Proceedings of a Symposium on Current Research Topics in the Marine Environment, San Francisco, March 21, 1987

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OP c

NOAA Technical Memorandum

NOS MEMD 2

GULF OF THE FARALLONES,
~ NATIONAL MARINE SANCTUARY

CURRENT RESEARCH TOPICS
IN THE MARINE ENVIRONMENT

COASTAL WIN, H
INFORMATION CENTER

O ~Washington, D.C.

.N6
no. 2

~~QMI~IERCE Mn~osptienc Adrmnistrati~~f~ Maniagement Division

NOAA Technical Memorandum
N0OS MEMD 2

CURRENT RESEARCH TOPICS
IN THE MARINE ENVIRONMENT

Miles M. Croom* and Nancy Stone**, Editors

*Sanctuary Manager, **Deputy Sanctuary Manager,
Gulf of the Farallones National Marine Sanctuary,
Fort Mason, Building #201, San Francisco, CA 94123

U.S. DEPARTMENT OF COMMERCE NOAA
COASTAL SERVICES CENTER
Washington, D.C. 2234 SOUTH HOBSON AVENUE
August 1987 ~CHARLESTON, SC 29405-t24i3

UMTED STATES IlS OcaMIC and NMaion Ocean Sric
DEPARTMENT OF CGUMEACS AugphAminislraUa /

NOAA TECHNICAL MEMORANDA

National Ocean Service Series

Marine and Estuarine Management Division

The National Ocean Service, through its Office of Ocean and Coastal Resource Management, conducts
natural resource management related research in its National Marine Sanctuaries and National Estuarine Reserve
Research System to provide data and information for natural resource managers and researchers. The National
Ocean Service also conducts research on and monitoring of site-specific marine and estuarine resources to
assess the impacts of human activities in its Sanctuaries and Research Reserves and provides the leadership
and expertise at the Federal level required to identify compatible and potentially conflicting multiple uses of
marine and estuarine resources while enhancing resource management decisionmaking policies.

The NOAA Technical Memoranda NOS MEMD subseries facilitates rapid distribution of material that may
be preliminary in nature and may be published in other referreed journals at a later date.

MEMD 1 M.M. Littler, D.S. Littler and B.E. Lapointe. 1986. Baseline Studies of Herbivory and Eutrophication
on Dominant Reef Communities of Looe Key National Marine Sanctuary.

MEMD 2 M.M. Croom and N. Stone, Eds. 1987. Current Research Topics in the Marine Environment.

National Marine Sanctuary Program
Marine and Estuarine Management Division
Office of Ocean and Coastal Resource Management
National Ocean Service
National Oceanic and Atmospheric Administration
U.S. Department of Commerce

NOTICE

This report has been approved by the National Ocean Service of the National Oceanic and
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signify that the contents of this report necessarily represent the official position of NOAA or
of the Government of the United States, nor does mention of trade names or commercial
products constitute endorsement or recommendation for their use.

REPORT TO
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
U.S. DEPARTMENT OF COMMERCE

NOAA TECHNICAL MEMORANDA SERIES NOS/MEMD

Proceedings of a Symposium on

Current Topics in the Marine Environment

A Symposium sponsored by the Gulf of the Farallones National
Marine Sanctuary, Point Reyes National Seashore, and the
Environmental Action Committee of West Marin

March 21, 1987

Miles M. Croom and Nancy Stone, Editors

August 1987

U.S. DEPARTMENT OF COMMERCE
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
NATIONAL OCEAN SERVICE
OFFICE OF OCEAN AND COASTAL RESOURCE MANAGEMENT
MARINE AND ESTUARINE MANAGEMENT DIVISION
WASHINGTON, D.C.

REPORT TO
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
U.S. DEPARTMENT OF COMMERCE

NOAA TECHNICAL MEMORANDA SERIES NOS/MEMD

Proceedings of a Symposium on
Current Topics in the Marine Environment

A Symposium sponsored by the Gulf of the Farallones National
Marine Sanctuary, Point Reyes National Seashore, and the
Environmental Action Committee of West Marine

March 21, 1987

Miles M. Croom* and Nancy Stone**, Editors

* Sanctuary Manager, ** Deputy Sanctuary Manager, Gulf of the Farallones National Marine Sanctuary:
Fort Mason, Building #201, San Francisco, California 94123
(415) 556-3535

This work is the result of research sponsored by the U.S.
Department of Commerce, National Oceanic and Atmospheric
Administration, National Ocean Service, Office of Ocean and
Coastal Resource Management, Marine and Estuarine Management Division

FORWARD

The Gulf of the Farallones National Marine Sanctuary is pleased to present these Proceedings of the Symposium
on Current Research Topics in the Marine Environment. The projects described here represent a sampling of
the research sponsored by the National Oceanic and Atmospheric Administration's (NOAA) Marine and Estuarine
Management Division in the Gulf of the Farallones region to refine our understanding of the resources within the
Sanctuary, the natural processes that occur there, and the effect of human uses and interactions with the
environment.

The Sanctuary was designated in 1981 for the purpose of ensuring the long-term protection of the resources
within the boundaries of this marine protected area. To achieve this primary management goal, the Sanctuary
conducts programs in research, education and interpretation, and resource protection. The various programs are
integrated in such a way that the products or results of one reinforce and enhance the others. Research is
aimed toward identifying and examining specific Sanctuary resources. Results from research activities, for
example, are used to improve resource protection efforts and, as in the case of this Symposium, to inform the
public about the Sanctuary- how it "works," why it is special, and what we can do to protect and preserve its
values.

But the Gulf of the Farallones National Marine Sanctuary does not and cannot exist in a vacuum. Vigorous
public support -- the kind of support that led to the designation of the Sanctuary - is essential for a vital
Sanctuary presence that will ensure the long-term health and stability of the habitats and inhabitants that make
the Gulf of the Farallones a place of such magnificent beauty and powerful inspiration. Wise management of
these protected areas also depends on the best use of all the program resources that we can muster; the
coordinated efforts of agencies like NOAA and the National Park Service are also essential for the responsible
management of the public's resources and the protection of the public's interest.

By these criteria, the Symposium was a demonstration of new knowledge of Sanctuary resources shared with
the public and which will be incorporated into other program activities. Also, the Symposium was delivered in a
forum that resulted from the cooperative efforts of the Gulf of the Farallones National Marine Sanctuary and the
Point Reyes National Seashore. For those of you who couldn't attend, please enjoy these Proceedings. We
feel and hope you agree after reading the Proceedings, that the Symposium was a valuable experience that left
us all with a better understanding of the Gulf of the Farallones.

Finally, a special word of thanks to Nancy Stone, Deputy Sanctuary Manager, and to Armando Quintero,
Supervisory Park Ranger, for their efforts in organizing and coordinating the myriad details that resulted in a very
worthwhile Symposium.

Miles M. Croom
Lieutenant Commander, NOAA
Sanctuary Manager

CONTENTS

Page

FORWARD v

Humpback Whale Studies in the Gulf of the Farallones
National Marine Sanctuary. James C. Cubbage,
Cascadia Research. 1

Cetacean Studies in Marine Sanctuaries.
Steven L. Swatrz, Cetacean Research Associates. 11

Harbor Seals and Northern Elephant Seals in
Point Reyes. Sarah G. Allen, Point Reyes
Bird Observatory. 16

Potential Bioaccumulation of Long-lived Radionuclides
by Marine Organisms in the Vicinity of the Farallon
Islands Nuclear Waste Dump Site. Thomas H. Suchanek,
Division of Environmental Studies, University of
California, Davis, California. 20

Field Studies of the White Shark, Carcharodon carcharias,
in the Gulf of the Farallones National Marine Sanctuary.
A. Peter Klimley, Bodega Marine Laboratory. 33

Harbor Porpoise, Phocoena phocoena, in the
Gulf of the Farallones National Marine Sanctuary.
Isadore D. Szczepaniak, California Academy of Sciences. 37

Cordell Bank: What We Know and What We Don't.
Robert W. Schmieder, Cordell Bank Expeditions. 41

Acknowledgements 47

Humpback Whales in the
Gulf of the Farallones National Marine Sanctuary:
Report of Ongoing Research

James C. Cubbage
John Calambokidis
Kenneth C. Balcomb &
Gretchen H. Steiger

Cascadia Research, Olympia, Washington 98501

BACKGROUND

Humpback whales (Megaptera novaeangliae) occur throughout the
world and generally migrate from winter breeding grounds in low
latitudes around 20 degrees to high latitudes during summer to feed.
Portions of the North Pacific stock summer in the Aleutian Islands,
Prince William Sound and the Alexander Archipelago in Alaska and winter
off southern Baja California, the Hawaiian Islands and the Ryukyu
Islands south of Japan. From the start of commercial whaling, humpback
whale populations in the North Pacific were reduced from an estimated
15,000 animals to little over 1,000 animals in the 1960's (Leatherwood
et al. 1982, Rice 1977). In recent history (late 1950's to 1962) about
755 humpbacks were taken from within the present day Gulf of the
Farallones National Marine Sanctuary area (Rice 1963). Though recent
marine mammal observations started in 1968, humpbacks were first seen in
numbers in the Sanctuary in 1977 (Ainley et al. 1978). Recent research
(Dohl et al. 1983) has suggested a continual increase in the number of
humpbacks found in the early 1980's in this Sanctuary.

This abstract reviews preliminary results of research on marine
mammals, particularly humpback whales, in the Gulf of the Farallones
National Marine Sanctuary and Cordell Bank area. The research was
contracted by National Oceanic and Atmospheric Administration
Sanctuaries Program through the National Park Service to Cascadia
Research. A complete annual report will be available.

The primary objectives of the proposed three-year study are to: 1)
develop a photographic catalog of humpback whales, 2) determine the
abundance and distribution of humpback whales in the study area, and 3)
identify seasonal movements of humpback whales and their interchange
with wintering grounds and other summer feeding areas. Other research
components include: incidental observations of other marine mammals,
aerial photogrammetry, and observations of humpback whale - vessel
interactions.

METHODS

Vessel survey effort consisted of two components: 1) dedicated
research by Cascadia personnel using three vessels and 2) incidental
effort during whale watch cruises conducted by Oceanic Society
naturalists under subcontract to Cascadia. Aerial surveys were

conducted to provide a far-ranging, somewhat synoptic search for whales
in the Sanctuary.

The three primary vessels used by Cascadia consisted of: 1)
Noctilio, a 44' motor sailer, 2) Shachi, a 19' Boston Whaler, and 3) a
13' inflatable Zodiac. Both the Shachi and Noctilio were based out of
Bodega Bay and were equipped with Loran, radar, depth sounder, and VHF
radio. The Noctilio served as the primary base of operations logging
330 hours of survey effort on 32 days between 23 July and 15 September
1986. The Shachi operated on 13 days between 23 July and 2 September
and logged 69 hours of survey effort. The Zodiac operated primarily in
conjunction with the Noctilio, within 5nm, though on calmer days
operated independently. The Zodiac was operated for 114 hours on 24
days between 27 July and 15 September 1986. Tracks of all dedicated
surveys are shown in Figure 1. The Oceanic Society whale watch cruises
were conducted on weekends from 7 June to 26 October and originated from
San Francisco Bay and travelled around the Farallon Islands. All
sightings recorded by experienced marine mammal observers on board were
examined. In the aerial survey the primary search aircraft was a
Cessna 172 that flew for about 37 hours.

The flukes of humpback whales show coloration and scar patterns
that are individually unique. These patterns allow unequivocal
identification of individual whales over several years. "Humphrey," the
wayward humpback that wandered up the Sacramento River in 1985, was
identified near the Farallon Islands in 1986 through these fluke
markings. His whereabouts were unknown from November 1985 until found
by this research in the Sanctuary. Locations of sightings of "Humphrey"
are shown in Figure 2.

We photographed whale flukes of most animals seen and from these
data, not only can individual movements be determined, but an estimate
of the population in the area can be calculated through mark-recapture
statistics. The initial photograph of an individual serves as a mark
and subsequent resightings can be considered recaptures using the
Schnabel (1938) method.

All three vessels had at least one researcher/photographer on board
at all times, and during some photographic forays, as many as 6
researcher/photographers were operating on three vessels simultaneously.
Vessel survey effort was concentrated at locations where humpbacks were
found because the primary objective for the vessels was to-,develop a
photographic catalogue of whales.

PRELIMINARY RESULTS

Humpback whales

Distribution and Abundance A total of 256 sightings of 707
humpback whales were recorded during dedicated vessel surveys and 40
sightings of 162 humpbacks were made during aerial surveys. Relative
densities of humpback whale seen per hour of survey from the Noctilio
are shown in Figure 3 (aerial sightings are not included). Most

animals were seen and photographed in the region between Pt. Reyes and
Fanny Shoal north of the North Farallon Islands.

Though a few sightings of humpbacks were made in the beginning of
August, the major "herd" of animals was first seen on 14 August and were
in the study area intermittently through 15 September, when major field
effort ceased. Oceanic Society cruises conducted past the end of the
dedicated vessel surveys indicated humpback whales remained in the study
area through the last survey on 26 October. No calves were seen
throughout the surveys.

Photographs Approximately 7,000 35mm photographs were taken during
the survey period. These photos yield at least 88 positively identified
individual humpback whales photographed throughout the season. Obviously,
many individuals were photographed more than once, and these resights
form the basis of a crude estimate of numbers of animals in the study area
in 1986 through mark-recapture statistics. The mark-recapture estimates
show the numbers of animals in the area to number about 100. These esti-
mates are preliminary and require additional years of sampling to confirm.

Fluke photographs from 1986 were matched to those taken by other
researchers (M. Webber, I. Szczepaniak, J. Stern) during previous years
and these show that some individuals have occurred in and around the
Sanctuary in more than one year. A catalog of 1986 photos of whales
taken in the Sanctuary was sent to various researchers to compare fluke
photographs to their collections of approximately 80 identified whales
from Mexico and approximately 1600 identified whales from Hawaii.
Mexican researchers found eight matches to humpbacks wintering in Mexico
and none have been reported by the Hawaiian researchers, a strong
indication of the wintering grounds of animals at the Gulf of the
Farallones National Marine Sanctuary. However, a current hypothesis
(Baker et al. 1986) suggests that humpbacks from several different
summering grounds mingle on wintering grounds. The extent to which
humpback visitors to Farallon Islands may be found on other summering
grounds in other years is still not known.

Blue whales

Distribution and Abundance Ninety-four sightings of 193 blue
whales were made during dedicated vessel surveys and 31 sightings of 52
blue whales were made during aerial surveys. Relative densities of blue
whales seen from the Noctilio are shown in Figure 4. Boat and aerial
censuses indicate that at least 20-25 blue whales were in the study area
throughout much of the study period. The high relative abundance of
blue whales in the study area was surprising. Timing of blue whale
occurrence in the study area closely paralleled that of humpbacks,
though blue whales appeared to arrive in numbers a little earlier than
the main "herd" of humpback whales.

Photography Blue whale identification photographs offer a
significant opportunity to determine the recurrence of individuals of
this endangered species in the Sanctuary. These photos may also help
determine the relationship of these animals to those photographed
elsewhere along the California and Mexico coast.

Association of whales with water depth, birds and boats

Depth Preliminary analysis of the survey effort and sighting data
indicated a significant association between sighting frequency of both
humpback and blue whales and water depth. Because different water
depths were not sampled equally we first had to calculate the amount of
survey effort at different depths. We restricted the analysis to data
gathered from the Noctilio, because it provided the largest data set and
water depths were recorded every 15 minutes during surveys. These water
depths were used to determine the amount of time spent at different
depths. Sightings at different depths could then be translated into
sightings per hour of effort at that water depth (Figure 5). For both
humpback and blue whales, sightings per hour varied significantly by
depth (chi-square, p<O.001 for both cases). Highest sighting rates for
both species occurred at 250-350' depth. Dall's porpoise sightings also
varied significantly by depth (chi-square, p<0.025) with the highest
sighting frequency in waters deeper than 450 feet. Sightings of other
species were too limited to allow accurate statistical tests of
sightings by.depth.

Birds We found a significant association between humpback whales
and mari-ne birds. We collected data on the presence of birds within
200 m of the survey vessel during all surveys from the Noctilio and when
whales were sighted. These data allowed us to compare the average
number of birds encountered during surveys to those present where the
whales were seen. Humpback whale sightings occurred at a significantly
higher than expected rate (chi-square, p<.001) when high concentrations
of birds were present. Blue whale sightings followed a similar pattern,
but just failed a test of statistical significance (chi-square, p>O.05).

Other marine mammals

Several other marine mammal species were seen during this study.
Cetaceans sighted included sei whale, killer whale, minke whale, Risso's
dolphin, Dall's porpoise, harbor porpoise, and Pacific white-sided
dolphin. Pinnipeds seen were California and northern sea lion, harbor
seal and elephant seal.

REFERENCES

Ainley, D.G., H.R. Huber, S. Morrell, R. LeValley. 1978. Studies at
the Farallon Islands, 1977. Final report to U.S. Marine Mammal
Comm. Contract MM6AC027. Point Reyes Bird Observatory.

Baker, C.S., L.M. Herman, A. Perry, W.S. Lawton, J.M. Straley, A.W.
Wolman, G.D. Kaufman, H.E. Winn, J.D. Hall, J.M. Reinke, and J.
Ostman. 1986. Migratory movement and population structure of
humpback whales (Megaptera novaeangliae) in the central and eastern
North Pacific. Mar. Ecol. Prog. Ser. 31:105-119.

Dohl, T.P., R.C. Guess, M.L. Duman, and R.C. Helm. 1983. Cetaceans of
central and northern California, 1980-1983: status, abundance and
distribution. OCS Study MMS 84-0045.

Leatherwood, S., R.R. Reeves, W.F. Perrin, and W.E. Evans. 1982.
Whales, dolphins and porpoises off the eastern North Pacific and
adjacent Arctic waters: A guide to their identification. NOAA
Tech. Rept. NMFS Circ. 444. 245 pp.

Rice, D.W. 1963. Progress report on biological studies of the larger
cetacea in the waters off California. Norsk Hvalfangst-Tidende
7:181-187.

Rice, D.W. 1977. The humpback whale in the North Pacific:
distribution, exploitation, and numbers. Prepared for Workshop on
Humpback Whales in Hawaii, July 1977. 21 pp.

Schnabel, Z.E. 1938. The estimation of the total fish population of a
lake. Amer. Math. Mon. 45:348-352.

Dom 2 :0I :123: 00, 6

...................... .. ....Bodega Bay .........

37:50 1

Figure 1. Tracklines of all dedicated vessels (Noctillo, Shachi, and
Zodiac) throughout study period. See text for effort summary
and vessel description.

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.......:I .:.. o,

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SI

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Figure

Figure 2. Locations of sightings of whale # 21 ("Humphrey") in 1986.

38:20'1 :.123:0 'u' 123:20 '0 123:00 '4 :122:40 U

>5.50

>4 .50

38:10H I N >1.50

>.50

38*oN7:0' Iys

37:501 I

3?:qO'tl / 7"

~~~~~~~3 I: 7s 0 ' N ' � q/0/~~~~~~~~~~~ ~ ~~~~~~~~~ ...0.

Figure 3. Number of humpback whales seen per hour from Noctilio in 1986.
All grids have at least one hour of search.

'p 3~~~~~~~~"
8:0'AD :i42:*0 :H :123:20'J 123 Ou'U .122:I0'U
>1.50

> 1.25

>1.00
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0.50

>0.25

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~~~~~~~~~~~~~~~~~~~~~~~~~........

.8 .' . . . . . . .....i . . . .

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. . . . . . . . . . . . . . . . . . . . . . . .... . '.. . ..... . . . .

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Figure 4. Number of blue whales seen per hour from Noctilio in 1986.
All grids have at least one hour of search.

1 17j HUMPP~AS

048 9 I-' BLRIUE
60
0.9 -

OZ 0.7

0.26-

<150 15o- 200- 250- 300 350 >400
DEPTH IN FEET

Figure 5. Sightings of humpback and blue whales per hour of boat survey by
depth class. Numbers at top of bars indicate number of
sightings in each depth class. Data from Noctilio (auxiliary
sailer) only. The differences by depth class are significant
(chi-square p<0.001)
DET I25 FEET

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Cetacean Studies in Marine Sanctuaries

Steven L. Swartz, Ph.D.
Cetacean Research Associates, Inc.
San Diego, California 92107

Marine sanctuaries have traditionally concerned themselves with
things that occur within the marine protected areas themselves, that is,
coral reefs, resident populations of fish, archeological sites, unique
underwater formations, and the like. More difficult to consider are the
transitory resources that occur seasonally within a protected area and
remain there for a period of time while they complete a portion of their
life history. Examples include migratory populations of pelagic fish,
birds, and marine mammals including the cetaceans -- the whales,
dolphins and porpoises. Because transitory species pass through or
visit marine areas for finite periods of time rather than residing within
them permanently, they are difficult to think about, and therefore they
pose challenging management and research tasks. Marine protected areas
may be equally critical to the survival of both migratory and resident
wildlife populations.

The world's great whales are seasonal migrants that spend roughly
half of each year migrating to the higher latitudes to feed in areas of
high prey concentration, and the other half reproducing in tropical and
sub-tropical waters. They continuously follow the seasonal distribution
of their food and seasonal changes in climate. Their migrations take
them across political boundaries and through a wide range of
oceanographic conditions. This constant movement coupled with the fact
they spend only brief periods at the surface makes it difficult to
observe whales and to document their activities.

The study of whales is further complicated by the fact that they
are long-lived animals which respond to long-term changes in their
habitats. It is believed that some species of great whales may live as
long or longer than their human investigators. To acquire meaningful
data on the needs of these kinds of animals, and to develop useful data
bases with which to evaluate trends, observations must be conducted over
many years. This in turn requires a long-term cormmitment on the part of
the sponsoring agency. Often one or two seasons of research cannot
provide the information necessary to address questions regarding the
seasonal abundance, distribution and behavior of whale populations and
how these may change over time. But, if well planned, they may form the
foundation of a data base that, once established, may be added to as
often as needed or desired.

Once a data base of sufficient length is established, the manager
of a marine protected area may put recent information on whale
populations within the sanctuary into the proper perspective. Then,
using a trend analysis approach, appropriate management decisions may be
made regarding whales and their use of the protected area. Although
whale research requires extended effort and expense over prolonged
periods, the return of useful information provided by a well planned and

properly executed long-term program is well worth the investment in terms
of successful management of marine protected areas for the benefit of
both the wildlife and man.

From January 18 to February 4, 1986, the Channel Islands National
Marine Sanctuary sponsored a pilot study with the overall goal of
producing baseline information on gray whales (Eschrichtius robustus)
during the peak period of their southward migration through o--thern
California. This was the first step toward establishing a data base for
an ongoing program to identify long-term changes in the gray whale's use
of this portion of their range that may result from increased levels of
human activities.

The specific objectives of this project were to:

1. estimate the number and distribution of gray whales within the
CINMS during the peak of their southward migration,

2. determine the duration of stay of gray whales, or the rate at
which whales migrate through the CINMS,

3. determine their day and night travel rates through the
Sanctuary,

4. document inter-island migration routes, local whale movements,
behavior, and resource use in the CINMS,

5. opportunistically document the occurrence of other cetaceans
within the Sanctuary, and

6. make recommendations to appropriate wildlife management
agencies charged with the responsibility of monitoring the
welfare of the gray whale population and its habitat.

The Channel Islands National Marine Sanctuary (CINMS) is a tract of
ocean, about 1,252 nm2, encompassing the waters within 6 nm of San
Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara Islands.
This island system is uniquely positioned in the Southern California
Bight, being the first islands south of Point Conception where the
mainland coast turns east toward Santa Barbara. Two techniques, aerial
surveys and radiotelemetry, were employed.

Strip-surveys were flown to determine the abundance, distribution,
behavior, and resource use of gray whales throughout the CINMS. During
strip-surveys, two replicates were flown of a systematic grid.of north-
south transects spaced 4 nm apart. On each replicate, requiring 6 hours
to complete, we surveyed 265.46 nm2 of water, an estimated 25% of the
surface area of the sanctuary. Survey 1 (on January 20 and 21) produced
32 sightings totaling 67 whales and 8 calves, Survey 2 (on January 21,
24 and 25) produced 23 sightings totaling 61 whales and 9 calves, and
the average count was 64 whales and 8.5 calves. Based on these data,
the ratio of means estimator (modified) yielded a population estimate
(corrected for submerged whales) of 676 � SD 206 whales in the CINMS

during Survey 1, and 613 +_ SD 211 whales during Survey 2, with a mean
estimate of 643 +_ S 173 whales (95% C.I. 683, 703). Animals clearly
identifiable as calves of the season comprised 13.3% of all grays seen
during strip-surveys. The abundance of calves (uncorrected) was
estimated at 32 +_ SD 15 for Survey 1, and 36 + SD 15 for Survey 2, with
a mean estimate of 34 + SD 11 calves (95% C.I. 30, 38).

A near-shore aerial survey (100% coverage) was flown on January 20
and 24 to document the numbers, distribution, and behavior of whales
within 0.75 nm of the sanctuary islands. Twenty-nine sightings totaling
58 whales and 2 calves were observed; an additional 22 whales and 1 calf
were sighted on connecting flights between the northern islands.

Gray whales were observed throughout the CINMS, but were primarily
distributed within waters 3 nm or less from the island shores; during
strip transects, for example, 94 % of the mother-calf pairs and 91% of
the whales without calves were within 3 nm of shore. Although the mean
distance from shore for both groups was similar (1.53 + SD 1.138 nm
versus 1.95 + SD 1.088 im, respectively), mothers and calves were
generally nearer to shore than were other whales; 82% of the mother-calf
pairs were within 2 nm of shore compared to 58% of the other whales. In
relation to water depth, 60% of the mother-calf pairs were in water
30 fm (54.4 m) or less in depth, while the remaining 40% were in waters
up to 300 fm (548.6 m) deep over the Santa Cruz Canyon. The majority of
the other whales (86%) were in waters up to 50 fm (91.4 m) deep.
Overall, there did not appear to be a strong trend for whales to prefer
a particular bottom type. Areas where whales tended to cluster included
the channels between the northern islands, particularly Santa Cruz
Channel, and points, reefs, and headlands including Point Bennett, Beacon
Reef, West Point, and Cavern Point. Locations where few or no whales
were seen included the south side of San Miguel Island, the southeast
side of Santa Rosa Island, the north side of Middle and West Anacapa
Island, and the east side of Santa Barbara Island.
The predominant behavior of all gray whales observed during aerial
surveys was traveling (70% of mother-calf pairs and 73% of whales
without calves); but mothers with calves traveled more slowly than other
whales. Overall, directional preference was southeast for whales
without calves (64%), east-southeast for mother-calf pairs (29% E, 21%
SE), and appeared related to the direction of the southward migration.
Courtship and mating, seen for 42 animals, comprised 22% of the behavior
of whales without calves. Resting and milling were seen for 25% of the
mothers and calves, compared to 2% of the other whales. Potential
feeding was seen for 3% of whales without calves and 5% of mother
whales; feeding behavior was observed 5 times within kelp beds and once
over a sand bottom. Group size varied from 1 to 14 animals, with most
whales without calves in pairs or groups; 22% were lone animals, 19%
were in pairs, 18% were in trios, and the remaining 41% were in groups
of from 4 to 14 animals. In contrast, each of the mothers was alone
with her calf. Twenty-three instances of apparent disruption to whales
due to the activities of commercial whale-watching boats were observed.

Radiotelemetry was used to track grays over 24-hour periods to
determine their day and night travel rates, inter-island migration

routes, duration of stay, local movements, and behavior in the CINMS.
Nine whales were tagged from January 21 to February I with a small (1.5
cm by 6 cm), implantable, capsule radio-tag applied with a crossbow
(developed by J. Goodyear). Each whale was tagged, monitored, and
tracked from a 68-foot motor-sailer until the whale exited from the
CINMS (6 cases), its radio signal was lost (2 cases), or it was
abandoned by the tracking vessel (1 case); locations of whales were also
determined using receivers aboard aircraft. Daytime and nighttime rates
of swimming (i.e. south migration rates) were not significantly
different. During 29.96 hours of daylight trac--ing, the 9 whales
traveled at a mean rate of 3.02 � SD 0.442 kts (5.59 � SD 0.819 km/hr)
with a range from 2.11 to 3.65 kts; during 25.5 hours of nighttime
tracking, the whales traveled at a mean rate of 3.45 � SD 0.452 kts
(6.39 � SD 0,.837 km/hr) with a range of 2.99 to 4.19 kts. The overall
mean duration of surfacings (i.e. the time the tag was above the water's
surface) was 2.05 + SD 0.731 sec, ranging from 0.29 to 4.5 sec (n =
702). The mean length of long dives (> i min) was 3.06 � SD 2.175 min,
ranging from 1.00 to 28.08 min (n = 829). The minimum duration of stay
within the CINMS varied from 3.9 to 60.7 hours for the six whales that
were monitored until their departure.

In the northern portion of the CINMS, the 9 radio-tagged whales
migrated along both the inner leeward-side (north) and the outer
weather-side (south) of San Miguel, Santa Rosa, Santa Cruz, and Anacapa
Islands; four inter-island routes were documented for these southward
migrants. Finally, 6 of the 9 grays radio-tagged from January 4 to 18,
1986, during the National Marine Mammal Laboratory sponsored study near
Granite Canyon, California were relocated a total of 17 times within the
CINMS. The time from the last detection of these whalers off central
California to the first detection in the sanctuary ranged from 3 to 14
days. Radio signals were received from these whales over I to 4 day
periods within the CINMS.

The occurrence of other cetaceans was documented opportunistically.
There were 26 sightings of 4 odontocete species and 15 sightings of
unidentified dolphin species, totaling 4,098 animals. No attempt was
made to estimate the size of these populations.

The gray whale is clearly an important species from the standpoint
of public education and recreational value, aesthetic appeal, economic
significance, and scientific interest. Because of its coastal habits,
the gray is the only large whale that can be regularly observed from
shore, and its lengthy annual migration is one of the world's
outstanding wildlife spectacles. Yet, it is this affinity for coastal
waters that poses a very real threat to the species. Concern exists
that gray whales may be moving their migration farther and farther
offshore in response to disturbance from increasing levels of inshore
small boat traffic. Successful management of the CINMS with regard to
gray whales requires an understanding of their natural history and
ecological relationship to this habitat in which they seasonally
concentrate. The importance of the CINMS as a habitat for these whales
must be ascertained in order to insure that the area will remain
available as a migratory corridor between their winter and summer

grounds, or as an area in which to overwinter. If continued for a
number of years, research programs like the one described here will
contribute the background information over the long term to guide
management decisions regarding the use of the CINMS as a habitat by gray
whales and other cetacean species as well.

For further information on this research program see:

Jones, M.L. and S.L. Swartz. 1986. Radio-Telemetric Study and Aerial
Census of Gray Whales in the Channel Islands National Marine
Sanctuary During the Southward Migration, January 1986. Final
Report to the National Marine Mammal Laboratory, NMFS, Seattle,
Washington, Contract No. 50-ABNF-6-00067. 144 pp.

Harbor Seals and Northern Elephant Seals
in Point Reyes

Sarah G. Allen
Point Reyes Bird Observatory
4990 Shoreline Highway, Stinson Beach, California 94970

HARBOR SEALS

Harbor seals are the most prevalent of the four species of pinniped
that inhabit the Point Reyes Peninsula. There are several primary sites
where seals congregate on shore including Tomales Bay, Tomales Point,
Point Reyes Headland, Drakes Estero, Double Point, Duxbury Reef and
Bolinas Lagoon. From previous studies we have found that large numbers
of seals congregate at these sites during the breeding season from March
through June. Maximum counts have been around 2500 seals. During fall
and winter months, the number of seals declines to around 1000. The
breeding season peak represents about 20% of the estimated California
population of harbor seals, and as a consequence the breeding population
in Point Reyes has gained considerable attention from the agencies
responsible for their management.

From previous studies we also determined that diurnal and tidal
effects on seal haul-out behavior varied within an optimum range with
most seals hauled out from mid-day to late afternoon at low to medium
tides, depending on the physical attributes of each location. Although
we had gathered considerable information on these shore based habits,
very little is known regarding the pelagic activities of this species.
And so we embarked on a new study in 1985.

Our main objectives were to 1) determine if the apparent decline in
seal numbers during the winter months was due to the seals spending more
time in the water, or if seals were moving to haul-out sites outside of
Point Reyes, 2) if seals did move to other areas, where did they go, 3)
did females behave differently from males, and 4) what were their daily
activity patterns (how long did they haul-out in a day, how many days in
a row, and how these patterns changed seasonally). To accomplish this
range of objectives we undertook a capture and radio tagging program.

In August of both 1985 and 1986, we captured around 20 adult seals
over a two-day period at Drakes Estero. We chose Drakes Estero because
it is one of the largest breeding areas in Point Reyes, and because the
capture technique we wished to use was only possible in an estuarine
environment. The seals were captured with a 300' eight-inceh mesh gill
net which was set off of the haul-out site and then pulled ashore, a
method successfully used in Oregon and Washington. Seals which were
encircled became entangled as the net was brought to shore in a beach
seine fashion. Seals to be tagged were removed and placed in hoop nets.
Seals were weighed, measured, dye-marked, flipper tagged, and radio
tagged. The transmitter was glued to the fur with 5 min epoxy, and
would be shed when the seal molted its fur the following summer. It
took us about 15 minutes to process each animal. Several agencies were
involved in the capture including the California Department of Fish and

-16

Game, the National Marine Fisheries Service, the Gulf of the Farallones
National Marine Sanctuary and the Point Reyes National Seashore.

We are using two techniques for tracking seals. We are monitoring
their presence or absence at Drakes Estero on a 24-hour basis with a
programmable receiver and an event recorder. To locate dispersing
seals, we fly on a bi-weekly basis along the California coast from
Monterey Bay to the Oregon border.

To date, our results indicate that equal numbers of seals departed
from Drakes Estero and stayed there through the winter months. Of the
seals that departed, most left within one month, and there were slightly
more females than males. Most departing seals moved to one or two other
sites and stayed there for the entire winter rather than continuing to
travel. Seals were highly individual in their movements and may be
expressing a preference for location based on past experience, including
foraging success, rather than responding to a predetermined migratory
path or in response to changes in abundance of a single prey item.
Locations where seals departed to included Hopkins Marine Station in
Monterey Bay, the Klamath River near the Oregon border, the Russian
River, Tomales Bay and Double Point. Distances traveled ranged from
480 km to 10 kin, and females appeared to travel longer distances than
males. In all cases seals traveled to an established seal haul-out
site.

From the seals that remained at Drakes Estero we have learned that
they are strongly diurnal in their haul-out pattern in both summer and
winter, and rarely haul-out at night. The largest percentage of seals
were hauled out between 0400 and 1600 hr, and this represented between
53% and 71% of the estimated number of seals in the area. Resident
seals were hauled out on fewer days during the winter (77% of the days
monitored) than the summer (92% of the days monitored). On average,
seals spent seven hours per day on shore both in summer and winter.
Though our sample size was too small to make statistical comparisons,
two pregnant females appeared to spend more time in the water than males
during the winter months. When seals were in the water, they either
remained in Drakes Estero until the next low tide, or they traveled to
nearby areas to feed such as Point Reyes Headland and Bolinas Point.

As the breeding season rolled around again in 1986 almost all
tagged seals returned to Drakes Estero indicating that Drakes Estero is
a focal breeding area for seals ranging as far south as Mon~terey Bay and
as far north as the Klamath River.

So preliminary results indicate that the winter decline in seal
numbers is related to both migration and a reduction in the number of
days spent on shore. In addition, our findings suggest that Point Reyes
may be a focal breeding area for seals of Central and Northern
California. The protection of seals at Point Reyes, therefore, is
important to maintaining the health of the population of this region.
The qualities which attract seals to Point Reyes may include preferred
substrates upon which to haul-out, bountiful food during the peak of the
breeding season, and inaccessibility to human activities.

From this study, we hope to design a more comprehensive management
plan for protecting seals by identifying the location and season of use
of sensitive areas, and by devising better estimates of population
numbers.

NORTHERN ELEPHANT SEALS

The northern elephant seal is another pinniped which we are closely
monitoring in Point Reyes since a new mainland colony was formed there
in the past few years. From historical reference, we know that elephant
seals once resided in Point Reyes, but we do not know in what numbers or
in what locations they were present. Northern elephant seals have
recovered from near extinction by commercial sealers in the 19th
century, and began recolonizing former rookery sites in California in
the 1950's. From a mere 100 animals, the population has grown
logarithmically to the current estimate of about 80,000.

Individual elephant seals began arriving in Point Reyes in the
early 1970's, but a colony did not form until 1981. From observing
flipper tags, we have determined that the colonizers came from Ano
Nuevo, San Miguel Island and the Farallon Islands as these other
colonies expanded to overflowing. The Farallon Island colony is close
enough for seals to travel back and forth to Point Reyes, and during the
breeding season we have identified seals that have done so within a
single day.

Unlike harbor seals, elephant seals come onshore during two periods
of the year, during the breeding season (December through March) and
during the molt period, and currently those are the only times when they
can be observed in Point Reyes. However, in an established colony seals
are present year round because each sex and age class molts at a
different time of year.

The current estimated population of breeding animals in Point Reyes
is about 60 seals including 22 pups. Based on the recolonization
process in other areas, we can expect this colony to continue to grow
and perhaps expand into new areas in Point Reyes. If we assume a
projected 40% increase per year, we can expect the population in Point
Reyes to be about 250 animals in 1990. By that time, a management plan
protecting seals from people and people from seals should be instituted.

REFERENCES
Ainley, D.Go, H.R. Huber, R.P. Henderson, and T.J. Lewis. 1977.
Studies of marine mammals at the Farallon Islands, California 1970=
1975. NTIS No. PB-274 046.
Allen, S.G., D.G. Ainley, G.W. Page, and C.A. Ribic. 1985. The effect
of disturbance on harbor seal haul out patterns at Bolinas Lagoon,
California. Fish. Bull. 82:493-50.

Allen, S.G., and H.R. Huber. 1983. Pinniped assessment in the Point
Reyes/Farallon Islands National Marine Sanctuary, 1982-83. Final
Rpt. NOAA Sanctuary Programs Office. 75 pp.

Allen, S.G., and H.R. Huber. 1984. Pinniped assessment in the Point
Reyes/Farallon Islands National Marine Sanctuary, 1983-84. Final
Rpt. NOAA Sanctuary Programs Office. 71 pp.

Beach, R.J., A. Geiger, S. Jeffries, S. Treucy, and B. Troutman. 1985.
Marine mammals and their interactions with fisheries of the
Columbia River and adjacent waters, 1980-1982. Third Annual Rpt.
U.S. Dept. of Comm., Nat. Marine Fish. Serv. 234 pp.

Boulva, J. and I.A. McLaren. 1979. Biology of the harbor seal, Phoca
vitulina, in eastern Canada. Bull. Fish. Res. Bd., Can. 200:T-3.

Brown, R.F. and B.R. Mate. 1983. Abundance, movements, and feeding
habits of harbor seals, Phoca vitulina, at Netarts and Tillamook
Bays, Oregon. Fish. Bu1T :291-301.

Fancher, L. 1979. The distribution, population dynamics, and behavior
of the harbor seal, Phoca vitulina richardsi, in south San
Francisco Bay-, California. MS Thesis. Calif. St. Univ.,
Hayward, California. 109 pp.

Hanan, D. 1986. California Department of Fish and Game, Coastal Marine
Mammal Study, Annual Report for the period July 1, 1984 to June 30,
1985. U.S. Dept. Comm., NMFS. Adm. Rept. LJ-86-25C. 46 pp.

Herder, M. 1986. Seasonal movements and haul out site fidelity of
harbor seals, Phoca vitulina richardsi, tagged at the Klamath
River, California. MA Thesis, Humbo-t St. Univ., Arcata,
California. 52 pp.

Pitcher, K.W. and D.C. McAllister. 1981. Movements and haul out
behavior of radio-tagged Harbor Seals, Phoca vitulina. Can. Field-
Natur. 95:292-297.

Stewart, B.S. 1984. Diurnal hauling patterns of harbor seals at San
Miguel Island, California. J. Wildl. Manage. 48:1459-1461.

Stewart, B.S., and P.K. Yochem. 1984. Radiotelemetry studies of
hauling patterns, movements, and site fidelity of harbor seals
(Phoca vitulina richardsi) at San Nicolas and San Miguel Islands,
California, 1982. Hubbs Sea-World Res. Inst. Tech. Rpt. No. 83-
152.

Potential Bioaccumulation of Long-lived Radionuclides
by Marine Organisms in the Vicinity of
The Farallon Islands Nuclear Waste Dump Site

Thomas H. Suchanek
Division of Environmental Studies
University of California, Davis, California 95616

and

Bodega Marine Laboratory
P.O. Box 247
Bodega Bay, California 94923

ABSTRACT

An estimated 47,500 containers (mostly 55-gallon drums) of
radioactive waste were dumped into the Farallon Islands Nuclear Waste
Dump Site (FINWDS), a region of approximately 530 square miles, mostly
overlapping with the Gulf of the Farallones National Marine Sanctuary.
Previous studies conducted in the early 1970's showed that at least some
barrels had imploded and leaked their contents into the surrounding
environment.

Sediment cores from the vicinity of the FINWDS may show
concentrations of 239,240-Plutonium at levels up to 1064 times expected
background concentrations. Cores from about 3.2 km away from the dump
site may show concentrations up to 134 times expected background levels
for these same radionuclides.

Marine organisms (invertebrates and fishes) collected from the
vicinity of FINWDS also show some elevated levels of 137-Cesium and
239,240-Plutonium. In the 1970's organisms containing tissue loads of
137-Cesium greater than 100 pCi/kg dry wt. were: INVERTEBRATES =
polychaete worms, sea cucumbers; FISH = Short-spined thornyheads, Rat-
tail, Sablefish, Deepsea Sole, Pacific Flatnose, Lanternfish, Pacific
Hake, Deep Sea Smelt, Dover Sole. Organisms containing tissue loads of
239,240-Plutonium greater than 100 pCi/kg dry wt were: INVERTEBRATES =
sponge; FISH = Rat-tail, Pacific Sandab.

Intertidal mussels from Southeast Farallon Island showed
concentrations of 239,240-Plutonium of 3.4 + 0.14 pCi/kg (dry wt)
compared with a mean of 1.0 + 0.68 pCi/kg for many other California
sites pooled (n=19, range = 0.14-2.09 pCi/kg). Mean levels for 241-
Americium were 8.91 + 0.68 pCi/kg compared with 2.68 + 2.95 pCi/kg for
all other California sites pooled (n=17, range = 0.04-7.86 pCi/kg).

Surface and bottom currents in the vicinity of the FINWDS are
complex and not well understood. Some studies indicate that bottom
currents from the dump site flow in a northerly direction, toward the
vicinity of Cordell Banks. Other studies indicate that bottom currents
could potentially transport radionuclides in an eastwardly direction

- 20 -

from the dump site up-slope onto the shelf and into San Francisco Bay
and San Pablo Bay.

Ongoing studies of bottom-feeding fishes collected from the
vicinity of the FINWDS are insufficient to adequately assess the
potential transfer of long-lived radionuclides from sediments to
invertebrates to commercially exploitable fishes. More in-depth studies
with in-situ experiments are needed to properly address this complex
issue.

INTRODUCTION

Between 1946 and 1970, at least 47,500 containers (mostly 55 gallon
drums) of radioactive waste were dumped into a region of approximately
530 square nautical miles, roughly southwest of Southeast Farallon
Island and mostly within the Gulf of the Farallones National Marine
Sanctuary (Joseph et al., 1971). In 1946 an estimated 150 containers
were dumped at a 91 m depth site (ca. 300 ft. 50 fm) at roughly 370 37'
N; 1230 00' W. From 1951-1953 another 3,600 containers were dumped at a
914 m site (ca. 3,000 ft; 500 fm) at roughly 370 38' N; 1230 08' 30" W.
Finally, from 1945-1950 and from 1954-1970 an additional 44,000
containers were dumped at an 1829 m site (ca. 6,000 ft; 1000 fm) in the
vicinity of 370 37' N; 1230 20' W (Joseph, 1956; Waldichuk, 1960; Joseph
et al., 1971). Apparently, adequate inventories of the contents of these
containers were not kept or are not available today. However, excluding
3-H ("tritium" with a 12.2 year half-life), an estimated 14,500 Curies
(Ci) of radioactive materials (including 30-y 137-Cesium, 432-y 241-
Americium, 88-y 238-Plutonium, 24110-y 239-Plutonium, 6560-y 240-
Plutonium and other anthropogenic transuranic radionuclides) were
deposited at these sites.

PREVIOUS STUDIES:

Several studies on the levels and distribution of long-lived
radionuclides have been conducted at or near the Farallon Islands
Nuclear Waste Dump Site (FINWDS). As early as 1974, some waste
containers were viewed with the remotely controlled submersible CURV III
and were shown to have imploded and leaked their contents into the
surrounding environment (Dyer, 1976). Sediment cores taken from the
vicinity of (ca. 3.2 km from) the 900 m dump site have been reported to
have 137-Cesium concentrations significantly higher than expected
"background" levels.1 In addition, sediment cores taken from the
immediate vicinity of one of the dump sites have been reported to have
2-25 times higher concentrations of 239,240-Plutonium than expected

1 Expected background radiation levels are derived from estimates
of fallout mostly from atmospheric weapons testing during the 1950's and
1960's. At this latitude, expected background levels for 137-Cs are
9.0-77.0 pCi/kg in surface sediments (0-5 cm depth) and 2.0-23.0 pCi/kg
in sediments 5-10 cm depth. For 239,240-Pu these expected levels are
4.5-18.0 pCi/kg for surface sediments and 0.5-7.0 pCi/kg for sediments
5-10 cm depth. (See Bowen in Dyer 1976.)

background levels (see Dyer, 1976; Schell & Sugai, 1980). However,
reanalysis of Dyer's values for radionuclide concentrations reveals that
cores taken from this site may actually range up to 1064 times expected
background radiation levels. Similarly, cores taken 3.2 km from the
specified dump site may range up to 134 times expected background
radiation levels (see Table 1).

Deep-sea organisms collected from the vicinity of the FINWDS have
been shown to contain some elevated levels of short and long-lived
radionuclides (Schell & Sugai, 1980) (Table 2). Organisms containing
tissue loads of 137-Cesium greater than 100 pCi/kg dry wt are:
INVERTEBRATES = polychaete worms, sea cucumbers; FISH = Short-spined
thornyheads, Rat-tail, Sablefish, Deepsea Sole, Pacific Flatnose,
Lanternfish, Pacific Hake, Deep Sea Smelt, Dover Sole. Organisms
containing tissue loads of 239,240-Plutonium greater than 100 pCi/kg dry
wt are: INVERTEBRATES = sponge; FISH = Rat-tail, Pacific Sandab. The
significance of these radionuclide concentrations, their actual
bioaccumulation rates and the relationship to concentrations found in
organisms away from the dump sites is as yet unknown.

Mussels are efficient filter feeders, and as such have been used
effectively in statewide, nationwide and worldwide programs to monitor
pollutant levels in the natural environment. Mussels have been found to
concentrate radionuclides ca. 200-300 times the level found in
surrounding seawater. The Farallon Islands have also been used as one
of many California sites with which to compare national pollutant levels
on both coasts of the United States through a program known As Mussel
Watch (Goldberg et al., 1978). However, no "regular" transuranic
radionuclide analyses have been performed on mussels during the
California Mussel Watch program reported by Ladd et al. (1983). This is
surprising since one set of data from the EPA National Mussel Watch
program clearly indicates that mussel tissues from the Farallon Islands
site (collected in 1976) yielded the highest levels of 239,2340-
Plutonium and the highest levels of 241-Americium of any samples
collected from both coasts of the United States (Goldberg et al., 1978).

The EPA reported that mussel tissues from the FINWDS contained
roughly 3.3 times the mean radionuclide concentration found at all other
California sites pooled. Mussel samples from FINWDS have mean dry
weight radionuclide concentration levels for 239,240-Plutonium of 3.4 +
0.14 pCi/kg compared with a mean of 1.0 + 0.68 pCi/kg for all other
California sites pooled (n=19, range = 0.14-2.09 pCi/kg). Mean levels
for 241-Americium were 8.91 + 0.68 pCi/kg compared with 2.68 + 2.95
pCi/kg for all other California sites pooled (n=17, range = 0.04-7.86
pCi/kg). No radionuclide analyses were performed on any specific organs
or the shells of mussels from the Farallon Islands site.

Both surface and bottom currents have also been studied in the
FINWDS region (Conomos et al., 1971; Conomos, 1975; D. Lindberg, pers.
comm., unpublished data; Dyer, 1976; Conomos & Peterson, 1977). These
results indicate that surface currents from FINWDS generally show
significant northward and/or southward movement along the coast, whereas
bottom currents are more complex (Fig. 2). One current meter placed on
the bottom at the 1829 m Farallon Islands dump site during 1975 showed

essentially northward bottom current movement at speeds of ca. 1.17
km/day (Dyer, 1976). Bottom currents moving in this direction would
likely transport particles toward the vicinity of Cordell Banks, a
region known to be used extensively for commercial and sport fisheries.
However, another bottom current study (using seabed drifters released in
the Gulf of the Farallons) indicates consistent eastward movement of
bottom currents at speeds of at least 0.5 km/day (Conomos et al., 1970,
1971; McCulloch et al., 1970; Conomos & Peterson, 1977). Significantly,
these currents move particles along the sea floor up-slope from deep
water, traveling onto the shelf with final destinations in San Francisco
Bay and San Pablo Bay (Fig. 2).

ONGOING STUDIES

Four taxa of bottom-feeding fishes and one taxon of mussels are
currently being collected from the FINWDS and from a comparison site to
the north to be analyzed for concentrations of long-lived radionuclides
under a contract through the State of California Department of Health
Services (Suchanek & Lagunas-Solar, 1986). Included in these
collections are: four species of fishes (Dover Sole = Microstomus
pacificus, Sable fish = Anoplopoma fimbria, Short-spined Thornyhead =
Sebastolobus alascanus and Long-spined Thornyhead = Sebastolobus
altiveles) and one species of mussel (Mytilus californianus). These
species are being collected from the FTINWDS at three sampling periods
during 1986-1987. In addition, samples of these same species are being
collected for control (comparison) purposes during the same periods from
comparable depths off Point Arena (ca. 100 km north of the FINWDS).

Most of the bottom-feeding fishes being studied are quite mobile.

DOVER SOLE (Microstomus pacificus): Dover Sole generally occurs on
muddy bottoms and ranges from ca. 180-3900 ft depth. Its larvae have
been found offshore to 280 miles. It is not a widely migrating species,
but has some coastwise movement, and several isolated sub-populations
are believed to exist (Frey, 1971). Dover Sole does, however, undergo
extensive onshore-offshore seasonal movements related to its spawning
cycle. During spring through summer it can generally be found more
inshore where it feeds extensively. During fall and winter (November-
March) it moves offshore for spawning, where it produces buoyant
planktonic eggs. Adults feed exclusively on benthic invertebrates:
bivalves, scaphopods, sipunculids, polychaetes, chinoids, ophiuroids,
gastropods and crustaceans (Frey, 1971).

THORNYHEADS (also called Idiots or Channel Rockfish - Shortspine =
Sebastolobus alascanus; Longspine = Sebastolobus altiveles): These
species are non-migratory deep-water species that are generally known to
range from 1800-2520 ft depth although they likely occur deeper
(Phillips, 1957; Frey, 1971).

SABLEFISH (Anoplopoma fimbria): This species prefers soft bottom
habitats like the Dover Sole and are usually found deeper than 300 ft.
They are not known to migrate for spawning, but migration may be
important, as one individual tagged in Japan was later found in the
United States (Frey, 1971). Spawning generally occurs from December-

April with a peak in January-February. Juveniles are known to feed on
the following benthic invertebrates: copepods, amphipods, euphausids,
fish eggs, fish larvae and the larvacean Oikopleura. Subadults and
adults generally are believed to feed on euphausids, tunicates and fish
(especially anchovy) (Frey, 1971; Cailliet et al., 1987).

Although these fish species may be caught at the FINWDS, there is
no knowledge of their past history or amount of time spent in the
vicinity of the dump sites feeding on benthic invertebrates. Therefore,
"negative" data (i.e., no or low radionuclide concentrations in these
species) would not necessarily indicate that fish are not a vector for
radionuclides entering the human food chain. What is needed is a more
complete and in-depth analysis of the potential pathways by which these
radionuclides may be concentrated in human food resources.

As extremely efficient filter-feeders, mussels are being used as an
effective radionuclide monitoring device. Higher absolute
concentrations of radionuclides should increase the precision for the
determination of differences between levels found at the FINWDS and
those at the Point Arena control site.

RECOMMENDED STUDIES

Because many marine organisms (taken either commercially or by
sport fishermen) from the region surrounding the Farallon Islands are
used as food, it is especially important to determine the nature and
extent of any bioaccumulation of long-lived radionuclides which may have
taken place in these organisms. In addition, it is important to
evaluate to what extent, if any, this source of radionuclides may be
affecting other marine life or the natural environment in the local
region.

One species of fish that is currently used only for pet food or
fish meal and that has been considered a "trash fish" for some time is
the Pacific Hake (Merluccius productus) (Alverson & Larkins, 1969). It
is expected, however, that this species will be exploited for human
consumption in the relatively near future. Pacific Hake populations
undergo long seasonal feeding migrations. They migrate from winter
spawning grounds in Southern California to several locations along the
West Coast from Central California to British Columbia (including the
Farallon Islands) to feed during summer months. It is not known whether
discreet sub-populations exist, or whether panmixia occurs in the
spawning grounds. However, during summer feeding in the Farallon
Islands region, this species also has the potential to accumulate
radionuclides from the FINWDS. Therefore, the importance of analyzing
both local and widely migratory fish species should not be overlooked.

Bioturbation, the process of sediment disturbance by organisms
feeding upon or moving through sediments, has also been documented in
the region of the FINWDS (Dyer, 1976; Reish, 1978; Dayal, 1979; Schell &
Sugai, 1980). In most areas of the shallow and deep-sea, some of the
most important bioturbators are sediment-dwelling worms and crustaceans
(Toots, 1961; Suchanek, 1983; Suchanek & Colin, 1986; Suchanek et al.,
1986). Many of these organisms (especially the crustaceans) burrow

deeply into the sediment (often 1-2 m) and may contribute to the
mobilization or remobilization of materials (both physical and
biological) both down into the sediment and/or up from depths within the
sediment (Clifton & Hunter, 1973; Ott et al., 1976; Pemberton et al.,
1976; Suchanek, 1985).

In regions where radionuclides are found associated with or
incorporated into sediments, bioturbators are likely to influence the
vertical distribution of the radioactive particles, either through
burial or through remobilization of particles back to the sediment/water
interface or into the water column (Bowen et al., 1976; McMurtry et al.,
1985, 1986; Colin et al., 1986; Suchanek & Colin, 1986; Suchanek et al.,
1986). This process can facilitate the consumption of radionuclide-rich
sediments by deposit-feeding invertebrates which, in turn, may be
consumed and further concentrated by commercially exploited bottom-
feeding fishes. Near the Farallon Islands Nuclear Waste Dump Site, this
concern is especially relevant for such bottom-feeding fishes as the
Dover Sole, the Short-spine and Long-spine Thornyheads and the
Sablefish, all of which are consumed by humans. Therefore, in-situ
bioturbation studies would yield valuable data on mixing rates of
sediments in the vicinity of the barrels and allow estimation of
radionuclide transfer rates from the sediment surface to depth and of
remobilization of radionuclides from regions deep within sediments back
to the surface.

Even if the radionuclide levels determined for sediments and
organisms in the early 1970's were within acceptable and/or expected
background levels, the intervening 15+ years has further acted upon the
16-gauge steel 55-gallon drums. In 1987, some 30-40 years after many of
these barrels were deposited, an unknown amount of deterioration of
barrels has taken place. A more in-depth study should now be initiated
in which the processes and pathways of any potential bioaccumulation of
long-lived radionuclides is evaluated for this site.

These studies should include at the minimum:

1. Gross determination of radionuclide concentrations found both
at the dump site and at a control (comparison) site including
concurrent sampling of:

a) Sediments
b) Water Column
c) Invertebrates
d) Fishes

2. Modeling of radionuclide concentrations and transfer rates
between the physical (sediment and water) components and
biological components of the deep-sea community found at the
FINWDS.

3. Rigorous oceanographic current studies (both surface and bottom
currents) to determine more accurately the pathways along which
radionuclide particles from the FINWDS may pass. Data

available from currently published literature conflict
significantly (see above).

4. Initiation of in-situ bioturbation studies to determine to what
extent and to what sediment depth radionuclides are being mixed
and potentially remobilized into the water column.

5. Expansion of present biological studies to include Pacific Hake
populations.

LITERATURE CITED

Alverson, D.L. & H.A. Larkins. 1969. Status of knowledge of the
Pacific Hake resource. California Marine Resource Commission,
CalCOFI Report 13:24-31.

Bowen, V.T., H.D. Livingston & J.C. Burke. 1976. Distribution of
transuranius nuclides in sediment and biota of the North Atlantic
Ocean. pp. 107-120. In: Transuranium Nuclides in the
Environment. Proceedings of a Symposium - IAEA - Vienna. IAEA-SM-
199/96.

Cailliet, G.M., E.K. Osada & M. Moser. 1987. Ecological studies of
Sablefish in Monterey Bay. California Fish and Game Bulletin (in
press).

Clifton, H.E. & R.E. Hunter. 1973. Bioturbational rates and effects in
carbonate sand, St. John, U.S. Virgin Islands. Journal of Geology
81: 253-268.

Colin, P.L., T.H. Suchanek & G.M. McMurtry. 1986. Water pumping and
particulate resuspension by callianassids (Crustacea;
Thalassinidea) at Enewetak and Bikini Atolls, Marshall Islands.
Bulletin of Marine Science 38:19-24.

Conomos, T.J. 1975. Movement of spilled oil as predicted by estuarine
nontidal drift. Limnology & Oceanography 20:159-173.

Conomos, T.J. & D.H. Peterson. 1977. Suspended-particle transport and
circulation in San Francisco Bay. In: Estuarine Processes II.
Circulation, Sediments, and Transfer of material in the Estuary.
Academic Press, New York.

Conomos, T.J., D.H. Peterson, P.R. Carlson & D.S. McCulloch. 1970.
Movement of seabed drifters in the San Francisco Bay estuary and
the adjacent Pacific Ocean. U.S. Geological Survey Circular 637-B.
7 pp.

Conomos, T.J., D.S. McCulloch, D.H. Peterson & P.R. Carlson. 1971.
Drift of surface and near-bottom waters of the San Francisco Bay
system, California: March 1970 through April 1971. U.S.
Geological Survey - Open File Map and USGS-HUD Basic Data
Contribution 22.

Dayal, R., I.W. Duesdall, M. Fuhrmann & M.G. Heaton. 1979. Sediment
and water column properties at the Farallon Islands radioactive
waste dumpsites. Marine Sciences Research Center, State
University of New York, Stony Brook.

Dyer, R.S. 1976. Environmental surveys of two deep-sea radioactive
waste disposal sites using submersibles. In: International
Symposium on the Management of Radioactive Wastes from the Nuclear
Fuel Cycle. IAEA-SU-207/65 (IAEA - Vienna, 1976).

Frey, H.W. (Ed.). 1971. California's Living Resources and Their
Utilization. Department of Fish and Game. 148 pp.

Goldberg, E.D., V.T. Bowen, J.W. Farrington, G. Harvey, J.H. Martin,
P.L. Parker, R.W. Risebrough, W. Robertson, E. Schneider & E.
Gambel. 1978. The Mussel Watch. Environmental Conservation
5:101-125.

Joseph, A.B. 1956. United States Sea Disposal Operations - A summary
to December 1956. Mimeo report Washington - 734.

Joseph, A.B., P.R. Gustafson, I.R. Russell, E.A. Schuert, H.L. Volchok &
A. Tamplin. 1971. Sources of radioactivity and their
characteristics. In: Radioactivity in the Marine Environment.
Washington, D.C.: NAS) pp. 6-41.

Ladd, J.M., S.P. Hayes, M. Martin, M.D. Stephenson, S.L. Coale,
J. Linfield & M. Brown. 1984. Trace metals and synthetic organic
compounds in mussels from California's coast, bays and estuaries.
California State Mussel Watch: 1981-1983 Biennial Report. Water
Quality Monitoring Report no. 83-6TS.

McCulloch, D.S., D.H. Peterson, P.R. Carlson & T.J. Conomos. 1970.
Some effects of fresh-water inflow on the flushing of South San
Francisco Bay: a preliminary report. U.S. Geological Survey
Circular 637-A. 27 pp.

McMurtry, G.M., R.C. Schneider, P.L. Colin, R.W. Buddemeir & T.H.
Suchanek. 1985. Redistribution of fallout radionuclides in
Enewetak lagoon sediments by bioturbation. Nature 313:674-677.

McMurtry, G.M., R.C. Schneider, P.L. Colin, R.W. Buddemeir &.T.H.
Suchanek. 1986. Vertical distribution of fallout radionuclides in
Enewetak lagoon sediments: effects of burial and bioturbation on
the radionuclide inventory. Bulletin of Marine Science 38:35-55.

Ott, J.A., B. Fuchs, R. Fuchs & A. Malasek. 1976. Observations on the
biology of Callianassa stebbingi Borrodaille and Upogebia litoralis
Risso and their effect upon the sediment. Senckenbergiana Maritima
8:61-79.

Pemberton, G.S., M.J. Rish & D.E. Buckley. 1976. Supershrimp: deep
bioturbation in the Strait of Canso, Nova Scotia. Science 192:790-
791.

Phillips, J.oB. 1957. A review of the rockfishes of California.
California Department of Fish and Game Bulletin No. 104. 158 pp.

Reish, D.J. 1978. Survey of the marine benthic infauna collected from
the United States radioactive waste disposal sites off the Farallon
Islands, California. (Unpublished report.)

Schell, W.R. & S. Sugai. 1980. Radionuclides in the U.S. radioactive
waste disposal site near the Farallon Islands. Health Physics
39:475-496.

Suchanek, T.H. 1983. Control of seagrass communities and sediment
distribution by Callianassa (Crustacea, Thalissinidea)
bioturbation. Journal of Marine Research 41:281-298.

Suchanek, T.H. 1985. Thalissinid shrimp burrows: ecological
significance of species-specific architecture. Proc: Fifth
International Coral Reef Congress, Papeete, Tahiti 5:205-210.

Suchanek, T.H. & P.L. Colin. 1986. Rates and effects of bioturbation on
invertebrates and fishes at Enewetak and Bikini Atolls. Bulletin
of Marine Science 38:25-34.

Suchanek, T.H., P.L. Colin, G.M. McMurtry & C.S. Suchanek. 1986.
Bioturbation and redistribution of sediment radionuclides in
Enewetak Atoll lagoon by callianassid shrimp: biological aspects.
Bulletin of Marine Science 38:144-154.

Suchanek, T.H. & M.C. Lagunas-Solar. 1986. Bioaccumulation of long-
lived radionuclides by marine organisms from the Farallon Islands
Nuclear Waste Dump Site. Sate of California Department of Health
Services: Interagency Agreement.

Toots, H. 1961. Burrowing organisms and their effects on sediments.
Geol. Soc. of America Special Paper 68:1-107.

Waldichuk, M. 1960. Containment of radioactive waste for sea disposal
and fisheries off the Canadian Pacific coast. In: Proc. IAEA
Symposium, Disposal of Radioactive Wastes (IAEA, Vienna, 1960)
Volume 2:57-77.

FIGURE CAPTIONS

Figure 1. Results of (A) surface current and (B) bottom current studies
in the Gulf of the Farallons in 1970 and 1971. Figures
reproduced from Conomos et al., 1971.

Figure 2. Migratory route of the Pacific Hake (Merluccius productus)
along the West Coast showing winter spawning grounds in
Southern California and summer feeding grounds in the
vicinity of the Farallon Islands. Figure reproduced from
Alverson & Larkins (1969).

TABLE 1. Recalculation of values for 230,240-Plutonias (given in pCilkg dry wt) fromee Dyer (1976: Table 2) showing relative
magnitudes above expected background concentrations. Results given for data from three independent laboratories.

(A)a ()b (C)
Sediment 'Values from nagnitude Values from Hagnitude Values froee agnitude
Depth in EPA Lab Above LFE Lab Above WHOI Lab Above
Core ice) (pCi/kg) Background (pCi/kq) Background fpCil/kg) Background

CORES TAKEN
FROM DUhPSITE:
(code number)

CORE 1 0-5 26 +1- 3 1-6 23 +1- 3 1-5 46 +I- 4 3-10
(134273)

CORE 2
(1342741 0-5 360 +1- 14 20-60 447 +1- 13 25-99 482 +/- 48 27-107

5-10 - - 532 +1- 77 76-1064

CORE 3 0-10 66 +- 17 4-132 55 +- 4 3-10 - -
(134271)

CORE 4 0-10 91 +1- 20 5-182 50 +1- 5 3-100
(134272)

CORES TAKEN
3.2 KR
Southeast of
Duepsite:

CORE 5 0-5 67 +/- 14 4-134 - 0 +/- 9 4-1B
(134270)
5-10 - - - 62 +/- 4 9-124

10-15 ? ? ? ? 15 +1- 4 ??

CORE 6 0-10 29 +I- 12 2-58 0 +1- 4 background -
1134269)

(A)a Environmental Protection Agency: Environmental Monitoring and Support Laboratory

(B) : LFE Environmental Analysis Laboratories

(C)C: Mood Hole Oceanographic Institution

TABLE 2. Invertebrates and fishes from the Farallon Islands Nuclear Waste Dump
Site containing radionuclide concentrations (for 137-Cesium and
239,240-Plutonium) greater than 100 pCi/kg dry wt. Data extracted
from Schell & Sugai (1980:Table 2).

Taxa Tissue 137-Cesium 239,240-Plutonium

INVERTEBRATES:

Polychaete worm Evicerated whole 131 +/- 113 46 +/- 8

Sea cucumber Viscera 199 +/- 55 84 +/- 21

Sponge Entire N.D. 362 +/- 38

FISHES:

Deep-sea Smelt Entire 351 +/- 222 < 26

Deep-sea Sole Skin 128 +/ 11 -

Dover Sale Liver 361 +/- 293 20 +/- 1

Lanternfish Entire 233 +/- 158 < 11

Midshipman Skin 155 +/- 113 < 7

Pacific Flatnose Liver (solids) 161 +/- 105 ( 7

Pacific Hake (juvenile) Entire 451 +/- 432 < 41

Pacific Sandab Skin N.D. 482 +/- 95

Rat-tail S.I.T. contents 310 +/- 279 40 +/- 10
Rat-tail Liver N.D. 142 +/- 23

Sablefish Viscera 113 +/- 91 < 3

Short-spine Thornyhead Skin 278 +/- 213 < 16

FIGU RE 1
Aa\N1 \ w 31
A

*mm-

SAN JOSE

FIGURE 8
SURFACE DRIFT
RELEASES; 2-6 MARCH 1971
RECOVERIES THROUGH 25 APRIL 1971

121- 122-

13?
W\\_z CRYES

FIGURE I
BOTTOM DRIFT
RELEASES: 5-6 MARCH 1970 2o 0\
RECOVERIES THROUGH 10 MAY 1970 jEr

Figure 1. Results of (A) surface current and (B) bottom current studies
in the Gulf of the Farallons in 1970 and 1971. Figures
reproduced from Conomos et al., 1971.

FIGURE 2

WINTER�
,at,~ Sa

Figure 20 Migratory route of the Pacific Hake (Merluccius productus)
along the West Coast showing winter spawning grounos in
Southern California and summer feeding grounds in the
vicinity of the Farallon Islands. Figure reproduced from
Alverson & Larkins {1969).
Al verson & Larki ns ( 1969) .

Field studies of the white shark,
Carcharodon carcharias, in the
Gulf of the Farallones National Marine Sanctuary

A. Peter Klimley
Assistant Research Behaviorist, Bodega Marine Laboratory
University of California, P.O. Box 247, Bodega Bay, California 94923

From 1985 to 1987 I have conducted field studies of the white shark
in the Gulf of the Farallones with support from NOAA. My first
objectives were: 1) to establish a study site where white sharks were
relatively abundant, and 2) develop a method for affixing ultrasonic
pingers and transmitters to the sharks. Field work was carried out May
and September-December 1985. The latter time period was chosen because
white shark predatory attacks on seals and sea lions are most commonly
witnessed at Southeastern Farallon Island by field biologists of the
Point Reyes Bird Observatory at that time. During May we made six one-
day cruises, and during September and October we made four three-day
cruises aboard the R/V Susan K of the Bodega Marine Laboratory to sites
within the Sanctuary. The order in which sites were visited was based
on evidence for the presence of white sharks (i.e., a high frequency of
white shark captures, attacks on humans, and attacks on pinnipeds) and
the convenience of working at each location (i.e., closeness of port,
protection from rough seas, and absence of divers). We firstly visited
Bird Rock, secondly Southeastern Farallon Island on two occasions, and
thirdly Elephant Rock and Drake's Estero. During these cruises we
baited continuously, standing four-hour watches, for time periods
averaging 40 hours.

During these cruises we only attracted one shark, and that was at
Southeastern Farallon Island. The shark was not attracted to the R/V
Susan K moored at East Landing, but a hang-bait station deployed in
Mirounga Bay. The station consisted of an anchor, chain and line
leading to a surface buoy and back down along the first line where a
breakaway connection held the lines together in a midwater position. A
buoy and radio pinger were attached to the doubled back line at this
point. Also attached to the line was a burlap bag of fish, a plastic
container of blood, a similar container of betaine and glycine (two
amino acids which evoke feeding responses in sharks), and a sheep with
an attached ultrasonic telemetry transmitter with a temperature sensor.
If the shark were to swallow the bait and transmitter, it would monitor
with its thermistor ingestion of warm-bodied seals or sea lions. We
were alerted that a shark had fed on the bait by the signal of the
surfacing radio pinger. Upon our arriving at the bait station, we
observed that the sheep had been removed from the station. A
Carcharodon appeared soon, feeding firstly on the burlap bag of fishes
and secondly on the container of blood. We received a very weak signal
on the DuKane. We assumed the signal was attenuated due to sound
reflection from the fatty layer of ingested seals or sea lions. A
second transponding tag will be attached externally to the shark at the
time of internal tag implantation to increase the signal's range.

- 33 -

It is difficult to believe that white sharks were not encountering
the long corridors of olfactory stimulants created during our lengthy
baiting sessions. I speculated whether the sharks might be avoiding the
vessel after swimming up the corridor. Our failure to attract a white
shark to the vessel but our success in attracting a shark to the remote
bait station led me to hypothesize that the shark's motivation to
approach the vessel, orienting to the odor corridor, sound playback, and
baits, might be opposed by the motivation to withdraw. This conflicting
motivation could be based on: 1) the vessel's large size, 2) the high
amplitude, low frequency sounds from the waves splashing against the hull
and continuously operating generator, and 2) the large array of lights.
The motivation to withdraw might overcome that of approach. I decided
that future search activities should be concentrated at Southeastern
Farallon Island, the site providing the greatest success until this
time, and performed from our outboard skiff. The outboard skiff was
only the size of the largest conspecific, and for this reason, would not
frighten sharks from feeding on a bait.

The logistics to conducting research activities from Southeastern
Farallon Island were formidable. Although lodging and meals were
available at the Point Reyes Bird Observatory field station, we had to
ship large amounts of bait to the island weekly and keep it frozen until
use. Furthermore, we needed to be constantly vigilant of inclement
weather. Originally, we were not allowed to lift our skiff onto our
cradle kept on East landing because the field biologists feared the
crane cable might break. For this reason, we motored in an inflatable
out to our skiff tethered to the mooring in Fisherman' s Bay. The
inflatable was attacked and sunk by a white shark while we worked
elsewhere in Mirounga Bay. We then lifted our research skiff into the
water with the crane before loading supplies. This was hazardous due to
the swell, surging back and forth within Garbage Gulch.

Several search strategies were used at Southeastern Farallon
Island. We repeatedly baited at a single location to habituate the
white sharks to the presence of the skiff near a bait with an attached
transmitter. From a record of the locations, dates, and time of day of
white shark attacks on pinnipeds transcribed from the Point Reyes Bird
Observatory field journals, we noticed that sharks appeared to feed in
bouts separated by one to two days at a single location. One such bout
had occurred on 15 and 16 October east of Saddle Rock less than a week
prior to our arrival at the island.

We encountered sharks every time we baited out of the Small skiff
at Southeastern Farallon Island: almost always if we baited longer than
two hours. A chronological record of our baiting periods as well as a
chart with the positions of attracted sharks is given in rig. 1. In
their first appearances, the sharks remained by the boat only briefly,
passing under its hull two to three times before departing without
feeding on the bait. This may be a predatory strategy of the sharks to
minimize the time at the surface in prey investigation, capture, and
handling to minimize the opportunity of surface positioned pinnipeds
from learning the shark's role as a predator. At this time I was unable
to attach an external transmitter with a long pole spear.

The sharks later began to feed near the skiff, firstly on a burlap
bag of fish and secondly on the sheep, although the sheep was only
mouthed. This careful inspection and reluctance to feed is contrary to
the shark's highly publicized image of an indiscriminate predator. To
increase the positive reinforcement for sharks to approach the bait, we
deployed bait stations at our baiting site. Eventually, sharks commenced
to mouth the bait more than a single time. We could then lure them to
the side of the skiff by retrieving the tethered bait.

We attached an 18-month position-indicating beacon to Delta, a
4.25 m female white shark, from the end of a pole spear after luring her
by the side of the skiff on 14 November. Tag attachment caused little
apparent trauma to her as she continued to swim at the same rate after
tag attachment. She did, however, move away from the island after
mouthing the bait several times. Her departure may have been caused by
aggressive exclusion by Beta, a 5.25 m male, who appeared immediately
after she left, swimming up out of the water and grasping the bait in
his mouth before releasing it. This shark also moved away as a third
shark surfaced, a massive individual near 6 m in length (based on tape
marks separated by 20 cm along the chine of the skiff). This shark also
swam up out of the water, grasped the bait, and then spit it out. The
appearance of these three sharks on 14 November corroborated our
estimate of the number of white sharks currently in Mirounga Bay, based
on: 1) our encounter with Delta, a small individual in the western bay,
2) the observation of Gamma, the largest shark, to kill a pinniped in
the center of the bay, and 3) repeated baiting encounters and the
observations of three pinniped kills east of Saddle Rock by Beta, an
intermediate-sized shark (see times and locations of sightings in
Fig. 1.) Epsilon, a fourth shark even smaller than Delta, was
encountered west of Indian Head on 19 November.

We were not able to track Delta as she swam away from the island
because the seas were increasing and night was approaching. However,
based on this tagging, we have formulated a plan of how to successfully
tag and track sharks in the future. The RIV Susan K will tow the
smaller skiff to the island. The larger vessel will be moored then at
East Landing while we bait for sharks from the small skiff within
Mirounga Bay. Upon tag application, we will tie the smaller skiff off
to the mooring at Fisherman's Bay and follow the shark aboard the larger
vessel. Future research planned for the white shark will be carried out
at Southeastern Farallon Island and will be directed toward
understanding the predatory-prey relationships between the white shark
and its pinniped prey.

Y CHANNEL SOUTH FARALLON ISLAND
-~i~ Mirounga angus/iostris
~,Z/ophous cc/ifornionus

A�LOW
INDIAN U ARCH GARBAGE GULCH
HEAD

8+ EAST LANDING_/ 43 �

MUSSEL
(ca. Ikm) FLAT hSEA
1/ MIROUNGA PIGEON
BAY, GULCH
'3~~~~~~~~~~
9+ 12
TIME OF YEAR a(9-I6tagged 4
OCT 15 18 21 24 27 30 I internally) 2 -
0800' ''''IIIIII5~iO~~~m-..
oeoo i i ~~~~~~~~~~~~~~14 c-
1200 .%..;.*.
40 ~ --IOin --- a
o1600 - P Xffi'-
U- '0�(2) (3) (4) tagged
o ~~~~~~~~~~~~~~~~externally N
0 NOV I 4 7 10 13 16 19 N
rO800 1/ 310~1~9~1~~: Ipi I I WHITE SHARK
L (14) 00 IDENTIFICATIONS
4 3 5.25mnTL (tagged) 0 50 100 200
1600 - :O-P;.5mL ...
1 (4) (1)52mT
Y = 6.00m TL meters
Li BAITING - SHARK SIGHTING S 4.25mTL (tagged)
3 E�~~~~~~~~~~~~~~~~~~~~E=3.50m T 13'0

I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~c

t 4 1~~~~~~~~~~~~~~~~~~~~~~~~~~o

Harbor Porpoise, Phocoena phocoena, in the
Gulf of the FaralTlTones
National Marine Sanctuary

Isadore D. Szczepaniak
Department of Ornithology and Mammology
California Academy of Sciences, San Francisco, California 94118

The harbor porpoise, Phocoena phocoena, is the smallest cetacean
found in northern California waters. The average adult length is 1.5 to
1.6 m and the average adult weight is 45-60 kg. Maximum length and
weight of North Pacific harbor porpoise are 1.86 m and 90 kg. Females
are slightly larger than males. Length at birth ranges from 65-90 cm
and birth weight is approximately 5 kg.

The body is robust and chunky. The snout is blunt with no
prominent forehead or beak. There is a single, crescent shaped
blowhole. The dorsal fin is triangular with a blunt tip. The small
flippers are oval in shape and taper to a blunt point. The flukes are
distinctly notched.

The color pattern is variable, usually dark brown, black or gray
above and light brown, gray or white below. The flukes, flippers and
dorsal fin are usually dark gray or black.

The harbor porpoise has a circumpolar distribution in the northern
hemisphere. It is found in the cool, shallow ice-free waters of the
North Atlantic and North Pacific including adjacent bays, rivers and
estuaries. In the eastern North Pacific they can be found from Point
Barrow, Alaska to Morro Bay, California (Leatherwood, Reeves, Perrin and
Evans, 1982). They are the most common nearshore cetacean north of
Morro Bay. Historically they have been known to inhabit San Francisco
Bay, but there are few records of porpoise sightings in San Francisco
Bay in the last 10 years (Szczepaniak, Webber and Markowitz, in prep.).

Harbor porpoise are not very gregarious, and sightings are usually
of single animals or of groups of up to 10 animals. The mean group size
of harbor porpoise sightings in the Gulf of the Farallones is 2.6 animals
(Szczepaniak, Webber and Markowitz, in prep). On 4 occasions groups of
20 or more animals were encountered in the Gulf of the Farallones.
Harbor porpoise are shy and elusive and rarely, if ever, do they approach
vessels to ride the bow wave.

Juvenile rockfish (Scorpaenidae), northern anchovy (Engraulis
mordax), Pacific hake (Merluccius productus), Pacific tomcod (Microgadus
proximus) and market squid (Loligo opalescens) are the major prey items
of harbor porpoise in the GulTf--f-the Farallones (Jones, 1981).

Known predators of harbor porpoise along the coast of California
are the great white shark (Carcharodon carcharias) and the killer whale
(Orcinus orca).

- 37 -

Parturition in harbor porpoise off California occurs from May to
July and mating takes place from June through August (Stuart and
Morejohn, 1980). Harbor porpoise reach sexual maturity at approximately
3-6 years (Fisher and Harrison, 1970; Van Utrecht, 1978). Although
females usually give birth every two years, there is some evidence that
they can calve in successive years (Fisher and Harrison, 1970; Smith and
Gaskin, 1983). The maximum recorded lifespan of harbor porpoise is 13
years, but few appear to live beyond 7-8 years (Gaskin and Blair, 1977;
Stuart and Morejohn, 1980).

Beginning in 1982 there was an increase in set-net fishing vessels
operating in California waters. Associated with the increase in fishing
activities was an increase in the incidental kill of marine birds and
marine mammals. The estimated annual take of harbor porpoise is 200-300
animals (Hanan and Diamond, in prep.). From 1972-1981, a total of 45
harbor porpoise were reported stranded in the Gulf of the Farallones and
adjacent waters. From 1982-1985, a total of 123 harbor porpoise were
collected in the same area, 33% of which showed direct evidence of gill-
net entanglement (Szczepaniak, Webber and Markowitz, in prep.).

This high porpoise kill prompted studies to determine abundance and
stock structure of harbor porpoise in the eastern North Pacific,
particularly along the coast of California. Dohl, Guess, Duman and Helm
(1983) estimated the number of harbor porpoise found in California
waters as 1600-3000 animals. Their estimate was based on results of
aerial surveys which were found to be relatively ineffective at sighting
harbor porpoise (Kraus, Gilbert and Prescott, 1983). As a result this
estimate was probably too low. Based on data collected during four
shipboard surveys Barlow (in press) estimated that the number of harbor
porpoise inhabiting California waters is 8,865 animals. Barlow reported
that the population size of harbor porpoise in the Gulf of the
Farallones to Bodega Bay region to be 89 animals. He explained that
very little of the area in the Gulf of the Farallones was surveyed and
as a result he had low confidence in that estimate (Barlow, personal
communication).

Since 1977, over 1,000 sightings of harbor porpoise were collected
from whale watching vessels, Cordell Bank Expeditions research vessels
or dedicated survey vessels in the Gulf of the Farallones and adjacent
waters (Szczepaniak, Webber and Markowitz, in prep.). Based on data
collected, harbor porpoise in the Gulf of the Farallones seem to display
the following depth distribution: linearly increasing from shore to
35 m, linearly decreasing from 35 m to 125 m, and zero abundance in
waters deeper than 125 m.

Although Dohl, Guess, Duman and Helm (1983) recorded most harbor
porpoise sightings within 2.5 nm of shore in the Gulf of the Farallones,
the majority of harbor porpoise sightings (59.9%) occurred between 2.5
and 6.0 nm from shore. This seaward displacement of harbor porpoise
distribution is probably a function of underwater topography. The broad
Farallon Basin provides a shallow, protected habitat for harbor
porpoise.

Harbor porpoise sightings in this region appear to be related to
tidal activity. In a study funded by the Gulf of the Farallones
National Marine Sanctuary 70% of harbor porpoise sightings occurred
during the flood-high slack period.

Dohl, Guess, Duman and Helm (1983) found that harbor porpoise
abundance in the Gulf of the Farallones varied according to the region
of the gulf. The Gulf of the Farallones was divided into 4 quadrants
and density ranged from 0 - 0.25 animals/km2. Based on surveys
conducted in September and October, 1986. porpoise density in the same
quadrants ranged from 0 - 2.4 animals/km . The area bordered by
San Francisco, the San Francisco Bay Entrance Buoy and Duxbury Point was
found to be the area of greatest porpoise abundance. The total porpoise
population in the Gulf of the Farallones was calculated to be 1033
animals. Barlow (in press) found that approximately 23% of porpoises
are not sighted by the primary observers. Correcting the population
count for the animals not sighted, the total population of harbor
porpoise in the Gulf of the Farallones is estimated as 1268 animals.

LITERATURE CITED

Barlow, J. (In press). Abundance estimation for harbor porpoise
(Phocoena phocoena) based on ship surveys along the coasts of
California, Oregon and Washington.

Dohl, T.P., R.D. Guess, M.L. Duman, R.C. Helm. 1983. Cetaceans of
central and northern California, 1980-1983: status, abundance and
distribution. Report prepared for U.S. Minerals Management
Service, contract #14-12-0001-29090.

Fisher, H.D., and R.J. Harrison. 1970. Reproduction in the common
porpoise (Phocoena phocoena) of the North Atlantic. J. Zool.
161:471-486.

Gaskin, D.E., and B.A. Blair. 1977. Age determination of harbor
porpoise, Phocoena phocoena (L.) in the western North Atlantic.
Can. J. Zoo.355: 8-30.

Hanan, D.A., and S.L. Diamond. (In prep.). The incidental take of
harbor porpoise in California fisheries.

Jones, R.E. 1981. Food habits of smaller marine mammals from Northern
California. Proc. C.A.S. 42:409-433.

Kraus, S.D., J.R. Gilbert, J.H. Prescott. 1983. A comparison of
aerial, shipboard, and land-based survey methodology for the harbor
porpoise, Phocoena phocoena. Fish. Bull. 81:910-913.

Leatherwood, S., R.R. Reeves, W.F. Perrin, W.E. Evans. 1982. Whales,
dolphins and porpoises of the eastern North Pacific and adjacent
Arctic waters. NOAA Tech. Rept. NMFS Circ 444. 245 pp.

Stuart, L.J., and G.V. Morejohn. 1980. Developmental patterns in
osteology and external morphology in Phocoena phocoena. Rept. Int.
Whaling Comm. Spec. Iss. 3:133-142.

Szczepaniak, I.D., M.A. Webber, H. Markowitz (In prep.). Sightings and
strandings of harbor porpoise, Phocoena phocoena, in the Gulf of
the Farallones and adjacent waters.

van Utrecht, W.L. 1978. Age and growth in Phocoena phocoena, Linnaeus
1758 (Cetacea:Odontoceti) from the North S--ea. Bijdragen tot de
Dierkunde 48(1):16-28.

Cordell Bank:
What We Know and What We Don't

Robert W. Schmieder
Cordell Bank Expeditions
4295 Walnut Blvd., Walnut Creek, California 94596

I NTRODUCTI ON

Lying 20 miles offshore west of Pt. Reyes, the rocky seamount
called Cordell Bank is tantalizingly close and frustratingly far. For
ten years we have mounted expeditions to explore and document this
watery oasis. The first thing we found was that it harbors an
extraordinarily vigorous and photogenic community of benthic organisms,
algae and invertebrates, and supports large numbers of fish, birds and
marine mammals. This community is so productive that the National
Oceanic and Atmospheric Administration (NOAA) is in the process of
designating it as a national marine sanctuary.

But as much as we have learned about Cordell Bank, there remain
large gaps in our description and understanding of this remarkable
place. Doubtless some of these blanks will be filled in by future
expeditions. Perhaps it will be of value to describe what we presently
know, and what we presently don't know. If this looks like a program
for research, well, that's not entirely accidental!

WHAT WE KNOW

By and large, we know the recent history of Cordell Bank. We know
that it was accidentally discovered on October 22, 1853, by George
Davidson of the U.S. Coast and Geodetic Survey. Davidson was passing
Pt. Reyes in the fog and made a single cast of the lead of 30 fathoms.
Some 16 years later, Edward Cordell, also an Assistant in the Coast and
Geodetic Survey, made five separate attempts to locate the Bank, finally
succeeding on June 18, 1869. Cordell came from Germany, from the town
of Philippsburg, near Karlsruhe. He was active in the revolution of
1848, was charged with high treason, and escaped to America. Thanks to
records in the archives in the U.S. and in Germany, we know his ancestry
back five generations, and where he was and what he was doing almost
every day of his adult life.

We also have a general understanding of the geologic history of
Cordell Bank. The Bank itself is a huge rock of granite, formed as part
of the Sierra Nevada and transported from Southern California by
movement along the San Andreas fault. From a highly detailed
bathymetric survey carried out by NOAA in 1985, the topography of the
Bank is known perhaps as well as any place in the ocean. An. exciting
discovery was that the hard rocks carry the record of their sculpturing:
cut into the Bank is a series of terraces formed when the level of the
ocean was lower than today. The details of the terraces are sufficient
to indicate that the topography of the Bank was almost entirely
controlled by this surf erosion, and to give precise depths for the
minima and maxima of the sea level.

-41-

We also know something of the oceanic conditions at Cordell Bank:
During most of the year, relatively strong currents sweep southward, the
so-called California Current. This current, the topography of the
continental shelf, and the Coriolis effect combine to cause upwelling,
the slow movement of cold water from deep regions far offshore to
shallower regions nearshore. This cold water is loaded with organic
materials that can be used by algae and other organisms as food, with
the result that a lush population grows where upwelling occurs. Cordell
Bank is a prime recipient of this upwelled water, which partially
accounts for its biological activity.

But another major factor is the clarity of the water: visibility
normally is greater than 20 meters, sometimes more than 30 meters. This
means that the light penetrates to the rocks lying shallower than these
depths, providing energy for photosynthesis. Growth of plants in turn
provides food for invertebrates, which in turn support fish, birds, and
mammals. We find the dense biological cover on the shallowest ridges
and pinnacles; it thins out with increasing depth.

The general appearance of the bottom is now reasonably well-
documented in photographs taken on our expeditions. It has a
characteristic knobby appearance: there are lumps and bumps, typically
50 cm high, covered with sponges, tunicates, and anemones. This
knobbiness is an expression of the fact that the main limitation to the
number of individuals is available substrate. One organism, the
California hydrocoral Allopora californica, constructs rigid tree-like
colonies that are encrusted by other animals. Besides the texture of
the bottom, the color is characteristic: due to fluorescence in the
strawberry anemone, Corynactis californica, diving visitors to Cordell
Bank are treated to a blaze of red color, even at depths of more than 50
meters, where there is no red light.

We now have a species list with about 450 entries. This probably
represents more than 80% of the species larger than a few mm. Of
course, there is a plethora of microscopic organisms, of which we have
identified about 30, a tiny fraction of what's there. The phyla with
most identifications so far are: Mollusca (138 species), Arthropoda
(29), Annelida (29), Porifera (25), and Cnidaria (15). Essentially all
the birds (47 species), fish (38) and mammals (14) that regularly
frequent Cordell Bank have been sighted, but their habits are the
subject of continuing study.

WHAT WE DON'T KNOW

There are, of course, many relatively small or straightforward
issues that remain to be resolved: completion of the species list,
detailed numerical counts to elucidate statistical differences from one
place on the Bank from others, detailed description of the topography of
specific sites on a scale of meters, and so on. The vast majority
(perhaps 97%) of the Bank lies at depths too deep for diving.
Exploration of this important area is probably best done with a remotely
operated vehicle (ROV). But there are many larger issues about which we
have, as yet, no information. These questions are of wider significance

than just Cordell Bank: they relate to the general nature and evolution
of the landscape and marine biological populations. To the extent that
Cordell Bank may provide insight into these issues, we will find value
in pursuing the answers at the Bank.

One of the most significant questions is the relationship of the
populations on the Bank to the populations on the mainland. The Bank is
like an island: relatively small and isolated, yet in communication with
the large reservoir of the mainland. There exists a model for insular
populations in which immigration from the mainland increases the number
of species, while local extinction decreases them. To what extent does
the community on Cordell Bank fit this description? Alternatively, we
could ask whether it is possible to formulate a theory of underwater
islands, taking into account the currents, depth, light penetration,
etc. To reasonably test such models, we will need a much more extensive
sample of the populations on Cordell Bank.

Another important question relates to the variation of the
communities with time. Is the Bank in equilibrium? That is, are the
relative numbers of the various species and the numbers of individuals
relatively constant, or are there major changes occurring? Equilibrium
does not mean total absence of change, of course. In fact, the Bank has
many tiny pinnacles and ridges, each of which might be considered to be
a tiny local island. These individual sites are small enough that a
chance immigration could suddenly establish a population, say, of
barnacles on one ridge but leave another ridge unpopulated. In the same
way, the ridges are so small that normal fluctuations will sometimes
lead to local extinction on a particular ridge. This exchange of
species among the local sites could be going on constantly, producing an
equilibrium, but clearly it is not static. We have., at present,
practically no details about these processes at Cordell Bank.

A related question is the response of the Bank to trauma. What
would happen if one species, say, hydrocoral, were suddenly depleted?
Which organisms would be the first colonizers in an area that is
suddenly denuded? If equilibrium exists, how long would it take to re-
establish it if it were suddenly altered, say, by a chemical spill that
killed a large number or fraction of the population? Some questions
like these are susceptible to experiment: in 1982 we actually cleared a
small area completely, and returned-in 1982 to examine it. We found
that the area was exclusively, and completely, covered with Corynactis
anemones. Many of these questions come under the general title of
robustness: is Cordell Bank robust or fragile? At present, no one
knows the answer.

CONCLUS IONS

It is easy to see that what we don't know about Cordell Bank far
exceeds what we do know at the present time. But it is precisely those
questions that are unanswered that are relevant to areas beyond Cordell
Bank, and are therefore the most important. It is a piece of good
fortune that the special conditions at Cordell Bank probably will make
possible the investigation of some of the significant questions

described earlier. If so, the benefits of detailed study of the natural
laboratory provided at Cordell Bank will far exceed its cost, and might
even be fun in the process!

BIBLIOGRAPHY

Federal Register. 1981. Placement of Cordell Bank, Calif., on the
Marine Sanctuary List of Recommended Areas. Vol. 46, No. 168,
p. 43731.

Federal Register. 1983. Announcement of Cordell Bank as an Active
Candidate for National Marine Sanctuary Designation. Vol. 48,
No. 127, pp. 30178-30180.

Schmieder, R.W. 1984. Cordell Bank: Marine Sanctuary Candidate Rises
from Obscurity. Ocean Magazine, Vol. 17, No. 4, pp. 22-25.

Schmieder, R.W. 1985. Cordell Bank Expeditions, 1978-1979. National
Geographic Research Reports, 1979 Projects, pp. 603-611.

Schmieder, R.W. 1987. Terraces, Tilting, and Topography of Cordell
Bank, California. California Geology, in press.

Weisburd, S. 1986. Mapping an Underwater Oasis: The Cordell Bank
Rediscovered. Sci. News., Vol. 130, No. 16, pp. 250-251.

r3oDF-4A
&4Y

COIRt)?LL &1iJK

LA4IEA'

FARALLOd iA/C5
ISLANDtS

Figure 1. Location of Cordell Bank relative to the
coastline, north of San Francisco U

Figure 2. Contour Map of Cordell Bank
with locations of several shallow peaks
indicated in fathoms (1 fathom = 6 feet)

G O 787-727/79.54 +

ACKNOWLEDGEMENTS

The Marine and Estuarine Management Division wishes to acknowledge the support provided by the Point Reyes
National Seashore, who graciously provided their Clem Miller Environmental Education Center for this
Symposium, and the Environmental Action Committee of West Marin. Their support in this cooperative effort was
vital to the success of this Symposium.