NOAA Technical Memorandum NMFS 

DECEMBER 1983 

DISTRIBUTION OF FOUR DOLPHINS [Stenella spp. 

TROPICAL PACIFIC, WITH AN ANNOTATED 

CATALOG OF DATA SOURCES 

and Delphinus delphis) IN THE EASTERN 

W. F. Perrin 

M. D. Scott 

G. J. Walker 

F. M. Ralston 

D. W. K. Au 

NOAA-TM-NMFS-S WFC-38 

U.S. DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric Administration 

National Marine Fisheries Service 

Southwest Fisheries Center 
NOAA Technical ldlemorandunl NMFS 

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NOAA Technical Memorandum NMFS 

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DISTRIBUTION OF FOUR DOLPHINS (Stenella spp. 

TROPICAL PACIFIC, WITH AN ANNOTATED 

CATALOG OF DATA SOURCES 

and Delphinus delphisl IN THE EASTERN 

W. F. Perrin, M. D. Scott? 

G. J. Walker, F. M. Ralston and D. W. K. Au 

Southwest Fisheries Center 

National Marine Fisheries Service, NOAA 

La Jolla, California 92038 

* Inter-American Tropical Tuna Commission 

La Jolla, California 92038 

NOAA-TM-NMFS-SWFC-38 

U.S. DEPARTMENT OF COMMERCE 

Malcolm Baldrige. Secretary 

National Oceanic and Atmospheric Administration 

John V. Byrne. Administrator 

National Marine Fisheries Service 

William G. Gordon, Assistant Administrator for Fisheries 
CONTENTS 

Page 

ABSTRACT.............................................,...........,..... 1 

INTRODUCTION ........................................................... 2 

MATERIALS AND METHODS 

Sources and Treatment of Di stri buti on Data 

Tunaboat Observer Data....................................... 3 

IATTC Logbook Data........................................... 4 

Other Sources................................................ 4 

Data on Sighting Effort. .......................................... 6 

Computer Programs ................................................. 6 

SPECIES ACCOUNTS 

Stenella attenuata................................................ 6 

- S. longirostris ................................................... 9 

S. coeruleoalba. .................................................. 13 

Delphiqus delphis ................................................. 13 

- 

DISCUSSION AND RECOMMENDATIONS. ........................................ 17 

ACKNOWLEDGEMENTS....................................................... 20 

LITERATURE CITED.................................................. ..... 21 

APPENDICES 

Appendix 1. Catalog of sources of data on the distribution 

of dolphins in the eastern tropical Pacific... ..... 26 

Appendix 2. Collection and management of dolphin-sighting 

data in the NMFS tuna/dol phin observer programs.. .. 40 

Appendix 3. Computer analysis of the distribution and effort 

data.........................,..................... 60 
DISTRIBUTION OF FOUR DOLPHINS (STENELLA SPP. 

AND DELPHINUS DELPHIS) IN THE EASTERN TROPICAL 

PACIFIC, WITH AN ANNOTAT ED CATALOG OF DATA SOURCES 

W. F. Perrin, M. D. Scott*, G. J. Walker, 

F. M. Ralston and D.W.K. Au 

Southwest Fisheries Center 

National Marine Fisheries Service, NOAA 

La Jolla, California 92038 

AB ST RAC T 

This paper presents distributional data on the primary dolphin species 

affected by the tuna purse-seine fishery in the eastern tropical Pacific 

(ETP). The distributional plots presented at the 1979 Status of Porpoise 

Stocks (SOPS) Workshop for the spotted dolphin (Stenel la attenuata 1, spinner 

dolphin (S. longirostris), striped dolphin (S. coeruleoalba), and common 

dolphin (D2lphinus del his) are updated. Past nterature is reviewed and the 

available sources o 

Approximately 30,000 sightings of S. attenuata, 16,000 sightings of S, 

longirostris, 2,000 sightings of S. coeruleoalba, and 9,000 sightings of E. 

ave been included in the-plots. e bulk of these sightings were 

moahrd tuna purse-sei ners by observersThemployed by the National Marine 

Fisheries Service and the Inter-American Tropical Tuna Commission. A plot of 

sighting effort for these observed trips is also included. The NMFS observer 

data collection and editing program is described in detail, as are the 

computer programs used in this analysis. 

* sig ting data from the ETP are listed and described. 

The "SOPS '79" distributions for all four species have been extended, 

particularly at the western and southern edges of the ranges. Range 

boundaries which are not imbedded in areas of moderate or high search effort 

have been marked as uncertain. The known range of S. attenuata has been 

extended northward to -27"N latitude off Baja Cal iforn5, westward to -158"W 

longitude at the western boundary, and southward along the entire southern 

boundary, extending to -17"s at the southeastern corner. The known range of 

- S. longirostris has been extended in a similar fashion. The known range of S. 

coeruleoal ba has been extended primarily westward along the northern axd 

western edges, as far as -155"W at the western extreme. The known range of D. 

del his has been expanded slightly along all boundaries. Populations 5f 

&a spp. in the Hawaiian, Christmas, Marquesas, and Society Islands have 

-visionally considered to be disjunct from populations in the ETP. 

*Inter-American Tropical Tuna Commission, La Jolla, California 92038. 
2 

INTRODUCTION 

The formal program of research at the Southwest Fisheries Center (SWFC) 

on the populations of dolphins involved in the purse-seine fishery for 

yellowfin tuna in the eastern tropical Pacific (ETP) began in 1969, and the 

first document issuing from the program that contained extensive information 

on distribution of the species in the ETP was a doctoral dissertation on 

spotted dolphins, Stenella attenuata, and spinner dolphins, S. longirostris, 

submitted to U.C.L.A. (Department of Zoology) by W. F. Perrin-(l9/2, 19i3 and 

1975a). Earlier pub1 ished information on the species consisted of scattered 

single specimen records (reviewed in Perrin, 1975a) and summaries of sightings 

by both lay observers and biologists (Nishiwaki, 1967 and Morzer-Bruyns, 

1971). The latter are discussed in the appended catalog of data sources 

(Appendix 1). The same distribution information presented by Perrin (1972) 

(including maps of records through 1970) appeared again in an appendix to the 

Report of the NOAA Tuna-Porpoise Review Committee (NOAA, 1972). The first 

review of the distribution of S. coeruleoalba in the ETP was published the 

next year (Hubbs, Perrin and-Balcomb, 19/31 . Perrin (1974 and 1975b) 

presented outline maps of the distributions of S. attenuata and S. 

longirostris incorporating additional data, and these were used in estimating 

population sizes (Smith, 1975), in stock assessments (Perrin, Smith and 

Sakagawa; 1974, 1975, 1976 and 1982) and in a review document (Barham, 

1974). The report of a workshop on stock assessment in 1976 (SWFC, 1976) 

included maps of expanded known distributions of S. attenuata and S. 

lon irostris that incorporated data collected through part of 1916 . It also 

presente a map for S. coeruleoalba based on plotted records through part of 

1976 in Kimura and PFrrjn and a range map for Del hinus del his based 

on SWFC-col lected data ani19dn6)material presented by~(lT"&Znd b). 

Perrin, Sloan and Henderson (1978 and 1979) presented range maps including 

extensions of distribution below the equator for S. attenuata and S. 

lon irostris Updated maps for all four species appearFd in Au, Perryman an'd 

, and these were used in a 1979 assessment of the status of the 

populations (Smith, 1979 and 1983; Holt and Powers, 1982). The species' 

distributions were subsequently reviewed by A1 verson (1980 and 1981) and Scott 

(19811, who incorporated data through 1980. 

_ea_ 

The purposes of this paper are to survey and evaluate sources of data on 

distribution of these species of dolphins (called "target species") in the ETP 

and to review the known distributions based on data available through 1982. 

This document does not estimate predicted total distribution (based on 

environmental variables) or distribution at any one time (considering seasonal 

and year-to-year variation), but rather only establishes the total envelope 

within which reliable records of the species exist. 
3 

METHODS AND MATERIALS 

Sources and Treatment of Distribution Data 

Tunaboat Observer Data 

The primary source of data on distribution was the information collected 

by observers aboard commercial tuna seiners (described in Appendix 1) . The 

observers were employed by the U. S. National Marine Fisheries Service (NMFS) 

or the Inter-American Tropical Tuna Commission (IATTC). For this review, data 

were available for cruises carried out from 1966 to 1983 (partial). 

Procedures for data collection and management are described in Appendix 2. 

The data were extensively reviewed through 1976 by two of us (Perrin and 

Au) in preparation for the stock assessment exercise reported in Smith 

(1979). The species boundaries used in the 1979 assessment (the "Status of 

Porpoise Stocks Workshop") are referred to below as the "SOPS '79" 

boundaries. The review focused on records lying outsi de boundaries delineated 

on the basis of earlier data. A similar review was carried out by Perrin in 

1980 duri ng the course of an admini strati ve heari ng concerned with dolphin 

mortality in the tuna fishery, covering NMFS data for 1977 through 1979. For 

the present report, we have reviewed NMFS data for all years through part of 

1983 and IATTC data for 1979 through most of 1983, using procedures similar to 

those used previously to screen the data for processing errors (co 

keypunching, etc.) and likely misidentifications (see Appendix 2). 

Factors considered in reviewing these sighting records and those 

other sources discussed bel ow include: 

a. documentation of diagnsstic characters (including behavior 

narrative description, sketch or photograph( s 1; 

ing, 

from 

in 

b. sighting distance and conditions; 

c. whether or not the vessel pursued the animals to identify them or, in 

the case of tuna seiners, to catch them; 

d. experience of the observer, including number of previous cruises, 

training, and professional background; 

e. qual i ty of documentation and identifications for other si ghti ngs made 

by the same observer; 

f. in the case of commercial tuna seiners, confirmation of 

identification by members of the crew; 

g. geographical locations, i.e., degree of anomaly with regard to 

previously-known distribution and oceanographic conditions such as surface 

temperature. 
4 

Where the observer qual if i ed the i denti f icati on with "possibly , 'I 

"probably," 'I?," etc. , we upgraded the identification from "unidentified 

dolphin" to a specific identification only when the diagnostic characters had 

been unequivocally described, sketched or photographed. In most cases we let 

the unidentified status stand. In some few cases, especially in the data from 

miscellaneous sources, where the records were in far-outlying areas and the 

evidence to support upgrading (or downgradi ng ) was marginal ly equi vocal , we 

included the record as "probable" but treated it in a separate category (see 

species accounts below). 

We assumed that members of the crews of the tuna purse seiners in all 

cases correctly identified spotted and spinner dolphins and accepted these 

identifications without further documentation. We did not do this for the 

striped and common dolphins, because many fishermen refer to both (and in some 

cases Fraser ' s dol phi n , Lagenodel phi s hosei ) as "whi tebel 1 i es . I' 

IATTC Logbook Data 

An additional source of distribution data for S. attenuata and S. 

1 ongi rostri s was the system of 1 ogbooks maintained by the-IATTC (Source VI I Tn 

Appendix 1). Logbook data are supplied voluntarily by the operators of 

tunaboats fishing in the eastern Pacific. Data from individual purse-seine 

sets are extracted by the IATTC (although the identities of individual boats 

are kept confidential). A computerized file of dolphin data was extracted for 

1959-1982. These distribution records overlap those col lected by the 

observers to a considerable degree. The two data sets do not coincide 

completely, because not all trips were accompanied by observers and because 

not all vessel operators made their logbook data available. For the analyses 

here, we considered only those records lying outside the 1979 SOPS boundaries 

and not represented in the observer data. 

The IATTC logbook data also contain records of sets made on unidentified 

"porpoise." Some of these were in areas for which no sets on identified 

dolphins were reported. In order to ascertain the likely identity of the 

uni denti f i ed dol phi ns , we exami ned the dolphi n-speci es composi ti on of sets i n 

1978-82 (NMFS data) on identified dolphins by 5-degree block (Fig. 1). This 

analysis showed that nearly all sets in offshore peripheral areas were on 

spotted dolphins, although some were on spinner dolphins and a very few on 

striped dolphins. We accordingly consider the outlying "unidentified 

porpoi sell-set records as "probable" spotted-dol phi n records and, because of 

the possibility that other species were involved, we kept these records in a 

separate category in describing the distribution of the spotted dolphin 

(below). 

Other Sources 

Other sources of distribution data, including sources not used in this 

review for various reasons, are described and evaluated in Appendix 1. We 

also reviewed extra1 imi tal records summarized by Alverson (1980 and 1981 1, 

using the same review criteria as for the tunaboat data. 
5 

I I I I I 1 I I I I 1 

c 

.C 
6 

We limited this review to the eastern Pacific (from 35"N latitude to 20"s 

latitude) and the eastern portions of the Central Pacific and South Pacific 

(to 160"W longitude). All four species occur around the world in the 

tropics. Distribution in the central , southern and western Pacific was 

reviewed by Hubbs et a1 . (1973) , Perrin (1975a) and Alverson (1980 and 1981). 

Data on Sighting Effort 

The main source of effort data was again the tunaboat observer 

programs. Details of data collection and management are presented in 

Appendix 2. Data were available for the NMFS observer program for 1971-1982 

and for the IATTC program for 1980-1982. Effort data were also available for 

the series of marine-mammal sighting cruises carried out by the SWFC during 

the period 1976-1983 (Sources I11 and 1V.A. in Appendix 1). A total of almost 

3 million miles of sighting effort is represented in the available data 

(Figure 2). In addition to these data, we also took into account the portions 

of tracklines lying outside the 1-degree squares for which effort data were 

available from two aerial surveys (Jackson, 1980 and SWFC, 1977; included in 

Source VI in Appendix 1) and from three research cruises for which effort data 

were not collected (Figure 2). 

Computer Programs 

Computer programs used in plotting and analyzing the data are described 

in Appendix 3. 

SPECIES ACCOUNTS 

Stenel la attenuata 

There were approximately 30,000 sightings of spotted dolphins. Confirmed 

sightings that fell outside the SOPS '79 boundary (Fig. 3) were mainly in 

regions adjacent to the SOPS '79 range: in the northeastern corner near Baja 

California, to the west of the westernmost extension of the range at 10-15"N 

latitude, to the southwest between about 130" and 140"W longitude, and in the 

southeastern corner near South America. In addition, there are good records 

of the species from Hawaii and the Marquesas Islands. In the northeastern 

corners and in the far southeastern corner, the outlying sightings are 

imbedded in large areas of considerable sighting effort; therefore the edge of 

the species' range in these areas can be defined with some confidence. This 

is also true to a lesser extent for the balance of the northern boundary west 

from about 130"W longitude and a portion of the southern boundary between 

about 130" and 145"W longitude. For the far western region and most of the 

southern boundary, however, the outlying sightings extend to the edge of the 

area covered by recorded sighting effort. These sightings are not numerous, 

but then the effort coverage in the peripheral areas has also been light. We 

conclude that the western and southern extents of the continuous range in the 

eastern Pacific are unknown. This is lent emphasis by three "probable" 

records to the southwest of the western extension of the tuna seining grounds 
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(to the north and east of Christmas Island). 

In depicting the extent of the known distribution (Figure 41, we have 

assumed that the Hawai i an and Marquesan animal s occupy di s junct ranges. We 

have included a1 1 other conf i rmed records ( "probable" and ''possible" not 

included) in a continuous envelope. We have identified those portions of the 

edge of the known range that are adjacent to areas of no effort with a dashed 

line indicating the uncertainty of the envelope. The fit of the boundary line 

to the data is a smoothed one, with the implication that we believe that more 

sighting effort would result in fewer irregularities in the edge of the swarm 

of points. The boundary is not as smooth as the SOPS '79 boundary, however, 

because such would require inclusion of very large expanses of unsurveyed 

ocean. Again, we emphasize that we are depicting the known distribution, not 

the expected distribution. 

It should be noted that the envelope contains several areas that have 

received moderate to heavy survey effort (the two darkest symbols in Figure 3) 

but within which no sightings or only a few sightings have been made. One 

such area is the Gulf of Tehauntepec (15"N latitude, 959 longitude). Another 

is an area off Costa Rica (about 8"-12"N latitude and 86"-9O"W longitude). 

Other areas include the band just north of 5"N latitude and extending from 

about 95" to 125"W longitude, the area off Mexico between 15'-20"N latitude 

and 105°-1100W longitude, the region extending from about 12" to 16"N latitude 

and 118-125"W longitude, the region of the Galapagos Islands, and the eastern 

Panamanian Bight (off Colombia). The low-density band just above 5"N latitude 

may be in part an artifact related to international tuna management (the Fifth 

Parallel was a southern boundary of a closed fishing zone during parts of the 

years 1976-1979 -- IATTC, 19801, but the other gaps may well represent regions 

of very low density of spotted dolphins. Au et a1 . (1979) and Au and Perryman 

(MS) have examined oceanographic and ecological correlates of density of this 

and other species of dolphins in the ETP. They have also addressed the 

question of seasonal occurrence within the overall ranges. Density of dolphin 

schools in the peripheral portions of the ranges has been treated by Holt and 

Powers (1982 ) . 

- S. longirostris 

The pattern for this species is very similar to that for S. attenuata. 

Outlying records (of approximately 16,000) are for the most part -from areas of 

minimal recorded sighting effort (Figure 5). As for S. attenuata, the 

outliers in the northeastern and southeastern regions are bordered by bands of 

sighting effort, but those in other areas run out to the edge of the recorded 

effort coverage and beyond. In addition to being recorded from Hawaii and the 

Marquesas, there are records for Tahiti and Christmas Island. 

We have delineated the distribution envelope using the same criteria as 

for S. attenuata, and the two envelopes are very similar in extent and shape 

(compare kigures 6 and 4). The assumption that the island-associated 

populations are disjunct is less supportable than in the case of S. attenuata, 

because of the closer proximity of the open-ocean sightings to tFe Marquesas, 

but we retain it provisionally. The envelope does not include the two 
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"possible" records to the north and one to the south in oceanic areas far 

outside the tuna-sei ni ng grounds. 

Apparent gaps within the envelope are of the same nature and in the same 

areas as for S. attenuata. Comparison of the distribution of S. lon irostris 

with that of .Z attenuata (Figure 31, however, suggests that thz + ormer may e 

the more reytricted to tropical conditions. In the northeastern and 

southeastern corners of the common range, water temperature can be assumed to 

be a direct or indirect factor limiting distribution. In these areas, S. 

attenuata sightings are relatively more numerous than those of S. 

on irostris, to a greater degree than would be predicted by the overall 

re ative sig ting ratio (about 2:l). In the south, there are several records 

of S. attenuata south of the southernmost record of - S. longirostris. 

+-h 

- 

- S. coeruleoalba 

There are records of the striped dolphin from northern temperate waters 

in the eastern Pacific (Hubbs et al., 19731, and the sightings considered here 

do extend north beyond the recorded sighting effort (Figure 7). The 

southernmost sightings in the southeastern corner of the ETP fall well within 

the recorded effort, however. The species occurs in Hawaiian waters, but the 

present data do not include any sightings from northeastern Polynesia (the 

Marquesas, Tuamotus, and Society Islands). In the south and west, the 

sightings extend to the edge of the recorded effort. 

Because the record from about 34'N latitude and 138OW longitude is so far 

distant from the nearest records, we have treated it as disjunct in 

delineating the known distribution (Figure 8). As for the previous two 

species considered, large segments of the western and southern boundaries of 

the distribution are unknown. The bilobed structure of the envelope as known 

previously remains in this updated version. 

The boundary for the striped dolphin must be treated as more tentative 

than those for S. attenuata and S. lon irostris because of the apparent 

records, as opposed to about 30,000 and about 16,000 for S. attenuata and S. 

lon i rostri s, respectively 1. The apparent absence from some of the periphera 

in the invagination between the two western lobes) may be an artifact of 

inadequate sampl i ng. 

rareness of the animal relative tothe + ot er two species (only about 2,000 

b portions o the area of recorded effort (e.g., in the Marquesas, off Peru and 

h 

Del Dhi nus del Phis 

The distribution of outlying records (45 out of about 9,000 sightings) is 

not as far-flung as for the other three species, and except in the north, all 

lie well within areas of recorded sighting effort (Fig. 9). As in the case of 

S. coeruleoalba, the distribution is continuous with a temperate-water 

aistribution to the north. This may be true for the south as well; the 

sighting effort to the south has been minimal. The species has not been 
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recorded from Polynesia or from the open ocean in the Central Pacific. 

Inclusion of the outlying records expands the known distribution in the 

eastern tropical Pacific only slightly (Figure 10). It can be said that the 

distribution of this species in the region is now known with some certitude. 

The common dolphin exhibits more regional variation in apparent abundance 

within the envelope than do the other three species. The relatively high 

number of sightings and the very high levels of recorded sighting effort in 

the regions of apparent low density suggest that the distributional gaps are 

real. Furthermore, the gaps and the areas of apparent high abundance for this 

species complement those for the two strictly tropical species S. attenuata 

and S. longirostris. Regions in which apparent relative a3undance of + Del hinus delphis is high and that of S. attenuata and S. lon irostris low 

inc u e the areas around the tip of Baja-California (ab062 hde) , off Central America (about 10°N latitude), in the eastern Panamanian Bight 

(about 5'N latitude), off the Gulf of Guayaquil (about 3's latitude) and 

around the Gal apagos Is1 ands. The ecol ogi cal correl ates and imp1 i cati ons of 

this complementarity are treated in detail by Au and Perryman (MS). 

DISCUSSION AND RECOMMENDATIONS 

Alverson (1980 and 1981) made a point not directly addressed in the 

present study: that the three species of Stenella have trans-Pacific 

distributions, i.e., they occur in the central, southern and western 

Pacific. This has been established elsewhere by several workers (Perrin, 

1975a; Hubbs et al., 1973; and others); the primary subject of the present 

study was the distribution of the four species in the eastern Pacific and 

imnediately adjacent Central Pacific only. 

In using the range estimates developed here in any extrapolation of 

density to total population size, it should be kept in mind that abundance in 

areas between the regions of apparent high population density may be very 

low. Also, comparative morphological studies, e.g., Perrin (1975a and b), 

Evans (1976a) and Perrin, Scott, Walker and Cass (in press), indicate that 

exchange among such regions can be low. 

More surveys should be done at various times of the year along the 

southern edges of the known distribution, contemporaneously with surveys of 

adjacent hi gh-densi ty areas. This woul d a1 1 ow def i ni ti on of seasonal and 

year-to-year variation in the extent and structure of the continuous 

distribution. 

More effort should be given to examination of the regions between the 

known continuous distribution in the ETP and the island groups to the 

northwest, west and southwest. Given the levels of effort to date, the 

apparent discontinuities may be artifacts, i .e. the apparent island-related 

distributions may not be disjunct. The internal cruise reports and data 

records of NMFS cruises out of Hawaii contain many records of large schools of 

mostly unidentified dolphins. While these schools cannot be assumed to be of 

19 

. Stenella spp. (because other small cetaceans known to inhabit the Central 

Pacific, such as La enodel his hosei and Pe onoce hala electra, also form 

large schools), some - o t em probably were *gh our review of a 

subsample of these volumnious data files did not yield any records of 

sufficient detail and reliability to merit inclusion in the distribution maps 

(see Catalog), at some point the entire files should be searched for possible 

useful information. In addition, an effort could be made on future cruises 

out of Hawaii to collect adequately documented sightings identified to species 

(some training of observers may be necessary). 

8 
20 

ACKNOWLEDGEMENTS 

We wish to thank the following people for their assistance in this study 

and/or in review of the manuscript: I. Barrett, J. S. Cole, P. S. Hammond, A. 

Jackson, J. L. Laake, J. G. Mead, K. S. Norris, G. T. Sakagawa, G. M. Ver 

Steeg; F. G. Alverson, R. S. Holt, P. T. Major, S. B. Reilly, J. P. Ross, the 

scientists and others who collected the data, and the vessel owners, operators 

and crewmen who made the observer programs possible. 
21 

LITERATURE CITEU 

(including citations in appendices) 

Alverson, F. G. 1980, Distribution of spotted, spinner, comnon, and striped 

dolphin stocks in the eastern tropical Pacific Ocean. U. S. Tuna 

Foundation Publ. 80-2, Tech. Bull .. 3, 53 p. 

Alverson, F. G. 1981. Comments on the distribution of spotted, spinner, 

common and striped dolphin in the tropical Pacific Ocean. Appendix 5 to 

P. S. Hammond (ed.). Report on the Workshop on Tuna-Dolphx 

Interactions, Managua, Nicaragua, April 6-10, 1981. Inter-American 

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1979, Expedition 17, Ocean Research Rep +.=ton, 43 p. 

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progress. Southwest Fisheries Center Admin. Rep. LJ-74-4, 164 p. 

Evans, W. E. 1976a. Distribution and differentiation of stocks of Delphinus +-- del his Linnaeus in the northeastern Pacific. Doc. ACMRR/MM/SC/18, FA0 

cientific Consultation on Marine Mammals, Bergen, Norway, August 31- 

September 9, 1976, 72 p. 

Evans, W. E. 1976b. Potential stocks of Delphinus in the Pacific. Hubbs-Sea 

World Research Inst. Res. Note 7603, Sea World Res. Rep. 7615, 6 p. 

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stomachs and their importance in interpreting feeding habits. J. Fish. 

Res. Bd. Canada 25(12):2561-2574. 

Holt, R. S. 1983. Report of porpoise experiment testing detection of ontrack schools (PET DOTS) March 7 - April 5, 1981. NOAA-TM-NMFS-SWFC-27, 

80 p. 
22 

Holt, R. S. and J. E. Powers. 1982. Abundance estimation of dolphin stocks 

involved in the eastern tropical Pacific yellowfin tuna fishery 

determined from aerial and ship surveys to 1979. NOAA-TM-NMFS-SWFC-23, 

104 p. 

Hubbs, C. L., W. F. Perrin and K. C. Balcomb. 1973. Stenella coeruleoalba in 

the eastern and central tropical Pacific. J. Mamm. 54:549-552. 

IATTC. 1980. Annual report, 227 p. 

Jackson, T. 0. 1980. Trip report: porpoise population aerial survey of the 

eastern tropical Pacific Ocean, January 22-April 25, 1979. Southwest 

Fisheries Center Admin. Rep. LJ-80-01, 74 p. 

Kimura, M. and W. F. Perrin. 1976. Progress report on studies of the biology 

of the striped dolphin, Stenella coeruleoalba, in the eastern tropical 

Pacific. Southwest Fisheries Center Admin. Rep. LJ-76-11, 51 p. 

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porpoises of the eastern north Pacific. Guide to their identification 

in the water. Naval Undersea Center Tech. Pub. 282, 198 p. 

Love, C. M. (ed.). 1972. EASTROPAC Atlas. U.S. Dept. of Commerce Circ. 330, 

Morzer Bruyns. W. F. J. 1971. Field guide of whales and dolphins. 

vol . 6, 168 p. 

Uitgeverij Tor, Amsterdam, 258 p. 

Mullen, D. A. 1977. The striped dolphin, Stenella coeruleoalba, in the Gulf 

of California. Bull. So. Calif. Acad. Sci. 76 : 131-132. 

NOAA. 1972. Report of the NOAA Tuna-Porpoise Review Committee. National 

Oceanic and Atmospheric Administration, Washington, D.C. , 63 p. and 4 

append. 

Nichols, G. and K. Payne. 1979. Marine mammal sightings in the east Pacific, 

R/V Regina Maris, Expedition #13, Ocean Research Rep., ORES, Boston, 

6 P. 

Nishiwaki, M. 1967. Distribution and migration of marine mammals in the 

North Pacific area. Bull. Ocean Res. Inst. Univ. Tokyo 1, 64 p. 

Norris, K. S. and T. P. Dohl. (1980). Behavior of the Hawaiian spinner 

dolphin, Stenella longirostris. Fish. Bull. 77(4):821-849. 

Norris, K. S., W. F. Perrin, 

the Westward cruise to 

Norris, K. S., 8. Wursig, R. 

and J. Solow. 1982. 

Stenel 1 a longi rostri s . Service. SWkC C ontract 

R. Costello and J. D. Bryant. MS. Cetaceans of 

the southeastern central Pacific, 35 p. 

S. Wells, M. Wursig, S. M. Brownlee, C. Johnson, 

The behavior of the Hawaiian spinner dolphin, 

Draft final report to the Nat. Marine Fisheries 

NO. 79-ABC-00090, 203 p. 
23 

Perrin, W. F. 1972. Variation and taxonomy of spotted and spinner porpoises 

(genus Stenella) of the eastern tropical Pacific and Hawaii. Ph.D. 

dissertation, Univ. of Calif., Los Angeles, 490 p. 

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(abstract). Dissert. Abstr. Internat. 33(10), 4 p. 

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in the eastern tropical Pacific. Working paper for meeting of Small 

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Commission, Montreal, April 1-12, 1974, 14 p. 

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Stenella) in the eastern Pacific and Hawaii. Bull. Scripps Institution 

Oceanogr. 21, 206 p. 

Perrin, W. F. 1975b. Distribution and differentiation of populations of 

dolphins of the genus Stenella in the eastern tropical Pacific.. J. Fish. 

Res. Bd. Can. 32: 1059-1061. 

Perrin, W. F., M. D. Scott, G. J. Walker and V. L. Cass. (In prep. ). Review 

of geographical stocks of tropical dolphins (Stenella spp. and Del hinus 

delphis) in the eastern Pacific. Southwest Fisheries Center Ad* 

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of spotted dolDhin, Stenella attenuata and winner dolphin. Stenella 

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of spotted dolphin, Stenella attenuata and spinner dolphin, Stenella - lon irostris in the eastern tropical Pacific. D0C.ACMRRIM.m 

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longirostris, in the eastern tropical Pacific. Addendum. Doc. 

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Bergen, Norway, August 31-September 9, 1976, 23 p. 

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amma s in the Seas Vol. IV. Small cetaceans, seals, sirenians, and 

otters. FAO, Rome. 

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spotted dolphin, - S. attenuata. Southwest Fisheries Center Admin. Rep. 

LJ-78-6, 35 p. 
24 

Perrin, W. F., P. A. Sloan and J. R. Henderson. 1979. Taxonomic status of 

the "southwestern" stocks of spinner dolphin Stenella lon irostris and 

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Sherman, K. and R. P. Brown. 1962. Oceanographic and biological data, 

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51 p. 
25 

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fishery and environmental data, October 1957 - June 1958. U.S. Fish. 

and Wildl. Serv. Spec. Sci. Rep.-- Fisheries 283, 105 p. 
26 

APPENDIX 1. Catalog of sources of data on the distribution 

of dolphins in the eastern tropical Pacific.* 

*I. NMFS Tuna Purse-Seiner Observer Data 

Since 1965, the NMFS observers have been placed on tunaboats in 

order to gather biological data on dolphins and to monitor dolphin mortality 

associated with the U. S. purse-seine fishery for tropical tunas. The area , 

covered by observed trips is within the ETP (see Text Figure 1). The numbers 

of trips made annually are given in Appendix Table 1-1. 

The fishermen use 25X binoculars and helicopters to search for 

dolphin schools and bird flocks that are associated with tuna. The ship 

typically alters course to identify schools of dolphins, but small schools or 

non-target species are usually not approached very closely. The observer's 

ability to identify the species sighted is greatly influenced by whether the 

ship approaches, chases and captures a school. 

NMFS observers are trained in species identification prior to 

making their first trip (see Appendix 2). Field experience, however, is the 

key factor in making accurate identification of species, and since experience 

varies amongst observers, data from first-time observers have been treated 

more cautiously than data from those with more experience. 

The NMFS sighting and set record forms have changed in format and 

information collected over the years (see Appendix 2). The observer is 

currently required to record the following distributional information: 1) 

sighting location, 2) species identification and composition by both observer 

and crew, 3) the closest distance to the dolphin school , 4) a sketch by the 

observer depicting the key characteristics observed, and 5) a written 

description of these characteristics. Observers occasionally bring back 

photographs and specimens from animals that are killed during the sets, 

allowing further confirmation of identifications. 

The combination of observer training, crew and observer experience, and 

editorial review makes this a reliable data source. This body of data, and 

that of the IATTC observer data (Source 111, together are the most extensive 

of all the sources and comprise the bulk of the distributional data available. 

*Sources used in the present study are marked with an asterisk. 
27 

Appendix Table 1-1. Number of trips and sightings made by NMFS 

and IATTC observers, 1965-1982 sightings 

made by NMFS observers in 1983 are included 

in the 1982 data base. 

the 1983 IATTC data has been included. 

Only a portion of 

NMFS IATTC 

No. No. 

No. sightings No. sightings 

Year trips (of all species) trips (of all species) 

1965 

1966 

1967 

1968 

1971 

1972 

1973 

1974 

1975 

1976 

1977 

1978 

1979 

1980 

1981 

1982 

1983 

Total 

1 

1 

1 

1 

6 

13 

25 

41 

32 

75 

109 

119 

78 

45 

37 

33 

0 

617 

9 

49 

0 

25 

511 

820 

2,706 

3 , 482 

4,418 

7,516 

13,241 

14,031 

10,696 46 

5 , 548 63 

4,444 59 

6 , 139 48 

0 25 

73 , 635 24 1 

2,133 

6 , 925 

7,495 

5,864 

2,711 

25 , 128 

*II. IATTC Tuna Purse-Seiner Observer Data 

An observer program similar to that of the NMFS was begun in 1979 

by the IATTC and was designed to sample the international fleet. The area 

covered in the ETP by boats sampled by the IATTC program is similar to that 

covered by NMFS-observed boats. The number of trips made annually is given in 

Appendix Table 1-1. Countries that have participated in this program have 

incl uded Canada , Cayman Is1 ands , Costa Rica, Mexico , New Zeal and , Nicaragua , Panama, United States and Venezuela. Biologists are seconded by a 

participating country to the IATTC to serve as observers aboard vessels 

registered in that particular country. 

IATTC observers are given similar training to that of NMFS 

observers. U.S. observers are given both NMFS and IATTC training, while 

non-U.S. observers are given only IATTC training. Information collected by 

the IATTC program differs somewhat from that collected by NMFS program (see 

Appendix 21, but it includes the same distributional information listed 

above. The debriefing procedures and the reliability of the data are also 

comparable to those of the NMFS program. 
28 

*III. NMFS Dol phin-Distribution Research Cruises 

From 1974 to the present, 15 cruises have been made to the ETP to 

study dolphin distribution (Appendix Table 1-2). Some of these studies were 

designed to determine the southern and western edges of the ETP dolphin 

populations. The ships were diverted off trackline in order to identify 

dolphin schools. Typically, experienced NMFS observers were on watch using 

20X or 25X binocul ars. 

A total of 2,911 cetacean sightings was made during these 

cruises. The information collected and the editing procedures were the same 

as for the tunaboat observer data. These data are considered reliable because 

of the observer experience, editorial review, and, particularly, the ability 

to closely approach dolphin schools for identification. 

Appendix Table 1-2. NMFS dolphin-distribution research cruises. 

Year Vessel 

Dolphin Research 

Cruise number 

1974 

1976 

1976 

1976 

1976 

1977 

1977 

1977 

1979 

1979 

1980 

1980 

1982 

1983 

1983 

R/V David Starr Jordan 

R/V Townsend Cromwell 

R/V David Starr Jordan 

R/V David Starr Jordan 

R/V Surveyer 

R/V David Starr Jordan 

R/V Townsend Cromwell 

R/V David Starr Jordan 

R/V David Starr Jordan 

R/V Townsend Cromwel I 

R/V David Starr Jordan 

R/V Townsend Cromwell 

R/V David Starr Jordan 

R/V David Starr Jordan 

R/V Surveyor 

~~ 

-- 

___~ 

-~ 

-~ 

~- 

~~ 

~~ 

-~ 

04 

168 

169 

207 

212 

213 

2 14 

319 

463 

464 

598 

599 

80 1 

843 

852 
29 

IV. Other NOAA Research Cruises 

*A. With Experienced Observers 

Since 1969, trained observers have made dolphin sightings in 

the ETP aboard NOAA ships involved in non-marine mammal research (Appendix 

Table 1-3). Since dolphin studies were a secondary objective of these 

cruises, the ships did not divert from the trackline to identify dolphin 

schools. Sightings were made by one or more experienced observers. From 1976 

on, observers were equipped with 20X or 25X binoculars with which to watch 

specifically for dolphin schools. 

A total of 1046 sightings was made on these cruises. These 

data are considered reliable because of the experience of the observers. 

Appendix Table 1-3. NOAA non-marine-mammal research cruises 

with experienced observers aboard. 

Year Vessel 

(Dolphin Research) 

Cruise Number 

1969 R/V Miss Behavior 

1976 R/V Oceanographer 

1977 R/V Oceanographer 

1977 R/V Oceanographer 

1980 R/V Oceanographer 

1980 R/V Researcher 

- 

216 

232 

310 

642 

648 

1981 R/V Oceanographer 

1981 R/V Oceanographer 

687 

716 

*B. With Inexperienced Observers 

Marine mammal sighting data were available for ten cruises 

made in the ETP aboard NOAA ships involved in non-marine mama1 research from 

1967 through 1980 (Table 1-4). Observers recorded cetacean sightings but 

lacked experience at species identification. Sightings were made with 7X 

binoculars or the naked eye. The ships did not divert to approach dolphin 

school s . 

This data base is considered less reliable than Source 1V.A. 

due to the inexperience of the observers. These sightings have been reviewed, 

and 40 sightings of target species have been included in this report. 
30 

Appendix Tab1 e 1-4. NOAA research cruises with inexperienced 

observers aboard. 

Year Vessel 

1967 

1967 

1967 

R/V David Starr Jordan 

R/V David Starr Jordan 

R/V Undaunted 

~- 

-- 

1970 

1971 

1971 

1973 

1979 

1980 

19&1 

R/V ~- David Starr Jordan 

R/V David Starr Jordan ~~ 

R/V David Starr Jordan 

R/V David Starr Jordan 

R/V Oceanographer 

-- 

-- 

R/V Oceanographer 

R/V Oceanographer 

"V . Non-NOAA Research Cruises With Experienced Observers 

From 1972 through 1982, NMFS technicians were placed aboard vessels 

conducting non-marine mammal research in the ETP. Most of these vessels were 

chartered commercial albacore boats, but one was a Scripps Institution of 

Oceanography research vessel. The technicians' primary duties were not 

concerned with marine mammal s, but some were experienced as marine mammal 

observers and kept detailed logs of sightings. The cruises for which marine 

mammal data are available are listed in Table 1-5. Identifications were made 

with 7X binoculars or the naked eye. The ships did not routinely divert from 

the track1 ines to approach cetacean school s, a1 though this may have occurred 

on occasion. 

A total of 29 sightings of target species was recorded by these 

technic i ans. The data are considered reliable due to the observers' 

experience. 

Appendix Table 1-5. Non-NOAA research cruises with 

experienced observers aboard. 

Year Vessel 

1972 

1974 

M/V Jinita (albacore research cruise) 

M/V Deep Six (albacore research cruise) 
31 

Appendix Table 1-5. Continued 

Year Vessel 

1975 

1975 

1975 

1975 

1976 

M/V Kamchatka (a1 bacore research cruise) 

M/V -~ Sun Dance (albacore research cruise) 

M/V -- Lady Olga (albacore research cruise) 

R/V Agassiz (Scripps Institution of 

Oceanography research vessel ) 

M/V Sunrise (a1 bacore research cruise 

1976 M/V Lusty (a1 bacore research cruise) 

*VI. Aerial Survey Data 

NMFS has conducted four series of aerial surveys since 1974 to 

study dolphin densities in the ETP (Appendix Table 1-6). The IATTC also 

conducted an aerial photographic study in 1980. In the NMFS studies, species 

identification was a secondary objective, particularly for small schools and 

probable non-target species. In the IATTC study, only those schools that were 

photographed, mainly large schools, were recorded. Species identification for 

these schools, however, was a prime objective. 

Passes over the schools for identification purposes were usually at 

an altitude of 180 m or lower. Experienced cetologists used handheld 

binoculars or the naked eye to identify the schools. For all of the IATTC 

sightings and some of the NMFS sightings, large-format photographs were taken 

that could confirm species identification. 

A total of 1414 sightings were recorded on these surveys. This 

data base is considered to be reliable. 

Appendix Table 1-6. NMFS and IATTC aerial surveys. 

Year 

1974 

1977 

1979 

1981 

1980 

NMFS aerial survey (unpub. NMFS data) 

NMFS aerial survey (SWFC, 1977) 

NMFS aerial survey (Jackson, 1980) 

NMFS aerial survey (Holt, 1983) 

IATTC aerial photography study (unpub. IATTC data) 
32 

*VII. IATTC Tunaboat Logbook Data 

Many tunaboat captains fishing in the eastern Pacific have allowed 

the IATTC to extract data from their logbooks. Often the set information from 

these logbooks include whether dolphins were set upon and the species of the 

dolphins. Identifications are usually made by the captain or navigator, who 

are typically experienced at identification of target species, particularly 

spotted dolphins, Stenella attenuata, and spinner dolphins, S. longirostris. 

Species are listed in the IATTC d ata base as either 1) spotred dolphins, 2) 

spinner dolphins, 3) mixed spotter and spinner dolphins, 4) unidentified 

dolphins, 5) "whitebelly" dolphins (either common dolphins, D. delphis, 

striped dol phins , S. coerul eoal ba , or Fraser Is dol phins , Lagenodel pi sX%&T, 

or 6) probable dorphin set. Only the spotted and spinner dolphin semve 

been used for the distribution plots, although dolphins classified as 

"unidentified" or "whitebelly" dolphins are probably of a target species, 

since a set was made on them. 

Usually no species characteristics are listed by the skippers, and 

errors in identification cannot be checked. Since the dolphins have been 

captured, identifications are likely to be re1 iable. Set locations 

occasionally have been reported incorrectly for various reasons, however , and 

such errors may be present in the data base. 

Perrin (1975a) has previously reviewed IATTC 1 ogbook data from 

1963-1970, and 1970-1979 data have been partially plotted by Alverson 

(1981). This data base has been extensively edited since these reviews, 

however, and the revised data from 1959-1982 were examined in this study. A 

total of 321 S. attenuata and S. longirostris sets which were outside the 1979 

SOPS boundarik were plotted: Add i tionall y , out1 yi ng uniden ti f ied dol phi n 

sets were plotted as "probable" - S. attenuata sightings. 
33 

*VIII. IATTC Tuna-Tagging Cruises 

The IATTC has conducted tagging crui ses aboard tuna purse-seiners 

and baitboats since 1955 for the purpose of estimating the abundance of 

tunas. During 100 cruises to the eastern and central Pacific, marine mammal 

sightings have occasional ly been recorded. Experience of the IATTC observers 

varied, but sightings were sometimes confirmed by the skippers and crews who 

presumably were experienced at identifying spotted and spinner dolphins. 

A total of 1,924 cetacean sightings were recorded, of which 364 

were identified as of target species. Of the remainder, a large number were 

unidentified-dolphin sightings, many of which were set upon by purseseiners. These data are likely to be reliable, as most of the identified 

sightings were made by experienced observers and could be confirmed by the 

crews. 

*IX. Pacific Tuna Development Foundation (PTDF) Cruises 

Exploratory cruises by tuna purse-seiners have been made to the 

central and western Pacific since 1976 (Appendix Table 1-7) under the auspices 

of the PTDF (Alverson, 1981). The crews aboard these boats were experienced 

at identifying dolphins associated with tuna in the ETP. PTDF observers, 

often former NMFS observers, were also aboard to record cetacean sightings. 

Sighting methods were similar to those of other tuna seiners except that 

dolphins were not set upon, because they are not usually associated with tuna 

in the western Pacific. A total of 299 cetacean sightings were made during 

these cruises. Three sightings were made in the ETP, two were made in the 

Marquesas Islands, and two were made in the Hawaiian Islands. The rest were 

from the western Pacific and thus out of the scope of the present study. Of 

the seven sightings included in this analysis, all were of target species, and 

they are considered re1 iable. 

Appendix Tab1 e 1-7. PTDF expl oratory cruises . 

Year Vessel Areas of Sightings 

1974 M/V Sea Treasure 

1976 M/V Mary El izabeth 

1976 M/V Zapata Pathfinder 

1976 M/V Apol lo 

1977-78 M/V Jeanette - C. 

1979 M/V Bold Venture 

Marquesas Is1 ands 

New Guinea, Marshal 1 , Carol ine, 

New Guinea, Caroline, Solomon and 

S. of Indonesia, ETP 

New Guinea 

Guam 

Solomon and Gilbert Islands, ETP 

Gi 1 bert Is1 ands , ETP 
34 

Appendix Table 1-7. Con t i nued 

Year Vessel Areas of Sightings 

1979 M/V Island Princess 

1979 M/V Jeanette - C. 

1980 M/V ~- White Star 

1980 M/V Island Princess 

1981 M/V Island Princess 

1982 M/V Western Pacific 

Marshall , Caroline, Gilbert and 

Sol omon I sl ands ; Nauru Atoll 

Hawaii, NW of Midway Island; E of 

Japan; Philippines, Solomon 

I sl ands 

Well N. of Wake Island, Wake, 

N. of New Guinea 

No sighting data available. 

SW of Japan, Caroline and Gilbert 

Is1 ands 

Hawaiian and Caroline Islands. 

*X . Naval Ocean Systems Center (NOSC) Cruises 

Sightings data gathered during NOSC studies on cetaceans have been 

provided by W. E. Evans and S. Leatherwood to the NMFS. These data include 

sightings made aboard the U. S. Saluda, U. S. Sea See and other naval vessels 

and aircraft. Methods of sightiid identification are not known, but the 

observers were experienced cetologists and the data were reviewed by NMFS 

personnel in the 1970s. The raw data were not available for this review. 

A total of 109 sightings of target species was considered reliable 

and used in the report. 

*XI. U. S. Whal e-Tagging Cruises 

In the mid-to-late 1960s several whal e-tagging cruises to the ETP 

were conducted by the U. S. National Marine Mammal Laboratory (now under 

NOAA/NMFS) in Seattle, Washington (Appendix Table 1-8). The vessels were 

mainly chartered commercial whale catchers, and the chief scientists were 

marine mammalogists experienced at identification at sea. 

A total of 551 cetacean sightings was recorded. These data are 

considered reliable due to the experience of the observers. 
35 

Appendix Table 1-8. U. S. whale-tagging cruises. 

Year Vessel 

1965 

1965 

1965 

1966 

1967 

1967 

1968 

1968 

1969 

Lynn Ann 

Sioux City 

Graciel a 

Sioux City 

Sioux City 

Washinqton 

-- 

-- 

-- 

-- 

Allen B. Cody -- - 

Washington 

-- Sioux City 

*XII. U.S.S.R. - U.S. Cooperative Whale-Tagging Cruises 

Two cooperative whal e-tagging cruises were made aboard Soviet 

whaling ships, with experienced cetologists from both the U.S.S.R. and the 

U.S. aboard. Observers aboard the Vnushitel'nyi made sightings in 1975 in the 

ETP, particularly south of the equator. Th e Zharkyi did not operate in the 

ETP, but searched near the islands of Fiji, Newdonia and Tonga in 1977. 

The ships apparently diverted from the trackline to identify schools. 

A total of 166 cetacean sightings was made during the cruise of the 

Vnushitel 'nyi. These sighting data are considered reliable due to the 

observers' experience and the ability to closely approach the schools for 

i den ti f icati on. 

XIII. Pub1 ished Literature Containing Original Sighting Data 

(full citations in Literature Cited) 

*A. Wells, R. S., B. G. Wursig, and K. S. Norris (1981) A survey 

of marine mammals of the umer Gulf of California. Mexico. with an assessment 

ofstatus of Phocoena sinus. 

A 1981 survey was funded by the Marine Mammal Commission to 

locate and identify cetacean species present in the northern Gulf of 

California. The status of the Gulf of California porpoise, Phocoena sinus, 

was of particular interest. The observers were all experienced marine 

mammal ogi sts aboard an 8-m powerboat. Si ghtings were made with 7X binocul ars 

or the naked eye, and sighted schools were approached for identification. A 

total of 138 sightings was made. However, of the target species, only 

Delphinus (70 sightings) was seen. The data are considered reliable due to 

the observers' experience and the high priority and effort given to 

- 
36 

identification of si ghtings. 

B. W. F. J. Morzer-Bruyns. (1971) --- Field Guide of Whales - and 

Dolphins. 

Morzer-Bruyns, a sea captain and amateur zoologist, spent 40 

years at sea, and 18 years sketching dolphins at sea. He made 15 trips across 

the ETP and many more across the Pacific Ocean. He presented distribution 

envelopes comprised of his own sightings and a few from the literature, but 

did not distinguish between the two sources. Few, if any, individual 

sightings are presented. His sighting data are given as the total number of 

all species sighted in each 10" square. One can construct a crude estimate of 

effort from his data ("crossings1'/1O0 square). The distributions are often 

stretched by linking widely separated sightings, although he may not have 

visited or seen anything in the intervening squares (particularly true of the 

"longbeaked dolphin" - a spinner in the South Equatorial Current). However, 

he showed a very limited distribution in the ETP for spotted, spinner, and 

common dolphins despite several trips out of Mexico. For these and other 

reasons, we do not have confidence in his published distribution maps and did 

not include them in this study. 

*C. F. Alverson (1981). Comments on the distribution of spotted, 

spinner, common and striped dolphin in the tropical Pacific Ocean. 

Alverson presented a 1981 review of dolphin distributions in 

the ETP. The sighting sources included a previously unpublished sighting of 

S. attenuata by T. Tafoya, an experienced tuna seiner captain. The sighting 

Sy T. Tafoya is likely to be reliable due to the captain's experience at 

identifying target species. 

D. M. Nishiwaki (1967). Distribution and migration of marine 

mammals in the north Pacific area. 

Ni shi waki reviewed si ghtings made by "fi shermen , whal ers , and 

scientists," mainly in the North Pacific. No information is available to 

determine the observer experience or the methods of sighting and identifying 

animals. Nishiwaki informed one of us (Perrin) that the data collection was 

retrospective, that is, the fishermen were asked to recall what they had seen 

and where. Nishiwaki also indicated (to Perrin) that the distribution 

envelopes were based on oceanic current patterns as well as on sightings 

data. The distributional envelopes for S. attenuata and S. longirostris were 

presumed to be the same. No individual- sightings or species breakdown are 

given. Due to the lack of data necessary to evaluate the basis of these 

distributions, they have not been included in the present analysis. 

E. EASTROPAC Cruises 

A series of cruises was conducted during 1967-1968 to collect 

data on oceanographic and biological features of the ETP (Love, 1982). 

Incidental sightings of marine mammals were recorded on some of these cruises 

by inexperienced observers. The sightings were classified as 1) porpoise, 2) 

pilot whales, 3) other whales or 4) unidentified cetaceans. These data were 

not included in this study because of the lack of species identifications. 
37 

*F. Fitch, J. E. and R. L. Brownell, Jr. (1968). Fish otoliths 

in fish stomachs and their importance in interpreting feeding habits. 

As part of a study on dolphin feeding habits, the authors 

used 8 Stenella specimens (5 spinner and 3 spotted dolphins) that had been 

captured by tuna purse-seiners in 1967-1968. The capture locations were 

recorded. Since the specimens were identified by experienced cetologists, the 

data are considered re1 iable. 

*G. Norris, K. S. and T. P. Dohl. (1980). Behavior -- of the

Hawaiian spinner dolphin, Stenella longirostris. 

The authors summarized sightings of spinner dolphins in the 

Hawaiian Islands. Surveys were conducted by experienced catalogists from the 

brigantine Westwood, the motor sailers R/V Hikino and R/V Inua, the U.S. Coast 

Guard vessel Buttonwood and small fixed-wing aircraft. Locations of spinner 

dolphin captures made by Sea Life Park personnel were a1 so recorded. A total 

of 59 sightings were plotted east of 160"W. 

These sightings were considered reliable due to the 

experience of the observers. 

*H. Shallenberger, E. W. (1981). - The status - of Hawaiian 

cetaceans. 

The author reviewed sighting and stranding locations of 

Hawai ian cetaceans from both pub1 i shed and unpubl i shed sources. The 

unpublished sources included sightings made by Sea Life Park collecting 

crews. A total of 86 sighting or stranding locations (E. of 160"W) of 

Stenell a spp. were used in this report. The data are considered re1 iable. 

*I. Norris, K. S., B. Wursig, R. S. Wells, M. Wursig, S. M. 

Brownlee, C. Johnson, and J. Solow (1982). - The behavior _L- of the Hawaiian 

spinner dol phin, Stenel 1 a 1 ongi rostri s. 

The authors conducted boat and aerial surveys around the 

Island of Hawaii. They presented radio-tracking and natural -mark sightings 

data which indicate that the nearshore S. longirostris population are 

Dermanent residents of the Island. The report presents only their aerial 

kightings of S. longirostris-- a total of 98 'sightings. The data are 

considered re1 iible due to experience of the observers. 

*J. Other published sources which reported only one or a few 

records are included in the analysis and listed in the Literature Cited (Van 

Gelder, 1960; Mullen, 1977, Scott and Wussow, 1983). 

*XI v. Dolphin Tag Returns 

Since 1969, the NMFS has conducted a dolphin-tagging program in the 

ETP. Tags were recovered from dolphins brought aboard ship during captures by 

tuna purse-seiners. The tags were returned to SWFC by fishermen and by 

observers aboard the tunaboats. When positions could be accurately assigned 

to a tag return, the information was included in this data base. All tag 
38 

returns were reviewed by NMFS personnel. 

were considered reliable and non-overlapping with other data sources. 

A total of 55 tag-return localities 

xv . Si ghti ngs From Pri vate Vessel s 

*A. With Experienced Observers 

A single S. coeruleoalba sighting in 1979 was reported off 

the coast of Baja Californix by C. Peters, a former NMFS observer. 

A single S. longirostris sighting in 1981 was recorded by 

naturalists aboard the M/T Lindblad txplorer. Sighting methods for this 

cruise are not known. The sighting is considered a "possible" record due to 

this and the inexperience of the observers. 

A cruise was conducted in 1970-1971 aboard the R/V Westward, 

a brigantine operated by the Oceanic Institute of Hawaii (Norris, Perrin, 

Castello and Bryant, unpub. MS). Two experienced observers were aboard to 

coll ect cetacean sightings. Fourteen sightings were recorded near the 

Marquesas , Tuamotu and Austral Is1 ands. Additionally, several dolphins were 

captured for taxonomic examinations. 

Sightings made by experienced observers during marine mammal 

surveys in 1978-1979 by the R/V Regina Maris are also available (Balcomb, 

Villa and Nichols, ..1979; Nicholas~a~1979; Balcomb, 1979; Balcomb, 

Miller, Wells and Wursig, 1979; also unpublished data provided by K. Balcomb, 

P. Ross and P. Major). A total of 522 sightings, including 144 target-species 

sightings were made in the Gulf of California, the west coast of Baja 

Cal ifornia and between Central America and the Galapagos Is1 ands (Expeditions 

Nos. 9-14, 17). An additional three sightings made by B. Villa, a Mexican 

cetologist, in 1976 are also reported. A total of 7 cetacean sightings, 

including one sighting of D. delphis, was made in 1983 by experienced 

observers aboard the sail ing-vesn- Ragtime (unpub. data provided by J. 

Barlow, A. Hohn and M. Scott). 

*B. With Inexperienced Observers 

In 1975 and 1976, sightings were reported to the NMFS by the 

crew of the S/V Serenity, a private yacht. The sightings were made off the 

Marquesas Islands and off Panama. Members of the crew were inexperienced 

observers but were attempting to tag dolphins, which involved closely 

approaching schools. Standard NMFS sighting forms were filled out by the 

crew, but the methods of sighting and identification are not known. These 

have been plotted as "possible" records due to the inexperience of the 

observers and the 1 ack of information needed to eval uate the identification. 

*XVI. Museum Specimens 

Location records associated with museum specimens have been used in 

this report. Specimens have been collected by harpooning or from tuna purseseine kills. We have data on specimens in the collections of the U. s. 

National Museum, Los Angeles County Museum, San Diego Natural History Museum, 
39 

National Marine Mammal Laboratory and the Southwest Fishery Center (NMFS). A 

total of 88 location records have been considered reliable. 

XVI I. SWFC Honol ul u Laboratory Research Cruises 

Research cruises in the central Pacific were conducted between 1952 

and 1982 by the Honolulu Laboratory of the NMFS Southwest Fisheries Center. 

Cetaceans for the most part were sighted and recorded as either 1) whales, 2) 

porpoises or 3) seals. Search methods are not known and the observers were 

apparently not experienced cetologists. Pub1 ished reports for some of the 

cruises include Sherman and Brown, 1961 and 1962; Austin, 1957; Wilson et a1 . , 1958; and Wilson and Rinkel, 1957. We examined a subsample of internal cruise 

reports and new data. We did not use the data in this report because of the 

questionable re1 iabil ity of the (very few) species identification that were 

recorded. However, see DISCUSSION AND RECOMMENDATIONS. 

*XIX Pacific Ocean Biological Survey Program Cruises 

An unpublished body of data which was gathered between 1963 and 

1969 during a series of cruises made in the Central Pacific by the Pacific 

Ocean Biological Survey Program of the Smithsonian Institution National Museum 

of Natural History was examined. These cruises were primarily to survey 

seabird populations, but cetacean sightings were a1 so made. Sightings were 

made by both experienced and inexperienced marine mammal observers. On at 

least some of these cruises a bridge watch was maintained while at sea to 

record bird and cetacean sightings. It is not known how the observers 

searched or whether the ship diverted from the track to identify cetaceans. 

In some cases, identification could be confirmed from photographs or by 

collecting an animal. Seventeen certain and nine probable sightings of target 

species have been extracted from the data, but only two (one certain, one 

probable) sightings were within the ETP boundaries used in this report. 

xx. California Cooperative Oceanic Fisheries Investigations 

(CALCOF I ) Crui ses 

Since 1950, surveys have been conducted to sample fisheries 

resources within the California Current System by CALCOFI, a research 

consortium of several federal , state, university, and Mexican agencies. Data 

reports on the results of these cruises have been published since 1965 

(California Cooperative Oceanic Fisheries Investigations Data Report, Vols. 1- 

31). A large array of vessels have been used since 1950 to survey off the 

California coast, but some surveys covered the west coast of southern Baja 

California. Incidental sightings of marine mammals were recorded in some 

cases, but the observers were inexperienced at cetacean identification. It is 

not known how searches were conducted or whether cetacean schools were 

approached. This data base was not included in this report due to the 

inexperience of the observers and the inability to evaluate individual 

sighting data. 
40 

APPENDIX 2. Collection and management of dolphin sighting 

data in the NMFS tuna/dolphin observer programs. 

Marine mammal sightings data have been collected since 1971 by employees 

of the National Marine Fisheries Service (NMFS) and are archived at the 

Southwest Fisheries Center (SWFC) in La Jolla, California. These data include 

some 77,259 separate cetacean sighting events recorded during 642 crui ses. 

The data are also computer-accessi ble and are available to staff researchers 

in a series of twelve annual data bases. 

The vast majority of these sighting records were recorded by scientific 

observers stationed aboard commercial tuna purse seine vessels fishing in the 

eastern tropical Pacific Ocean. Twenty-five cruises in the ETP were of 

vessels other than seiners; most of these were National Ocean Survey 

(NOS )/NOAA research vessel s. 

Observer t r a i n i na 

The sea-going observers, are employed under the job classification of 

Biological Technician (Fisheries) . Minimum qualifications for this 

classification include completion of 24 college-level semester units in the 

sciences or equi valent experience. Most are graduates in the biological 

sciences from 4-year colleges. Additional training was provided for each of 

the observers before they go to sea. Training sessions are prepared and 

presented by staff of both the Southwest Fisheries Center and the Southwest 

Region's San Diego Branch Office. During these sessions the newly hired 

observers are given intensive training on correct data forms usage and on the 

i d e n t i f i c a t i o n o f cetaceans of the eastern tropical Pacific. Special emphasis 

is placed on the identification of species and stocks of the family 

Del phi ni dae. Training on cetacean identification has included slide 

presentations of schools at sea as well as of specimens. Since 1972, the seagoing observers have been issued an illustrated field guide to cetaceans 

(Leatherwood, Evans and Rice, 1972). 

Instructions to observers 

Since 1971, tuna/dol phi n observers have been instructed to stand marine 

mammal watch using binoculars when a vessel was underway and the environmental 

conditions affecting sightability were favorable. While on watch, observers 

are asked to position themselves on the flying bridge near the crew's 

high-powered binocular sighting station in order to ensure that they have a 

reasonably good vantage point for observations. The number of hours expended 

in this manner are recorded as marine-mammal watch effort. The searching 

technique typically used by the crew aboard tuna purse seiners relies on at 

least two crewmen looking for signs of fish using high-powered (2OX - 25X) 

binoculars. The crew members scan the horizon looking for cues such as birds, 

splashes or surface turbulance which sometimes are an indication of marine 

mammals. Because of the association between schools of certain dolphins and 
41 

ye1 1 owf i n tuna (Thunnus a1 bacares 1, sighti ngs of dol phi ns are usual ly 

investigated more by the crew for the presence of fish. As a result 

of the observers' close proximity to the crew sighting stations, his sighting 

effort is augmented by that of the crew. A great many of the sightings 

recorded by observers are first seen by the crew while looking for fish. 

Observers stand watch using 7X or 1OX handheld binoculars. They scan the area 

between the horizon and the vessel, generally concentrating their attention 

closer to the vessel than does the crew. The combination of techniques used 

by the crew and the observer provide for good coverage of the vessel's search 

path. 

Observers are required to complete a sighting record for every distinct 

sighting of cetaceans made by anyone aboard the vessel, regardless of whether 

the observer saw the ani mal s. 

The siahtina record form " " 

Since 1971, six different types of data-collection forms have been used 

(see Appendix Table 2-1 and forms included at the end of this appendix). Each 

has been used in conjunction with a particular "observer's field manual" which 

contains the instructions for correct forms usage. The forms have evolved 

from the non-coded, loosely standardized "marine mama1 log" to the present 

'lmarine mammal sighting record." The current form utilizes stringently 

documented coll ecti on procedures and is composed of we1 1 -defi ned, coded data 

elements. Each of the six forms contains a unique combination of data 

elements. This evolution of forms content has taken place in response to 

changes in the data requirements of NMFS researchers. There is continuity, 

however, for certain of the central data elements from the earliest to the 

most recent record types. These core elements include items such as cruise 

number, date of sighting, time of sighting, position of sighting, estimated 

school size, identification of species/stocks present and estimated 

species/stock proportions of the school. These forms have also been used by 

observers aboard research vessels. 

Identifications by the crew 

The sighting-record forms used since 1977 contain coding fields for 

recording both the crew Is and the observer Is independent identifications. 

From 1971 to 1977 there were no dedicated fields on the sighting record for 

recording this information. Where identifications by crew exist, they 

generally have been for schools which were eventually the target of a net 

set. The identifications are transcribed from set-log data in these cases. 

Sighting information provided by the crew since 1977 has been routinely 

recorded by the observer. When the data are returned to La Jolla for 

processing, species/stock identification codes are assigned to the crew 

i denti f i cati ons exactly as they are recorded wi thout regard to thei r probable 

accuracy or re1 i abi 1 i ty . 

Identifications bv observers 

Particular attention has been directed to the identifications of 

species/stock as recorded by the observer on the sighting records. In order 
42 

to improve the accuracy and re1 i abi 1 i ty of observer i denti f i cati ons, each 

sighting record is scrutinized during a cruise processing at the SWFC in La 

Jolla. The recorded diagnostic criteria used by the observer in making the 

f iel d i denti f i cation are evaluated. The experience of the observer is 

considered. After weighing these and a variety of other factors such as 

photographs of the school, the distance away from the school, the length of 

observation time and the environmental factors affecting the ability to 

observe the school, each observer i denti f i cati on is assigned a speci es/stock 

identification code. 

The size of the observer force grew dramatically during 1976, as the 

Southwest Regional Office (SWR) of NMFS became involved with the 

fleet-sampling effort. It became more difficult to weigh intangible coding 

criteria such as the observer's experience with ETP cetaceans. At this point 

it was recognized that for observer i denti f i cati ons to be better supported, 

more i nformati on veri fyi ng the accuracy of the observer i denti f icati on was 

needed on the source document. During 1977, the observer training sessions 

began placing heavier emphasis on collection procedures requiring fully selfsupported si ghti ng records. 

Assigning identification codes 

The sighting record used during 1974 was the first source document 

formatted with coded data elements. The sightings data collected during 1974- 

1976 were assigned species/stock codes by senior scientists at the SWFC. This 

was very time-consuming for these individuals. It was believed that a 

standardized methodology could be developed by which the sightings could be 

coded for the most part by skilled technicians (data editors) familiar with 

pertinent taxonomic criteria and the special problems of identification. It 

was a1 so believed that these individuals should have substantial experience 

with the field identification of ETP cetaceans. In 1977 a contract report 

outlining a procedure of this type was completed by S. Leatherwood. Sightings 

from 1977 to the present have been coded in conformance with this procedure. 

Additional ly , si ghti ngs data from 1971-1973 which were transcribed in 1981 

onto coded formats more compatible with recent sightings data have been 

species-coded using this particular algorithm. 

The Leatherwood Guidelines 

The Leatherwood algorithm is based upon a set of interrelated 

They include a set of guidelines for weighing recorded diagnostic 

They also provide for a method 

procedures. 

information contained on each sighting record. 

of indicating the reliability associated with assigned species/stock codes. 

The Leatherwood method requires that observers become trained on the 

identification of ETP cetaceans. Since 1977, the San Diego branch office of 

the SWK has provided training on cetacean identification, using lectures and 

slide presentations. The observers are presented with the diagnostic 

characters associated with each of the cetaceans involved to any extent with 

the tuna f i shery and tested on correct field i denti f i cati on techniques. 
43 

Once the sightings have been returned to the SWFC for cruise processing, 

data editors follow the Leatherwood guidelines in assigning species/stock 

codes. For unusual sightings or records where the identification of 

species/stocks is not straightforward, advice is obtained from senior 

scientists to determine appropriate identification. Data editors review each 

sighting, checking the recorded diagnostic information before assigning the 

species/stock codes. Species/stock codes are usual ly assigned to correspond 

with the observer's field identification. However, when the recorded 

information indicates that the observer's identification is clearly incorrect 

and there are sufficient characters to permit correct identification, the 

editor assigns a new species/stock code. Once the coding process has been 

completed, the data editor evaluates the observer Is performance on correct 

procedures for recording sightings data. This provides the SWR office with a 

feedback mechanism to identify and retrain observers whose performance is 

inadequate. 

Under the Leatherwood guidelines, a reliability code is assigned to each 

observer species/stock identification. These codes reflect the relative 

reliability of the identification. There are four encoded states of relative 

reliability: 1) that there is not a sufficient basis upon which to verify the 

correctness of a single assigned species/stock code, 2) there is a sufficient 

basis to verify the correctness of all assigned species/stock codes, 3) there 

is not a sufficient basis upon which to verify the correctness of all assigned 

species/stock codes, or 4) the observer clearly misidentified a sighting to 

species/stock, and the species/stock code has been corrected by the editor. 

Editing of sightings data 

In addition to the post-cruise processing steps described above, the 

sightings data have been edited in order to improve their accuracy. The 

editing process has evolved from relatively simple manual checks conducted in 

the early years (1971-1974) into a more complex, computer-assisted 

procedure. Until 1975, the year when formalized data editing programs using 

FORTRAN were first developed, the observer bore the responsibility for 

checking his data for accuracy and for correcting errors. No systematic data 

check lists were used, and guidelines in this area were loosely defined. This 

early editing effort re1 i ed upon loosely i denti f i ed procedures. It was 

difficult to establish that all the data were systematically edited in a 

thorough or standardized manner. Although the data were edited, the kinds of 

error checks performed were not documented. 

In 1975, FORTRAN programs were developed by computer programming staff at 

the SWFC according to i nstructi ons provided by the tuna/dol phin programs data 

manager and applied to all new data and to re-formatted data from 1971-73. 

The programs perform a variety of error checks on the computer-accessible 

sightings data. The editors use the edit program output as a method for 

locating potential error in the data. They correct those errors where 

sufficient information exists to reconcile error. It should be emphasized 

that the edit programs do not of themselves change data; they provide output 

which identifies unusual , conflicting or unexpected data. 
44 

The editors are a1 1 experienced sea-goi ng observers fami 1 i ar with marine 

mammal sightings data as a result of previous cruises to the ETP. Some of the 

information used in reconciling error is not recorded in coded format. The 

edi tors must frequently read narrative descriptions and examine other sources 

in order to assess the validity of data items. When the editor corrects the 

data, he enters his correction on the sighting form using red ink; the 

correction is also made on the computer disk file. All corrections made on 

the sighting forms are made on the computer-stored data files and vice versa. 

The editing programs have evolved since 1975 in order to accommodate 

changes in the layout and content of the sighting forms. Additionally, these 

programs have become progressively better documented. In 1979, an error 

statement data base was developed which describes each logical check performed 

by the program. 

The use of FORTRAN edit programs to improve the accuracy of the sightings 

data does not mean that this enormous set of data is error-free. Rather it 

means that the checks of the data have been performed in a very systematic and 

we1 1 -documented manner. 

Presently the data are archived at the SWFC. The sighting forms are kept 

in locked cabinets, and procedures for gaining access to the data have been 

implemented in order to improve control over this data resource. Requests for 

access to the raw data or the computerized files are directed to the Director 

of the NMFS Southwest Regional Office in Terminal Island, California. 

Appendix Table 2-1. Sighting forms used in the NMFS and IATTC observer 

programs, 1971-1983 (sample forms follow). 

Form Type Agency Years Cruises 

I 

I1 

I11 

IV 

V 

VI 

VI I 

VI11 

IX 

NMF S 

I1 

11 

IATTC 

I1 

I1 

1971-73 

1974 

1975-76 

1977-78 

197 9 -80 

1981 -82 

1979 

1980 

1981-83 

44 

42 

113 

235 

131 

76 

46 

63 

132 
45 

size; direction of travel; behavior; associated animals 

(birds, fish) FEATUP.F,S USED FOR IDENTIFICATION, 

course changes of vessel. 

Form Type I 

Address: 

Tel. No. 

PJARINZ mrmu~ CESERVATICX LOG 

Page of - 

LTSSCL DATF 

Chscvntion Fffort (even if nothng seen): 

Time: Prom 

Weather 

- To §ea State 

Position: From To Water Temp. 

Average Cpeed Knots or mph (circle one) 

.oca tion 

* include the following when poss 

Notes * 

ble: sketch; photograph;/ h'ame: 
46 

mfe: Period no. 

Cr. SQ. "10. day pr. (for hv) 

I I I I 

Form Type I1 

Time: 

to Comments: :aril from 

'I 1'1 

Bearing 

Card Time I L2tlNdr XIS LonSiNdr E/IV from ship #'*I /I , 1 I/ , , I I!II !I 

Distlnce from mrcciton 

ship of travel Dam Loc.lSlght. 

fni~ S lOlkl of school code codelcode 

.-k) ! j 

2 Emor (of lhu su. I 

I I!! !!I 

-(u mom thm ow sight@ II) ~rlcd. go to Conliiualion sheet) Photos: mll fr3mcs 

IQLU3U.L) 

I /!i 18, 

- 

Other species ~n school: 
47 

Form Type I1 

(Conti nuati on sheet) 

Notes: 

Photos: rull frames 
48 

ESTIMATE OF TOTAL 

+ 

SCHOOL SIZE 

Form Type I11 

SPECIES (1) SPECIES (2) SPECIES. (3) POSITIOll OF SIGHTING 

% :bE 4 :LbE 'd z?,bE LATITUDE LONGITUDE 

SHIPBOARD MAMMAL WATCH 

SIGHTING RECORD 

II I Ill II I 

VESSEL 

OBSERVER 

II I II I Ill Ill1 

SPECIES NAMES 

SP. (1 1 SP. (2) SP. (3) 

PHOTOS: ROLL 5- FRAME i. 
49 

CRUISE OBSEPVER DATE SERIES LEG d f rt YEAR MONTH PAY 

Form Type IV 

SURFACE ' CARD ~~~1~~ DISTANCE SET TE!:? 

i"F 5 

'',5 

F SIGHTItlG OF !ip! Inn)& IOIhs TR:[EL 1 

TARGET 

1977A SHIPBOARD MAMMAL WATCH 

SIGHTING RECORD 

II II 

NO.. . " I DFPT OF co** 

I I I I II Ih II II 14 

SPECIES lli 

mi POSITION 

38 41 43 4s 

X CODE NAME :: CODE NAME 1 SPECIESill 0 2 

I I I I 

1 ~~ 1 AVERAGED CREW ESTIMATE OF SCHOOL SIZE 

55 59 

SIGHTING CUE :COCE TABLE 13. PART A. 

0 A9 

WHO MADE INITIAL SIGHT I NG? 

CODE TABLE 13. PART E! 

0 OBSERVER ESTIMATE OF 

SCHOOL SIZE 

WIGHEST LOWEST 

63 67 . 71 74 

DESCRIBE AND ILLUSTRATE EVERYTHING YOU SAW CONTINUE ON BACK 

PHOTOS ROLL - FRAME(S1 - 
50 

SIGHTING CUE 

TIME VU ZV FRC\I SHIP 'n 6 lOlnS 

Form Type V 

ENVIR. COND. POSITION AT TIME OF CUE y 

5- 'F d 10th~ L4TITUOE 5 LONGllUOF 5'. VIL 

0IR05 AT CUE 

SIGHTED 

*ou - "I Dtlr OT COV" 

PAGE 1 

1979 SHIPBOARD MAMMAL 

WATCH SIGHTING RECORD 

j CRUISE I , I1 "E~ 

o~y 1 sf; ISEYES 1 L; 1 ;; 1 1 4 6 8 10 12 14 16 

111 I1 I1 II Ill Ill1 

SCHOOL SEE 

51 50 62 

d ,o fg oo BEARING DISTANCE SURF TEMP N 25 1 MI 1 IS:rl I ;, 

OBSERVER ESTIMATE OF 

SCHOOL SRE 

HIGHEST SOURCE CODES 

I DR 

66 70 74 77 16 

SPECIES ill 

. % CODE NAME 1 

, I 

EWlR CON0 AM1 OF TIME 

AT CLOSEST 

OlSTANCE 

TOTAL TIME (RAIN OVERCAST CLOSEST DISTANCE OF OBSERVATION FOG CHOPPY) OF OBSERVATION 

NOTES DESCRIBE AND ILLUSTRATE EVERY~HING YOU SAW SEE BACK OF PAGE 

23 

(21 , 

26 

I (21 I , I 
51 

Form Type V 

( Con ti nued ) 

SIGHTING SUMMARY 

1979 SHIPBOARD MAMMAL 

WATCH SIGHTING RECORD 

IDENTIFYING CHARACTERISTICS - 

BEHAVIOR - (DESCRIBE AGGREGATION MOVEMENT BOW AND STERN RIDING BLOWS. ETC) 

ASSOCIATED ANIMALS - IINCLUDE NU1ABER AND SPECIES OF BIRDS) 

VJ..-"I 35s. WCO"" 

PAGE 2 

PHOTOS ROLL#- FRAMEIS) #- 
52 

X CODE 

Form Type VI 

NAME 

MARINE MAMMAL 

SIGHTING RECORD 

1 4 6 8 IO 12 14 16 

I SIGHTINGCUE POSITION AT TIME OF CUE AT CUE 8 

E sg LATIWOE $ LONGllUDE % 

Ill I .I IL II Ill I II I 

I8 22 23 24 27 XI 31 34 38 3P 44 45 

AVERAGE CREW ESTIMATE OF 

SCHOOL SUE 

MEAN I HIGHEST I LOWEST 

II n II II 50 Ill 62 I I I1 

12) 

28 31 

*O*r--usOfn wcw 

PAGE 1 

BIRDS’ 

OBSERVER ESTIMATE OF 

scnmL SIZE 

HIGHEST SOURCE CODES 

$ - DR 

2 = Veroal 

66 70 74 77 16 

SPECIES 11) 

23 26 

TOTAL ENVIR. COND. CLOSEST 

TIME OF IRAIN. OVERCAST, DISTANCE OF 

OBSERVATION - FOG, CHOPPY) -OBSERVATION - AMT. OF TAGS METHOO OF TIME 

AT CLOSEST ASSOCIATED OBSERVATION 

DISTANCE - W/SIGHTING (EYE. 7x. lox. 20~)- 

NARRATIVE: DISCUSS EVENTS DURING THIS SIGHTING 
53 

Form Type VI 

(Continued) 

MARINE MAMMAL 

SIGHTING RECORD 

LSlGKTlNG SUMMARY PAGE 

SKETCH FEATURES OF ANIMALS SIGHTED LIST ALL DIAGNOSTIC FEATURES OBSERVED 

(INCLUDE ESTIMATED BODY LENGTH) 

BEHAVIOR - (DESCRIBE AGGREGATION, MOVEMENT, BOW AND STERN RIDING, BLOWS. ETC.) 

ASSOCIATED ANIMALS -(INCLUDE NUMBER AND SPECIES OF BIRDS) PHOTOS ROLL#- FRAME@) I- 
54 

I. ESTIMATE OF NUMBER AND SPECIES COMPOSITION OF ENTIRE PORPOISE SCHOOL 

010 

Form Type VI1 

DESCRIBE AND ILLUSTRATE ON BACK OF 

PAGE EVERYTHING YOU SAW 

PORPOISE SIGHTING AND 

SET RECORD 

TIME 

DATE _____ CRUISE NO ,___ PORPOISE SIGHTED ____ SIGHTING NO. __- SET NO. ___ PAGE 1 

O/o 

TOTAL '/o EASTERN 

NUMBER SPOTTED SPINNER 

OTHER OTHER 

WHITE- '/o O/O O/O 

BELLY UNIDENT. OTHER OTHER 

SPINNER SPINNERS SPECIES ;I) SPECIES (2) SPOTTED SPECIES/STOCK SPECIES/STCCK 

2. ESTIMATE OF NUMBER OF PORPOISE THAT EVADED THE SET 

APPROX.# MAJOR SPECIES /STOCK 

EVADED CHASE / HERDING . ---- 

EVADED ENCIRCLEMENT .---- 

DELIBERATELY CUT OUT . ---- 

EVADED CAPTURE . ---- 

OTHER OTHER O/O O/O 

TOTAL '10 OTHER OTHER 

NUMBER SWTTED SPECIES(1) SPECIES (2) SPOTTED SPECIES/ STOCK SPECIES /STOCK 

STOCK (1) 12) 

3. CHASE AND SET TIMES 

CHASE 

CALLEDOFF 2 

CHASE OR SET a LET RINGS SKIFF 

START ABORTED GO UP START FINISH ABOARD 

---- ---- ------------- -------- TIME TIME TIME TIME TIME TIME TIME 

NAME NAME NAME 

CREW I I I I I : _-__ I---I--_ --- --- __- --- 

5.LlVE PORPOISE RELEASED AND/OR ESCAPED AFTER RINGS UP 

(0) PRIOR TO BACKDOWN [IF NO 

BACKDOWN GO TO ITEM (d)} 

--- 

NO METHODS NQ 

RELEASED ESCAPE0 

(b) BY BACKING 

DOWN 

------- --- NO. FISH LOST 

BACKED OUT (TONS) 

(C) DURING BACKDOWN BY 

OTHER METHODS [DOES 

NOT INCLUDE THOSE 

ANIMALS BACKED OUT] 

--- 

NO METHODS ?€LEASED 

(d) FOLLOWING BACKDOWN, OR IF 

NO BACKDOWN 

b LIVE 

PORPOISE LEFT IN 

NET AFTER BACK 

DOWN 

--- --- --- NO. METHODS NQ 

RELEASED ESCAPED 

IATTC TUNA-PORPOISE FORM 3 10/78 
55 

Form Type VI1 

(Continued) 

CRUISE NO. 

SET NO. 

PORPOISE SIGHTING AND 

SET RECORD 

PAGE 2 

6. OBSERVATIONS 

(a) CHARACTERISTICS USED TO IDENTIFY PORPOISE 

(b) NOTES ON PORPOISE BEHAVIOR WHEN SIGHTED, DURING CHASE AND DURING SET 

(C) NOTES ON RESCUE EFFORTS AND BACKDOWN 
56 

ACTIVITY I HERDING I NUMBER 

BEFORE CHASE :-I-I 

DURING CHASE : - I - I____ 

AFTER LET GO :-I - I____ 

DELIBERATELY CUT OUT ._-__ 

DIVED UNDER NET ._-__ 

SWAM OVER NET .____ 

Form Type VI11 

ACTIVITY I HERDING I NUMBER ACTIVITY I HER DING^ NUMBER 

:-I-I *- 1 _I 

: - I - I____ .- I - I___- 

: - I - I____ : - I - I-__- 

.-___ .__-- 

.--__ .___- 

.-___ .-_-- 

MARliJE MAMMAL SIGHTING 

AND SET RECORD 

TIME 

DATE CRUISE NO. MARINE MAMMALS SIGHTED SIGHTING NO. SET NO. PAGE 1 

1. INITIAL ESTIMATE OF NUMBER AND SPECIES COMPOSITION OF ENTIRE SCHOOL OTHER OTHER 

SKIFF 

ABOARD 

---- 

SPOTTED SPECIES/STOCK SPECIES/STOCK 

% % % STOCK 111 121 

IF EVENING SET INDICATE 

TIME OF SUN DOWN 

DESCRIBE AND ILLUSTRATE 

ON BACK OF PAGE EVERYTHING YOU OBSERVED 

---- 

START 

3. CHASE 

FINISH 

-------- 

CHASE 

START 

---- 

TIME 

,ND SET TIMES 

CHASE 

----- I TIME 

IATTC Tuna-Propoise 

Form3 4/80 
57 

Form Type VI11 

(Continued) 

MARINE MAMMAL SIGHTING 

CRUISE NO. SET NO. AND SET RECORD PAGE 2 

4. OBSERVATIONS 

(a) CHARACTERISTICS USED TO IDENTIFY MARINE MAMMALS. DESCRIBE ONLY THOSE 

CHARACTERISTICS ACTUALLY SEEN, MAKE A DRAWING OF AN INDIVIDUAL TO 

ING: 1. SHAPE AND SIZE OF DORSAL FIN (INDICATE DIRECTION OF CANT); 2. SIZE 

MATE LENGTH; 4. MARKINGS, CAPE DEFINITION, AND COLOR PATTERN OF FINS 

AND BODY. 

SUPPLEMENT YOUR DESCRIPTION. BE SURE TOTRY TO DISTINGUISH THE FOLLOW. 

OF SNOUT OR, IF NO SNOUT, SHAPE OF HEAD; 3. SHAPE OF BODY AND APPROXIINDICATE THE CLOSEST DISTANCE THE MAMMALS WERE OBSERVED: 

(b) DETAILED NOTESON MARINE MAMMAL EVASION BEHAVIOR DURING CHASE (IF 

YOU ARE RECORDING A SIGHTING ONLY, USE THIS SPACE TO NARRATE BEHAVIOR 

OF MAMMALS SIGHTED AND ACTION TAKEN BY VESSEL, HELICOPTER, ETC.) 

CREW'S ESTIMATE OF TOTAL NUMBER & %SPECIES COMPOSITION 

BEFORE LET GO CAPTURED 

TOTAL NO. 96 SPECIES COMPOSITION TOTAL NO. OU SPECIES COMPOSITION 

11 --- 
58 

TOTAL 

NUMBER 

Form Type IX 

SPOTTED STOCK STOCK 

%OTHER ?L OTHER STOCK (1) (2) % % % % % SPECIES SPECIES 

SPOTTED E-SPIN WB.SPIN UNlDSPlN COMMON (1) (2) 

MARINE MAMMAL SIGHTING 

AND SET RECORD 

TIME 

DATE- ___ - - CRUISE NO. __ - MARINE MAMMALS SIGHTED ___ - SIGHTING NO. ---SET NO. ___ PAGE 1 

NAME NAME NAME 

AERIAL :---J-,J---I---I---I _----_ I I___ 

2. CHARACTERISTICS USED TO IDENTIFY MARINE MAMMALS. DESCRIBE CHARACTERISTICS ACTUALLY SEEN AND MAKE A DRAWING 

OF AN INDIVIDUAL. 

CREW'S ESTIMATE 

TOTAL NO. % COMPOSITION 

--- 

INDICATE CLOSEST DISTANCE MAMMALS WERE SIGHTED 

IATTC Tuna-Dolphin 

Form3 10/81 
59 

;P. N0.2 CTlVlTY cODE NO ESCAPED. 

- EVADED 

CUT OUT OR 

Form Type IX 

(Continued) 

MARINE MAMMAL SIGHTING 

AND SET RECORD 

3. MARINE MAMMAL EVASION AND ESCAPE BEHAVIOR 

SP. NO. 3 ACTIVITY 

C~~~ NO.ESCAPE0, CUT OUT OR 

- EVADED 

SCHOOL 

HERDING 

CODE 

BEFORE CHASE - 

DURING CHASE - 

DURING ENCIRCLEMENT - 

DELIBERATELY CUT OUT 

EVADED UNDER NET 

ESCAPED OVER NET 

CHASE NO. CHASE REASON LET REASON RINGS BACK DOW N 

START SPBTS CALLED CHASE GO SET UP START 

OFF CALLED ABORTED 

OFF 

____ ___ __-_ ___ ---_ __-- ---- TIME TIME TIME TIME TIME TIME 

;P. NO. 1 

SKIFF IF EVENING SET INDICATE 

ABOARD TIME OF SUNDOWN 

---- ---- TIME TIME 

XTIVITY 

CODE NO. ESCAPED, 

- EVADED 

CUT OUT OR 

a,) CETNLED NOTES ON MARINE MAMMAL EVASION BEHAVIOR 

DURING CHASE 

b.) DESCRIBE MARINE MAMMAL EVASION AND ESCAPE BEHAVIOR 

DURING ENCIRCLEMENT AND THROUGH REMAINDER OF SET 

P.NO.4 

CTlVlTY 

CODE NO. ESCAPED, 

CUT OUT OR 

- EVADED 

PAGE 2 

TOTAL BY 

SPECIES THAT 

EVADED. ESCAPED 

OR WERE CUT OUT 

---- 

GRAND TOTAL: - - - - 
60 

APPENDIX 3. Computer analysis of the distribution 

and effort data. 

Distribution Data 

The computer system set up to aid in the analysis of these data involved 

4 tasks: 

Task 1 The data bases of sightings covering the period 1966 to 1982 have 

over 20 million bytes of information. To reduce storage space and 

make data manipulation easier, new data bases of reduced size were 

made which consisted only of a sighting identification code (cruise 

number, date, sighting number), the species stock code, and the 

geographic position. 

Task 2 Plots were produced showing the distribution of sightings for each 

of the four species. 

Task 3 Sightings outside of the SOPS '79 range boundaries were identified. 

Task 4 A report was produced showing the number of sets for each species 

A brief description of each task follows (refer to the schematic diagram): 

group by local i ty ( i .e. 5-degree square 1. 

Task 1 Data sources for the sightings are the National Marine Fisheries 

Service Cruises from 1971 to 1983, Inter-American Tropical Tuna 

Commission Cruises for 1979 to 1983 (partial), and other 

mi scel 1 aneous si ghti ngs from 1966 to 1982. Programs were written 

for each type of data source to produce a data base of sighting 

records of reduced size. Separate data bases were produced for 

each data source (NMFS, IATTC and MISCELL), by species and year. 

Task 2 The Southwest Fisheries Center has a general plotting program 

call ed GPACK whi ch uti 1 i zes a commerci a1 pl otti ng package call ed 

DISSPLA. A slightly modified version of GPACK called GPACKP was 

used to produce the plots for this system. Plots were produced by 

species for each year and for all years combined. 

Task 3 Southwest Fisheries Center has a program called FINDACELL which 

determines if a geographic position is located in a user-defined 

cell. XFINDCELL is a modification of FINDACELL which takes a 

polygon, in this case the SOPS '79 boundary for a species, and 

determines if a point, or sighting, lies inside or outside of the 

polygon. Points lying outside of the polygon were written to an 

outlier list. The original data sources for these sightings were 

then examined to determi ne thei r re1 i abi 1 i ty . Task 4 The program SLSUMENC was written to determine the species 

composition of each set at the time of capture and to count the 

number of sets by species group in each 5-degree square. This 

program was run for each year from 1977 to 1982 using the set-log 

databases. The data was then summarized into a final report using 

the SLENCREP program. 
61 

Sighting 

Databases 

1979- 1982 

ANALYSIS OF SIGHTING DATA BY SPECIES 

Sighting 

Databases 

1966- 1982 

Sighting 

Databases 

197 1-1982 

TASK 1 T 

--- 

TASK 2 

Programs to reduce 

the size of the 

sighting files * 

Reduced size 

sighting 

databases 

(by data source, 

year and 

~7 - -\- 

7 I--- I I I I GPACKP + Plotting program 

I 

I 

T I 

by species type, 

year and all years w and year) 

"Includes: RDCNMFS, RDCNMFS 79, Y RDIFF, SPSPLIT, RDCTUNA, MlSCY EAR, 

RDMISC 

*4 Includes: ATTNPOLY, LONGPOLY, DELPOLY, COEPOLY 
62 

ANAL 

0 SLENCREP 

SLENCREP. 
63 

Effort Data 

The computer system set up to aid in the analysis of this data involved 3 

tasks. 

Task 1 Computing the nautical miles of effort from the National Marine 

Fisheries Service (NMFS) cruises and Inter-American Tropical Tuna 

Comnission (IATTC) cruises for each year and summarizing the data 

by 1-degree square. 

Task 2 Merging the effort sumnaries for the NMFS and IATTC cruises for 

each year and for all years combined. 

Task 3 Producing plots of effort for each year and for all years combined. 
64 

Following is a schematic diagram and a brief description of each task: 

Task 1 Data sources for the effort were the NMFS cruises from 1971 to 1980 

and the IATTC cruises for 1980 through 1982. Programs were written 

to compute the starting and ending position for each leg of effort, 

determine the nautical miles covered and determine which 1-degree 

square(s) the effort took place in. The data were then summarized 

for each 1-degree square. Separate sets of programs were written 

for the NMFS and IATTC effort, since the data are stored on 

different computer systems. The series of programs was run on the 

effort data for each year separately. 

Task 2 The final effort summaries were put in compatible form and merged 

for each year and for all years combined. 

Task 3 The plots were produced by a plotting program called EFFPLOT, which 

is a modification of the AMP plotting program. The program allows 

the user to show effort density by using amounts of shading in each 

1 -degree square. 
65 

Programs to 

compute and 

summarize miles 

of effort by ,1-degree square& . 

ANALYSIS OF EFFORT DATA 

TASK 1 

Effort 

Databases 

197 1-1982 

MEEFIN. / DY / 

L 

Effort 

Databases 

1979-1982 

Programs to 

compute and 

summarize miles 

of effort by I-degree square** 

Note: the symbol YJ indicates the year. 

For example MEVY FN.DAT represents 

ME7 lFN.DAT, ME72FN.DAT. etc. 

---------- 

1 

Merge of effort 

summaries for each 

year and for all 

years combined 

TASK 2 

DIST. 

vv 

------ ------------- 

+ 

TASK 3 EFFPLOT 

*Includes: DUMPDB, DRECKX, EFFREDVC, 

**Includes: IATTCCONV, SUBMES, ATLINES, 

EFFSUM 

Effort plots 

DIST 
RECENT TECHNICAL MEMORANDUMS 

Copies of this and other NOAATechnical Memorandums are available from the National Technical 

Information Service, 5285 Port Royal Road, Springfield, VA 221 67 Paper copies vary in price Microfishe copies cost $3 50 Recent issues of NOAATechnical Memorandumsfrom the NMFS Southwest 

Fisheries Center are listed below 

NOAA TM-NMFS SWFC 28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

'Two computer programs to project populations with time-varying 

vital rates '' 

T GERRODETTE, D GOODMAN & J BARLOW 

(February 1983) 

Report of eastern tropical Pacific research vessel marine mammal 

R S HOLT 

(March 1983) 

Estimating age of spbtted and spinner dolphrns(Stenella attenuata 

A C MYRICK JR, A A HOHN, P A SLOAN, M KIMURA 

(April 1983) 

Re-estimation of three parameters associated with anchovy 

egg and larval abundance Temperature dependent incubation 

time, yolk-sac growth rate and egg and larval retention in 

mesh nets 

NCHLO 

(May 1983) 

"NMFS guidelines on economic valuation of marine recreational 

D D HUPPERT 

(June 1983) 

survey, May 15-August 3, 1982 

and Stenella longirostris) from teeth 

and D D STANLEY 

fishing" 

"Summary of environmental and fishing information on Guam and 

the Northern Mariana Islands: A review of the plankton 

communities and fishery resources of Guam and the Commonwealth of the Northern Mariana Islands" 

R. N. UCHIDA 

(July 1983) 

"Some data on dolphin mortality in the eastern tropical Pacific tuna 

T. D. SMITH and N. C. H. LO 

(July 1983) 

"Precision of age determination of northern offshore spotted 

dolphins." 

S. 6. REILLY, A. A. HOHN, and A. C. MYRICK, JR. 

(August 1983) 

"Recovery of adult green turtles observed or originally tagged at 

G. BALAZS 

(August 1983) 

"Report of the workshop on long-range planning for the North 

D. J. MACKETT, Editor 

(November 1983) 

purse seine fishery prior to 1970." 

French Frigate Shoals, Northwestern Hawaiian Islands." 

Pacific albacore fishery."