Dudzik Et Al

OCTOBER 2005

MARK-RECAPTURE ABUNDANCE ESTIMATE OF CALIFORNIA COASTAL STOCK BOTTLENOSE DOLPHINS: FEBRUARY 2004 TO APRIL 2005

Kimberly J. Dudzik, Karen M. Baker, David W. Weller1 California Center for Marine Science San Diego State University San Diego, California 92182 USA

Report prepared under Contract # AB133F-03-SE-7140 to Southwest Fisheries Science Center NOAA Fisheries 8604 La Jolla Shores Drive La Jolla, CA 92037 USA

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Corresponding Author – [email protected]

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ABSTRACT The occurrence, distribution, group size and abundance of California coastal stock bottlenose dolphins (Tursiops truncatus) were assessed during a boat-based photo-identification study between February 2004 and April 2005 off San Diego, California. A total of 27 photographic surveys were completed and dolphin groups were encountered on 20 (74%) of them. A total of 43 dolphin groups were observed and 164 individuals photographically identified. All groups were sighted within ~1 km of shore. The mean group size was 9.1 (SE = 1.5) and the average number of dolphins and groups encountered per survey was 19.7 (SE = 3.1) and 2.1 (SE = 0.3), respectively. Low resighting rates (mean = 1.8; SE = 0.08) of identified individuals in combination with an ever-increasing rate of discovery of previously unidentified dolphins provided little evidence for site fidelity. Mark-recapture analysis using Chao’s model Mth produced an abundance estimate of 323 dolphins (SE = 42.5, 95% CI = 259 – 430). While subtle differences in encounter rates, group size and number of groups encountered per survey were apparent when compared to earlier studies conducted in the same area between 1984 and 1998, the current estimate of abundance is directly comparable to previous estimates which suggests that the stock has remained relatively stable for nearly 20 years.

INTRODUCTION The bottlenose dolphin (Tursiops truncatus) is the most common cetacean in nearshore waters off San Diego County. This stock has been under nearly continuous scientific study by researchers at San Diego State University (Weller, 1991; Defran and Weller, 1999; Defran et al., 1999; Dudzik, 1999) and the National Marine Fisheries Service (Carretta et al., 1998; Hansen, 1990) since the early 1980s. An offshore form (Walker, 1981) of bottlenose dolphin also exists off California but its distribution appears not to overlap with the coastal form discussed here (Shane, 1986; DeDecker et al., 1999; Lowther et al., 2005) and the National Marine Fisheries Service manages the coastal and offshore stocks separately (Carretta et al., 2005). The distribution of coastal bottlenose dolphins identified off California extends from at least Ensenada in northern Baja California to Monterey Bay, California, with occasional sightings as far north as San Francisco (Defran et al., 1999). Despite their broad coastal distribution, these dolphins typically occur no further than 1 km offshore, and are most commonly found just outside of the breaking surf in waters ~10 m deep and within 0.25 km of the beach (Carretta et al., 1998; Hanson and Defran, 1998; Ward, 1999). Thus, the distribution of bottlenose dolphins off California can be described as a narrow “coastal corridor” extending at least 900 km north-south but for the most part limited to 1 km from shore. Within their distribution, dolphins exhibit extensive coastal movements and demonstrate little site fidelity to any one area. Although much of the photo-identification research on this stock has been conducted off San Diego, studies completed off Orange County, Santa Barbara, and Monterey Bay, California and in

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Ensenada, Baja California, Mexico show that most of the dolphins identified in those areas have also, at some point, been sighted off San Diego (Defran et al., 1999). Coastal bottlenose dolphins off California are not listed as threatened or endangered under the Endangered Species Act or as depleted under the Marine Mammal Protection Act. Although the abundance of this stock has been seemingly stable for the last two decades (based on photographic markrecapture studies) its size is comparatively small (~350 individuals) and the coastal nature of its distribution makes it vulnerable to a number of possible human-related threats. The mark-recapture estimation of abundance for California coastal stock bottlenose dolphins for the period February 2004 to April 2005 was the objective of the present study.

METHODS

Study area Photo-identification surveys took place in the same San Diego study area as has been used by San Diego State University researchers since 1984 (see Defran and Weller, 1999), consisting of a 32 km strip of coastline between Scripps Pier (32° 52’ N) and South Carlsbad (33° 08’ N) (see Fig. 1).

Photographic surveys Survey, photo-identification and data collection methods followed those described by Defran and Weller (1999) and Dudzik (1999) with the exception that digital photography was employed during the current study. Photographic surveys involved slow travel in a 4.3-m outboard-powered inflatable boat moving parallel to the shoreline, 90-180 m offshore of the surf line. All surveys were conducted in Beaufort Scale ≤ 3 and under visibility conditions adequate for sighting and photographing dolphins. The research team consisted of a boat driver, data recorder and photographer. Systematic visual search of the area from the shore to 2 km offshore was maintained until a dolphin sighting was made. Upon initial sighting of a group, the survey vessel slowed to idle speed, and maneuvered to a vantage point approximately 50 m from the dolphins. From this position, observations on group location (as determined by GPS), time, behavior, and number of dolphins were recorded. The research vessel was then moved within approximately 30 m of the group and individuals were photographed with a Nikon D2H digital camera equipped with a 70-300-mm telephoto lens. In all cases, attempts were made to photograph every dolphin in a group.

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Figure 1. San Diego study area and 2004-2005 group sighting locations.

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A group was defined as either a solitary individual, or two or more dolphins observed in close spatial proximity and swimming in close association and generally coordinating their diving or direction of movement (see Defran and Weller, 1999). Group size estimates were based on field observations and represented the product of a consensus among observers on the survey vessel. The term “calf” is used herein to refer to young of the year and defined by the observation of fetal folds.

Two survey types were conducted during the study: complete and partial. Complete surveys covered the entire study area while partial surveys, those which covered only a portion of the study area but encountered at least one dolphin group, were those curtailed by deteriorating weather. Some surveys were conducted using a north to south route (i.e. departure from Oceanside Harbor) while others consisted of a south to north route (i.e. departure from Mission Bay). In the current study, dolphins encountered while transiting to the study area from either Oceanside Harbor or Mission Bay were also photographed and included in the analyses reported here. In addition, opportunistic surveys to collect biopsy samples from coastal dolphins off San Diego were conducted separately but concurrent (see Lowther et al., 2005) to the present study and all photo-identification images collected during this effort were used for the current abundance estimate and rate of discovery plot but not for any other analyses. These data are included in Table 1 and the Appendix and referred to as “NMFS” data.

Image analysis Only good quality photographs (in focus, complete fin out of the water, near perpendicular to the camera), and those considered to be reliably identifiable over time (see Defran et al., 1999) were used in the analysis (Fig. 2). Differences in the number of notches an individual has can affect resightability and

Figure 2. Dorsal fin of a coastal bottlenose dolphin off San Diego County. 5

thereby contribute to heterogeneity in capture probabilities (Hammond, 1986). The issue of heterogeneity, resulting from fin “distinctiveness”, was minimized in the current study by limiting the analysis to “marked” dolphins that had more than one notch on the trailing edge of the dorsal fin (see Dudzik, 1999). While dorsal fins with a single notch can, in some cases, be used to reliably identify individuals, it is also true that such fins are often ambiguous and can potentially introduce matching errors. Thus, only dolphins with two or more notches on their dorsal fins were used in the current study as was also the protocol used in past studies on the population (see Defran and Weller, 1999; Dudzik, 1999). This procedure, therefore, effectively removed “unmarked” individuals from the individual identification data set.

Mark-recapture analysis Both open and closed population models share an equal catchability assumption that is difficult to meet in most population studies (Hammond, 1986; Pollock et al., 1990). Several closed models have been developed, however, to allow for certain varying capture probabilities to occur (Pollock et al., 1990). In a previous study on coastal bottlenose dolphins off San Diego several open and closed model estimators were tested, and Chao’s model Mth was found to be the least biased (Dudzik, 1999). This model assumes that capture probabilities can change from one sampling period to the next (time variation), and that each member of the population has a unique capture probability due to sex, age, home range, etc., that is independent of all other members of the population (Chao et al., 1992; Otis et al., 1978). Therefore, Chao’s model Mth was selected for the present study and the program CAPTURE (Rexstad and Burnham 1991) was used to generate the abundance estimate. Capture histories of each individual were partitioned for mark-recapture analysis in the following manner: the first six months of the study were the "mark" period (first occasion) and six subsequent occasions were the "recapture" periods (Table 1). Regardless of the number of times an identified dolphin was sighted within each occasion, it was recorded as only one sighting during that period.

Table 1. Capture history partitioning for mark-recapture analysis. Description

Dates

Number of Surveys

Number of IDs

Mark Period

Feb-Jul 2004

11

106

Recapture 1 Period

Aug 2004

2

30

Recapture 2 Period

Sept 2004

1

18

Recapture 3 Period

Oct 2004

3

13

Recapture 4 Period

Nov-Dec 2004

3

32 6

Table 1. Continued Recapture 5 Period

Jan-Feb 2005

2

37

Recapture 6 Period

Mar-Apr 2005

2

18

*Table includes data from complete, partial and opportunistic “NMFS” surveys.

RESULTS AND DISCUSSION Survey effort and encounter rate Between February 2004 and April 2005, a total of 27 photo-identification surveys were conducted, 43 dolphin groups encountered and 19.3 hours of direct observation recorded (see Appendix). Twenty-four of the 27 surveys covered the entire study area (i.e. complete surveys) while three were partial surveys that covered only a portion of the study area due to poor weather. Of the 24 complete surveys, dolphins were encountered on 17 (71%) of them and on all (100%) of the three partial surveys. Thus, in total, dolphins were encountered on 20 (74%) surveys (17 complete and 3 partial). The 71% encounter rate for complete surveys is similar, albeit slightly lower, than rates reported for studies between 1984-1989 (79% encounter rate) and 1996-1998 (79% encounter rate). This change in encounter rate may simply be an artifact of the more limited effort/duration of the current study. It is interesting to note, however, that a high number of surveys (n = 6) in a relatively short period during October to November 2004 found no dolphins. This lack of sightings over such a high number of complete surveys is rare for the San Diego area; an explanation for the lack of dolphins during that period is unknown.

Individual identification A total of 2190 digital images were taken during the study and 164 dolphins individually identified. This number of identifications is directly comparable to that reported by Dudzik (1999) for a similar number of surveys during the 1996-1998 period. The rate of discovery for newly identified individuals is shown in Figure 3. This function shows a continuous increase in the number of “new” dolphin identifications throughout the study period.

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180 160 140 120 100 80 60 40 20 0 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Consecutive Surveys with New Individual Dolphin Sightings

Figure 3. Rate of discovery for individuals identified in 2004-2005.

The subset of unmarked dolphins (n = 97) consisted of 23 single notch individuals, 61 dolphins with only distinctive scarring (e.g., tooth rakes) or dorsal fin shape but no dorsal notches and 13 calves without any identifiable markings or notches. When this subset of 97 unmarked dolphins was added to the subset of 164 marked individuals used in the mark-recapture analysis, it can be crudely estimated that 63% of the population is marked. This said, it is important to recognize the limitations and difficulties associated with attempting to estimate the number of unmarked dolphins in the population (see Hansen and Defran, 1990). Sighting frequencies for the 164 dolphins identified ranged between 1 and 5 (mean = 1.8; SE = 0.08) and 86 (52.4%) individuals were sighted only once (Table 2). The rate of discovery curve and sighting frequency distribution both suggest that dolphins do not exhibit long-term site fidelity in the San Diego study area.

Table 2. Resighting numbers for dolphins identified in 2004-2005 Number of Sightings 1 2 3 4 5

Number of Individuals 86 46 18 8 6

Percentage 52.4% 28.0% 11.0% 4.9% 3.7%

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The lack of site fidelity observed here has also been reported during previous studies off San Diego (Weller, 1991; Defran and Weller, 1999; Dudzik, 1999) and suggests that the coastal stock is panmictic. Further support for this assumption comes from surveys conducted in different geographic locations along the California and Baja coastlines. Between 88% and 94% of the dolphins photographed off Santa Barbara, Orange County, and Ensenada from 1981 to 1989 were also photographically captured in San Diego (Defran et al., 1999). Similarly, 81% of dolphins photographed in Monterey Bay between 1992 and 1994 were previously identified in San Diego as determined by a reanalysis of data from D. Feinholz (Defran unpublished data; Feinholz, 1996).

Group size Group sizes ranged from 1 to 50 dolphins with a mean group size of 9.1 (SE = 1.5) dolphins. Eight groups contained at least one calf and 13 calves (as determined by the presence of fetal folds) were observed over the course of the study. The mean group size reported herein is notably smaller than that reported for 1984-1989 (mean = 19.8, SE = 1.5) and 1996-1998 (mean = 17.8, SE = 2.5). However, the average number of dolphins encountered per survey (mean = 19.7; SE = 3.1) is similar to results from 1984-1989 (mean = 26.8, SE = 2.5) and 1996-1998 (mean = 21.1, SE = 5.9). Of the 17 complete surveys on which dolphins were sighted, the mean number of groups encountered was 2.2 (SE = 0.3). On 53% (n = 9) of these surveys only one group was encountered while multiple groups (range = 2-5) were sighted on 47% (n = 8) of the surveys. In contrast, the same analysis for the 1984-1989 study of Defran and Weller (1999) showed that 75% of their complete surveys encountered a single group. Thus, for the current study mean group size was smaller than reported in the past but the number of surveys that encountered multiple groups was higher. This pattern may help to explain why the number of dolphins encountered per survey during the current study is similar to that reported from previous studies.

Abundance The population size estimate, as generated by using Chao’s model Mth mark-recapture analysis, was 323 (95% CI = 259 – 430, SE = 42.5). This estimate is similar to the estimates of 354 (95% CI = 330-390, SE unavailable) and 356 (95% CI = 306-437, SE unavailable) in 1987/1989 and 1996-1998, respectively (Table 3).

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Table 3. Abundance estimates using Chao’s model Mth. Time Period

Estimate and (95% CI)

Reference

1984-1986

289 (230-398)

Dudzik 1999

1987-1989

354 (330-390)

Dudzik 1999

1996-1998

356 (306-437)

Dudzik 1999

2004-2005

323 (259-430)

This report

Fewer surveys were conducted and fewer dolphins were encountered during the current study than in past studies and this may account for the slightly lower estimate in 2004-2005. The current estimate is also likely to be negatively biased due to geographic survey coverage of the population range, variable sighting frequencies and a reliable estimation of the number of unmarked dolphins in the population. For example, the present population estimate may be negatively biased due to the exclusion of unmarked dolphins (37%) in the mark-recapture model. It should be emphasized, however, that estimating the proportion of unmarked dolphins is hindered by a variety of limitations and thereby difficult to accurately ascertain. Variability in the probability that a dolphin will visit the San Diego study area diminishes equal catchability and may also introduce a negative bias in the population estimate. However, the panmictic nature of the coastal stock (as discussed above) helps counter this negative bias and provides support for the assumption that sampling off San Diego alone will likely result in an abundance estimate representative of the entire population. That said, it is important to note that dolphins occurring off California also travel into waters off Baja. Thus, the weighted average abundance estimate of 206 (CV=0.12) from tandem aerial surveys along the California coast in 1999-2000 represents an estimate for coastal bottlenose dolphins in U.S. waters (Carretta et al., 2005) while the photo-based mark-recapture estimate reported here is likely to be more inclusive of the stock as a whole, and thereby higher in nature.

CONCLUSIONS Findings from the present study of coastal bottlenose dolphins off San Diego, California closely parallel those reported from previous studies in the same area between 1994-1998. While subtle differences in encounter rates, group size and number of groups encountered per survey vary between the 2004-2005 and 1984-1989 and 1996-1999 studies; it is likely that such simply represent inter-annual variation and/or survey effort and study duration. Perhaps most important from a management perspective, however, is 10

that the estimate of abundance for the stock is very similar to previous estimates and suggests that the overall trend has remained relatively stable for nearly 20 years. Despite the apparent stability in abundance, this stock is comparatively small and in combination with its coastal distribution places it at risk from a variety of potential human-related threats. Interactions with coastal set gillnet fisheries are a potential source of mortality or injury to dolphins. Although these fisheries have been restricted or banned off the coast of California, coastal gillnets are still in use off Baja California and may result in some mortality. Contaminant levels, including residues from DDT and PCBs, documented in stranded bottlenose dolphins off southern California are among the highest reported for any cetacean. Long-term exposure to pollutants may lead to reproductive impairment, population reduction and immune suppression. Morbillivirus, an infectious disease implicated as the cause for several mass die-offs of coastal bottlenose dolphins along the US Atlantic and Gulf coasts, is known to occur in marine mammals off the coast of California and is therefore also of concern. Therefore, it is recommended that ongoing monitoring of this stock be conducted to aid in its continued management.

ACKNOWLEDGEMENTS This project was funded under contract # AB133F-03-SE-7140 from National Marine Fisheries Service, Southwest Fisheries Science Center. We would like to thank the following people for their assistance with fieldwork, logistics, and data analysis: Erin Bardin, Stacie Davison, John Day, R.H. Defran, Holly Fearnbach, Shelley Hanish, Eric Howarth, Sandy Hu, Janet Lowther, Kim Miranda, Greg Morris, Julie Oswald, Renee Roberts, Sheyna Wisdom, Suzanne Yin and Jon Zadra. Theresa Miller generously provided GIS mapping and the assistance and support of Jay Barlow and Jim Carretta has been invaluable. This study was conducted under NMFS/SWFSC Scientific Research Permit No. 774-1437 and 774-1714.

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LITERATURE CITED Carretta, J.V., Forney, K.A. and Laake, J.L. 1998. Abundance of Southern California coastal bottlenose dolphins estimated from tandem aerial surveys. Marine Mammal Science 14: 655-675. Carretta, J.V., Forney, K.A., Muto, M.M., Barlow, J., Baker, J., Hanson, B. and Lowry, M.S. 2005. U.S. Pacific Marine Mammal Stock Assessments: 2004. NOAA Technical Memorandum NMFS. NOAA-TMNMFS-SWFSC-375. 316 pp. Chao, A., Lee, S.M. and Jeng, S.L. 1992. Estimating population size for capture-recapture data when capture probabilities vary by time and individual animal. Biometrics 48: 201-216. DeDecker, T., Defran, R.H. and Weller, D.W. 1999. Occurrence patterns of offshore bottlenose dolphins (Tursiops truncatus) in the Southern California Bight. Thirteenth Biennial Conference on the Biology of Marine Mammals, Maui, HI. Defran, R.H., Campbell, G.S., Kerr, K.A., Toperoff, A.K., Dudzik, K. and Bilgre, B.A. 1999. Judging the quality of bottlenose dolphin dorsal fin photographs. Abstract - Thirteenth Biennial Conference on the Biology of Marine Mammals, Maui, HI. Defran, R.H. and Weller, D.W. 1999. Occurrence, distribution, site fidelity and school size of bottlenose dolphins (Tursiops truncatus) off San Diego, California. Marine Mammal Science 15:366-370. Defran, R.H., Weller, D.W., Kelly, D.L. and Espinosa, M.A. 1999. Range characteristics of Pacific coast bottlenose dolphins (Tursiops truncatus) in the Southern California Bight. Marine Mammal Science 15:381-393. Dudzik, K.J. 1999. Population dynamics of the Pacific coast bottlenose dolphin (Tursiops truncatus). M. S. thesis, San Diego State University, San Diego, CA. 63 pp. Feinholz, D.M. 1996. Pacific coast bottlenose dolphins (Tursiops truncatus) in Monterey Bay, California. M.S. thesis, San Jose State University, San Jose, CA. 78 pp. Hammond, P.S. 1986. Estimating the size of naturally marked whale populations using capture-recapture techniques. Report of the International Whaling Commission (Special Issue 8): 253-282. Hansen, L.J. 1990. California coastal bottlenose dolphins. Pages 403-420 in S. Leatherwood and R.R. Reeves (eds.). The Bottlenose Dolphin. Academic Press, San Diego, CA. Hansen, L.J. and Defran, R.H. 1990. A comparison of photo-identification studies of California coastal bottlenose dolphins. Report of the International Whaling Commission (Special Issue 12): 101-104. Hanson, M.T. and Defran, R.H. 1993. The behavior and feeding ecology of the Pacific coast bottlenose dolphin (Tursiops truncatus). Aquatic Mammals 19:127-142. Lowther, J.L., Archer, F.I. and Weller, D.W. 2005. A genetic analysis of coastal and offshore bottlenose dolphins, Tursiops truncatus, off the western United States. Abstract - Sixteenth Biennial Conference on the Biology of Marine Mammals, San Diego, CA. Otis, D.L., Burnham, K.P., White, G.C. and Anderson, D.R. 1978. Statistical inference from capture data on closed animal populations. Wildlife Monographs 62:1-135. 12

Pollock, K.H., Nichols, J.D., Brownie, C. and Hines, J.E. 1990. Statistical inference for capture-recapture experiments. Wildlife Monographs 107:1-97. Rexstad, E. and Burnham, K. 1991. User’s guide for interactive program CAPTURE. Colorado Cooperative Fish and Wildlife Research Unit, Colorado State University, Fort Collins, Colorado 80523 USA. Shane, S.H. 1994. Occurrence and habitat use of marine mammals at Santa Catalina Island, California from 1983 to 1991. Bulletin of the Southern California Academy of Sciences 93:13-29. Walker, W.A. 1981. Geographical variation in morphology and biology of bottlenose dolphins (Tursiops) in the eastern North Pacific. NOAA Administrative Report No. LJ81-03C. Ward, B.G. 1999. Movement patterns and feeding ecology of the Pacific coast bottlenose dolphin (Tursiops truncatus). M.S. thesis, San Diego State University, San Diego, CA. 98 pp. Weller, D.W. 1991. The social ecology of Pacific coast bottlenose dolphins. M.S. thesis, San Diego State University, San Diego, CA. 93 pp.

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Appendix 1. Summary information for photo-identification surveys conducted in 2004-2005 Survey Date 8-Feb-04 8-Feb-04 20-Mar-04 20-Mar-04 20-Mar-04 20-Mar-04 28-Mar-04 10-Apr-04 10-Apr-04 10-Apr-04 24-Apr-04 15-May-04 15-May-04 31-May-04 12-Jun-04 19-Jun-04 19-Jun-04 19-Jun-04 19-Jun-04 17-Jul-04 24-Jul-04 14-Aug-04 14-Aug-04 28-Aug-04 12-Sep-04 26-Sep-04 28-Sep-04 28-Sep-04 9-Oct-04 16-Oct-04 22-Oct-04 24-Oct-04

Group Number 1 2 1 2 3 4 1 1 2 3 None 1 2 1 1 1 2 3 4 1 1 1 2 1 1 1 1 2 None None 1 None

Group Start 8:47 11:10 7:28 8:30 8:53 9:24 8:52 8:09 8:39 9:53

Group End 9:43 11:20 7:40 8:40 9:20 10:18 9:38 8:28 8:45 10:26

Observation (min) 54 10 12 10 27 54 46 19 6 33

6:49 7:56 8:09 7:17 7:27 7:45 8:05 10:08 8:07 9:00 8:25 10:13 8:04 8:41 9:36 10:05 14:30

7:07 8:22 8:41 7:55 7:40 7:52 8:27 10:32 8:33 9:44 9:05 10:46 9:15 9:05 9:45 10:20 14:45

18 26 32 38 13 7 22 24 26 44 40 33 71 24 9 15 15

11:30

11:45

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Latitude 32:56.069 33:07.598 32:52.706 32:59.851 33:00.639 33:01.394 32:57.682 33:05.450 33:04.460 32:53.147 No dolphins 32:47.991 32:54.093 33:06.509 33:08.500 32:56.461 32:55.731 32:57.246 32:48.723 32:58.307 32:54.140 32:57.145 33:08.067 32:54.130 33:00.291 32:58.079 32:54.400 33:04.000 No dolphins No dolphins 33:05.000 No dolphins

Longitude 117:15.816 117:20.318 117:15.265 117:16.823 117:16.993 117:17.352 117:16.471 117:19.122 117:18.851 117:15.454 117:15.876 117:15.412 117:19.654 117:21.091 117:15.929 117:15.752 117:16.265 117:16.566 117:16.408 117:15.452 117:16.270 117:20.329 117:15.427 117:16.837 117:16.420 117:15.800 117:18.500

117:18.800

Complete (C) or Partial (P) C C C C C C C C C C C C C P C P P P P C C C C C C C P P C C P C

Field Estimate 50 4 6 3 3 23 8 10 2 9 0 12 2 7 11 3 3 4 14 10 24 15 7 18 3 1 5 14 0 0 12 0

Calf Estimate 2 0 0 0 0 1 0 1 0 0 0 0 0 1 2 0 0 0 0 0 1 3 0 0 0 0 ? ? 0 0 ? 0

Data Source CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS NMFS NMFS CCMS CCMS NMFS CCMS

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Survey Date 30-Oct-04 12-Nov-04 20-Nov-04 10-Dec-04 12-Dec-04 22-Dec-04 1-Feb-05 4-Feb-05 4-Feb-05 5-Feb-05 5-Feb-05 5-Feb-05 5-Feb-05 5-Feb-05 8-Feb-05 8-Feb-05 27-Feb-05 27-Feb-05 27-Feb-05 16-Apr-05 16-Apr-05 16-Apr-05 30-Apr-05 30-Apr-05 30-Apr-05 30-Apr-05 30-Apr-05

Group Number None None None 1 1 1 1 1 2 1 2 3 4 5 1 2 1 2 3 1 2 3 1 2 3 4 5

Group Start

Group End

Observation (min)

11:30 8:35 10:36 11:30 14:30 ? 8:42 9:40 10:17 10:39 11:45 11:43 12:30 7:37 8:53 10:14 7:46 8:18 9:26 8:30 9:44 11:45 12:16 12:29

12:00 9:29 10:53 ? ? ? 9:28 10:00 10:27 11:18 11:50 12:12 12:55 8:14 9:17 10:32 7:57 8:30 9:43 9:15 11:20 12:00 12:17 12:30

30 54 17 ? ? ? 46 20 10 39 5 29 25 37 24 18 11 12 23 45 96 15 1 1

Latitude No dolphins No dolphins No dolphins 32:58.200 32:52.986 33:03.036 32:51.495 Scripps pier 32:55.000 33:02.530 33:01.930 33:00.150 32:58.488 32:56.494 32:57.000 32:55.000 33:10.650 33:05.566 32:53.419 33:11.307 33:08.490 33:00.984 33:06.522 33:03.992 32:58.268 32:56.530 32:54.891

Longitude

117:16.500 117:15.296 117:18.216 117:15.926 ? ? 117:17.960 117:17.660 117:16.930 117:16.991 117:16.107 117:16.000 117:16.000 117:22.082 117:19.097 117:15.380 117:23.076 117:20.647 117:17.240 117:19.617 117:18.609 117:16.399 117:15.963 117:15.836

Complete (C) or Partial (P) C C C P C C P P P C C C C C P P C C C P P P C C C C C

Field Estimate 0 0 0 8 40 2 20 2 12 11 2 2 10 6 5 3 20 5 4 5 4 3 9 8 4 2 4

Calf Estimate 0 0 0 ? 0 0 ? ? ? 0 0 0 0 0 ? ? 0 0 0 2 0 0 0 0 0 0 0

Data Source CCMS CCMS CCMS NMFS CCMS CCMS NMFS NMFS NMFS CCMS CCMS CCMS CCMS CCMS NMFS NMFS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS CCMS

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