesis that the conversion of tidal flats was a major portion of the

mangrove increase.

It is apparent that the protection and preservation of mangroves in

the Charlotte Harbor area has helped to stabilize the existence of this

habitat component for fisheries utilization.

Non-Vegetated Tidal Flat (651)

I ~~~~Section II C 4 provides a discussion of tidal flats, i.e., mud flats.

A 76% decrease in non-vegetated tidal flats (from 11,206 acres to 2,723

acres) was observed. As discussed in the preceding category, mangrove

increases appear to account for loss of tidal flat. Pine Island Center

experienced the largest decrease in tidal flats and the largest increase in

I ~~mangroves. This is a natural loss of tidal flats and the total acreages

involved account for only a small fraction of the entire area of fisheries

habitat components considered.

131

Oyster Reefs (654)

Section II C 5 discusses oyster reefs as a habitat component. The

acreages observed for oyster reefs are most likely low for two reasons:

(1) The reefs are often too small for photointerpretation, and (2) turbid

waters often associated with these areas render the reefs difficult to

remotely sense. Larger reef areas have been delineated and show a 38% de-

cline from 806 to 488 acres. Punta Gorda SW (Turtle Bay) and Pine Island

Center (Matlacha Pass) supported the historical highest acreages with 173

and 515 acres respectively. The recent interpretations indicate that Pine

Island Center and Placida have the highest acreages, with 303 and 56 acres

respectively. Reasons for loss are purely speculative but could involve

overharvesting, circulation changes, and particularly salinity changes.

Salt Marshes (642)

Section II C 3 contains a detailed discussion on salt marshes. A 51%

decrease in salt marsh acreage, from 7,521 to 3,547 acres, was observed in

the study area. El Jobean comprised a historical high of 1,762 acres (24%

of the total) and also contains the highest recent acreage of 1,528 acres

or 43% of the total. Punta Gorda, Punta Gorda SE, Matlacha, and Pine

Island Center, and Fort Myers SW incurred the greatest losses (as much as

100%) accounting for 77% of the salt marsh loss.

The loss of salt marshes can be directly attributed to the major land

developments. Although these developments did not always directly destroy

the marshes, they apparently indirectly destroyed them by canalization.

The digging and networking of canals (see Drainage Maps 1 and 2 for visual

impact) in order to drain the low-lying uplands has apparently served to

132

divert the natural flow of freshwater away from the salt marshes. This

would cause saltwater intrusion allowing mangroves to outcompete and

succeed the marsh habitat. This succession is well documented in four

quads: Punta Gorda, Punta Gorda SE, Matlacha, and Pine Island Center.

The direct loss (removal) of salt marshes could be catastrophic to

many organisms, but the impact caused by succession from saltmarsh to

mangroves is unknown. The major losses occurred where there was relatively

low marsh acreage originally. The greatest acreage of salt marshes

occurred up the Myakka and Peace Rivers, out of the study area. Succession

from marsh to mangrove may be immaterial at least to fisheries species,

however, it is certainly significant to the above water community, such as

birds, and also to the benthic infauna.

Seagrasses (645 historical; 901, 903, 904 recent)

A complete discussion on seagrasses is found in Section II B. Also

Section II C 2 should be consulted in reference to problems encountered in

mapping seagrasses (specifically the historical photointerpretation). The

level of accuracy in delineating historical extent of seagrasses cannot be

assessed by groundtruthing. The fact that they are submerged introduces an

optical variation not found in emergent vegetation and can affect the

interpretation. The 1982 photointerpretations, however, were of

exceptional quality and extensively groundtruthed; we are quite confident

in their accuracy.

A 29% decrease in seagrass, from 82,959 acres to 58,495 acres, was

observed between 1944 and 1982. This is substantial and surprising since

the Charlotte Harbor estuary is perceived as an area of little detrimental

133

impact. Virtually every quad experienced decreases in seagrass acreages.

The largest loss occurred in the Captiva quad with a 9,745 acre loss or 40%

of the total Charlotte Harbor seagrass decline. The adjacent Wulfert,

Sanibel, and Pine Island Center quads also accrued substantial losses;

these four quads comprise Pine Island Sound and account for 57% of the

total loss in seagrasses.

Several factors that most likely account for the loss of seagrasses in

this specific area. When reviewing nautical charts of Pine Island Sound, a

subjective analysis of tidal circulation can be made by observing

topographic patterns. A shallow bar extending entirely across Pine Island

Sound (<5 ft depth) is a prominent feature and was apparently the location

of the first channel dredging operation (sometime before 1948) in the area.

Deeper tidal channels (8-15 ft) existed on both sides of the bar. It was

likely that this bar area represented a tidal node. During an ebb tide,

flow occurred to the north above the bar and to the south below the bar.

Coastal Engineering Laboratory (1958, c.f. Esteves 1981) determined the

tidal node to be just to the north and south of Redfish Pass, substanti-

ating the implication that the shallow bar historically delineated the

tidal node.

In the early 1960's, several major alterations to the Pine Island

Sound area occurred that appear to have dramatically affected the

ecosystem. (1) The Intracoastal Waterway was dredged through Pine Island

Sound and up the Caloosahatchee River, (2) The Sanibel Causeway was con-

structed across San Carlo Bay. Even before 1960, the Caloosahatchee River

was channelized to Lake Okeechobee and lock systems were installed.

Prior to these alterations, Pine Island Sound was under oceanic in-

134

fluence, with sponges, some corals, Thalassia and other higher salinity

species growing within the Sound (Art Marshal, personal communication).
I ~~Esteves et a]. (1981) presented excerpts from a U.S.F.W.S. report to the

U.S. Army Corp. of Engineers on the construction of the Sanibel Causeway:

The U.S. Fish and Wildlife Service has reviewed the
application of the Board of Lee County Commissioners,
Fort Myers, Florida, for a Department of the Army
permit (Bridges 1057) to construct a causeway with
three bridges across San Carlos Bay so as to connect
Sanibel Island with the mainland at Punta Rassa in
Lee County, Florida.

The project as proposed would adversely affect the
I ~ ~~~fish and wildlife resources of the area in two dif-
ferent ways. One of these would be the effect of
dredging and filling. The bottom plant and animal
I ~ ~~~communities in the areas to be filled would be per-
manently destroyed. The communities in the areas to
be dredged would be destroyed at least temporarily and
I ~ ~~~~permanently if frequent maintenance dredging were required
Such reduction in bottom communities would have the
effect of reducing important fish populations to some
I ~~~~~degree.
A second effect of the project, and a much more damag-
ing one, would result from reduced salinities in lower
I ~ ~~~~Pine Island Sound, San Carlos Bay, Matlacha Pass, and
the lower estuary of the Caloosahatchee River. With
lowering of the salinity, changes in the biota would
result. As a particular example, the scallop beds of
lower Pine Island Sound might very well be eliminated,
inasmuch as these mollusks reqiuire salinities of
better than 20 parts per thousand. In more complex
fashion, the abundance of some of the brackish and
marine fishes in the area would be reduced.

I ~~~~The above report was very prophetic. After causeway construction in

1 ~~~1962, the area went from a major scallop producer in Florida (as great as
180,000 lbs/yr) to no scallop population by 1964. Circulation alterations
caused by the causeway diverting flow into Pine Island Sound from the
Caloosahatchee River were probably the primary reasons for the scallop

* ~~~loss.
1 ~~~~~~~~~~~~~~135

The effects on seagrass communities are as apparent as that on the

scallops, perhaps compounded by dredging for the Intercoastal Waterway.

The 13,936 acre seagrass loss in the four mid and lower Pine Island SoundI

quads primarily occurred in the deeper portions of the water (>3 ft). With

the described construction projects the location of the tidal node has most

likely been artificially destroyed or dramatically shifted. Thi s may be

explained if the causeway is considered a dam impeding the outflow of

freshwater from the Caloosahatchee. This would create a high pressure at

the low end of the sound inducing a net flow of freshwater up Matlacha Pass

and Pine Island Sound. The tannins and particulates associated with theI

freshwater would increase turbidity and consequently reduce water clarity.3

Compounded by direct destruction and reintroduction of fine sediments into

the environment by dredging, a decrease in seagrasses would be expected and3

has certainly occurred.

Although exact explanations cannot account for seagrass losses in

other portions of the study area, some analogies may be implied. Primary

seagrass loss has been in the deeper portions of the Harbor, at the fring-

ing bars, and in lagoonal-type areas. Very little direct destruction has3

occurred. It is likely that overall changes in drainage patterns and

introduction of sewage pollutants and storm water runoff has served to3

increase the suspended load in the Harbor. The loss of natural filtration

of nutrients also has probably increased the phytoplankton production. AllI

of these factors would synergistically act to increase turbidity in the

Harbor and eliminate seagrass meadows in the deeper waters.

Whether the loss is continuing is unknown and can only be assessed3

through periodic monitoring and mapping. The predominant grass beds are

136

located in the very shallow waters behind protective sandbars. if

circulation patterns change and bars are altered, additional losses may be

I ~~~expected. If turbidities increase, the seagrass meadows will exist only in

3 ~~the shallowest waters.

The long term alteration of this fisheries habitat component may one

3 ~~~day have a pronounced effect on fisheries of the area. With every new

canal, lawn, road, storm pipe, sewage treatment facility, septic tank,

I ~~~etc., additional nutrients and particulates are introduced into the system.

This can potentially increase turbidity and alter water quality to an

extent that further losses may occur. In addition, as the human

3 ~~~population increases, boating pressure and propeller damage to the

shallower seagrass beds will occur. On-site management of this habitat

3 ~~component, which the Department of Natural Resources Aquatic Preserve

Program provides in Charlotte Harbor, is important. However, concurrent

I ~~~upland management must occur also. Unlike for mangroves and other emergent

3 ~~~vegetation types, seagrasses are not readily observable and, unfortunately,

management considerations typically have not applied to seagrasses. This

3 ~~trend is changing, but further research must be conducted on declining

seagrass populations to determine exact causative factors of loss and

3 ~~~determine the best possible approaches for management. This should not

preclude effective management today.

3 ~~~VI D 4. COMPARISON BETWEEN FISHERIES STATISTICS AND HABITAT ALTERATION

3 ~~~At the onset of this project it was realized that the available

commerci al fi sheri es stati sti cs as landings data were inadequate for a

3 ~~~~~~~~~~~~~137

confident comparison to habitat alterations and loss (see Section VI 8).

At this point, in the total scope of the project, a comparative analysis

will not be attempted. Certain subjective comparisons can be made such as5

the total loss of the scallop industry discussed in Section VI D 3, but

quantitative analysis is not possible. We have documented the areal extentI

and location of many of the fisheries habitat components and have docu-

mented their alterations over a 35-40 year period. Florida is attempting

to develop a State fisheries statistics program in cooperation with NMFS

which will provide the proper data needed for area-specific commercial

catch and effort data, as well as recreational data.5

Section V E 2 presents existing fisheries statistics for the Charlotte

Harbor area. The general trend for the target species is for increases in

landings. But we do not know how much effort (man hours, number of trips,5

length of trips, etc.) was required per pound landed to assess if this

reflects an increase, decrease, or stability in the total population.

However, the trends are evident and may prove beneficial for comparative

purposes.I

With this in consideration, a future report (CM-69) will compare

habitat component alterations and fisheries statistics of Charlotte Harbor

and Tampa Bay. This comparative analysis will provide a basis for manage-

ment decisions even though the results may be subjective in their presen-

tation. We can logically deduce that loss of fisheries habitat will

eventually result in changes in fisheries yield. Loss in habitat

components may be a direct or indirect cause and, thus, a direct or in -

direct measure of fisheries population changes. Only continued research on

the entire life hi stories of the species in different areas will provide

the direct or synergistic relationships to the habitats in which they live.

138

VI E. LAKE WORTH

U ~~~VI E 1. GENERAL SITE DESCRIPTION

As sea levels declined following the Ice Age, Lake Worth, then a

j ~~saltwater lagoon, became elevated above sea level and became a predomi-

nately freshwater system. Extreme high tides and waves, high freshwater,

and storms occasionally breached the thin eastern rock and sand ridge (now

the island of Palm Beach) that separated Lake Worth from the Atlantic

I ~~Ocean, forming natural inlets. These inlets were unstable and closed

I ~~spontaneously within a short period of time, returning the system to

freshwater. A sand ridge immediately west of Lake Worth separated the lake

from the mainland. This ridge ran continuously from the Hillsborough River

north to the Loxahatchee River where it then turned east, connecting to the

I ~~eastern sand-rock ridge. The ridge was bordered on the north and west by a

3 ~~~system of lakes and sawgrass sloughs. By 1845, two islands in Lake Worth

existed naturally: Big Munyon Island and Hypoluxo Island. Vast freshwater

1 ~~marshes surrounded the lake and freshwater grassbeds grew within.

In the 1860's, the first manmade inlet to the Atlantic Ocean was

1 ~~excavated north of the present site of the North Palm Beach inlet, but it

soon closed naturally. In 1877, a relatively stable inlet was cut through

I ~~~a section of the eastern ridge that stood 25 feet above sea level. A rapid

3 ~~~conversion took place changing the freshwater system to a saltwater

environment. Beach sand swept in through tidal action smothering the

3 ~~bottom vegetation and benthic organisms, replacing them with organic muds.

By the late 1800's, mangroves replaced the freshwater marshes.

139

The area's resident population was approximately 1,000 persons in

1894. During the 1890's, resort developers began filling the wetland edges

of Lake Worth . At the same time, the East Coast Canal Company finished

dredging a navigational canal, now part of the Intracoastal Waterway, that

extended from the north end of Lake Worth through the northern sand ridgeI

and sawgrass sloughs to the Jupiter Inlet. Water that had previously

flowed from portions of the mainland inland to the Jupiter Inlet was now

directed south into Lake Worth, thus increasing the organic load of the

Ilake. In the early 1900's, the Intracoastal Waterway was completed from

the south end of Lake Worth to Biscayne Bay.I

By 1915, the Port of Palm Beach created an inlet 4' deep at the north

end of Lake Worth. Dredge and fill activities replaced more and more acres

of mangroves in the 1920's. By 1925, 4 additional alterations were com-

pleted. (1) The North Lake Worth inlet was deepened to 16' and bulkheaded.

Peanut Island was created by the dumping of dredge spoil during creation of

North Lake Worth Inlet. (2) The South Lake Worth inlet was constructed to

help flush Lake Worth, however, tidal action increased sand deposition intoI

Lake Worth. (3) The West Palm Beach Canal was completed by the EvergladesI

Drainage District (EDO), connecting Lake Okeechobee to the Atlantic Ocean.

This canal functioned for drainage and transportation and was provided with

two water control structures, one at Lake Okeechobee and the other on the

coast at the fresh and salt water interface. (4) Part of the naturalI

sawgrass slough system of the mainland was impounded and inflow was

diverted into Clear Lake and Lake Mangoni a to serve as a water supply for

the cities of West Palm Beach and Palm Beach. Resident population at this

time was approximately 30,000.

140

The West Palm Beach Canal and alteration of the mainland drainage

pattern greatly affected urbanization. Prior to these changes, settlement

I ~~~occurred primarily on the island of Palm Beach and along the high and dry

sand ridge bordering Lake Worth. Now, however, drainage made available

much more l and f or development. Urbanization and agriculture quickly

spread west, placing additional pressures on surface waters of the area,

including Lake Worth.

I ~~~~By 1950, resident population of West Palm Beach increased to over

43,000. The entire urban development at that time was discharging 10

million gallons of raw sewage daily directly into Lake Worth or through

septic tanks into ground waters. Already, much of Lake Worth shoreline

had been dredged, filled, and bulkheaded. The cumulative effect of

5 ~~~interior drainage, agricultural and urban runoff, sewage disposal, and

shoreline development peaked in the early 1950's. Concurrently the cost of

I ~~~waterfront property skyrocketed. In 1959, Munyon Island was significantly

enlarged by deposition of dredge spoil. In 1967 North Palm Beach Inlet was

further dredged to 35'. By 1972, almost the entire Lake Worth shoreline

5 ~~~was urbanized with half the shoreline bulkheaded. Figure 26 describes

Lake Worth.

I ~~~~Between 1950 and the present, several steps to improve the lake have

been taken. Dredge and fill and bulkhead operations have been prohibited.

By mid-1960, 70% of the urban population was served by sewage treatment

facilities. A massive cleanup occurred through the 1970's resulting i11 all

sewage receiving secondary treatment prior to disposal.

5 ~~~~Today, Lake Worth receives saltwater input from the intracoastal

waterways and from the two inlets directly opening Lake Worth to the

5 ~~~~~~~~~~~~~~141

� .; .,'...~.~ ': � �'4

Intracooastal waterway

Munyon Islands
':: 4 '~ C17 Canal

* g fPeanut Island
il, T -----North Lake Worth Inlet

* .: ,.w,.. - '
.. eF3 3 km N

�- -~ - Loke Worth

K. ,i C51 Canal

Atlantic Ocean

C16 Canal
Hypoluxo Island
Beercan Island
.... ----South Lake Worth Inlet

Intracoastal waterway

Figure 26. Lake Worth..

142

Atlantic. Freshwater input arrives from 7 sources with the C-51 canal

being the major source of freshwater and a major source of nutrients and

pollutants (Table 8).

Table 8. SOURCES OF FRESHWATER FLOWING INTO LAKE WORTH

SOURCE % OF TOTAL FRESHWATER INPUT

C-17 canal 12.1%

C-51 canal 49.7% (75% flows north,

25% flows south)

C-16 canal 10.7%

WPB Sewage Treatment Plant 1.3%

Boynton Sewage Treatment Plant 0.3%

Surface runoff 4.1%

Groundwater discharge 22.3%

In summary, Lake Worth naturally evolved from a saltwater lagoon to a

fresh-water lake. Man-made changes modified the lake into an estuarine

lagoon. Though it is not feasible to return Lake Worth to its original

freshwater condition, it is desirable to maintain the lake as a productive

estuary.

143

VI E 2. GENERAL ACREAGE VALUES

Several inconsistencies exist with the interpretation of the threeI

Lake Worth quads that did not occur with any of the Charlotte Harbor quads.

The Lake Worth study site did not extend entirely to the western boundaries

of the three quads; it stopped approximately 1.5 km east of the western

edge (See Figure 24). However, the contractor continued interpretation to

the western boundary on the 1975 Riviera Beach quad. Since the extended

interpretation also included acreage values, only those categories that are

not included within the 1.5 km interpretation extension are accurate forI

comparing the historical and recent Riviera Beach quads. These include

only marine waters and marine wetlands. However, all categories were

compared between historical and recent interpretation of the other two

Lake Worth quads. Also the Atlantic Ocean was classified as "Bays and

Estuaries" on both the historical and recent Lake Worth quad maps.

Another interpretation error is the delineation of reefs for all 1940 quads

but not for the 1975 quads. Reviewing the 1975 aerial photographs and

ground truthing revealed that these reefs still exist.I

Table 9 lists the eight general categories and their associated

historical and recent acreage values. Since seagrasses. were classified as

a special category (900) for the recent interpretation, these values were

added to the recent wetlands' values (600). Historically, seagrasses wereI

classified under the wetlands category.

The following paragraphs describe the Level I acreage changes. The

numbers in parentheses following the category name relate to the

interpretation index numbers as found on the maps.

144

Table 9. LAKE WORTH ACREAGE VALUES

Level 1 Land Use name Urban Agriculture Rangeland Forestland
Level 1 Land Use code 100 200 300 400
Year 1940 1975 T940 IT~ T-40T75 T940 T975

USGS Quadrangle Name

Riviera Beach 5274 15499 1217 1440 15408 2015 3493 4204

Palm Beach 8788 16910 525 427 6599 427 809 1326

Lake Worth 3490 14500 4340 1633 4663 1324 5566 2201

TOTAL ACRES 17552 46909 6082 3500 26670 3766 9868 7731

Acreage Change1 +19132 -2805 -9511 -2848
Percent (%) Change1 + 159% - 58% - 84% - 45%

Transportation
Level 1 Land Use name Water Wetlands Barrenland and Utilities
Level 1 Land Use code 500 600 700 800
Year 1940 1975 1940 1975 1940 1975 1940 1975

USGS Quadrangle Name

Riviera Beach 31255 16168 13863 1226 896 1060 732 1001

Palm Beach 13740 15962 5691 212 461 111 658 2676

Lake Worth 15307 16911 4733 373 420 838 211 1147

TOTAL ACRES 60302 49041 24287 1811 1777 2009 1601 4824

Acreage Change1 +3826 -22476 + 68 +2956
Percent (%) Change1 + 13% - 93% + 08% + 341%

1The Riviera Beach quad acreage values are not included in these totals since different
size areas were photointerpreted for that quad.

145

Urban (100)1

Urban area increased 159%, from 12,278 acres to 31,410 acres. The

Palm Beach quad nearly doubled in urban area while the Lake Worth quad

quadrupled. The majority of the urban category is residential housing.

Since much of the area immediately surrounding Lake Worth was already

urbanized by 1940, much of this increase occurred farther inland.

Agriculture (200)1

Agriculture land decreased by 3,805 acres, a 58% decrease. The Lake

Worth quad experienced 97% of this loss accounting for 2,707 acres. Most

of the lost agricultural land was replaced by urban area and occurred

inland from Lake Worth.

Rangeland (300)1

Rangeland decreased by 84%, a loss of 9,511 acres. This rangeland was

converted into urban area and, like the agriculture class above, occurred

inland of Lake Worth.

Forestland (400)1

Forestland lost 2,848 acres, a decrease of 45%. This value does not

reflect a true loss of natural forestland because it includes acreage

increases of exotic species. These increases include 1,514 acres of

Brazilian Pepper, 331 acres of Melaleuca, and 215 acres of Australian Pine.

'Does not include acreage data from the Riviera Beach quad.

146

Conversely, natural pine flatwoods lost 3,680 acres, a decline of 76%. In

addition, sandpine scrub, one of Florida's most unique natural upland

habitats, lost 511 acres, an 85% decline.

Water (500)1

Water area increased 13%, a gain of 3,826 acres. Most, if not all, of

this increase can be explained by the loss of acreage from the seagrass

category.

Wetlands (600)1

Wetlands experienced an overall decrease of 22,476 acres, a decline of

93%. Wet prairies and freshwater marsh lost 7,017 acres, a 97% decline.

Marine wetlands will be discussed in detail in the followinq section.

Barrenland (700)1

Barrenland increased by 8%, a gain of 68 acres. These lands were

generally the result of land clearing and other construction activities.

Transportation and Utilities (800)1

This category increased 341%, from 867 acres to 3,823 acres. Much of

the increase can be explained by the addition of Interstate 95 and

expansion of West Palm Beach International Airport. In addition, several

other factors, such as bus terminals and sewage treatment plants, have

increased the acreage value for this category.

1Does not include acreage data from the Riviera Beach quad.

147

VI E 3. FISHERIES HABITAT COMPONENT ACREAGES

Section VI 0 3 defines ,fisheries habitat components. Table 110

provides historical and recent acreage values for fisheries habitat in Lake

Worth. Acreage values for the Riviera Beach quad can be included within

this sectio Olsi nce the i nterpretati on error does not include marine

wetlands.

Mangroves (612)I

Mangroves lost 1,881 acres, a decrease of 87%. Mangroves appear to be

replaced by Australian Pines and urbanization in the form of seawalls andI

resi denti al and commerci al housi ng. The remai ni ng 276 acres of mangroves

occur in very small scattered areas and are now protected by strict

regulations.

Non-Vegetated Tidal Flat (651)1

Mudflats apparently did not exist either historically or presently

within the Lake Worth study site.

Oyster Reefs (654)

Oyster reefs did not exist either historically or presently within the

Lake Worth study site.

Saltmarshes (642)1

Only one site of saltmarsh occurred historically within the study

si te, which was located in the Riviera Beach quad. All 130 acres of this

marsh was replaced by residential area and a small lake. Some tropical

148

Table 10. LAKE WORTH FISHERIES HABITAT COMPONENT ACREAGES

Habitat Component Non-Vegetated
Mangrove Tidal Flat Oyster Reef Saltmarsh Seagrass
Year 1940 1975 1940 1975 1940 140 975 1940 1975

USGS Quadrangle Name

Riviera Beach 1667 112 0 0 0 0 130 0 1995 152

Palm Beach 66 46 0 0 0 0 0 0 1014 0

Lake Worth 424 118 0 0 0 0 130 0 1262 9

TOTAL ACRES 17552 46909 0 0 0 0 130 0 4271 161

Acreage Change - 1881 - 130 -4110
Percent (%) Change - 87% - 100% - 96%

149

hammock also occurred there possibly as a result of natural succession but

more likely a result of residential trees planting.

Seagrasses (645 historical; 901, 903, 904 recent)

Due to the poor quality of photography (for seagrass interpretation)

in the Lake Worth study area, it has been determined that a historical

comparison is of unacceptable accuracy. Because of the long term turbidity

patterns in Lake Worth, even the recent photography was difficult to

interpret and much of the seagrass delineation was provided to the

contractor through ground truth efforts and personal communication. The

only substantial seagrass bed found in Lake Worth was north of Palm Beach

Inlet adjacent to John MacArther State Recreation Area. This seagrass bed

consisted of primarily Halodule and Thalassia. During the ground truth

efforts, the Thalassia was found to be highly reproductive with large

accumulations of viable seeds. This is of important consequence for future

restoration work in the Lake Worth area.

Some recollective communication with early researchers in the Lake

Worth area has provided some understanding of seagrass populations. Dr.

Gilbert Voss (personal communication) stated that seagrasses within Lake

Worth historically existed only near the inlets and were never very

abundant. In addition, Dr. Voss stated that no seagrasses ever existed

within mid Lake Worth; he described this area as a "big mud hole."

Seasonal and short term variations most likely occur, however, it is

probable that seagrass populations have remained relatively unchanged over

the past 40 years.

150

VI E 4. COMPARISON BETWEEN FISHERIES STATISTICS AND

HABITAT ALTERATION

Since commercial fisheries statistics were inadequate in general and

I ~~grossly inaccurate for the Lake Worth Study site (see Section V E 2), and

I ~~because the acreage values for the seagrass category are questionable, no

attempt was made to compare wetland loss to fisheries decline. Observing

the commercial catch values in 1951 (Fig. 15 through 22), however, shows

that before regulations were enacted that banned all net fishing other than

I ~~~cast nets in Lake Worth, a large commercial fishing industry existed in the

area. As discussed in Section V E 2, the catch may not have come from Lake

Worth. The data presents only the county in which the catch was landed.

Much of the catch may well have come from the Loxahatchee estuary.

Unfortunately, no data are available to clarify this discrepancy.

Until fisheries statistics are improved to include effort data and

knowledge of where the catch was made, no conclusions can be drawn to

I ~~~associ ate habitat alteration to fisheries decline.

I~~~~~~~~~~~~~~~~5

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
152
I
l
l
I
l
l
l
l
l
l
l
l
l
I

152
l

I
I
I
I
I
I
I
I Marine Resources Geobased Information
I System
I
I
I
I
I
I
I
I
I
I

VII. MARINE RESOURCES GEOBASED INFORMATION SYSTEM

VII A. DESCRIPTION

A Marine Resources Geobased Information System (MRGIS) has been

installed at the Florida Department of Natural Resources Bureau of Marine

Research (BMR) in St. Petersburg, Florida. The MRGIS is designed for

processing, analyzing, and integrating satellite data and other digital

data from a grid system with a variety of environmental and socioeconomic

data for resource analyses and applications modeling. The MRGIS will

be used primarily as a research tool for coastal zone resource management

and for integrating coastal zone data bases. The system is a research

prototype for the State of Florida and is being used to demonstrate

regional and state-wide applications.

The MRGIS was developed at the BMR with the following reasoning:

1. BMR has actively pursued research with satellite imagery since the

early 1970's and has participated in field experiments with NASA,

testing prototype sensors and applications of these sensors.

2. Scientists from BMR represented DNR on the LANDSAT Evaluation

Committee and, thus, the integration of the MRGIS as a prototype

for a statewide research system was consistent with the intent of

the committee.

3. BMR had the capability of assessing hardware and software

required to develop the MRGIS and was current with the latest

technology in the field by close association with NASA.

4. BMR Scientists had been trained on Earth Resources Laboratory

Applications System (ELAS) software and were computer-oriented.

153

This permitted the purchase, installation, and use of the system

without additional staffing.

5. Habitat loss is of critical concern to the State of Florida andI

the MRGIS provides an exemplary too] to establish a digital

data base for coastal habitats.

Since the MRGIS was the prototype for a State of Florida research

system, extreme caution was required in hardware configuration. With the

assistance of NASA Earth Resource Laboratory personnel, specific hardware

configurations to meet general budgetary constraints were developed. At

that time bid specifications were developed. Si nce the i ntent was toI

establish a turnkey system that would use ELAS as the operating software, a

major requirement to the vendor was the installation of ELAS on the model

they bid. In addition, specific hardware requirements to ensure expand-

ability and state of the art technology were included to maintain the

potential for future systems development.I

The image processor and display was purchased as a sole source item

because the software driver and interface to the mainframe were available

and ELAS was designed with I/O commands specific to the processor. Soft-

ware and hardware development would have been necessary if any other

approach had been taken.

The mainframe hardware (Fig. 27) consists of a 512 kilobyte core

memory and peripheral storage and retrieval devices. The image processingI

system (Fig. 28) is interfaced to the mainframe and is capable of image and

graphics display. The system configuration was designed by NASA Earth

Resources Laboratory (ERL) to satisfy requirements of the Earth Resources

Laboratory Applications Software (ELAS).

154

32/27 3510 3025 3025
CENTRAL FLOATING MEMORY MEMORY
PROCESSING APOINT MODULE MODULE
UNIT ACCELERATOR
I SELBUS
9203 8000 9131 9020-
CRT INPUT/OUTPUT HIGH LSTP
CR~T PROCESSOR SPEED DATA I
INTERFACE

I SEE FIG. I

MPBUS I
8030 8oo I 9
CONTROLLER IjCONTROLLER 8 LINE TA
LPFDC I IOPDC ASYNC TAPE DRIV
8580 o IPS
I I I DP 800/1600
t ~~~8310 GRS232
'8310
300 LPM I
PRINTER I DISK DRIVE MODEL
W/8317 300 MB 9 2 03 9568
IREMOVABL I CRT L _

I MODEL I
L 8144

Figure 27. MRGIS mainframe and peripheral hardware.

155

GOULD SELBUS
9131
HIGH SPEED DATA
INTERFACE
HSD

COMTAL
CONT- I 3
INTERFACE

IMAGE RESOURCES VIDEOPRINT
3M COMTAL CT-8H MODEL 5300
8000-30SER 512 x 512 4 x 5 INSTA PRINT
IMAGE PROCESSOR HIGH RESOLUTION OR
COLOR MONITOR 35 MM EXPOSURE
3 REFRESH MEMORY 19" DIAGONAL HARDCOPY OUTPUT

|TRACK BALL
LCONTROL LER

Figure 28. MRGIS graphics hardware.

156

----~C3 -- --- --- -

The software (Fig. 29) installed on the MRGIS consists of three

levels:

I 1. System Software - machine-specific operating software for primary

level communication.

2. FORTRAN, Symbolic Debugger, Scientific Run Time Library - Proqram-

ing language and programing aids.

3. Application Software - ELAS, Coastal Zone Color Scanner, and any

other level two programs.

The principal applications software installed on the system is ELAS.

This software was sponsored and developed by the Earth Resources Labora-

tory (ERL) of the National Space Technology Laboratories (NSTL) of the

National Aeronautics and Space Administration (NASA). ELAS software

development began in the early 1970's. The initial work was directed

towards supervised classification of LANDSAT and aircraft data. Develop-

ment progressed with the addition of the capability to geographically

reference the data to the Universal Transverse Mercator (UTM) grid. Also,

the data processing approach was changed from batch to interactive process-

ing. A data base program was added to allow the storage of numerous para-

meters, (i.e.) LANDSAT classifications, soil types, rainfall, elevation,

per-cent slope, slope length, aspect, ownership, oceanographic variables,

etc., by a selectable cell size. This permits manipulation of these

parameters through selectable application algorithms to produce resource

management information.

The ELAS software is divided into two components, the operatino sub-

system and the applications modules. The operating subsystem is FORTRAN-

based and uses some machine-dependent routines for INPUT/OUTPUT and control

functions.

157

GOULD SYSTEMS
MPX 32
OPERATING SYSTEMS

PROGRAMMING SUPPORT
SOFTWARE

FORTRAN 77+
SYMBOLIC DEBUGGER
SCTIENTIFIC RUNTIME
LIBRARY

FISHERIES STATISTICS
SOFTWARE DEVELOPMENT
I~~~~~~~~~~~~~~
EARTH RESOURCES LABORATORY APPLICATIONS

I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SOFTWARE

COASTAL ZONE COLOR
SCANNER IMAGERY
ANALYSIS SOFTWARE

Figure 29. HRGIS software configuration.

158

The applications modules are written in FORTRAN, utilizing the operat-

ing subsystem for the machine dependent functions. The application modules

exist generally as FORTRAN overlays or subroutines. Depending an the

application, needed modules are called or released by the operating sub-

system. Approximately 133 processing modules now exist within the ELAS

package. A complete description of ELAS is documented by ~Junkin et al.

(1980).

The usefulness of information derived from LANDSAT multispectral

scanner data has been recognized by state agencies primarily as a result of

the Florida LANDSAT Demonstration Project (Brannan et al. 1981). That pro-

ject was developed in conjunction with the NASA Earth Resources Laboratory

Regional Applications Program and the Florida LANOSAT Evaluation

Committee.

VII B. LANDSAT IMAGERY ANALYSIS OF CHARLOTTE HARBOR

General LANDSAT vegetation cover classifications have been developed

for the Charlotte Harbor area. Development of these classifications

represents the initial phase of the MRGIS operational development. These

initial classifications are at Level I/Level II resolutions and stati sti -

cal accuracies of the classifications have not yet been developed. As we

gain better familiarity with ELAS, it is certain that classifications will

be greatly enhanced and specific analysis techniques relative to the infor-

mation desired will be refined. A stepwise progression to provide a

general understanding of the process in developing these classifications,

including observations and comments for this report, follows:

159

1. LANDSAT: When utilizing LANDSAT data it is important to under-

stand physical processes of data acquisition. The LANDSAT program was

initiated in 1972 and data are available from 1972 to the present. This

report utilizes data collected by the multispectral scanner (MSS) located

on board all four LANDSAT satellites launched since 1972. The satellites

were launched into a polar sun-synchronous orbit at an altitude of 920km

and pass over a given area every 18 days. The MSS has a ground resolution

of one pixel (equal to 80m2 or 1.1 acres) and measures average reflectence

of the pixel in four wavelength bands (0.5-0.6, 0.6-0.7, 0.7-0.8 and

0.8-1.1 nanometers). Each LANDSAT scene (fixed image) covers an area

approximately 183 x 183km (115 x 115 statute miles). These data are

relayed to earth stations and radiometric and geometric corrections are

made by computer. The raw data, in several forms, are then available for

purchase (currently through NOAA) as computer compatible tapes. LANDSAT 4

contains the MSS and a new Thematic Mapper (TM) sensor with coverage every

16 days and a lower orbit. The TM measures seven wavelength bands and has

a ground resolution of 1/4 acre. These data are not yet available. One TM

scene has been installed on the MRGIS and initial review suggests a

tremendous increase in the ability to resolve fisheries habitat. TM data

will be compared to MSS and aerial photography in detail in subsequent

reports.

2. Acquiring data: Data are ordered on computer compatible tapes

from data centers located in several cities across the U.S. Prior to

ordering a scene it is important to know the percent cloud cover over the

area of interest. Usually, the best imagery has less than 20% cloud cover.

In addition, the type of information to be extracted from the data should

160

I ~~~be considered before or dering data. If, for example, the prime interest is

seagrasses, late fall to early spring (when the water is clearer) at low

tides provides the best data. 'If the interest is in deciduous forests then

a multitemporal analysis from summer (when leaves are present) and winter

(when leaves are absent) would provide the best data sources. It is

I ~~advised that the scene be personally scrutenized through microfiche or

hardcopy prior to purchase.

3. Processing: Raw computer compatible tape (CCT) imagery consists
of four data channels for each scene. The data consist of a numerical

value between 0 and 255 representing an average relative reflectance value

for each of the four spectral bands of each pixel. The raw data,

therefore, can potentially contain four of (256)4 possible values for each

I ~~~pi xel. ELAS contai ns numerous stati sti cal packages which can be used to

transform the raw data into a managable data set, a necessary step in

developing a vegetative and land use classification. By usi ng one or two

of the statistical classifiers, less than 62 classes will be developed

based upon the statistical boundaries set by the investigator. At this

I ~~~point, the investigator evaluates the classes broken out by the processing

techniques and assigns them a land cover type such as mangroves, pines or

hardwoods. During this interactive process, some classes may be lumped and
others may be further statistically evaluated.

4. Charlotte Harbor: The Charlotte Harbor study area required two

scenes of data, Upper and Lower Charlotte Harbor (Fig. 30 and 31).

Upper Charlotte Harbor (Fig. 30) was developed from an August 22, 1980

I ~~~scene. Originally, 54 classes were developed for this image, however, they

i ~~~have been combined to present nine final classes and are defined as
follows:

3 ~~~~~~~~~~~~~~~~161

Impacted/Cleared refers primarily to areas undergoing development.

The land has been cleared and has very little vegetation. The primary

component of the soil is sand and the reflectence values are high.

Some naturally occurring saltbarrens may be found within this

category.

Impacted/Urban are areas which are composed primarily of buildings

such as downtown areas or dense suburban areas, or any recent housing

developments with little vegetation.

Impacted/Vegetated are areas comprised primarily of cleared land which

has revegetated and exists in various stages of succession. The

majority of lands in this class were cleared, platted and installed

with roads during the 1960's - 1970's land boom period. This class

also includes crop and pasture land and housing developments that are

typically older and lushly vegetated.

The Palmetto Scrub/Pine Scrub/Tropicals refers to the predominant

natural vegetation types in a particular scene. Palmetto and pine

scrub contain from 0-30% pine with palmetto the predominant vegeta-

tion. These areas are typically on high ground that is rarely

flooded. Tropical vegetation (generally non-native introduced

species) were lumped into this class and consists of very small areas.

The type of tropicals included are primarily woody tree species such

as eucalyptus and members of the fig family.

Palmetto/Marsh/Mangrove classes were combined to present a subarborial

vegetation which is either seasonally or tidally wet. This refers to

vegetation types less than 3m in height. The palmetto areas in this

class have <30% pine and are seasonally wet with a high water table.

162

0;>00-40~~~~~~~--'~---- ~a,- V:4f' 4- f f - Sf---

00,~~~~~ 000 00 ~ ." ,g}6 ...... a s*,
lO T PM p *54z"

Figure 30 GeneralLANDSAT cassificaion of Uper Charltte HarbI SE
_Ii~~~~~~~~~~~~~~~~ i w l

Figure 30. General LANDSAT classification of Upper Charlotte Harbor.

- - -- -- - - -- - - - ---- I - -

0 0

Figure 31. General LArND$AT classification of Lower Charlotte Ha'bor.
~ r:"~'""- "| - -.

Figure l1 *eea LADA clsiiaino oe hrot abr

The marsh areas consist of Juncus, Spartina and other fresh and

brackish water species. The mangroves included in this class are

generally stunted and sparse. Batis, Salicornia and other salt-

tolerant species coinhabit these areas.

The Mangrove/Pine/Hardwood class is also characterized by seasonal

or tidal inundation. This vegetation class typically has a dense

canopy and is >3 m in height. The mangroves are typically so dense

that little water is reflected through the canopy. The pine areas

have a 30-60% canopy cover and usually have an understory of palmetto.

These pine flatwoods are seasonally wet although the pines individu-

ally inhabit the higher ground. The deciduous hardwoods inhabit pri-

marily bottom lands associated with the rivers and their tributaries

that comprise the Charlotte Harbor watershed. These hardwoods are

generally composed of cypress, sweetgum, oaks, bays, and others.

The Shallow/Turbid Water class represents those waters usually <3m in

depth and either have a bottom reflectance or are turbid.

Deep Water refers to those waters >3m and are less influenced by

bottom reflectance.

Figure 32, entitled Punta Gorda SW, is a section of the Upper

Charlotte Harbor satellite image. This imaqe has been corrected from

spacecraft coordinates to Universal Transverse Meridian (UTM) grid

coordinates. The conversion results in a north-south orientation of the

image, comparable to available aerial photography and map products. Figure

30 covers the same area as a quad map (7.5 x 7.5 minutes) and is,

therefore, compatible to the photointerpretation of the Punta Gorda SW

quad. A seperate set of statistics was developed for this image with 50

167

original land cover classes. Again, many of the classes were combined, but

in this case the final classification is more specific in vegetation type.

In addition to land cover classes, several Indian mounds and bald eagle

nesting sites have been integrated into this image.

The first two classes are identical to the Upper Charlotte Harbor

classification description. There are no urban areas in this image.

Palmetto Scrub refers to those areas with <30% pine and a palmetto

understory. These areas range from 90% palmetto to a mixture of

palmetto, xeric grasses, wax myrtle, and other subarboreal vegetation.

Pine scrub consists of >30% pine and generally has a palmetto under-

story.

Fresh/Brackish Marsh consists primarily of Juncus, Spartina and Typha

in areas of low salinity. Also included in this class are large sites

of Batis and Salicornia. These areas were typically found in the

center of mangrove islands or in supratidal areas with dead or stunted

and sparse mangroves.

Mangrove Predominant contains red, black and white mangroves. Quite

often man-impacted mangroves were interspersed with Brazilian pepper.

Vegetated Saltern or Tidal Flats primarily refers to the fringe areas

separating mangroves from palmetto and pine scrub habitats. Vegeta-

tion on these flats is patchy in nature and consists of grasses,

palmetto, mangroves and succulents tolerant to extreme wet and dry

periods. The barren areas are both organic and inorganic in nature.

Lower Charlotte Harbor (Fig. 31) represents a December 8, 1980

scene. Originally, 43 classes were developed for the image but have

been combined to a final 10 classes.

168

Figure 32. Detailed LANDSAT classification of the Punta Gorea SW quad.

Figure 32. Detailed LANDSAT classification of the Punta Gorta SW quad.

The classification scheme for this image is comparable to the Upper

Charlotte Harbor image with one exception. Since this was a winter scene,

the water was clear and submerged seagrasses were statistically separable

The two seagrass classes represent moderate or dense meadows versus sparse

or patchy meadows.

The above classifications (Fig. 30-32) are initial work products and

represent a stage in the development of the MRGIS. The Charlotte Harbor

area is being used as a training exercise to demonstrate the potential of

the MRGIS. Aerial photographs and associated digitized photointerpreta-

tions are being used to develop an accuracy assessment and comparison of

the aerials and LANDSAT images. The Punta Gorda SW image (Fig. 32) has

been analyzed and ground truthed for comparison to the Punta Gorda SW

digitized quad map (Map 7). Although the statistics for the image may not

yet be the best for all the classes, a comparison of mangrove acreages has

been made. The image contains 8,486 acres of mangroves while the photo-

interpreted quad contains 8,251 acres. This demonstrates a very close

agreement but can be misleading. For example, while the geographical

locations of the mangroves are very similar, some areas on the image that

depict mangrove are not found on the photointerpreted quad and vice-versa.

These differences are being addressed in a detailed, and eventually a

statistical, manner which will allow us to proceed to other areas of the

state with a developed level of accuracy.

VII C. ADDITIONAL USES OF THE MRGIS

The MRGIS is now being utilized in several other areas of research.

1. Coastal Zone Color Scanner (CZCS): In conjunction with the Gulf

171

States Marine Fisheries Commission SEAMAP program, we have installed

additional software into ELAS capable of analyzing imagery from the CZCS on

board the Nimbus 7 satellite.' The software was provided by the National

Marine Fisheries Service and is used to measure chlorophyll concentrations

and turbidity in coastal and ocean waters. CZCS data will be analyzed in

conjunction with ichthyoplankton surveys being made on the west Florida

Shelf. This will aid in determining larval fish distribution and recruit-

ment. We will be developing a CZCS analysis program to research migration

patterns of pelagic/coastal species such as mackerel. We will be cooperat-

ing with University of Miami personnel in using CZCS imagery in conjunction

with swordfish research.

The BMR has been using CZCS imagery in Red Tide research and this will

continue. With the CZCS capability now operating on the MRGIS, numerous

other requests and discussion from state, university and federal organiza-

tions have been enacted and it is assured the CZCS will greatly enhance our

understanding of the coastal environment.

2. LANDSAT: The DNR Bureau of Aquatic Plants is currently working with

the MRGIS to assess its use in monitoring the spread of aquatic weeds in

Florida.

We are working with the DNR Bureau of Environmental Land Management to

inventory Florida's aquatic preserves.

We will also be working with Rookery Bay National Estuarine Sanctuary

to provide an inventory of the sanctuary and the surrounding areas.

LANDSAT can also be applied to red tide research. The dinoflagellate

Ptychodiscus brevis is responsible for massive fish kills and neurotoxic

shellfish poisoning. Figure 30 is the first LANDSAT image to document a

172

Florida west coast toxic dinoflagellate bloom and possibly the first

LANDSAT image, world wide, to ever document a toxic dinoflagellate bloom.

This type of imagery can provide the scientific investigator and resource

manager with information pertinent to the development and dynamics of a

bloom simply unattainable by conventional shipboard measurements.

As visiting scientists and resource managers are introduced to the

technology of the MRGIS, immediate applications are conceived. This is a

relatively new technology that has not been adequately transferred to

scientists and/or resource managers. The MRGIS is bridging the gap.

VIID. GROUND TRUTHING

Ground truthing started in August 1982 and will continue for this

phase of the project through early 1984. Initial ground truthing served

two major purposes and currently serves two additional intentions.

Initial ground truthing efforts:

1. DNR personnel assisted DOT in verifying their photointerpretation

of Charlotte Harbor aerial photography. This involved visiting

specific sites in question by the interpretors and identifying the

vegetation. Representative areas of numerous vegetation types

were visited, including coastal habitats such as seagrasses and

mangroves.

2. DNR personnel, assisted by a DER staff member and the Lee County

Marine Extension Agent, ground truthed several seagrass areas to

verify DOT's system of classifying seagrasses. The original

classification delineated four categories: sparse, moderate,

173

dense, and patchy. Ten transects were assessed for spatial

distribution of seagrasses. These initial observations suggested

that the classification system be altered to three designates:

sparse, moderate-dense, and patchy.

Current ground truthing efforts:

1. When using remotely-sensed imagery it is important to understand

seasonal density changes in vegetation resulting from leaf drop

and leaf growth to allow multitemporal analysis. Five of ten

original preliminary transect sites were chosen for quarterly

investigations of seagrass density over one year.

Each sampling period and station requires measurements of several

parameters. Currently, measurements are taken only for the

dominant seagrass, Thalassia testudinum. (1) Seagrass density is

determined by counting the number of short shoots per 1/16 meter

quadrats. An average value is calculated and extrapolated

resulting with an average value per square meter. (2) Random

seagrass short shoots are measured to determine number of blades

and blade length and width. (3) Water temperature and salinity

are recorded. (4) If drift algae is present, random samples using

the 1/16m quadrat are taken. The algae is dried and an average

dry weight per square meter is determined.

A similar study will proceed for the Tampa Bay study (CM 69).

Data from Charlotte Harbor and Tampa Bay will be analyzed to

determine a method to seasonally assess seagrasses using remote

sensing techniques.

2. Statistical analyses of Landsat images sometimes delineate certain

174

areas as being different from sites that are actually of the same

classification. Conversely, analyses also classify very different

areas as being the same. Ground truthing may clarify these

I ~~~~~questionable sites. These preliminary observations will greatly
I ~~~~~facilitate future analyses involving Landsat images of other sites

of coastal Florida.

I~~~~~~~~~~~~~~~7

l
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I.
176
I

I
I
I
I
I
Appendices
I
I
Glossary
I
I
* Literaturature Cited
I
I
I
I
I
I
I
BG.GDG IIGOD IG

VIII. APPENDICES

VIII A. Appendix A

The following is a general description of the classification scheme

used on the map products. It is reproduced from Kuyper et al. (1981).

177

SECTION I

General Description The definitions which follow will provide understanding of
what is included in each category at Levels I, II and III. The
This land use, vegetation cover and land form classification definitions are largely based on U.S.G.S publications referenced
system is arranged in hierarchical levels with each level in this report.
containing land information of increasing specificity.

LEVEL I

This class of data is very general in nature. It can be
obtained from remote sensing satellite imagery with supplemental
information. Level I would normally be used for very large
areas, statewide or larger, mapped typically at a scale of
1:1,000,000 or 1:500,000. At these scales, one inch equals 16
miles or one inch equals eight miles, (1 centimeter per S
kilometer), respectively.

LEVEL II

This class of data is more specific than Level I. Level II
data is normally obtained from high altitude imagery (40,000 to
60,000 feet), supplemented by satellite imagery and other
materials such as topographic maps. Mapping typically might be
at a scale of 1:100,000 or one inch equals 8,333 feet (1
centir-eter per 1 kilometer).

LEVEL III

This class of data usually is obtained from medium altitude
photography flown between 10,00C and 40,000 feet. The mapping
scale typically is 1:24,000, or one inch equals 2,000 feet (1
centimeter per 0.24 kilometer).

LEVEL IV

This more specific class of data is obtained from low
altitude photography flown below 10,000 feet. In comparison
with the above mentioned levels, Level IV typically might be
mapped at a scale of 1:6000, or one inch equals 500 feet (1
centireter per 0.06 kilometer).

Scope and Use

The Florida Land Use, Cover and Land Form Classification
System is an important step toward the development of a
geographic data based information system. It serves to reduce a
large amount of prirmary data (such as remote sensing imagery or
field survey records) to a more understandable, smaller amount
of secondary data (such as a land use map). The system also
provides a useful structure of land concepts of properties.
Yet, it does not collect or analyze inferration or offer
conclusions.

178

100 URPAN OR BUILT-UP residential units may be found on military bases in the form of
barracks, apartments, dormitories or homes; and on college and
Urban or Built-up land consists of areas of intensive use, university campuses, in the form of apartments and dormitories
with much of the land covered by structures. Included in this in close proximity to instructional buildings. Agricultural
category are cities, towns, villages, strip developments along field operations and resort facilities commonly provide
highways, and such areas as those occupied by mills, shopping temporary lodging for their employees and these areas would be
centers, industrial and commercial complexes, and institutions classified under Agriculture, and Commercial and Services respec-
that may, in some instances, be isolated from urban areas. tively.

As developrment progresses, small blocks of land of less 110 Residential, Low Density (less than two dwelling
intensive or nonconforming use ray be isolated in the midst of units per acre]
built-up areas and will generally be included in this category.
Agricultural, forest, or water areas on the fringe of urban and 111 Single Family Units
built-up areas will not be included except where they are part
of low-density urban development. 112 Mobile Home Units

The Urban or Built-up category takes precedence over others 113 Mixed Units
when the criteria for more than one category are met. For
example, residential areas that have sufficient tree cover to 119 Low Density, Under Construction
meet Forestland Upland criteria will still be classified as
Residential in the Urban or Built-up category. 120 Residential, Medium Density [two-five dwelling
units per acre]
110 Residential
121 Single Family Unit
Residential land uses range from high-density urban
housing to low-density areas with relatively few dwelling units 122 Mobile Home Units
per gross acre. The variation extends from the multi-family
apartments generally found in larger urban centers to those 123 Mixed Units [fixed and mobile home units] *Note 1
single-family houses sometimes having lot sizes of more than one
acre. 129 Medium Density, Under Construction

Areas of sparse residential land use (generally less 130 Residential, High Density
than one dwelling unit per five acres), such as farmsteads, will
be included in other categories to which they relate. However, 131 Single Unit [six and over dwelling units per
rural residential and recreational type subdivisions will be acrel
included in the Residential category since the land is almost
totally committed to residential use, even though it may have 132 Mobile Home Units [more than six dwelling units
forest or range types. per acre]

In most instances the boundary will be clear when new 133 Multiple Dwelling Units, Low Rise [two stories or
housing developments abut clearly defined agricultural areas. lessl
conversly, the residential boundary may be vague and difficult
to discern when residential development is sporadic and occurs 134 Multiple Dwelling Units, High Rise [three stories
in smaller isolated units, develeped over an extended Feriod of or more]
time in areas with rixed or less intensive uses. A careful
evaluation of density and the overall relationship of the area 135 Mixed Units [fixed and mobile home units] Note 1
to the total urLan cromplex must bhe made.
139 High Density, Under Construction
Oter land use cteg-cries ray ermrace areas that meet
the Residential category recu:rrent. Often Fuch residential 1 4 Commercial and Services
sections are an integral rc .ent of the cat'gory with which
they~~~~~~~.. ae as s E tociatedC an t; l b e inoe wthi thath
.th.v are assoc;dted and 'hou ld be incl u e d within th.at Commercial areas are predoirinantly connected with the
ca tmguory. For exam: Ile, inr the Init tutionalI category, sale of products and services. This category is composed of a

179

large ,number of individual types of commercial land use, often 145 Tourist Services
occurring as a complex mixture of uses.
This category includes all those facilities that can be
The Commercial and Services category includes the main identified in support of a motel and hotel facility.
building plus secondary structures and integral areas assigned
to support the base unit. Included are sheds, warehouses, 146 Oil and Gas Storage [except those areas associated
office buildings, driveways, parking lots, and landscaped areas. with industrial use or manufacturing]

Other types of commercial areas include shopping This category identifies storage facilities used in the
centers and commercial strip developments. These areas have retail and wholesale sales of these specific products. The Port
distinctive patterns and are easily identifiable. Frequently, Everglades facility in Fort Lauderdale would be a typical
individual houses and other urban uses may be found in example.
commercial areas. These uses are not delineated, unless they
cannot be plotted into categorized cell size of at least one 147 Mixed Commercial and Service *Note 1
acre at Level III, in .hich case the Mixed category should be
used. 148 Cemeteries

Another commercial use that is not easily identifiable 149 Commercial or Service Under Construction
is the commercial resort. These businesses cater to vacationing
patrons and contain associated recreational facilities such as 150 Industrial
swimming pools and ball courts.
The Industrial category embraces those land uses where
141 Retail Sales and Services manufacturing, assembly, or processing of products is
accomplished. Industrial areas include a wide array of
The area of Retail Sales and Service is primarily industrial types ranging from light manufacturing and industrial
devoted to sale of products and the services. This category parks to heavy manufacturing plants. Included are facilities
will be comprised of elements of central business districts, for administration and research, assembly, storage and
shopping centers, and office buildings, with associated warehousing, shipping, and associated parking lots and grounds.
buildings, driveways and parking lots, etc.
Typical examples of industrial types found in Florida
142 Wholesale Sales and Service [except warehousing are pulp, or lumber mills, oil refineries with tank farms,
associated with industrial use] chemical plants and brickmaking plants. Stockpiles of raw
materials, larger power sources, and solid waste products
This element represents primarily structures identified disposal areas are visible industrial categories and are easily
by size, shape, and adjacent features. Normally, structures are identified on conventional aerial photography.
large and of boxlike shape, designed to hold large quantities of
products. Included in this category are open storage areas that 151 Food Processing
can be identified as being in use or the result of supplemental
data to support this classification. Citrus processing plants, sugar refineries, and seafood
packaging plants are typical of this category.
143 Professional Services
152 Timber Processing
This category is unique: associated elements with the
pri:.e structure, along with supplemental data, are the major Plywood manufacturing, woodchip plants, and saw mills
keys to category identification and location. The typical use are the prime components in this category.
would be lawyers, doctors, consulting firms, etc.
153 Mineral Processing
144 Cultural and Entertainment
Refining of basic earth materials such as Koalin,
This category includes theatres, museums, open air phosphates, heavy metals (Titanium, Zircon concentrates) is
theatres (such as rotion pictures and those for theatrical accomplished in Florida and the facilities for processing these
performances). Pecreational facilities such as skating rinks materials are located near the mining operations.
and tennis courts are not included in this category.

180

154 Oil and Gas Processing 161 Strip Mines

This category includes production of jet fuel, The mining method used in this category is easily
processing and recycling used petroleum products, also other identified by its land scarring, either in pit form or in Iona
products such as asphalt and liquid gases, as well as the trenches, with tailings along the trenching operation.
classic petroleum product, gasoline.
162 Sand and Gravel Pits
155 Other Light Industrial
The category of Sand and Gravel Pits will be relatively
Steel fabrication, small boat manufacturing, electronic small in area size when compared to the category of strip mining
manufacturing and assembly plants are typical light industry operations. These pits are used primarily to support
facilities. construction activities.

156 Other Heavy Industrial 163 Rock Quarries

Major ship repair, ship building, and large lumber This category identifies the excavation of building
mills can be placed in this category. In some instances mineral materials that can be found in part in the St. Augustine,
extraction can also be assigned here if the facility is B rooksville and Ft. Myers areas. Equipment used in this
processing a final and finished product. category is the major identifying feature.

159 Industrial Under Construction 164 Oil and Gas Fields

160 Extractive These are petroleum products sources and are found in
the Sunnyland and Jay areas. No processing facilities are found
Extractive lands encompass both surface and subsurface near these fields. The primary distinguishing feature will be
mining operations. Included are sand, gravel and clay pits, the well head sites, some pumping facilities, and small storage
phosphate mines, limestone quarries, plus oil and gas wells. tank facilities.
The recognition of these activities on the landscape varies from
the unmistakable giant pit mines covering vast areas, to oil 165 Abandoned mine and Fields
wells which cover only a few square feet. Obviously, uniform
identification of all these diverse extractive uses with their 166 Reclaimed Land
varied degrees of photographic expression is extremely difficult
from remote sensing data alone. Industrial complexes, where the This category primarily identifies phosphate mining
extracted material is refined, packaged, or further processed, areas that are being restored.
are included in this category.
167 Holding Ponds
Abandoned or inactive mining operations are a part of
the Extractive category until revegetation occurs. Flooded pits 170 Institutional
and quarries, which may be part of a mining operation, will be
included in this category. Educational, religious, health and military facilities
are typical components of this category. Included within a
The presence of water bodies does not necessarily mean particular institutional unit are all buildings, grounds and
inactive or unused extractive areas. Ponds or lakes are often parking lots that compose the facility. Those areas not
parkAreas of tailings specifically related to the purposes of the institution should
an integral part of an extractive operation.Araofting
and abar.doned pits and quarries way r era in recoulzable for a be excluded. For example, agricultural areas not specifically
long time. These areas ray be barren for decades after associated with correctional, educational or religious
deposition. During the interval from discontinued use until institutions are placed in the appropriate agricultural
revegetation occurs, the parcel will he retained in the categories.
Extractive catecory.
Educational institutions encompass all levels of public
and private schools, colleges, universities, training centers,
etc. The entire areas of buildings, campus open space,
dormitories, recreational facilities and parking are included
when identifiable.

181

military facilities have a wide variety of conditions 180 Recreational
including training camps, missile sites, etc. Administration,
storage, repair, security and other functional military Recreational areas are those areas whose phys icalI
buildings, plus the practice ranges, storage areas, equipment structure indicates that active user-oriented recreation is or
stcrage lots and buffer zones compose the institutional military could be occurring within the given physical area. This
facilities. Aux ilIiary land uses, particularly residential, category would include golf courses, parks, swimming beaches and
commercial, and other supporting uses located on a military shores, marinas, fairgrounds, etc. (Note: Swimming beaches are
base, are included in the Institutional category. identifiable by such features as bath houses, picnic areas,
service stands and large parking lots adjacent to the beach
171 Educational Facilities areas). In order to make this recreational determination,
supplemental information may be required.
This category includes all facilities, such as parking
lots, stadiums, all buildings and any other features that can be 181 Swimming Beach
related to the facility.
182 Golf Courses

172 Religious ~~~~ ~~~~~~~~~183 Race Tracks [horse, dog, car, motorcycle)

All buildings that can be related to this category are
included. many religious facilities have schools and day care 184 marinas and Fish Camps
centers within their prcperty. 8PakZo

173 military
186 Community Recreational Facilities
All buildings and grounds that compose the facility are
included, along with auxiliary land uses, particularly 18 7 Stadiums [Those facilities not associated with high
residential services and other supporting land uses. schools, colleges or universities.]

174 Medical and Health Care 188 Historical Sites [Prehistoric or historic)

All buildings and grounds that con-pose the facility are 189 Other Recreational [riding stables, go-cart tracks,
included. skeet ranges, etc.]

175 Governmental 190 Open Land

identifiable buildings and facilities are included, and This includes undeveloped land within urban areas, and
supplemental data is used to identify this category. inactive land with street patterns but without structures. Open
Land normally does not exhibit any structures or any indication
176 correctional of intended use. Often, urban inactive land may be in a
transitional state and ultimately will be developed into one of
This facility normally is confined, with multiple fence the typical urban land uses, although at the time of the
structure. All structures and grounds are included that are inventory, the intended use is impossible to determine.
known to be associated with this category, either by the
interpretation process or as the result of supplemental data 191 Undeveloped Land within urban areas

support. ~~~~~~~~~~~~~~~192 Inactive Land with street pattern but without

177 Social and Services srcue

This category is to list facilities which are unique in 193 Urban Land in transition without positive indicators
structure and location. Suppler~ental data is required for of intended activity
identification; e.g., Elks Club, Masonic Lodge, V.F.W., etc.
194 Other Open Land
179 institutional Under Construction

182

-Note Mixed 200 AGRICULTURE

I. This category is used where no single use pre-
dominates. When more than one-third intermixture of another use in a broad sense, agricultural land may be defined as
or uses occurs, the specific classification is changed to those lands which are cultivated to produce crops and
Mixed. But, where the sum of the intermixture Is less than livestock. The sub-categories of Agriculture are; Cropland,
one-third, it is mapped as the dominant land use. Pastureland, Orchards, Groves (except Citrus), Vineyards,
Nurseries, Ornamental Horticulture Areas, Citrus Groves,
The Mixed category includes developments along Confined Feeding Operations, specialty Farms, and Other
transportation routes and in cities, towns, and built-up areas Agriculture.
where separate land uses cannot be individually mapped.
Residential, commercial, industrial and occasionally other land 210 Cropland and Pastureland
uses will be included. ___

2. Abandoned or not in use This includes agricultural land which is managed for
the production of row or field crops, and improved, unimproved
Any land use classification that is confirmed as and woodland pasture.
abandoned or not in use will be preceded, in the numerical Cropland and Pastureland include:
identifier, by a zero ";i.e., 0175.

1. Cropland harvested or land from which crops are
harvested, other than tree and bush crops, and
horticultural crops.

2. Cropland used only for pasture or pasture in
rotation with crops.

3. Pastureland used more or less permanently for
that purpose.

Numerous variables must be recognized in identifying
crop and pasture uses of land in different parts of Florida.
Field size and shape are highly variable depending upon
topographic conditions, as well as soil types, sizes of farms,
kinds of crops and pastures, capital investment, labor
availability, and other conditions.

In Florida, supplemental irrigation of cropland and
pastureland by use of overhead sprinklers can be detected from
photography where distinctive circular patterns are created.
Drainage or water control on land used for cropland and
pastureland at times creates a recognizable pattern that may be
helpful in identifying this type of land use from photography.

The duration of crop growth in the field may be rather
limited. A false impression of non-agricultural use in a field
may result if the conditions of temporary inactivity are not
recognized. However, this can be substantiated by field
checking.

Pastures may he drained and/or irrigated lands. Where
the management objective is to establish or maintain stands of
grasses, such as bahia, pangola or bermuda grass, either alone
or in mixtures with white clover or other legumes, land can he

183

categorized as pastures regardless of treatment. Much of the 222 Fruit Orchards [Peaches are an example of a crop type
permanent" pastures occur on land which usually is not tilled which is typical for this category)
or used a s cropland. Topographically rough land, stream
floodplains, wooded areas, and wetlands often may be used for 223 other Groves [Pecan, avocado, coconut, mango, etc.)
pasture more or less permanently.
If specific crop type can he determined from aerial
211 Improved Pasture photography, Level TV classification will be used; e-g.,
2231 - Pecan Grove.
This category in most cases is composed of land which
has been cleared, tilled, reseeded with specific grass types and 230 Feeding Operations
periodically improved with brush control and fertilizer
application. Water ponds, troughs, feed bunkers, and in some Feeding operations are specialized, livestock
cases, cow trails are evident. production enterprises which include beef cattle feedlots, dairy
operations with confined feeding, large poultry farms and hog
212 Unimproved Pasture feedlots. These operations have large animal populations
restricted to relatively small areas. This restriction results
This category includes cleared land with major stands in a concentration of waste material that is an environmental
of trees and brush where native grasses have been allowed to concern. The attendant waste disposal problems justify a
develop. Normally, this land will not be managed with brush separate category for these relatively small areas. Some
control and fertilizer application. operations are located near urban areas to take advantage of
proximity to transportation facilities and processing plants.
213 Woodland Pasture
2 31 Cattle
This is an area where forestlanda are used as pasture.
Strong evidence of cattle activity, such as trails to feed 232 Poultry
bunkers, salt licks and watering areas, is required. in some
cases, detection of cattle in the area will be the clue used to. 2 33 Hogs
iaentify this category. When supplemental data is available,
this will be used along with verification during field checks. 240 Nurseries and Vineyards

214 Row Crops This category is composed of nurseries, floricultural
areas, and seed-and-sod areas used perennially and generally not
Corn, tomatoes, potatoes, and beans are typical row rotated with other uses.
crops found in Florida. Rows remain well defined even after
crops have been harvested. 241 Tree Nursery

215 Field Crops Areas in this category are not associated with the
timber industry; trees primarily are ornamentals.
Wheat, oats, hay and grasses are the primary types
identified as field crops. some problems may occur in 242 Sod Farms
identification of field crops, and field checks are necessary in
many cases, especially when crop growth is in the early stages. This category is unique, requiring the crop to be in
harvest stages for detection. Supplemental data can be used for
220 Tree Crops the Identification of this specific category.

Orchards and groves generally occur in areas possessing 243 Orniasentals [perennial]
a specific combination of soil qualities and climatological
factors. Water bodies, which moderate the effects of short This category is defined as plants or shrubs grown for
duration temperature fluctuations, often are in close proximity decorative effects.
to these types of farming. Site selection for air drainage on
sloping land also may be important.

221 Citrus Groves Icrange, grapefruit, tangerine, etc.)

184

244 Vineyards 300 RANGELAND

This category is defined as land devoted to cultivating Historically, Rangeland has been defined as land where
grape vines. the potential natural vegetation is predominantly grasses,
grasslike plants, forbs, or shrubs, and is capable of being
245 Floriculture [annual] grazed. Management practices may include brush control,
regulation of grazing intensity, and season of use. If
This category is defined as the cultivation of flowers revegetated to improve the forage cover, it is managed like
(decorative flowering plants.) native vegetation. Generally, this land is not fertilized,
cultivated, or irrigated.
246 Timber Nursery
The definition of Rangeland used in the CONSERVATION
Areas in this category are associated with the timber NEEDS INVENTORY by the U.S. Departments of Agriculture and
industry. Tree seedlings (primarily pine) are grown for Interior is used in This classification scheme and describes the
forestation of timber sites, natural potential (climax) plant cover as being composed of
principally native grasses, forbs, and shrubs valuable for
250 Specialty Farms forage. This category includes Grassland, Shrub and Brushland,
and Mixed Rangeland.
Specialty farms include a variety of special or unique
farming activities such as thoroughbred horse farms, dog kennels 310 Herbaceous
and aquaculture.
This category includes prairie grasses which occur on
251 Horse Farms the upland margins of the wetland zone and may be periodically
inundated by water. Generally, it is the marginal area between
This category defines farms which breed and train marsh and upland forested areas. These grasslands are generally
horses for sport uses in racing, riding and harness racing. treeless, but in wet areas would have many types of soils
resulting in a variety of vegetation types dominated by grasses
252 Dairy sedges, rushes and other herbs, while dryer grass areas would be
dominated by wire grasses with some saw palmetto present.
This is a commercial establishment which processes and
distributes milk and milk products. 320 Shrub and Brushland

253 Kennels This category includes saw palmettos, gallberry, wax
myrtle, coastal scrub, and other shrubs and brush. Generally,
In this category, specific uses of dogs are not saw palmetto is the most prevalent plant cover intermixed with a
defined. In most cases it will require ground "truthing" on an wide variety of other scrub forest plants such as scrub oaks,
extensive basis by visiting each site. sand pines, as well as various types of short grasses. Coastal
scrub vegetation would include pioneer herbs and shrubs composed
254 Aquaculture [Fish farms] of such typical plants as sea purslane, sea grapes, sea oats,
without any one of these types being dominant.
The definition of this category is the culture of
marine or aquatic species under either natural or artificial 321 Palmetto Prairies
conditions.
These are areas in which saw palmetto (Serenoa repens)
259 Other is the most dominant vegetation. Common associates of saw
palmetto in this cover type are: fetterbush, tar flower,
260 Other Open Lands [Rural] gallberry, wire grass and brown grasses. This cover type is
usually found on seldom flooded dry sand areas. These treeless
This category includes those lands whose intended usage areas are often similar to the pine flatwoods, but without the
cannot be determined. pines.

322 Coastal Scrub 400 FORESTLAND

This scrub category represents a conglomeration of
species found in the coastal zone. A few of the more common Forestland includes uplands, basically the drier areas,
components are saw palmetto, sand live oak, myrtle oak, yaupon, which have a tree crown density (crown closure of 10 percent or
railroad vine, bay bean, sea oats, sea purslane, sea grape, more), and are dominated by trees and other woody vegetation.
spanish bayonet and prickly pear. This cover type is generally
found in dune and white sand areas. Lands from which trees have been removed to less than
10 percent crown closure, but which have not been developed for
329 Other Shrubs and Brssh other use, are also included in this category. For example,
lands on which there are rotation cycles, involving
This category includes other shrubs and brush cover clear-cutting and block planting, are part of the forestland
types not previously mentioned. classification.

330 Mixed Rangeland Since most naturally seeded forestlands are composed of
a mixture of species, for purposes of classification a minimum
When more than one-third intermixture of either of 66 2/3 percent stand dominance (by crown area measurement) of
grassland or shrub-brushland range species occurs, the specific one species or species groups is necessary for inclusion into
classification is changed to Mixed Rangeland. Where the separate categories. Less than 66 2/3 percent stand dominance
intermixture is less than one-third, it is classified as the of one species or species groups is considered to be a mixed
dominant type of Rangeland, whether Grassland, of Shrub and category. It should be noted that classification is based on
Brushland categories. overstory species composition, as interpreted from aerial photo-
graphy. Forestlands are classified as follows:

410 Coniferous Forest

A Coniferous Forest is a forested area having a
dominant tree crown that is of coniferous species and is a
result of natural seeding.

411 Pine Flatwoods [undifferentiated]

This is a forested area dominated by longleaf pine on
the drier sites, and slash and/or longleaf pine on the wetter
areas. Common understory associates are saw palmetto,
wiregrass, wax myrtle, fetterbush, and gallberry.

412 Longleaf-Xeric Oak

This forest type is dominated by longleaf pine. Common
understory associates are bluejack oak, turkey oak, and sand
post oak.

413 Sand Pine Scrub

This forested area occurs on excessively drained sands,
often associated with former dune areas. The dominant overstory
tree is sand pine. Common understory trees are myrtle oak, sand
live oak, and chapman oak.

186

-_ '__mm - - - _- - _mm mm mm

414 Australian Pine 426 Tropical Hammock

This is not a true pine; the species is commonly found This is a cover type also referred to as a coastal
in almost pure stands with little or no understory vegetation. hammock. Common components of this cover type include gumbo
limbo, mastic, stoppers, wild lime, strangler fig, lancewood,
415 Longleaf-Upland Oak poison wood, sea grape, marl berry, and wild tamarind.

This forest type is dominated 'by an overstory of 427 Dpland Temperate Hammock
longleaf pine and upland oak, commonly live oak or laurel oak.
This is a cover type in which live oak is pure or
419 Other Pine predominant. Common associates are sweetgum, southern magnolia,
holly and laurel oak.
This category is composed of other coniferous cover
types not previously mentioned. 428 Cabbage Palm

420 Hardwood Forest This is a cover type in which cabbage palm is pure or
predominant. Associates are southern red cedar, southern
A Hardwood Forest is a forested area having a dominant magnolia, live oak, sand live oak with smaller quantities of
tree crown that is of hardwood species and is a result of laurel oak, red maple, redbay and holly.
natural seeding.
429 Wax Myrtle-Willow
421 Xeric Oak
This is a cover type in which wax myrtle -and/or willow
This forest area is dominated by xeric oak generally is pure or predominant. It is often an indicator of a disturbed
located on well-drained upland sands. Typical species include site and is commonly found on moist ground.
bluejack oak, turkey oak, and sand post oak.
430 Hardwoods Forest Continued
422 Brazilian Pepper
431 Beech-Magnolia
This cover type frequently occurs in dense pure stands
often excluding understory vegetation. It is generally andicator species of this forest type,
indicator of a disturbed site. although it may not be the most abundant. Southern magnolia and
a great variety of other moist site hardwoods occur in this
423 Oak-Pine -Hickory forest with common associates including sweetgum, blackgum,
yellow poplar, southern red oak, white oak, white ash and
This is a mixed forest type in which no one species is hickories.
consistently dominant. Major components of this cover type are
southern red oak, post oak, black oak, shortleaf pine, loblolly 432 Sand Live Oak
pine, mockernut hickory and dogwood.
Sand live oak predominates in this cover type.
424 Melaleuca Associates are cabbage palm, southern red cedar and southern
magnolia with smaller quantities of chapman oak, myrtle oak, red
This species occurs in almost pure stands. It is an maple, redbay, and holly. This cover type is generally found on
extremely aggressive competitor, often taking over a site, old coastal dune and white sand areas.
forming a dense impenetrable stand. Melaleuca generally is an
indicator of a disturbed site. 438 Mised Hardwood

42 5 Teimperate Ham~m~ock This is a mixed hardwood forest type in which no one
species achieves 66 2/3 percent composition by crown area
This is a cover type also referred to as a low measurement.
hammock. Cormon ccrponents of this cover type include cabbage
palm, caks (centrally live oak), red-hay, swentbay, yaupon and
cedar.

187

439 ~~~~~~~~~~~~~~~~~~~~~~~~~500 WATER
439 Other Hardwood

This category includes other hardwood cover types not The delineation of water areas depends on the scale and
resolution characteristics of the remote-sensor photography user
pr evi ousl1y mentioned.
for interpretation. One definition of water bodies, provided by
440 Tree Plantations the Bureau of Census, includes all areas within the land mass of
the United States that are predominately or persistently water
441 Coniferous covered, provided that, if linear, they are at least 1/8 mile
(660 feet or 200 meters) wide, and if extended, cover at least
These areas are forests created as a result of planting 40 acres (16 hectares).
coniferous seedling stock or by direct seeding methods.
Defining water boundaries at Level III, minimum size
442 Hardwood has been established to less than 10 acres. In some instances,
water bodies of one acre will be plotted and identified. Water
These areas are forests created as a result of planting bodies or those portions of the water body having emergent
hardwood seedling stock or by direct seeding methods. vegetation are placed in the Wetland category.

443 Regeneration Area 510 Streams and Waterways

Regeneration areas are forestlands where clearcutting This category includes rivers, creeks, canals, and
and block plant timber management practices are in evidence and other linear water bodies. Where the water course is
where it is evident that the intended future use will not be in interrupted by a control structure, the impounded area will be
another land use category. This category also includes areas of placed in the Reservoirs category.
site preparation and planting.
The boundary between streams and lakes, reservoirs, or
444 Experimental Tree Farms the ocean is the straight line across the mouth of the stream,
unless the mouth is more than one mile (1.85 kilometers) wide.
These areas are devoted to testing'-the growth response In that case, the rule given under Bays and Estuaries is
of different forest tree species to various experimental followed.
silvicultural treatments. 520 Lakes

The Lakes category includes inland water bodies, but
excludes reservoirs. Islands within lakes that are too small to
delineate will be included in the water area. The delineation
of a lake will be based on the size of the water body at the
time the remote-sensor data is acquired.

521 Lakes larger than 500 acres (202 hectares)

522 Lakes larger than 100 acres (400 hectares) but less
than 500 acres

523 Lakes less than 100 acres but greater than 10 acres (4
hectares)

524 Lakes less than 10 acres which are dominant features

530 Reservoirs

Reservoirs are artificial impoundments of water. They
are used for irrigation, flood control, municipal water
supplies, recreation, or hydro-electric power generation. Dams,

188

levees, other water control structures, or the excavation
itself, usually will be evident to aid the identification. 600 WETLANDS

531 Reservoirs larger than 500 acres
Wetlands are those areas where the water table is at,
532 Reservoirs larger than 100 acres but less than 500 near, or above the land surface for a significant part of most
532Reservoirslargerthan acres bu t lyears. The hydrologic regime is such that aquatic or
~~~~~~~~~~~~acres hydrophytic vegetation usually is established, although alluvial

533 Reservoirs larger than 10 acres but less than 100 and tidal flats may b e nonvegetated. wetlands are frequently
533 Reservoirs larger than 10 acres bu t l e ss than 100 associated with topographic lows. Examples of wetlands include
smarshes, mudflats, emergent vegetation areas, and swamps.

540 Bays and Estuaries Shallow water areas with submerged aquatic vegetation are
classed as Water and are not included in the Wetlands category.

Bays and estuaries are inlets or arms of the sea that Extensive parts of some river floodplains qualify as
extend into the land and, as such, are properly classified in Etnse s o oe rielan we as
this system only when they are included within the land mass of etlands. These do not include agriculture land where seasonal
Florida. wetness or short-term flooding may provide an important
component of the total annual soil moisture necessary for crop
In order that this land mass area be commensurate with production. But, uncultivated wetlands yielding products such
the area of the United States used in compiling census as wood, or grazed by livestock, are retained in the Wetlands
stharaoftheUitdSaeusedincomiln caegory.
statistics, the convention used by the Bureau of the Census in category.
setting the outer limits of the United States has been
followed. Where bays and estuaries are between 1 and 10 Wetlands areas drained for any purpose belong to other
nautical miles (1.85 and 18.5 kilometers) in width, the outer land use categories, whether they be Agriculture, Rangeland,
limit of the United States will be a straight line connecting Forested Uplands, or Urban or Built-up. When the drainage is
the headlands, except where the indentation of the embayment is discontinued and such use ceases, classification reverts to
so shallow that the water area would be less than the area of a Wetlands after characteristic vegetation is reestablished.
semicircle drawn with this straight line as the diameter. In Wetlands managed for wildlife purposes may show short-term
that event, the coastline itself would form the outer limit of changes in vegetation type and wetness condition as different
the United States. management practices are used, but are properly classified
Wetlands.

Embayments less than one nautical mile in width are
classed as Streams and Canals. Embayments or portions of 610 Hardwood Forest
embayments more than 10 nautical miles (18.5 kilometers) in Wetland-Hardwood Forest areas are those wetlands which
width are not considered included within the land mass. Wetland-Hardwood Forest areas are those wetlands which
meet the crown closure requirements for the Hardwood Forest and
541 Opening directly into the Gulf or Atlantic Ocean are a result of natural seeding. These wetland trees are found
both in salt and freshwater areas.

542 Not opening directly into the Gulf or Atlantic Ocean
611 Bay Swamp
550 Major Springs
-550~~~ Major Springs ~~~~~~This category is composed of dominant trees such as
The natural phenomena known as springs can easily be loblolly bay, sweetbay, redbay and slash pine. Large gallberry,
identified as points of origin of a water source. In many fetterbush, wax myrtle and titi are the understory vegetation.
instances, major springs such as Silver Springs and Homosassa
Springs can readily be identified' by the associated 612 Mangrove Swamp
recreational-commercial enterprises in the adjacent area.
This category is composed of red or black mangrove
560 Slough Waters which is pure or predominant. The chief associates are white
mangrove, buttonwood, cabbage palm and sea grape.
Slocghs are c,.Lnels of slow roving water in the
coacstal zarshland. The term also refers to "backwater sloughs",
those rnarrcw, often sta.narnt Iodies of water found near inland
rivers.

189

613 Gum Swamp 623 Atlantic White Cedar

This category is composed of swamp tupelo or water In this category, atlantic white cedar is the indicator
tupelo which is pure or predominant. Associated species are species although it may not always be the most abundant. Common
bald cypress and a great number of wet site hardwoods, with wide associates are slash pine, cypress, swamp tupelo, sweetbay,
variation in composition. redbay, loblolly bay, black titi and red maple.

614 Titi Swamp 630 Forested-Mixed

This category is composed of black titi and cyrilla This is a mixed wetland, hardwood coniferous forest
which are predominant. Associated species are bays, cypress, type in which neither hardwood nor coniferous species achieves
swamp tupelo, and a great number of wet site hardwoods. 66 2/3 percent stand composition, by crown area measurement.

615 Stream and Lake Swamp 640 Vegetated Non-Forested

This category is also referred. to as bottomland or Wetland-vegetated, non-forested lands are found in
stream hardwoods, and cover type is found on river, creek and seasonably flooded basins, meadows, and marshes. Wetlands are
lake overflow areas. It is a conglomeration of species, of usually confined to relatively level areas. This category does
which some of the more common components are: pond cypress, not include areas whose tree cover meets the crown cover
bald cypress, red raple, river birch, water oak, sweetgum, threshold for the forested categories. When the forested crown
willow, swamp tupelo, okeechee tupelo, water hickory, water ash, cover is less than the threshold for Wetland Forest or is
and buttonbush. non-woody, it will be included in this category. Sawgrass and
cattail are predominant communities in freshwater marshes, while
616 Inland Ponds and Sloughs spartina and needlerush are the predominant saltwater marsh
communities.
This category is found in depressions or drainage areas
not associated with streams or lakes. One of the following 641 Freshwater Marsh
species will generally predominate in these communities: pond
cypress, swamp tupelo, water tupelo, titi or willow. In this category, these communities will have pre-
dominantly one or more of the following species:
620 Coniferous Forest
Sawgrass and Cattail, Bulrush and Maidencane
Wetland-Coniferous Forest areas are wetlands which meet Marshes
the crown closure requirements for the Coniferous forest and are
a result of natural seeding. These species are commonly found Sawgrass - (Cladium jamaicensis)
in the interior wetlands in such places as river flood plains, Arrowhead - (Sagittaria sp.)
bogs, bayheads, and sloughs. Maidencane - (Panicum hemitomon)
Cattail - (Typha domingensis, T. latifolia, T.
621 Cypress angustifolia)
Pickerel Weed - (Pontederia lanceolata, P. cordata)
This category is composed of pond cypress or bald Buttonbush - (Cephalanthus occidentalis)
cypress which is pure or predominant. In the case of pond Spartina - (Spartina bakeri)
cypress, common associates are swamp tupelo, slash pine, and Switchgrass - (Panicum virgatum)
black titi. In the case of bald cypress, common associates are Bulrush - (Scirpus americanus, S. validus, S.
water tupelo, swamp cottonwood, red maple, american elm, pumpkin robustus)
ash, carolina ash, overcup oak, and water hickory. Bald cypress water lily - (Nymphea sp.)
may be associated with laurel oak, sweetgum and sweetbay on less Bladderwort - (Utricularia sp.)
moist sites. Needlerush - (Juncus effusus)
Common Reed - (Phragmites communis [australis))
622 Pond Pine
6411 Sawgrass (Cladium jamaicensis)
This catecory is crrosed of fond pine which is pure or
rrecr.inant. The nancr associate is titi. Minor associates are 6412 Cattail (Typha sp.)
sweetbay, lblolly lay, rcdbay and "wamp tupelo.

190

- _- _ _- _---- m - -

642 Saltwater Marsh 644 Emergent Aquatic Vegetation

In this category, these communities will have This category includes floating vegetation and/or
predominantly one or more of the following species: aquatic vegetation that is found partially or completely above
the surface of the water.
S__artina and Needlerush Marshes
6441 Water Lettuce - (Pistia stratiotes)
Cordgrasses
Cordgrasses - (Spartina alterniflora, S. 6442 Spatterdock - (Nuphar sp.)
cynosuroides, S. patens, S. spartinae)
Needlerush - (Juncus roemerianus) 6443 Water Hyacinth - (Eichhornia sp.)
Seashore Saltgrass - (Distichlis spicata)
Saltwort - (Batis maritima) 5444 Duckweed - (Lemna sp.)
Glassworts -(Salicornia sp.)
Fringerush - (Finbristylis castanea) 645 Submergent Aquatic Vegetation
Salt Dropseed - (Sporobolus virginicus)
Seaside Daisy - (Borrichia frutescens) This category is composed of those aquatic species
Salt Jointgrass - (Paspalum vaginatum) found growing completely below the surface of the water.

6421 Cordgrass (Spartina) 650 Non-Vegetated

Vegetation association is the same as listed in 642 Wetland non-vegetated areas are those areas where
(Saltwater Marsh) classification. However, dominant vegetation vegetation may be lacking due to the erosional effects of wind
is one of the following: (Spartina alterniflora, S. and water transporting the surface material so rapidly that
cynosuroides, S. patens or S. spartinae). plant establishment is curtailed. Also, submerged or saturated
materials often develop toxic conditions of extreme acidity from
6422 Needlerush (Juncus) sulfur generation. Tidal flats, shorelines and intermittent
ponds are a main component of this category.
Vegetation association is the same as listed in 642
(Saltwater Marsh) classification. However, dominant vegetation 651 Tidal Flats
is (Juncus roemerianus).
This category is composed of that portion of the shore
643 Wet Prairies environment protected from wave action, as in estuaries,
comprised primarily of muds drained by tidal channels. An
This category is composed of dominantly grassy important characteristic of the tidal flat environment is its
vegetation of wet soils, usually distinguished from marshes by alternate submergence and subaerial exposure during the tidal
having less water and shorter herbage. These communities will cycle.
have predominantly one or more of the following species:
652 Shoreline
Maidencane - (Panicum hemitomon)
C.Drigrasses - (Spartina bakeri, S. patens) This category is usually defined as the line where land
F ikerushes - (Eleocharis sp.) and water meet. Shorelines are formed mainly by marine or
Eeach Pushes - (Rhynchospora sp.) biological agents like coral reefs, barrier beaches, and
St. Jchns Wort - (Hypericum sp.) marshes. (The shore is defined as the zone from low tide to the
Sliderlily - (Hyrenocallis palmeri) farthest point on land where waves transport sands.)
Swar-plily - (Crinum americanum)
Yellow-eyed Grass - (Xeric ambigua) 653 Intermittent Pond
Whitetop Sedge - (Dichromrena colorata)
This category is defined as a waterbody which exists usually
only during a portion of the year. Its existence relies on
water received from direct precipitation, runoff or spring flow.

191

700 BARREN LAND 741 Rural land in transition without positive indicators
of intended activity

Barren land has very little or no vegetation and 742 Borrow Areas
limrited ability to support life. In general, it is an area with
only soil, sand or rocks. Vegetation, if present, is very 743 Spoil Areas
widelf spaced and scrubby. However, land also may be
temporarily barren due to man's activities. Generally, this 744 Fill Areas [highways-railways]
land is included in another land use category. Vast areas of
agricultural land are temporarily without vegetation cover due
to tillage practices, and areas of extractive and industrial
land use have dumps for wastes and tailings. Barren Land
categories are Beaches (areas exhibitinglittle or no evidence
of human encroachment), Sand Other Than Beach, Exposed Rock,
Disturbed Lands.

710 Beaches Other Than Swimming Beaches

Beaches are constantly affected by wave and tidal
action. The fine clays and silts are washed away leaving sand.
However, in protected bay and marsh areas, fine soil particles
from surface drainage waters may settle out. The beach areas
also are subject to water and wind erosion. Differing beach
dimensions are due to factors such as tides, soil material size,
water level and wave energy, all of which vary. When a stable
surface is observed inland, as another land use occurs and
erosion effects of water and wind decrease, the beach category
is then terminated.

720 Sand Other Than Beaches

Sand other than beaches is composed primarily of
dunes. These are of aeolian origin composed of sand grains
downwind from a natural source of sand. Dune sizes vary
greatly, with diameters ranging from a few feet to more than
several hundred. Their heights also vary and their shapes
display considerable variety. When the dunes are the major
feature, shore and strand lines, coastal plains, river flood
plains, and deltas are secondary.

730 Exposed Rock

Exposed rock areas consist of exposed bedrock and other
accumulation of rocks lacking vegetative cover. Exposed
bedrock, when weathered, ray be urvegetated due to fine soil
removal by water or wind erosion.

740 Disturbed Lands

Disturbed lands are te areas that have been changed
due to man's activities, other than rining activities. In
Florida, these areas ray be rather extensive aid often arpear
outside of urban areas.

192

800 TRANSPORTATION, COMMUNICATION AND UTILITIES 820 Communications

Airwave communications, radar and television antennas
810 Transportation with associated structures are typical major types that will be
identified, when stations are associated with a commercial or
Transportation facilities are used for the movement of governmental facility, they will be included in that specific
people and goods; therefore, they are major influences on land category when located within the bounds of the specific facility
and many land use boundaries are outlined by them. and will not be listed as a separate element.

Highways are easily identifiable on medium altitude 821 Transmission Towers [microwave are typical in this
photography. Highways include areas used for interchanges, category]
limited access rights-of-way, and service facilities. The
center median, pavement and sizable buffer zone should be B 22 Communication Facilities [includes transmitter
included even if exact boundaries cannot be detected. stations, telephone exchanges, antenna farms, etc.]

The Transportation category encompasses rail-oriented 829 Communication Facilities Under Construction
facilities including stations, round-houses, repair and
switching yards, and related areas. Airport facilities include 830 Utilities
runways, intervening land, terminals, service buildings,
navigation aids, fuel storage, parking lots and a limited buffer Utilities usually include power generating facilities,
zone, and fall within the Transportation category. water treatment plants and their related functions, such as
transmission lines for the electric power facilities, and
Transportation areas also em.b race ports, docks, aeration fields for the sewer treatment sites. Small facilities
shipyards, dry docks, locks and watercourse control structures or those associated with an industrial, commercial or extractive
designed for transportation purposes. The docks and ports land use, are included within the larger category.
include buildings, piers, parking lots and adjacent water
utilized by ships in the loading or unloading of cargo or 831 Electrical Power Facilities
passengers. Locks, in addition to the actual structure, include
the control buildings, power supply buildings, docks and This category includes hydropower, thermal, nuclear,
surrounding supporting land use, i.e. parking lots and green gas turbine plants, transformer yards, sub-stations.
areas.
832 Electrical Power Transmission Lines
811 Airports
833 Water Supply Plants [including pumping stations]
812 Railroads
This category includes treatment plants, settling
813 Bus and Truck Terminals basins, water storage towers and well fields.

814 Major Highways 834 Sewage Treatment

815 Port Facilities This category is composed of all related facilities
such as aeration fields, digesters, etc.
86 Canal and Locks
835 Solid Waste Disposal
817 Oil, Water, or Gas Long Distance Transmission Lines

This category is composed of controlled and managed
818 Auto Parking Facilities (when not directly related to s olid waste fields, non-permitted solid waste disposal sites,
other land use) etc.

819 Transrortation Faciliris Under Construction 839 Utilities Under Construction

193

900 This section is reserved for special
classification

This category is used primarily for specific topics to
be addressed for a specific user requirement of those land uses
and land comrer which require identification at Level III or IV.
e.g. Marine grasses - dense
- medium
- sparse

194

IX. GLOSSARY

abiotic - any inorganic part of the environment.

amphipod - small macroscopic crustacean; body is laterally compressed.

anaerobic - a condition associated with absence of free oxygen in the

environment.

benthic - living on the bottom.

brackish water - water that has a salt content intermediate between fresh

water the sea.

coastal wetland - land where the water table is at or near the surface or

the land is covered by shallow water or tidally influenced.

community - all the plants and animals of an area (or volume) which form a

interactive assemblage.

crustacean - a class of animals that have a hard outer shell; includes

shrimp, crabs, lobsters.

detritus - particles of non-living organic matter, usually in various

stages of decomposition.

dike - a dam or embankment erected to prevent flooding of a lowland area.

dredge spoil - sediment material removed from a wetland bottom during

dredging operations.

ecosystem - the community and its non-living environment, considered

collectively.

epibenthic - living on the surface of bottom.

epiphyte - plant or animal attached to a plant, typically not a parasitic

relationship.

euryhaline - able to tolerate wide variation of salinity regimes.

195

facultative halophyte - able to live under freshwater and saltwater

influences but living mostly under saltwater influence due to

exclusion of other species.

finfish - sharks, rays, and bony fishes.

fishery - the complex of interactions within and between the population~s)

of fish being harvested, the population~s) of fishermen, and the
environments of each.I

food chain - the series of nutritional steps through which food passes from

plants to herbivores to carnivores; also the nutritional steps in-

volved in parasite and microbial (decomposer) chains.

food web - the interlocking pattern formed by parallel and cross connectingI

food chains.

habitat - the natural environment in which an organism lives.

habitat component - a specific part, be it organic, inorganic, chemical,I

or environmental, of an organism' s environment.

hectare - a measure of area equal to 2.47 acres.I

infauna - animals living within the sediment.

isopod - small macroscopic crustacean; body is flattened.

life history - the series of stages through which an organism passes during

its entire lifetime.

macrophytes - plants larger than microscopic size.

meiofauna - microscopic and small macroscopic animals living on the bottom.

meroplankton - larval plankton 15-20 rmm in size.I

nekton - macroscopic swimming animals that can freely regulate their dis-

tribution against movements of water masses.

non-point source pollution - pollution originating from non-localized

sources such as storm drains.

1961

nutrient - an organic or inorganic chemical substance required for the

growth and reproduction of organisms.

I ~~~omnivorous - eating a diet of both plants and animals.

I ~~~pelagic -living offshore.

photic zone - surface zone of sea or lake sufficiently illuminated for

* ~~~~photosynthesis.

photosynthesis - the chemical processes through which green plants manu-

I ~~~~facture organic molecules from inorganic using sunlight as an energy

source.

I ~~~plankton -aquatic organisms that cannot freely regulate their distribution

against movements of water masses; includes microscopic plants (phyto-

plankton) and microscopic animals (zooplankton).

3 ~~point source pollution - pollution originating from known, localized

sources.

I ~~~polychaete - a marine worm.

1 ~~~productivity -the rate of production of organic matter by living organisms

(i.e., the amount per unit time).

* ~~~recruitment -the process of addition of animals to a population.

Typically, the term is used to describe when, or how large fishes are

1 ~~~when they first enter a fishery.

rhizome -a horizontal underground stern.

riprap -rock, stone, or other rough material placed on stream banks, dam

faces, and other structures to protect against erosion by the water.

sediment load - all particulate material (inorganic or organic) suspended

3 ~~~~in or transported downstream by water (may include clay, silt, sand,

organic detritus, etc.).

1 ~~~~~~~~~~~~~~197

sedimentation - the settling out of suspended matter from the water to the

bottom.

sessile - attached to a substrate; non-motile.

shellfish - oysters, clams, scallops, and conch.

species - a group of populations in which the organisms reproduce and main -

tain separateness, genetically.1

species diversity - the variety of types of organisms present in an area.

stress - a strain or pressure applied to an organism (or group of

organi sms) by an unfavorable or stress-producing factor.

tidal node - the area of no current velocity where an incoming tide meetsI

from opposite directions or from which an outgoing tide recedes in opposite

di recti ons.

trophic level - one of the several levels of a food chain; plants

constitute the primary level, herbivores the second level, and

carnivores the third and remaining levels.

turbidity - the condition of water resulting from the presence of suspended

material, often expressed as interference with light transmission.I

198~~~~~~~

X. LITERATURE CITED

1. Anderson, J. M. and M. R. Peterson. 1969. DDT: sublethal effects on brook
trout nervous system. Science 164: 440-441.

2. Bahr, L. M. and W. P. Lanier. 1981. The ecology of intertidal oyster
reefs of the South Atlantic coast: a community profile. U.S. Fish
and Wildlife Service, Office of Biological Services, Washington, D.C.
FWS/OBS - 81/15. 105 pp.

3. Barrett, B. B. and M. C. Gillespie. 1973. Primary factors which influence
commercial shrimp production in coastal Louisiana. La. Wildl. Fish.
Comm. Tech. Bull. 9. 28 pp.

4. Bass, R. J. and J. W. Avault, Jr. 1975. Food habits, length-weight re-
lationship, condition factor, and growth of juvenile red drum,
Sciaenops ocellata, in Louisiana. Trans. Am. Fish. Soc. 104(1): 35-
45.

5. Beal, K. L. 1980. Territorial sea fisheries management and estuarine
dependence. Pp. 67-77 in V. S. Kennedy (ed.), Estuarine Perspectives.
Academic Press, Inc., New York. 533 pp.

6. Beebe, W. and J. Tee-Van. 1928. The fishes of Port-au-Prince Bay, Haiti.
Zoologica 10(1): 1-26, 60-62, 124, 127-128.

7. Bjorndal, K. A. 1980. Nutrition and grazing behavior of the green turtle
Chelonia mydas. Mar. Biol. 56: 147-154.

8. Blake, N. J., L. J. Doyle, and T. E. Pyle. 1976. The benthic ecology of a
thermally altered area of Tampa Bay, Florida. Pp. 296-301 in G. W.
Esch and R. W. McFarlane (eds.), Thermal Ecology II. Atomic Enerqy
Commission Symposium Series (Conf. 750425), Augusta, Georgia.

9. Brannon, D. P., W. H. Kuyper, L. Clay, and K. Haddad. 1981. Florida
LANDSAT demonstration project report. NASA/NSTL Earth Resources
Laboratory DR-002. 35 pp.

10. Brook, I. M. 1978. Comparative macrofaunal abundance in turtlegrass
(Thalassia testudinum) communities in south Florida characterized by
high blade density. Bull. Mar. Sci. 28(1): 213-217.

11. Butler, P.A. 1966. The problem of pesticides in estuaries. Amer. Fish.
Soc. Spec. Publ. No. 3: 110-115.

12. Carlton, J. 1974. Land building and stabilization by mangroves. Environ.
Conserv. 1(4): 285-294.

13. Carlton, J. M. and M. D. Moffler. 1978. Propagation of mangroves by ai,-
layering. Environ. Conserv. 5(2): 147-150.

199

14. Carr, W. E. S. and C. A. Adams. 1973. Food habits of juvenile marine
fishes occupying seagrass beds in the estuarine zone near Crystal
River, Florida. Trans. Am. Fish. Soc. 102(3): 511-540.

15. Carr, W. E. S. and J. T. Giesel. 1975. Impact of thermal effluent from a
steam-electric station on a marshland nursery area during the hot
season. Fish. Bull. 73(1): 67-80.

16. Clark, J. R. 1977. Coastal ecosystem management. Conservation Founda-
tion, Washington, D. C. 921 pp.

17. Coastal Coordinating Council, State of Florida. 1973. Statistical inven-
tory of key biophysical elements in Florida's coastal zone. Talla-
hassee, Fla. 43 pp.

18. Conner, W. G. and J. L. Simon. 1979. The effects of oyster shell dredging
on an estuarine benthic community. Est. Coast. Mar. Sci. 9: 749-758.

19. Copeland, B. J. 1970. Estuarine classification and response to dis-
turbances. Trans. Am. Fish. Soc. 4: 826-835.

20. Copeland, B. J. 1965. Evidence for regulation of community metabolism in
a marine ecosystem. Ecology 46(4): 563-564.

21. Copi, I. M. 1972. Introduction to logic. Macmillan Publishing Co., Inc.,
New York. 540 pp.

22. Costello, T. J. and D. M. Allen. 1970. Synopsis of biological data on the
pink shrimp Penaeus duorarum duorarum Burkenroad, 1939. FAO Fish.
Rep. 57(4): 1499-537.

23. Costello, T. J. and D. M. Allen. 1966. Migrations and geographic distri -
bution of pink shrimp, Penaeus duorarum, of the Tortugas and Sanibel
grounds, Florida. Fish. Bull. 65(2): 449-459.

24. Coultas, C. L. 1980. Transplanting needlerush (Juncus roemerianus). Pp.
117-121 in D. P. Cole (ed.), Proceedings of the Seventh Annual
Conferenc6on the Restoration and Creation of Wetlands. Hillsborough
Community College, Tampa, Florida. 294 pp.

25. Craig, H. 1953. The geochemistry of stable carbon isotopes. Geochim.
Cosmochim. Acta 3: 53-92.

26. de la Cruz, A. A. 1973. The role of tidal marshes in productivity of
coastal waters. Assoc. Southeastern Biol. Bull. 20: 147-156.

27. Darovec, J. E., Jr., J. M. Carlton, T. R. Pulver, M. D. Moffler, G. B.
Smith, W. K. Whitfield, Jr., S. A. Willis, K. A. Steidinger, and E. A.
Joyce, Jr. 1975. Techniques for coastal restoration and fishery
enhancement in Florida. Fla. Dept. Nat. Res. Marine Res. Publ. No.
15. 27 pp.

200

28. Day, J. W., Jr. and A. Yanez-Arancibia. 1982. Coastal lagoons and estu-
aries, ecosystem approach. Ciencia Interamericana OAS Wash., D.C.
22: 11-26.

29. Day, J. W., Jr., W. G. Smith, P. R. Wagner, and W. C. Stone. 1973.
Community structure and carbon budget of a salt marsh and shallow bay
estuary system in Louisiana. Center for Wetland Resources. La. State
Univ.,Baton Rouge, LA. LSU-SG-72-04. 80 pp.

30. DeNiro, M. J. and S. Epstein. 1978. Influence of diet on the distribution
of carbon isotopes in animals. Geochim. Cosmochim. Acta 42: 495-506.
Department of Natural Resources, Bureau of Environmental Land
Management. 1983. Charlotte Harbor aquatic preservesmanagement plan.
120 pp.

31. Durako, M. J., J. A. Browder, W. L. Kruczynski, C. B. Subrahmanyam and R.
E. Turner. 1983. Florida aquatic habitat and fishery resources: salt
marshes. Proc. Fla. Chapt. Am. Fish. Soc. 3rd Ann. Mtg., Feb. 7-9,
1983, Brooksville, FL. In review.

32. Durako, M. J. and M. D. Moffler. 1981. Variation in Thalassia testudinum
seedling growth related to geographic origin. Pp. 99-117 in R. H.
Stovall (ed.), Proceedings of the Eighth Annual Conference- etlands
Restoration and Creation. Hillsborough Community College, Tampa,
Florida. 200 pp.

33. Eleuterius, L. N. 1976. The distribution of Juncus roemerianus in the
salt marshes of North America. Chesapeake Sci. 17: 289-292.

34. Estevez, E. D., J. M. Miller, and J. Morris. 1981. A review of scientific
information Charlotte Harbor estuarine ecosystem complex and the Peace
River. Report to South West Florida Regional Planning Council. Mote
Marine Laboratory, Sarasota, Florida.

35. Evans, M., T. Brungardt, and R. Evans. 1978. Shoreline analysis of Sara-
sota County bay systems with regard to revegetation activities.
Sponsored by Environmental Studies Program of New College of U.S.F.,
Sarasota County C.E.T.A. program, and Sarsota Board of County Com-
missioners. 71 pp.

36. Federal Water Pollution Control Administration, Department of the Interior.
1969. Problems and management of water quality in Hillsborough Bay,
Florida. Hillsborough Bay Technical Assistance Project. 88 pp.

37. Fehring, W. K., C. Giovenco, and W. Hoffman. 1979. An analysis of three
marsh-creation projects in Tampa Bay resulting from regulatory re-
quirements for mitigation. Pp. 191-206 in D. P. Cole (ed.), Proceed-
ings of the Sixth Annual Conference on t-e Restoration and Creation
of Wetlands. Hillsborough Community College, Tampa, Florida. 357 pp.

38. Finucane, J. H. 1969. Ecology of the pompano (Trachinotus carolinus) and
the permit (T. falcatus) in Florida. Trans. Am. Fish. Soc. 98(3):
478-486.

201

39. Florida Department of Natural Resources, Bureau of Marine Science and
Technology. 1950-1978. Summary of Florida commercial marine landings.
Tallahassee, Florida.

40. Fonseca, M. S., W. J. Kenworthy, J. Homziaki and G. W. Thayer. 1979.
Transplanting of eelgrass and shoalgrass as a potential means of miti-
gating a recent loss of habitat. Pp. 279-326 in D. P. Cole (ed.),
Proceeding of the Sixth Annual Conference on The Restoration and
Creation of Wetlands. Hillsborough Community College, Tampa, Florida.
357 pp.

41. Frayer, W. E., T. J. Monahan, D. C. Bowden, and F. A. Graybill. 1982.
Status and trends of wetlands and deepwater habitats in the conter-
minous United States, 1950's to 1970's. Mimei. Tech. Rep. Fish and
Wildlife Service, U.S. Department of the Interior. 18 pp.

42. Friedly, D. L. and F. A. Unger. 1981. Florida spatial data inventory,
1980-81. Florida Resources and Environmental Analysis Center, Talla-
hassee, Florida. 226 pp.

43. Fry, B., R. Lutes, M. Northam, P. L. Parker, and J. Ogden. 1982. A
13C/12C comparison of food webs in Caribbean seagrass meadows and
coral reefs. Aquat. Bot. 14: 389-398.

44. Fry, B. and P. L. Parker. 1979. Animal diet in Texas seagrass meadows;
13C evidence for the importance of benthic plants. Estuarine
Coastal Mar. Sci. 8: 499-509.

45. Fry, B., R. S. Scalan, and P. L. Parker. 1977. Stable carbon isotope
evidence for two sources of organic matter in coastal sediments: sea-
grasses and plankton. Geochim. Cosmochim. Acta 41: 1875-1877.

46. Futch, C. R. 1976. Biology of striped mullet. Pp. 63-69 in J. C. Cato
and W. E. McCullough (eds.), Economics, Biology, and Food Technology
of Mullet. State Univ. System of Florida Sea Grant Report No. 15.

47. Gilmore, R. G., D. W. Cooke, and C. J. Donohoe. 1982. A comparison of the
fish populations and habitat in open and closed salt marsh impound-
ments in East-Central Florida. Northeast Gulf Sci. 5(2): 25-38.

48. Godcharles, M. F. 1971. A study of the effects of a commercial hydraulic
clam dredge on benthic communities in estuarine areas. Fla. Dept.
Nat. Res. Tech. Ser. No. 64. 51 pp.

49. Gosselink, J. G., E. P. Odum, and R. M. Pope. 1974. The value of the
tidal marsh. Center for Wetland Resources, Louisiana State Universi-
ty, Baton Rouge, LA. LSU-SG-74-03. 30 pp.

50. Grey, W. F. and M. D. Moffler. 1978. Flowering of the seagrass Thalassia
testudinum, (Hydrocharitaceae) in the Tampa Bay, Florida area. Aquat.
Bot. 5:251-259.

51. Haines, E. B. and C. L. Montague. 1979. Food sources of estuarine
invertebrates analyzed using 13C/12C ratios. Ecology 60: 48-56.

202

52. Hannan, J. 1975. Aspects of red mangrove reforestation in Florida. Pp.
112-121 in R. R. Lewis (ed.)., Proceedings for Second Annual Confer-
ence on the Restoration of Coastal Vegetation in Florida. Hills-
borough Community College, Tampa, Florida. 203 pp.

53. Hansen, D. J. 1969. Food, growth, migration, reproduction, and abundance
of pinfish, Lagodon rhomboides, and Atlantic croaker, Micropogon
undulatus, near Pensacola, Florida, 1963-65. U.S. Fish WiTldlT. Serv.
Fish. Bull. 68(1): 135-146.

54. Harlin, M. M. 1980. Seagrass epiphytes. Pp. 117-151 in R. C. Phillips
and C. P. McRoy (eds.), Handbook of seagrass biology - an ecosystem
perspective. Garland STPM Press, New York.

55. Harrington, R. W., Jr. and E. S. Harrington. 1982. Effects on fishes and
their forage organisms of impounding a Florida salt marsh to prevent
breeding by salt marsh mosquitoes. Bull. Mar. Sci. 32(2): 523-531.

56. Harrington, R. W., Jr. and E. S. Harrington. 1961. Food selection among
fishes invading a high subtropical salt marsh: from onset of flooding
through the progress of a mosquito brood. Ecology 42: 646-666.

57. Heald, E. J. and W. E. Odum. 1970. The contribution of mangrove swamps to
Florida fisheries. Proc. Gulf Caribb. Fish. Inst. 22: 130-135.

58. Heck, K. L. and R. J. Orth. 1980. Seagrass habitats: the roles of habitat
complexity, competition and predation in structuring associated fish
and motile macroinvertebrate assemblages. Pp. 449-464 in V. S.
Kennedy (ed.). Estuarine Perspectives. Academic Press, Inc., New
York. 533 pp.

59. Herwitz, S. 1977. The natural history of Cayo-Costa Island. New College
Environmental Studies Program Pub. No. 14, Sarasota, Florida.

60. Hildebrand, S. F. and L. E. Cable. 1930. Development and life history of
fourteen Teleostan fishes at Beaufort, N.C. Bull. U.S. Bur. Fish. 46:
383-488.

61. Hildebrand, S. F. and W. C. Schroeder. 1927. Fishes of Chesapeake Bay.
Bull. U.S. Fish. Comm. 43(1): 1-366.

62. Hoffman, W. E., M. J. Durako and R. R. Lewis, III. 1983. Habitat restora-
tion in Tampa Bay, Florida. (in press). Proceedings Bay Area
Scientific Information Symposium (BASIS), May 3-6 1982, Tampa, FL.

63. Hoffman, W. E. and J. A. Rodgers, Jr. 1980. A cost/benefit analysis of
two large coastal plantings in Tampa Bay, Florida. Pp. 265-278 in
D. P. Cole (ed.), Proceedings of the Seventh Annual Conference
Restoration and Creation of Wetlands. Hillsborough Community College,
Tampa, Florida. 294 pp.

203

64. Hunt, L. J. 1979. Principles of marsh establishment. Pp. 127-142 in D.
P. Cole (ed.), Proceedings of the Sixth Annual Conference on the
Restoration and Creation of Wetlands. Hillsborough Community College,
Tampa, Florida. 357 pp.

65. Joseph, E. G. 1973. Analyses of a nursery ground. PD. 118-121 in A. L.
Pacheco (ed.). Proceedings of a Workshop on Egg, Larval, and Juvenile
Stages of Fish in Atlantic Coast Estuaries. Tech. Publ. No. 1, Mid-
Atlantic Coastal Fish Center, Highlands, N. J.

66. Junkin, B., R. Pearson, B. Seyforth, M. Kalcic, M. Graham. 1981. ELAS
Earth Resources Laboratory Applications Software. NASA/NSTL Earth
Resources Laboratory Rep. No. 183. NSTL Station, Mississippi.

67. Kelly, J. A., Jr., C. M. Fuss, Jr., and J. R. Hall. 1971. The transplant-
ing and survival of turtle grass, Thalassia testudinum, in Boca Ciega
Bay, Florida. Fish. Bull. 69(2): 2/3-280.

68. Kikuchi, T. and J. M. Peres. 1977. Consumer ecology of seagrass beds.
Pp. 147-193 in C. P. McRoy and C. Helfferich (eds.), Seagrass Eco-
systems. MaFcel Dekker, Inc., New York.

69. Kilby, J. D. 1955. The fishes of two Gulf coastal marsh areas of Florida.
Tul. Stud. Zoo. 2(8): 175-247.

70. Kjelson, M. A., D. S. Peters, G. W. Thayer, and G. N. Johnson. 1975. The
general feeding ecology of postlarval fishes in the Newport River
estuary. U.S. Fish. Wildl. Serv. Fish. Bull. 73(1): 137-144.

71. Knight, D. B., P. L. Knutson, and E. J. Pullen. 1980. An annotated bibli -
ography of seagrasses with emphasis on planting and propagation tech-
niques. U.S. Army Corps of Eng. CERC Misc. Rep. 80-7. 46 pp.

72. Kruczynski, W. L., C. B. Subrahmanyam, and S. H. Drake. 1978. Studies on
the plant community of a North Florida salt marsh, part 1, primary
production. Bull. Mar. Sci. 28: 316-334.

73. Kutkuhn, J. H. 1966. The role of estuaries in the development and per-
petuation of commercial shrimp resources. Pp. 16-36 in R. F. Smith,
A. H. Swartz, and W. H. Massmann (eds.), A Symposium on Estuarine
Fishes. Am. Fish. Soc. Spec. Publ. 3. 154 pp.

74. Kuyper, W. H., J. E. Becker, and A. Shopmyer. 1981. Land use, cover and
forms classification system. A technical manual. Department of
Transportation, State Topographic Office, Remote Sensing Center.
67 pp.

75. Lankford, R. R. 1977. Coastal lagoons of Mexico: their origin and
classification. Pp. 182-215 in M. L. Wiley (ed.), Estuarine
Processes. Academic Press, Inc. New York. 533 pp.

76. Lauff, G. H. (ed.). 1967. Estuaries. Am. Assoc. Adv. Sci. Spec. Publ.
83: 1-785.

204

77. Lewis, R. R., III. 1981. Economics and feasibility of mangrove restora-
tion. Pp. 88-93 in R. C. Carey, P. S. Markovits, and J. B. Kirkwood
(eds.), Proceedings U.S. Fish and Wildlife Service Workshop on Coastal
Ecosystems of the Southeastern United States. U.S. Fish and Wildlife
Service, FWS/OBS-80/59. 257 pp.

78. Lewis, R. R. and F. M. Dunstan. 1975. The possible role of Spartina
alterniflora Loisel in establishment of mangroves in Florida. Pp. 82-
100 in R. R. Lewis (ed.), Proceedings for Second Annual Conference on
the -Restoration of Coastal Vegetation in Florida. Hillsborough
Community College, Tampa, Florida. 203 pp.

79. Lewis, R. R., III and F. M. Dunstan. 1974. Use of spoil islands in re-
establishing mangrove communities in Tampa Bay, Florida, USA. Pp.
766-775 in G. Walsh, S. Snedaker, and H. Teas (eds.), Proceedings of
International Symposium on Biology and Management of Mangroves.
Honolulu, Hawaii, October 8-11, 1974.

80. Lewis, R. R., III, and R. C. Phillips. 1980. Experimental seagrass miti-
gation in the Florida Keys. Pp. 155-172 in D. P. Cole (ed.), Proceed-
ings of the Seventh Annual Conference on the Restoration and Creation
of Wetlands. Hillsborough Community College, Tampa, Florida. 294 pp.

81. Lindall, W. N., Jr., 1973. Alterations of estuaries of South Florida: a
threat to its fish resources. Mar. Fish. Rev. 35(10): 26-33.

82. Lindall, W. N., Jr., and C. H. Saloman. 1977. Alteration and destruction
of estuaries affecting fishery resources of the Gulf of Mexico. Mar.
Fish. Rev. 39(9): 1-7.

83. Lorio, W. J. and W. S. Perret. 1980. Biology and ecology of the spotted
seatrout (Cynoscion nebulosus Cuvier). Pp. 7-14 in R. O. Williams,
J. E. Weaver, and F. A. Kalber (eds.) Proceedings of the Colloquium on
the Biology and Management of Red Drum and Spotted Seatrout, Oct. 19-
20, 1978. Gulf States Marine Fisheries Commission. 117 pp.

84. Lugo, A. E. and S. C. Snedaker. 1974. The ecology of mangroves. Annu.
Rev. Ecol. Syst. 5: 39-64.

85. Macalaster, E. 1982. Probable causes for decline of submerged aquatic
vegetation disclosed in EPA's Chesapeake Bay Program Report. Tide-
water Fisheries News 15(6):1.

86. Mann, K. H. 1972. Macrophyte production and detritus food chains in
coastal waters. Mem. 1st Ital. Hydrobiol., Suppl. 29: 383. Proc.
IBP-UNESCO Symp. Detritus and its Ecological Role in Aquatic Eco-
systems.

87. Margalef, R. 1968. Perspectives in ecological theory. Univ. of Chicago
Press, Chicago, IL. 111 pp.

88. Margalef, R. 1963. On certain unifying principles in ecology. Am. Nat.
97: 357-374.

205

89. McHugh, J. L. 1976. Estuarine fisheries: are they doomed? Pp. 15-27 in
M. Wiley (ed.), Estuarine Processes, Volume I. Academic Press, New
York. 533 pp.

90. McLane, W. M. 1955. Fishes of the St. Johns River system. MS Thesis,
Univ. Fla. 370 pp.

91. McMillan, C. 1979. Differentiation in response to chilling temperatures
among populations of three marine spermatophytes, Thalassia testudi-
num, Syringodium filiforme, and Halodule wrightii. Amer. J. B-ot.T66:
810-819.

92. McMillan, C. 1978. Morphogeographic variation under controlled conditions
in five seagrasses. Thalassia testudinum, Halodule wrightii, Syringo-
dinium filiforme, Halophila engelmanii, and Zostera marina. Aquat.
Bot. 4:169-189.

93. McMillan, C. and R. C. Phillips. 1979. Differentiation in habitat re-
sponse among populations of new world seagrasses. Aquat. Bot. 7:185-
196.

94. McNulty, J. K., W. N. Lindall, Jr., and J. E. Sykes. 1972. Cooperative
Gulf of Mexico estuarine inventory and study, Florida. phase 1: area
description. NOAA Tech. Rep. NMFS Circ. 368. 126 pp.

95. Miller, J. M. and M. L. Dunn. 1980. Feeding strategies and patterns of
movement in juvenile estuarine fishes. Pp. 437-448 in V. S. Kennedy
(ed.), Estuarine Perspectives. Academic Press, Inc., New York. 533
PP.

96. Minson, D. J., M. M. Ludlow, and J. H. Troughton. 1975. Differences in
natural carbon isotope ratios of milk and hair from cattle grazing
tropical and temperate pastures. Nature 245: 602.

97. Moody, W. D. 1950. A study of the natural history of the spotted trout,
Cynoscion nebulosus, in the Cedar Key, Florida area. Q. J. Fla. Acad.
Sci. 12(3): 147-171.

98. Nakamura, E. L., J. R. Taylor, and I. K. Workman. 1980. The occurrence of
life stages of some recreational marine fishes in estuaries of the
Gulf of Mexico. NOAA Tech. Memo NMFS-SEFC-45: 53 pp.

99. National Park Service. 1982. Wild and scenic river study. Loxahatchee
Draft Environmental Impact Statement. U.S. Dept. Interior, National
Park Service, Atlanta, GA.

100. Nier, A. 0. and E. A. Gulbransen. 1939. Variations in the relative abund-
ance of the carbon isotopes. J. Am. Chem. Soc. 61: 697-698.

101. Odum, E. P. 1980. The status of three ecosystem-level hypotheses reqard-
ing salt marsh estuaries: tidal subsidy, outwelling, and detritus
based food chains. Pp. 485-495 in V. S. Kennedy (ed.), Estuarine
Perspectives. Academic Press, New York. 533 pp.

206

102. Odum, E. P. 1971. Fundamentals of ecology. W. B. Saunders Co., Phila-
delphia. 574 pp.

103. Odum, H. T. and B. J. Copeland. 1969. A functional classification of the
coastal ecological systems. Pp. 9-86 in H. T. Odum, B. J. Copeland,
and E. A. McMahan (eds.), Coastal EcoTgical Systems of the United
States. Rep. Fed. Water Pollut. Contr. Admin., Washington, D. C.

104. Odum, W. E. 1971. Pathways of energy flow in a south Florida estuary.
Miami Sea Grant Tech. Bull. No. 7. 162 pp.

105. Odum, W. E. 1970. Insidious alteration of the estuarine environment.
Trans. Am. Fish. Soc. 99: 836-847.

106. Odum, W. E. and E. J. Heald. 1972. Trophic analysis of an estuarine
mangrove community. Bull. Mar. Sci. 22(3): 671-738.

107. Odum, W. E., C. C. McIvor, and T. J. Smith, III. 1982. The ecology of the
mangroves of south Florida: a community profile. U.S. Fish and Wild-
life Service, Office of Biological Services, Washington, D. C. FWS/
OBS-81/24. 144 pp.

108. Odum, W. E. and T. J. Smith. 1981. Habitat value of coastal wetlands.
Pp. 30-35 in R. C. Carey, P. S. Markovits, and J. B. Kirkwood (eds.),
Proceedings-U.S. Fish and Wildlife Service Workshop on Coastal Eco-
systems of the Southeastern United States. U.S. Fish and Wildlife
Service, Office of Biological Services, Washington, D. C. FWS/OBS-
80/59. 257 pp.

109. Oesterling, M. J. 1976. Reproduction, growth and miqration of blue crabs
along Florida's Gulf coast. State Univ. Syst. Florida Sea Grant.
Rept. SUSF-SG-76-003. 19 pp.

110. Orth, R. J. 1977. The importance of sediment stability in seagrass commu-
nities. Pp. 281-300 in B. C. Coull (ed.), Ecology of Marine Benthos.
Univ. of South Caro6Tna Press, Columbia.

111. Packard, J. M. 1981. Abundance, distribution, and feeding habits of
manatees, (Trichechus manatus) wintering between St. Lucie and Palmin
Beach Inlets, Florida. Report prepared for the U.S. Fish and Wildlife
Service, 142 pp.

112. Park, W. M. and S. S. Batie. 1979. Methodological issues associated with
estimating the economic value of coastal wetlands in improving water
quality. International Estuarine Research Conference, Jekyll Island,
Georgia, Oct. 7-12.

113. Perret, W. S., J. E. Weaver, R. O. Williams, P. L. Johansen, T. D.
McIlwain, R. C. Raulerson, and W. M. Tatum. 1980. Fishery profiles of red
drum and spotted seatrout. Gulf States Marine Fisheries Commission,
Ocean Springs, Mississippi. 60 pp.

207

114. Peterson, C. H. 1981. The ecological role of mud flats in estuarine
systems. Pp. 184-192 in R. C. Carey, P. S. Markovits, and J. B. Kirk-
wood (eds.), Proceeding-s U.S. Fish and Wildlife Service Workshop on
Coastal Ecosystems of the southeastern United States. U.S. Fish and
Wildlife Service, Office of Biological Services, Washington, D.C. FWS/
OBS-80/59. 257 pp.

115. Phillips, R. C. 1980. Planting guidelines for seagrasses. U.S. Army
Corps of Engineers CERC Coastal Eng. Tech. Aid 80-2. 28 pp.

116. Phillips, R. C. 1974. Transplantation of seagrasses with special emphasis
on Zostera marina. L. Aquaculture 4(3): 161-176.

117. Phillips, R. C. 1960. Observations on the ecology and distribution of the
Florida seagrasses. Fla. St. Bd. Conser. Mar. Lab., Prof. Pap. Ser.
No. 2. 72 pp.

118. Pomeroy, L. R. 1959. Algal productivity in salt marshes of Georgia.
Limnol. Oceanogr. 4: 386-397.

119. Pritchard, 0. W. 1967. What is an estuary: physical viewpoint. In G. H.
Lauff (ed.), Estuaries. Am. Assoc. Adv. Sci. Spec. Publ. 83:3-5.

120. Pulver, T. R. 1976. Transplant techniques for sapling mangrove trees,
Rhizophora mangle, Laguncularia racemosa, and Avicennia germinans, in
Florida. -FTla. Mar. Res. Publ. No. 22. 14 pp.

121. Pulver, T. R. 1975. Suggested mangrove transplanting techniques. Pp.
122-131 in R. R. Lewis (ed.), Proceedings of the Second Annual
Conference on Restoration of Coastal Vegetation in Florida. Hills-
borough Community College, Tampa, Florida. 203 pp.

122. Reid, G. K., Jr. 1954. An ecological study of the Gulf of Mexico fishes
in the vicinity of Cedar Key, Florida. Bull. Mar. Sci. Gulf Caribb.
4(1): 1-94.

123. Robas, A. K. 1970. South Florida's mangrove-boarded estuaries: their role
in sport and commercial fish production. Univ. Miami Sea Grant Infor-
mation Bull. No. 4. 28 pp.

124. Robins, C. R., R. M. Bailey, C. E. Bond, J. R. Brooker, E. A. Lachner, R.
N. Lea, and W. B. Scott. 1980. A list of common and scientific names of
fishes from the United States and Canada. (4th Edition). Am. Fish.
Soc. Spec. Publ. No. 12. 114 pp.

125. Roessler, M. A. and J. C. Zieman. 1969. The effects of thermal additions
on the biota in southern Biscayne Bay, Florida. Gulf Caribb. Fish.
Inst. Proc. 22nd. 135-145.

126. Sacket, W. M. (in press). Stable carbon isotope studies on organic matter
in the marine environment. In P. Fritz and J. C. Fontes (eds.), Hand-
book of Environmental Geochemistry, Vol. III. Elsevier Publishing
Co., New York.

208

127. Saltwater Fisheries Study and Advisory Council. 1981. Progress report.
August 1980-January 1981. 38 pp.

128. Saurs, S. C. 1981. Seasonal growth of seagrasses in Sarasota Bay,
Florida, with notes on historical changes and considerations for
restoration. Pp. 118-139 in R. H. Stovall (ed.), Proceedings of the
Eighth Annual Conference onr-Wetlands Restoration and Creation. Hills-
borough Community College, Tampa, Florida. 200 pp.

129. Savage, T. 1972. Florida mangroves as shoreline stabilizers. Florida
Dept. Nat. Resour. Prof. Pap. Ser. 19. 46 pp.

130. Sheridan, P. F. 1979. Trophic resource utilization by three species of
Sciaenid fishes in a northwest Florida estuary. Northwest Gulf Sci.
3(1): 1-15.

131. Smith, B. N. and S. Epstein. 1971. Two categories of 13C/12C ratios in
dissolved and particulate organic matter in the sea. Deep Sea Res.
17: 19-27.

132. Springer, V. G. and K. D. Woodburn. 1960. An ecological study of the
fishes of the Tampa Bay area. Fl. State Board Cons. Prof. Pap. Ser.
No. 1. 104 pp.

133. Stickney, R. R., G. L. Taylor, and D. B. White. Food habits of five
species of young southeastern United States estuarine Sciaenidae.
Chesapeake Sci. 16(2): 104-114.

134. Subrahmanyam, C. B., W. L. Kruczynski, and S. H. Drake. 1976. Studies on
the animal communities in two North Florida salt marshes. Part II.
Macroinvertebrate communities. Bull. Mar. Sci. 26: 172-195.

135. Summerson, H. C. 1980. The effects of predation on the marine henthic
community in and around a shallow subtidal seagrass bed. M.S. Thesis,
Univ. North Carolina, Chapel Hill. 118 pp.

136. Sykes, J. E. and J. H. Finucane. 1966. Occurrence in Tampa Bay, Florida,
of immature species dominant in Gulf of Mexico commercial fisheries.
Fish. Bull. 65(2): 369-379.

137. Tabb, D. C. 1961. A contribution to the biology of the spotted seatrout,
Cynoscion nebulosus (Cuvier) of east-central Florida. Board of Con-
servation: Technical Series No. 35. 24 pp.

138. Tabb, D. C. and R. B. Manning. 1961. A checklist of the flora and fauna
of northern Florida Bay and adjacent brackish waters of the Florida
mainland collected during the period July, 1957 through September,
1960. Bull. Mar. Sci. Gulf Caribb. 11(4): 552-649.

139. Taylor, J. L. 1974. The Charlotte Harbor estuarine system. Fla. Sci.
37(4): 205-216.

209

140. Taylor, J. L., J. R. Hall, and C. H. Saloman. 1970. Mollusks and benthic
environments in Hillsborough Bay, Florida. U.S. Fish Wildl. Serv.
Fish. Bull. 68(2): 191-202.

141. Taylor, J. L. and C. H. Saloman. 1968. Some effects of hydraulic dredging
and coastal development in Boca Ciega Bay, Florida. U.S. Fish Wild-
life Serv. Fish. Bull. 67(2): 213-241.

142. Teas, H. J. 1981. Restoration of mangrove ecosystems. Pp. 95-103 in R.
C. Carey, P. S. Markovits and J. B. Kirkwood (eds.), Proceedings U.S.
Fish and Wildlife Service Workshop on Coastal Ecosystems of the South-
eastern United States. U.S. Fish and Wildlife Service, Office of Bio-
logical Services, Washington, D.C. FWS/OBS-80/59. 257 pp.

143. Teas, H. J. 1980. Mangrove swamp creation. Pp. 63-90 in J. C. Lewis and
E. W. Bunce (eds.), Rehabilitation and Creation of -Selected Coastal
Habitats: Proceedings of a Workshop. U.S. Fish and Wildlife Service,
Office of Biological Services. FWS/OBS-80/27. 162 pp.

144. Teas, H. J. 1977. Ecology and restoration of mangrove shorelines in
Florida. Environ. Conserv. 4: 51-58.

145. Teas, H. J., W. Jurgens, and M. C. Kimball. 1975. Plantings of red man-
grove (Rhizophora mangle L.) in Charlotte and St. Lucie Counties,
Florida. Pp. 132-161 in R. R. Lewis (ed.), Proceedings of the Second
Annual Conference on 1estoration of Coastal Vegetation in Florida.
Hillsborough Community College, Tampa, Florida.

146. Thayer, G. W. and J. F. Ustach. 1981. Gulf of Mexico wetlands: value,
state of knowledge and research needs. Proc. Gulf Coast Workshop.
NOAA/Office of Marine Pollution Assessment, Miami, Fla. Oct. 1979.

147. Thorhaug, A. 1980. Techniques for creating seagrass meadows in damaged
areas along the east coast of the U.S.A. Pp. 105-116 in J. C. Lewis
and E. W. Bunce (eds.), Rehabilitation and Creation of Selected
Coastal Habitats: Proceedings of a Workshop. U.S. Fish and Wildlife
Service, Office of Biological Services. FWS/OBS-80/27. 162 pp.

148. Thorhaug, A. 1974. Transplantation of the seagrass Thalassia testudinum
Konig. Aquaculture 4:177-183.

149. Turner, R. E., S. W. Woo, and H. R. Jitts. 1979. Estuarine influences on
a continental shelf plankton community. Science 206: 218-220.

150. Turner, R. E. 1977. Intertidal vegetation and commerecial yields of
penaeid shrimp. Trans. Am. Fish. Soc. 106:411-416.

151. Turner, R. E. 1976. Geographic variations in salt marsh macrophyte pro-
duction: a review. Contrib. Mar. Sci. 20: 48-68.

152. U.S. Department of the Interior, Bureau of Land Management. 1978.

153. Upchurch, S. B., E. D. Esteves, and R. Rea. 1976. Distribution and
possible effects of removal and sedimentary contamination offshore of
Gardinier, Inc. in Tampa Bay, Florida. Univ. Fla., Tampa, Fla. llOpp.

210

154. vanBreedveld, J. 1976. Transplanting of seagrasses with emphasis on the
importance of substrate. Fla. Mar. Res. Publ. No. 126, St. Peters-
burg, Florida. 25 pp.

155. vanBreedveld, J. F. 1975. The transplanting of seagrasses with emphasis
on the importance of the substrate. Fla. Dept. Nat. Res. Mar. Res.
Publ. No. 17. 26 pp.

156. Welsh, W. W. and C. M. Breder, Jr. 1923. Contributions to the life his-
tories of Sciaenidae of the eastern United States coast. Bull. U.S.
Bur. Fish. 39: 141-201.

157. Weinstein, M. P. and H. A. Brooks. 1983. Comparative ecology of nekton
residing in a tidal creek and adjacent seagrass meadows: community
composition and structure. Mar. Ecol. Prog. Ser. 12:15-27.

158. Whittaker, R. H. 1975. Communities and Ecosystems. 2nd Edition. McMillan
Publishing Co., Inc., New Yor-k-.

159. Wong, W. W. and W. M. Sacket, 1978. Fractionation of stable carbon iso-
topes by marine phytoplankton. Geochim. Cosmochim. Acta. 42: 1809-
1815.

160. Woodhouse, W. W., Jr., E. D. Seneca, and S. W. Broome. 1972. Marsh build-
ing with dredge spoil in North Carolina. N.C. Agric. Expt. Stn. Bull.
445. 28 pp.

161. Yokel, B. J. 1975. Rookery Bay land use studies: environmental planning
strategies for the development of a mangrove shoreline, No. 5. Estu-
arine Biology. Conservation Foundation, Washington, D. C.

162. Zieman, J. C. 1982. The ecology of seagrasses of south Florida: a com-
munity profile. U.S. Fish and Wildlife Service, Office of Biological
Services, Washington, D.C. FWS/OBS-82/25. 158 pp.

163. Zieman, J. C. 1981 The food within seagrass beds and their relationship
to adjacent systems. Pp. 115-121 in R. C. Carey, P. S. Markovits, and
J. B. Kirkwood (eds.), Proceedings U.S. Fish and Wildlife Service
Workshop on Coastal Ecosystems of the Southeastern United States. U.
S. Fish and Wildlife Service, Office of Biological Services, Washing-
ton, D.C. FWS/OBS-80/59. 257 pp.

164. Zieman, J. C. 1976. The ecological effects of physical damage from motor-
boats on turtle grass beds in southern Florida. Aquat. Bot. 2: 127-
139.

165. Zieman, J. C. 1974. Methods for the study of the growth and production of
turtlegrass, Thalassia testudinum Konig. Aquaculture 4:139-142.

166. Zimmerman, R. J., T. J. Minello, and G. Zamora, Jr. (1984). Selection of
vegetated habitat by brown shrimp, Penaeus aztecus, in a Galveston Bay
salt marsh. Fish. Bull. 82(2):(in press).

211

"We never know the worth of the water
'till the well is dry,"

-Thomas Fuller 1608-1666