Sighting patterns of coastal migratory bottlenose dolphins (Tursiops truncatus) in the near shore waters of Virginia and North Carolina final report

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

Sighting Patterns of Coastal Migratory Bottlenose
Dolphins (Tursiops truncatus) in the near shore Waters
of Virginia and North Carolina
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Final Report

15 November 1996

Submitted by

Susan G. Barco and W. Mark Swingle

Virginia Marine Science Museum
717 General Booth Boulevard
Virginia Beach, Virginia 23451

US Department of 'ommerce
'OAA Coastal Services Center Library
2234 South Hobson Avenue
Charles.ato, SC 29405-2413

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This project was funded, in part by the Virginia Department of Environ-
mental Quality's Coastal Resources Management Program through grant #
NA47OZ0287-01 of the National Oceanic and Atmospheric Administration,
Office of Ocean and Coastal Resource Management, under the Coastal Zone
Management Act of 1972, as amended. The views expressed herein are those
of the authors and do not reflect the views of NOAA or any of its subagencies.
The Virginia Marine Science Museum is devoted to increasing public
knowledge of Virginia's marine environment. The Museum is operated by the
City of Virginia Beach in cooperation with the Virginia Marine Science Mu-
seum Foundation and the Commonwealth of Virginia.

Please do not cite this document without permission from the authors.
I

TABLE OF CONTENTS

Acknowledgments ..............................................2
Abstract ......................................................3
Introduction....................................................4
Methods......................................................6
Results .......................................................8
Discussion.....................................................9
Summary .......................................................1
Literature Cited .................................................13
Tables and Figures...............................................16
Appendix....................................................28

LIST OF TABLES AND FIGURES

Table 1: Results of VMSM photo-identification and photo-comparison
with other research groups. 16

Table 2: Results of photo-identification matches between research groups. 1 7

Figure 1: Mid-Atlantic and southeast US coast showing the study areas which
were part of the project. 22

Figure 2: Example of identifiable bottlenose dolphin dorsal fin. 23

Figure 3: Virginia coastline showing VMSM primary study area. 24

Figure 4: Seasonal representation of dolphin sightings between Virginia
Beach, VA and Beaufort, NC. 25

Figure 5: Seasonal representation of dolphin sightings between Virginia
Beach, VA and Cape Charles, VA. 26

Figure 6: Seasonal representation of NCMM dolphin resight records for
individuals identified in the outer banks. 27

Figure 7: Potential overlapping migratory ranges for coastal migratory
dolphins. 28

ACKNOWLEDGMENTS
This project represents a collaborative effort between several research groups.
Each research effort is supported by many volunteers, students, staff and interested
citizens. We would Rie to thank everyone who contributed to dolphin photo-
identification in the mid-Atlantic. The authors would like to personally thank the
Virginia Marine Science Museum (VMSM), the VMSM Foundation, and the VMSM
Stranding Team.
We also recognize Wendy Walton, Anne Groth, Sean Bourgeois, Bob Marchant,
and Andi Poe for their help. This project would not have been possible without the
interest and support of the following organizations and individuals: Keith Rittmaster, Nan
Bowles and Vicky Thayer at the North Carolia Maritime Museum, Ann Pabst, Bill
McLellan and Laela Sayigh at the University of North Carolina in Wilmington, Sherman
Jones and Christopher Newport University, Kim Urian of the Dolphin Biology Research
Institute, Dave Schofield at the National Aquariumn in Baltimore, George Roundtree and
Rich Malon-Day.
2

ABSTRACT
The Virginia/North Carolina bottlenose dolphin photo-identification and migration project
has been very successful. The goals of the project were to: (1) promote photo-identification
research in Virginia and North Carolina and (2) bring researchers from North Carolina and
Virginia together to conipare data and learn more about dolphin movement along the mid-
Atlantic coast. The Virginia Marine Science Museumn (VMSM) conducted 58 research
cruises in the primary study area off Virginia Beach. Additional to the primary research
cruises, VMSM conducted two cruises off Assateague and Wallops Islands and five cruises
inside the outer banks of North Carolina in cooperation with the North Carolina Maritime
Museum and the University of North Carolina at Wilmington. Photographs taken on all 1996
research cruises are currently being analyzed. Bottlenose dolphin photographs taken in
previous years off Virginia Beach were compared with similar photo-catalogs from Cape
Charles, Virginia, Beaufort, North Carolina, Wilmington, North Carolina and to photographs
taken in the outer banks near Cape Hatteras. Twenty-four and twelve dolphin matches were
made from Virginia Beach to Beaufort and Cape Charles, respectively. Five matches were
also made between Cape Charles and Beaufort. No matches were made between Virginia
Beach and Wilmington, but several were made between Beaufort and Wilmington. In
addition, five of the nine dolphins identified at Cape 1Hatteras matched dolphins in Beaufort.
Matches between the Virginia Beach and Cape Charles research groups occurred primarily in
the summer, indicating that the samne population of dolphins may occur throughout the lower
Chesapeake Bay. Matches between Virginia Beach and Beaufort were seasonally separated
with dolphins photographed primarily in summer months (July-August) in Virginia Beach
occurring in the winter months (Jan.-March) in Beaufort. These data contribute substantially
to our knowledge of dolphin migration between adjacent state waters and, for the first time,
allow us to propose migratory ranges for coastal dolphins. A computer programmer was
contracted to develop a bottlenose dolphin database for Virginia and North Carolina.
Researchers from both states met to design the database and are currently entering data. This
project has been a very successful collaborative effort between research groups in Virginia
and North Carolina. Studying highly mobile animals such as dolphins requires cooperation
among research groups, conservation organizations, and government agencies. Collaboration
also makes good use of limited research funds for protected species such as dolphins.
3

INTRODUCTION
Bottlenose Dolphins in Virginia and North Carolina
Bottlenose dolphins (Tursiops truncatus) appear seasonally in the coastal
waters of Virginia (Barco, et al. 1995; Swingle 1994; Kenney 1990). The
Cetacean and Turtle Assessment Program (CETAP), a large scale aerial survey
which included continental shelf waters from Cape Hatteras, North Carolina to
Canada, demonstrated a bimodal distribution of bottlenose dolphins in the
Northwest Atlantic (Kenney 1990). The inshore component of the observed
distribution is now recognized as the coastal stock of Atlantic bottlenose dolphins
(Wang, et at 1994; Kenney 1990). In the CETAP survey area, the coastal stock
displays seasonal changes in abundance and distribution consistent with a
migrating population. For example, the CETAP abundance estimate for coastal
dolphins ranged from 0 in winter to 400-700 in summer (Kenney 1990).
Coastal dolphins north of Cape Hatteras are migratory, coastal dolphins
south of Cape Hatteras, however, are not exclusively migratory, some groups may
remain in one area all year. In the estuarine and ocean waters of Beaufort, NC,
bottlenose dolphins are present year round but individuals are apparently not
resident throughout the year (Rittmaster and Thayer 1995; Rittmaster and Thayer
1994). In the Indian and Banana River systems of eastern Florida, dolphins appear
to be resident throughout the year (Odell and Asper 1990). The residents of the
Indian and Banana river system have been termed "estuarine" dolphins and have a
distinctly different diet from coastal dolphins in Florida (Barros 1995; Barros and
Odell 1990). Thus, the coastal stock of Atlantic bottlenose dolphins can be further
divided into coastal migratory and coastal resident (and/or estuarine) groups.
Atlantic coastal dolphins gained national attention during a 10 month
period in 1987-88, when these dolphins experienced a mass mortality event that is
estimated to have decreased the population by over 50% (Scott, et at 1988). The
dolphins affected by this event were described as a separate group from other
coastal dolphins, because the mortalities started in New Jersey and Virginia in the
summer and moved southward in the fall and winter. This group of bottlenose
dolphins is currently referred to as the coastal migratory stock (Scott et at 1988;
Scott 1994). Coastal migratory dolphins are believed to be the portion of the
coastal stock which undergoes a yearly seasonal migration (Wang et al. 1994).
Currently, all coastal bottlenose dolphins north of Cape Hatteras are described as
coastal migratory. The distribution of stranded dolphins from 1987-88 provides
4

the only description of coastal migratory dolphins south of Cape Hatteras. Because
of the mass mortality, the National Marin'e Fisheries Service (NMFS) assigned a
"depleted" status to the coastal migratory stock in 1992. Even though coastal
migratory dolphins are now considered a depleted stock, we cannot yet define the
southern limit of coastal migratory dolphins or northern limit of coastal resident
dolphins (Wang, et aL 1994). Without such basic knowledge as the range of the
coastal migratory stock, wildlife managers and legislators cannot assess the impact
of human and other activities on this depleted stock. One way to learn more about
the movement of migratory dolphins is to identify dolphins north of Cape Hatteras
in the sunumer and follow them to their winter range.
CETAP surveys identified Cape Hatteras as an important dividing line
between seasonal and year round dolphin presence (Kenney 1990). Two well
established dolphin research groups operate on either side of Cape Hatteras. The
northern group is headed by Mark Swingle and Susan Barco at the Virginia Marine
Science Museum (VMSM). The VMSM primary study area is located
approximately 180 kilometers north of Cape Hatteras surrounding Cape Henry
(Figure 1). The southern research group is located at Cape Lookout and Beaufort
Inlet, 120 kilometers south of Cape Hatteras (Figure 1). The research is conducted
by Keith Rittmaster, Vicky Thayer and Nan Bowles of the North Carolina
Maritime Museum (NCMM). Both groups use photo-identification as their
primary research method.

Bottlenose Dolphin Photo-identification
Photo-identification is a non-invasive method for identifying animals which
relies on natural tags possessed by an individual (Lien and Katona 1990). Photo-
identification has been applied to many species of cetaceans across diverse
geographic areas (Hammond, et al. 1990). Photo-identification studies have been
conducted on mysticetes, particularly humpback, right, and bowhead whales
(Glockyer-Ferrari and Ferrari 1990; Hamilton and Mayo 1990; Rugh 1990). In
killer whales (Orcinus orca) near Vancouver Island, British Columbia, photo-
identification research resulted in the recognition of two discrete groups, resident
individuals and transient individuals, whose movement patterns, feeding habits,
and vocalizations are distinctly different (Bigg, et aL 1990; Morton 1990).
Methods of photo-identification of bottlenose dolphins which were
developed in the 1970's (Wursig and Wursig 1979), rely upon distinctive dorsal
features (e.g. Connor and Smolker 1985; Ballance 1990; Hansen 1990; Shane
5

1990; Wells and Scott 1990; Wursig and Jefferson 1990; Wilson, et al. 1993)
(Figure 2). Dolphin photo-identification may be a viable, relatively inexpensive
method of determining the range of coastal migratory dolphins along the Atlantic
coast of the U.S. This project will provide the first test of determining dolphin
movement along the Atlantic coast of the US using photo-identification.

Project Goals
The goals of this project were to: (1) promote photo-identification research
in Virginia and North Carolina and (2) bring researchers from Virginia and North
Carolina together to compare data and learn more about dolphin movement along
the mid-Atlantic coast. To achieve our first goal, we collaborated with North
Carolina researchers to design a relational database for photo-identification data.
The database will standardize most of the data collection and analyses between
VMSM and NCMM. We also used grant funding to document sightings of
identifiable bottlenose dolphins that appeared in Virginia waters. By providing
travel and consulting funds, we were able to bring researchers from Virginia and
North Carolina together to compare identifiable dolphins from different study
areas. The matches that we made as a result of comparing data provide new
evidence for patterns of dolphin migration between Virginia and North Carolina.

METHODS

VMSM used photo-identification to identifyt individual bottlenose dolphins
in a 24 km study area up to I km off the coast of Virginia Beach, Virginia (Figure
3). We conducted additional research cruises in northeastern Virginia off the coast
of Assateague and Wallops Islands and along the North Carolina outer banks at
Hatteras Inlet, Ocracoke Inlet, and around Roanoke Is land.
To collect data on dolphin associations, we photographed each group of
dolphins separately. For this study, we defined a dolphin "group" as a collection
of individuals observed within a given area. Dolphins separated by greater than
100 m were considered to be in different groups. The 100 m distance was chosen
because it represented the accuracy with which our global positioning system unit
(GPS) could determine position. The term "encounter" refers to a photographic
session with a group of dolphins. Photographs and associated data, such as
location, water temperature, group size and composition were collected for each
6

encounter. We used several different boats, ranging from 5-6 m throughout the
study. Optimally, three people were onboard during a cruise, a captain who
watched the course and speed (typically 3 0-40 kph when searching for dolphins),
an observer who recorded data, and a photographer who shot fin photographs.
When dolphins were encountered, the boat was slowed. Before moving
close enough to photograph individuals, the time of initial observation, behavior,
and direction of the group were recorded. The boat then moved parallel to the
group, and the location, number of dolphins, and group composition were
recorded. Position data were obtained using a Global Positioning System (GPS)
unit. The maximum, minimum, and best estimate of total group number were
recorded for each group. The "best estimate" was the observers' estimation of how
many dolphins were in the group. This number was not simply the average of
maximum and minimum number, but rather a point estimate that took observation
conditions into account. The final count was recorded after a consensus was
reached among observers.
Once location, behavior, number, and group composition data were
recorded, attempts were made to photograph each dolphin in the group. When the
dolphins were moving predictably in one direction, the captain placed the boat just
behind and to one side of the group and set the speed slightly faster than that of the
group. Thus, the boat would slowly pass by each dolphin. If the group was not
moving predictably in one direction, the captain attempted to keep the boat in
neutral and drift into the group or stay in gear and maintain minimal steerage while
approaching. Photographing was continued until sufficient photos were taken to
adequately document the group unless other vessels moved close to the group
and/or the water and weather conditions deteriorated.
All photographs for the study were taken using 35 mm SLR cameras with
zoom or telephoto lenses. VMSM used Kodak Ektachrome 100 or 200 ASA slide
films. Film and frame numbers were recorded for each encounter. To further
insure that each group was accurately recorded, a photograph of the data sheet was
taken at the beginning and end of each group encounter and each roll. All slides
were stamped with the trip number and the group number.
Slides were then sorted for usable photographs. Poorly focused shots and
other shots not useful for identification were discarded or catalogued elsewhere.
Slides of fins and other distinguishable characteristics were then sorted by group.
A system for categorizing fin markings was developed in order to systematically
7

examine the fin photographs. The system, developed by VMSM and NCMM, has
been adapted to each study area (Barco, et al. 1995).
For the purposes of this paper, a "sighting" will refer to a photographic
record of an identifiable dolphin. "Resights" of an individual are defined as
sightings that occur on different days within a study area. A resight record
includes all sightings of an individual plotted over time. A "Match" refers to
confirmned sightings of a dolphin in two different study areas.
All photographs of identifiable dolphins were first compared within an
encounter. We may collect several photographs of each individual during a single
encounter. All usable photographs of an individual are compared with individuals
identified on all other encounters during that year. We can then determine the total
number of individuals sighted in one year and the number of within-season
resights for each individual. A year-long population estimate can be calculated
from the above data using capture/recapture analyses (where a capture is
equivalent to an identifiable photograph of a dolphin) (Begon 1979). Coefficients
of association, which determine the likelihood of an individual being seen with
another individual, can also be calculated for dolphins with more than five
resights.
Following within-season analysis, photographs are integrated into the
VMSM master catalog which contains all previously identified individuals since
1989. During the entire process, sightings and resights must be confirmed by three
experienced researchers. All must agree before a resight, or a new sightingO is
confirmed (debate is allowed, but the decision must be unanimous).
For this project, dolphin sightings were also compared between research
groups. We developed additional fin matching standards to insure that confirmed
matches between study areas were acceptable. In order for a match between
studies to be confirmed, the following conditions had to be met: (1) there had to
be more than one photograph of each individual from each study site (more than
one photo in one sighting is acceptable), (2) the fin had to have more than one
unique feature, and (3) one researcher from each group plus a third unbiased
researcher had to agree that the dolphins were the same. Dolphin photographs
were compared between the VMSM primary study site and the following areas
(Figure 1): Assateague, Cape Charles (operated by Christopher Newport
University - CNU), NCNMM (Beaufort), Wilmington. Additionally, NCNMM
compared photographs with Wilmington and Cape Charles. The seasonality of
8

matches made between study areas was compared for trends in order to develop
hypotheses regarding dolphin migration.

RESULTS

VMSM conducted 58 research cruises in the Virginia Beach study area in
1996. Approximately 100 dolphin groups were encountered and photographed.
We counted 1501 dolphins during the 1996 season (April to October) (Table 1).
Results of the 1996 photo-identification are still being analyzed and entered into a
newly developed database. VMSM also conducted two cruises off
Assateague/Wallops Islands in northeastern Virginia and five cruises along the
North Carolina outer banks (Table IA). These cruises resulted in four encounters
with dolphin groups.
Comparing photographs with other research groups resulted in matches
between VMSM and Cape Charles, VMSM and NCMM, NCMIV and Cape
Charles, and NCMM and Wilmington (Table I B). Only one identifiable dolphin
was photographed in the Assateague/Wallops Island study area, and it did not
match any dolphins in the VMSM catalog. No matches were made between
VMVSM and Wilmington or the outer banks. Of the nine dolphins identified in the
outer banks study area, five matched NCNMI photographs.

DISCUSSION

The matches that were made between study areas provide valuable
information about the movement of dolphins along the Virginia/North Carolina
coasts. Dolphins photographed in both Virginia and North Carolina generally
appeared in different seasons (Figure 4). Most of the matches represent dolphins
appearing in Virginia Beach in the summer (July-August) and in Beaufort in
winter (January-March). With the exception of one individual (VMSM 0242),
none of the VMSM/NCMM matches were photographed in the same month in
both study areas (Figure 4). The exceptional individual was photographed in
Virginia Beach in August and/or September of 1992, 1993, and 1994. It was
photographed once in North Carolina in August of 1995 and was not photographed
9

in Virginia Beach in 1995, but was photographed in Virginia Beach in July and
August of 1996 (Table 2).
The matches between VMSM and Cape Charles occurred in the same
season and often in the same month of the same year (Figure 5). Seven of the
twelve VMSMICape Charles matches are actually resights because the
photographs taken by Cape Charles were taken within the Virginia Beach study
area. These resights provide valuable information about the presence of identified
individuals off Virginia Beach, but do not provide information about dolphin
movement between areas. There appears to be a seasonal component to the
VMSM!Cape Charles matches, with most of the Cape Charles sightings occurring
in May and June and most of the VMSM sightings in August.
When examining these photo-identification data, we must take effort into
account. The majority of the Cape Charles photo-identification cruises in 1993-
1996 occurred in May and June, during a Christopher Newport University Dolphin
Field Schools. The apparent seasonal trend actually reflects an effort bias toward
May and J-une. All but one of the July-September matches were collected in 1992
(Table 2). Since 1994, VMSM has consistently conducted photo-identification
cruises May through September (weather permnitting). Cruises are conducted
opportunistically in April, October, and November. No photo-identification
cruises are conducted December-March because there are no dolphins present in
the study area (Barco 1995). Fewer cruises were conducted from 1989-1993 and
most occurred June-August. From 1986-1994, NCMM did not conduct many
cruises in winter months. Cruises were conducted consistently April-October and
opportunistically in March, November and December. For the past two years,
NCMM has conducted cruises year round on a consistent schedule. It is
interesting to note that although the majority of the NCMM effort has been in non-
winter months, the majority (14/24 = 58%) of the VMSM/NCMM matches occur
in winter (Figure 4). Effort data are not available for the Wilmington study area.
The photographs that we examined were collected between 1992 and 1994. A new
research group is collecting photographs and plans are being made to examine
those photographs.
All of the outer banks photographs were collected during a research trip in
September 1996. There has been no other effort in the area. We had limited
success finding dolphin groups (2 encounters in five trips over three days). The
weather forced us to conduct all of the cruises in Pamlico and Roanoke sounds and
not in the ocean. We spent several hours on the beach scanning the ocean for
10

dolphin groups but did not observe any. Local pier operators and commercial
fishermen had seen dolphins recently but indicated that later in the year
(November-February) was the best time to encounter dolphins in the ocean. Of the
nine dolphins we identified, over half (5) were matched to the NCMM dolphin
catalog. There does not appear to be a strong seasonal presence for the
Beaufort/outer banks matches (Figure 6). None of the dolphins matched to the
outer banks were photographed in Beaufort in April, May, June or February. The
sample size is so small that lack of sightings in these months cannot be interpreted
as a trend. From the matching success rate between Beaufort and "inshore outer
banks " sightings, it is apparent that work should continue in this area. Dolphins
appearing along the ocean coast of the outer banks should also be studied to see
if/when they match individuals in the VMSM and NCMM catalogs.

SUNMVARY

Migration is the movement of organisms coordinated in space and time
(Quinn and Brodeur 1991). Although the data we collected is limited, sighting
dates support the existence of a group of dolphins migrating between Virginia
Beach, Virginia and Beaufort, North Carolina. Because of the timing of the
matches (i.e. summer in Virginia Beach and winter in Beaufort) the northern and
southern limits of these individuals may be close or equivalent to Virginia Beach
and Beaufort. If this is the case, then dolphins seen north of Virginia Beach in the
summer may not occur as far south as Beaufort in winter, and dolphins seen
between Virginia Beach and Cape Hatteras in summer may spend the winter south
of Beaufort. Atlantic coastal migratory dolphins may exhibit relatively discrete
migratory ranges that overlap spatially but not temporally (Figure 7). These ranges
may shift from year to year based on environ-mental conditions and/or prey
availability. The data we present support this migration model, but are not
inconsistent with other models. Clearly, we need more information about dolphin
movement between Virginia Beach and Beaufort before we can test this or any
model.
Additional evidence for discrete ranges comes from resights within each
study area and from association data. Individuals are often resighted each year at
roughly the same time and place. Two examples are: VMSM 00 16 which was
sighted in Virginia Beach in August of 1989, 1993,1994, 1995 and 1996, and
I1
I

NCMM 1120 which was sighted in February of 1987, 1994 and 1996. In addition,
several individuals maintain associations between study areas. They were
photographed in the same group in Virginia Beach and were also photographed
together in Beaufort (e.g. VMSM 0072 & VMSM 1996-2, VMSM 0079 & VMSM
0085). Other individuals were photographed within days of each other in each
area (Table 2). Matches made between Virginia Beach and Cape Charles suggest
that the summer range of migratory dolphins in Virginia encompasses both study
areas. Thus, dolphins found in the summer in Virginia Beach may be part of a
large, stable group of individuals that migrate together. The entire migratory range
of these dolphins include, but are not limited to, the Virginia Beach and Beaufort
study areas. Continued photo-comparison and association analyses are needed.
The matches between Beaufort and the outer banks and between Beaufort
and Wilmington indicate a more complex situation south of Cape Hatteras. Not
only do dolphins appear throughout the year in Beaufort, but they also appear to
exhibit a seasonal habitat preference (Rittmaster and Thayer 1995; Rittmaster and
Thayer 1994). Dolphins are seen more frequently in the ocean in the winter
months and in the estuary in the summer. Individuals matched to Virginia Beach
occur in the ocean or in the inlet adjacent to the ocean. Individuals matched in
Wilmington and on the outer banks occur at all times of the year and in both the
ocean and the estuary. Dolphins observed in the Beaufort, Wilmington and
inshore outer banks may belong to one of several possible groups. Dolphins may
exhibit stable, overlapping home ranges similar to dolphins in Sarasota, Florida
(Wells and Scott 1990). Dolphins in the ocean in summer may be migratory
individuals with a range different from the Virginia Beach/Beaufort individuals.
This work is beginning to answer the question of where migratory dolphins
in Virginia can be found in the winter. Much more work is needed to develop and
test migratory models. Photo-identification appears to be a viable tool for this
research. Collaboration between research groups is essential to determine the
movements of these highly mobile, marine mammals. We present this project as a
model of collaborative effort and hope that work similar to this will be supported
in the fuiture.
12

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Atlantic bottlenose dolphin: Status review and management. Wang, K., Payne, P.M.
and Thayer, V.G.(compilers)US Dep. Commer., NOAA Tech. Memo. NMFS-OPR-4,
45-52 p.
Rugh, D.J. 1990. Bowhead whales reidentified through aerial photography near Point
Barrow, Alaska. In: Individual Recognition of Cetaceans: Use of photo-
identification and other techniques to estimate population parameters (Eds.
Hammond, Mizroch, and Donovan). Report of the International Whaling
Commission, Special Issue 12. Cambridge. pp. 289-294.
Quinn, T.P. and Brodeur, R.D. 1991. Intra-specific variation in the movement patterns of
marine animals. American Zoologist. 31:231-241.
Scott, G.P., D.M. Burn and L.J. Hansen. 1988. The dolphin die-off: Long-term effects
and recovery of the population. Conference record, Oceans '88. Baltimore, MD,
October 1988.
Scott, G.P. 1994. The 1987 bottlenose dolphin die-off. In: Coastal stock(s) of Atlantic
bottlenose dolphin: Status review and management. Wang, K., Payne, P.M. and
Thayer, V.G.(compilers) US Dep. Commer., NOAA Tech. Memo. NMFS-OPR-4
Shane, S. H. 1990. Behavior and ecology of the bottlenose dolphin at Sanibel Island,
Florida. In: The Bottlenose Dolphin. (Eds.: Leatherwood, S; Reeves, R) Academic
Press, INC., New York, pp. 245-266.
Swingle, W. 1994. What do we know about bottlenose dolphins in Virginia? In:
Coastal stock(s) of Atlantic bottlenose dolphin: Status review and management.
Wang, K., Payne, P.M. and Thayer, V.G.(compilers) US Dep. Commer., NOAA
Tech. Memo. NMFS-OPR-4, 34-40 p.
14

Wang, K., Payne, P.M. and Thayer, V.G.(compilers). 1994. Coastal stock(s) of Atlantic
bottlenose dolphin: Status review and management. US Dep. Commer., NOAA Tech.
Memo. NMFS-OPR-4, 121p.
Wells, R.S. and M.D. Scott. 1990. Estimating bottlenose dolphin population
parameters from individual identification and capture-release techniques. In:
Individual Recognition of Cetaceans: Use of photo-identification and other
techniques to estimate population parameters (Eds. Hammond, Mizroch, and
Donovan). Report of the Intemational Whaling Commission, Special Issue 12.
Cambridge. pp. 407-416.
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15

Table 1: (A) Results of VMSM photo-identification and
(B) photo-comparison with other research groups
A-Photo-identification effort and results
Study Area # Cruises # Encounters # Dolphins
Virginia Beach 58 100 1501
Assateague/Wallops 2 2 43
Outer Banks 5 2 20
Total 65 104 1564
B-Photo-comparison results (Total IDed = # of dolphins identified in study area)
Study Area # Total IDed # Matches Matched with # Total IDed
Virginia Beach 500+ 24 Beaufort 1400+
Virginia Beach 500+ 5 (+7)* Cape Charles 200+
Virginia Beach 500+ 0 Wilmington 100+
Virginia Beach 500+ 0 Outer Banks 9
Beaufort 1400+ 5 Cape Charles 200+
Beaufort 1400+ 9 Wilmington 100+
Beaufort 1400+ 5 Outer Banks 9
* The Cape Charles research group photographed 7 of the matched dolphins in
the VMSM Virginia Beach study area; therefore, they do not represent matches
between different study areas.
16

Table 2: Results of photo-identification comparison between research groups. VMSM
sightings are listed in the left column and other research groups in the right column.

VMSM Photo-lD Matches
Catalog # Dates Research Group Catalog # Dates

VMSM 0014 20-Jul-93 NC Maritime Museum NCMM 1276 29-Oct-92

04-Jun-94 05-Apr-94
15-Jun-94 11-Apr-95

07-Jul-95
28-Jul-96
VMSM 0079 20-Jul-93 NC Maritime Museum NCMM 86Z 18-Nov-93
24-Aug-93 19-Nov-93
28-Jul-95 15-Mar-94
30-Jul-96 31-Mar-94
17-Aug-96 25-Nov-94
16-Mar-95
07-Feb-96
VMSM 0016 ??-Aug-89 NC Maritime Museum NCMM 1021Q 26-Jan-96
??-Sep-89
08-Aug-93
20-Aug-94
26-Aug-94

27-Aug-94
31-Aug-94
13-Sep-94
19-Aug-96
VMSM 0387 24-Aug-95 NC Maritime Museum NCMM 261Z 17-Jan-95
13-Mar-95
22-Feb-96
25-Feb-96
VMSM 0219 19-Aug-94 NC Maritime Museum NCMM 459Z 18-Nov-93
22-Oct-94
30-Nov-94
17
1

VMSM Photo-ID Matches
Catalog # Dates Research Group Catalog # Dates
VMSM 0085 20-Jul-93 NC Maritime Museum NCMM 257Z 12-Feb-94
24-Aug-95 13-Mar-94
06-Sep-95 15-Mar-94
17-Jan-95
22-Jan-96
26-Jan-96
30-Jan-96
07-Feb-96
14-Mar-96
VMSM 0268 24-Aug-93 NC Maritime Museum NCMM 1454 17-Jan-96
29-May-94 07-Feb-96
VMSM 0029 1 1-Jun-94 NC Maritime Museum NCMM 1261 24-Oct-95
13-Jul-94 31-Oct-95
16-Jun-95 16-Mar-96
05-Jul-96 17-Apr-96
04-Aug-96 08-May-96
21-Aug-96
27-Aug-96
VMSM 0036 04-Jun-94 NC Maritime Museum NCMM 1225 17-Jan-95
12-Jun-94 11-Apr-95
08-Aug-94 27-Apr-95
09-Jun-95 22-Feb-96
02-Jul-96
16-Jul-96
28-Jul-96
VMSM 0031 22-Aug-94 NC Maritime Museum NCMM 1502 22-Feb-96
16-Sep-94
22-Sep-95
VMSM 0002 18-Aug-92 NC Maritime Museum NCMM 1308 16-Apr-95
06-Jul-94 07-Feb-96
13-Jul-94 10-Feb-96
27-Jul-94
18
6

VMSM Photo-ID Matches
Catalog # Dates Research Group Catalog # Dates
12 VMSM 0004 18-Jul-94 NC Maritime Museum NCMM 1123 17-Jan-96
19-Jul-94 10-Feb-96
20-Jul-94 25-Feb-96
13 VMSM 0073 ??-Aug-89 NC Maritime Museum NCMM 1517 25-Jan-96
??-Sep-89
28-Aug-90
17-May-92
15-Jul-92
18-Aug-92
25-Jun-93
20-Jul-93
01-Jul-95
28-Jul-96
14 VMSM 0034 08-Jul-92 NC Maritime Museum NCMM 291Z 24-Nov-94
05-Aug-92
27-Sep-92
24-Aug-93
21-Jun-94
30-Jun-94
12-Aug-94
08-Jun-95
16-Jun-95
25-Jul-95
15 VMSM 0021 03-Aug-94 NC Maritime Museum NCMM 155 30-Nov-94
05-Aug-94
10-Aug-94
16 VMSM 0192 ??-Jun-89 NC Maritime Museum NCMM 636 24-Nov-92
??-Aug-89
05-Aug-92
08-Aug-93
07-Jun-94
17 VMSM 0242 09-Sep-92 NC Maritime Museum NCMM 191 26-Jan-95
27-Sep-92 01-Aug-95
24-Aug-93
03-Aug-94
28-Jul-96
17-Aug-96
19-Aug-96
19

VMSM Photo-ID Matches
Catalog # Dates Research Group Catalog # Dates
18 VMSM 0011 09-Aug-93 NC Maritime Museum NCMM 1111 22-Oct-94
14-Aug-94
19-Aug-94
08-Sep-94
24-Sep-94
19 VMSM 1996-1 22-Aug-96 NC Maritime Museum NCMM 1120 14-Feb-87
01-Feb-94
07-Feb-96
22-Feb-96
20 VMSM 1996-2 28-Jul-96 NC Maritime Museum NCMM 1531 25-Jan-96
21 VMSM 1996-3 16-Jul-96 NC Maritime Museum NCMM 1402 27-Dec-95
24-Aug-96
22 VMSM 1996-4 21-Aug-96 NC Maritime Museum NCMM 1288 27-Apr-95
14-Sep-96
23 VMSM 0445 15-Jul-92 NC Maritime Museum NCMM 116 10-Apr-92
24 VMSM 0177 24-Aug-95 NC Maritime Museum NCMM 842 25-Dec-95

1 VMSM 0053 6/93 Christpher Newport U. Z251 6/94
2 VMSM 0018 6/93 Christpher Newport U. Z218 5/94
5/94 6/94
6/94
7/94
3 VMSM 0025 8/94 Christpher Newport U. Z088 5/93
9/94 5/94
6/94
4 VMSM 0244 8/94 Christpher Newport U. Z250 6/94
5 VMSM 0155 8/94 Christpher Newport U. Z216 5/94
6 VMSM 0056 8/93 Christpher Newport U. Z049 7/92
9/92
7/93
6/94
8/94
7 VMSM 0072 8/92 Christpher Newport U. Z057 9/92
5/93
5/95
20

VMSM Photo-ID Matches
Catalog # Dates Research Group Catalog # Dates
8 VMSM 0073 8/89 Christpher Newport U. Z027 7/92
9/89 9/92
8/90
8/92
6/93
7/93
7/95
9 VMSM 0059 5/94 Christpher Newport U. Z226 6/94
6/94
8/94
6/95
10 VMSM 0242 9/92 Christpher Newport U. Z047 7/92
8/93 6/94
8/94
11 VMSM 0020 7/94 Christpher Newport U. Z151 6/93
8/94
9/94
7/95
12 VMSM 0234 8/94 Christpher Newport U. Z956 6/95
21

Figure 1: Mid-Atlantic and southeast US coast showing the study areas which
were part of the project.

I
I
l
I
I
I
I
I
I
I
I

I
a
I

I
II
tip missing
f
1tab

L-0. notch
Figure 2: Example of an identifiable bottlenose dolphin dorsal fin. This indiviual has at least four
distinctive features that make it identifiable.

Figure 3: Virginia coastline showing VMSM primary photo-identification
study area and location of Assateague/Wallops Island study area and Cape
Charles research group study area.

1996-4 - E
1996-3 El-El
1996-2 - ::
1996-1 - Lr
0177 * ---
0445 � .5
0011 D �
0242 _ I ;
0192 :'
0021
0034 ,
0073 -
10004 - L
,0002 t tI
0031 -E
0036 E
0029 * *
0268 _
0085 * * *
0219 *
0387 * * *
0016 -- :[-El
0079
0014 . . . . ,
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

El photographed in Vrginiua Beach study area 0 photographed in Beaufort study area

Figure 4: Seasonal representation of dolphin sightings between the Virginia
Beach, VA and Beaufort, NC study areas. Each horizontal line represents
the resight record of an individual dolphin. Circles represent sightings in
Beaufort and squares represent sightings in Virginia Beach.

0234*
0020*=
0242*
t~0059"*
0073*
.~0072*
0056
0155-
0244
'~ 0025=

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

*photographed in Virginia Beach study area

*photographed in Cape Charles study area

Figure 5: Seasonal representation of dolphin sightings between the Virginia
Beach, VA and Cape Charles, VA research groups. Each horizontal line
represents the resight record of an individual dolphin. Circles represent
sightings collected by the Cape Charles group and squares represent
sightings in Virginia Beach. The Cape Charles study area overlaps the Vir-
ginia Beach area. * indicates matches made in the overlapping area.
26

173 -

140

789 i

147 m

JAN FEB MAR APR MAY JUN JL AUG SiP OCT NOV DEC

[ photographed in Beaufort study area 0 photographed in North Carolina outer banks

Figure 6: Seasonal representation of NCMM dolphin resight records for
individuals identified in the outer banks. Each horizontal line represents the
resight record of an individual dolphin. Circles represent sightings
collected in the outer banks and squares represent sightings in Beaufort.
27

Figure 7: Potential overlapping migratory ranges for coastal migratory bottlenose
dolphins. Arrows indicate the Virginia Beach (top) and Beaufort (bottom) study
areas. Shaded oval represents the proposed migratory rage for dolphins sighted
in Virginia Beach in the summer and Beaufort in the winter.

APPENDIX 1: Examples of VMSM/NCMM matches.
VMSM 0242
NCMM 191
29

APPENDIX I cont.: Examples of VMSMINCMM matches.
VMSM 0036
NCMM 1225
30

APPENDIX I cont.: Examples of VMSM/NCMM matches.
VMSM 0034
NCMM 291Z
(Note: The string-like material on the fm is a barnacle called Xenobalanus. It is not a distinctive fin
feature.)
31

APPENDIX 2
Il Disk demnonstraing the dolphin photo-id relational database developed through this grant. The database
was created using Nicrosoft Visual Foxpro software by Justin Weaver. A customized version of the data-
base and software were provided to the North Carolina Ma-ritime Museum as a provision of the grant. A
I shareware version of the database is avaiable to other research groups free of charge.
32