SPECIAL ISSUE PUBLC ATIONS
No. 13
OKEANOS OCEAN RESEARCH FOUNDATION
278 East Montauk Hwy Haeptons Bay, NY 11946 SPECIES COMPOSITION AND DISTRIBUTION OF MARINE MAMMALS AND SEA TURTLES IN THE NEW YORK BIGHT
FINAL REPORT
UNITED STATES FISH AND WILDLIFE SERVICE SOUTHEKN NEW ENGLAND - NEW YORK BIGHT COASTAL ESTUARIES PROJECT
CHARLESTOWN, RHODE ISLAND
-. Okeanos Ocean Research Foundation, Inc. Hampton Bays, New York
by
Samuel S. Sadove and Phillip Cardinale
December, 1993 TABLE OF CONTENTS
Introduction
Methods and Materials
Results E. galcialis B. physalus B. acutorostrata B. borealis B. musculus
M.novaeangliae \ P. catodon K.breviceps T. truncatus D.delphis S. coeruleoalba S. plagiodon/attenuata D. leucas P. phocoena L. acutus L. albirostris G. melaena 0. orca Mesoplodon sp. 2. cavirostris G. griseusus P. vitulina P. hispida P. groenlandica H-grypus C. cristata L. kempi C. carretta C. mydas D.coriacea E. imbricata
Species list and Status Codes Conclusions Acknowledgements References Map Appendix INTRODUCTION
This document has been prepared to summarize the present knowledge of the distribution, abundance and species composition of marine mammals and sea turtles of the New York Bight. The information in this report represents over 15 years of data collected by the Okeanos Ocean Research Foundation through the NY State Marine Mammal and Sea Turtle Stranding Program (operated by Okeanos), the Foundation's own research projects involving cetaceans, sea turtles and seals, and sighting reports that have been collected from fishermen and boaters during this time. Although it does not provide detailed accounts of all sightings for these groups of animals within this region, this report does supply an accurate picture of the KNOWN diversity of the region with regard to these species. When the collection of this data began in the late 1970's little was known about these species. The area was assumed to have a low abundance of marine mammals and sea turtles, and many species were only recognized as having occurred here on a very rare basis. It is the authors' opinion that there is a great deal yet to be learned, therefore, the information here should not be treated as the final status of knowledge for marine mammals and sea turtles in the region. It is quite possible that the on-going studies may yet find, or clarify the status of a number of the species listed in this report. Much of what has been discovered and is summarized in this report is simply the result of the adage that "you find what you take time to look for.'' One of the many areas not within the scope of this document is an analysis of the historical abundance of the species recorded here. The Okeanos Foundation has been compiling historical data for marine species in New York's waters for over 15 years. Unfortunately, limited funds and time have prevented analysis of these trends. However, based on subjective analysis it can be largely assumed that there was, historically, a greater presence of all of the species listed. METHODS AND MATERIALS
The species accounts, summaries, and maps are the result of analysis of three primary sources which are archived and maintained by the Okeanos Ocean Research Foundation in their original hard records as well as on computerized databases using DBase IV format. These primary sources are: (1) Dedicated surveys; (2) Anecdotal reports; and (3) Stranded specimens. In all three of the record types certain consistent data are recorded in a standardized format including date, time, weather conditions, position in latitude and longitude, species, and reliability of identification. Dedicated surveys conducted from aircraft, ships, and land were defined primarily by the intentional effort of trained staff members surveying for marine species. This includes whale watch cruises during which data were collected, or an intentional search for and anecdotal sighting report of animal(s). The data collected in dedicated surveys involved over 15,000 hours and 8,300 records. These surveys always involved trained observers who collected voucher materials such as photographs and data on habitat, prey species and other species in the area. Anecdotal reports are defined as all reports of sightings from any source not subsequently verified by a direct observation by trained staff. Anecdotal reports were received from fishermen, private citizens, aircraft pilots, United States Coast Guard personnel and merchant vessels. Stranded specimens were recovered as a part of the Okeanos Foundation and New York State Department of Environmental Conservation's (DEC) Marine Mammal and Sea Turtle Stranding Program. In this Program all strandings of marine mammals and sea turtles are reported to a 24 hour system under which a team responds to the scene and recovers the specimen for detailed treatment or post mortem exam. The survey of data for this report is intended to be representative of the New York Bight. The coverage map demonstrates the differences in coverage for the entire region. Southern and extreme western portions of the Bight are not as well covered since the source of information for this area is largely anecdotal and not consistent. There are sources that we have identified, however, funding for development of those sources is lacking. During analysis factors such as group size and age classes were analyzed using one of two computer based statistical analysis programs (SPSS or STATGRAPHICS)*. Significance for data analysis was at the .05 level and correlation analysis were for R values >.80.Food habitats were based either on the direct observation and identification of prey species in the water or on the identification of hard parts from fecal material or stomach contents. The determination of the polygon shapes and locations for map distributions was made using plots of sightings that were subsequently analyzed using a modified home range cluster analysis program (Ackerman, et. al., 1990).This program was developed based on an extension of the harmonic mean utilization distribution (Dixon and Chapman 1980). This program make no assumption nor calculations for consistent use of an area by single individuals, rather, for this study maps were based on the programs home range polygon from cumulative sightings regardless of repetition. Although this may in some instances be misleading, marine mammals as a group are often limited by the technical abilities of individual resightings. All maps were generated using both Arclnfo* and AtlasGIS*. These were then converted into a WPG format for printing. The maps produced represent both the areas of occupancy and significant habitat use unless otherwise indicated. In some instances the details of habitat needs are unclear, therefore, such maps are impossible. =does not indicate endorsement RESULTS
CETACEANS
Eubalaena alacjails, Northern Right Whale
The right whale is extremely endangered and by the nature of that statement sightings are very rare. However, these whales are sighted regularly every year in the New York Bight. This species was once numerous, having been the main stay of the shore whaling industry during the seventeenth through nineteenth centuries (Reeves, 1988). Right whales are still sighted mainly along the south shore of Long Island, and sometimes within Long Island Sound, Block Island Sound, Gardiners Bay and south shore inlets and bays. Ail sightings have either been cowlcalf pairs or solitary individuals. All age classes have been observed, and many have been individually identified through the North Atlantic Right Whale Catalog. Most sightings are concentrated between the months of March through June. Very few of these sightings have involved individuals remaining in the area for an extended time. Most animals appear to be moving through, although several have been observed feeding in association with large blooms of calanoid copepods. Based upon the Okeanos Foundation's data it appears that New York's waters may function mainly as an area for migrating through with some opportunistic feeding, therefore population estimates are not relevant.
Balaeno~teraphvsa/us, Fin whale
This species is the most abundant baleen whale in the region, present year- round. There are distributional differences for the species by season. During April through August the fin whale is usually found in one of five areas located within 30 miles of land. These are largely feeding areas where intensive feeding activity occurs. During September through early December the whales usually move offshore along the continental shelf near the 200 meter contour. In January through March they are found very close to shore (within 1 mile) in the eastern portions of Long Island feeding again. During the summer, feeding groups often involve aggregations of more than 20 animals with incidence of over 200 not uncommon. In the winter, aggregations appear to involve small groups of 3-4 individuals. Calves are observed (Sadove, and Kiehn 1984) throughout the year with apparent newborns observed mainly in early July. There are some indications that calving may be occurring within the New York Bight, however, this has not been confirmed. Based on analysis of age data from length estimates by photogrammetry all age classes are found in the region. Fin whales have been found to be a diverse feeder in this region, having been observed feeding on herring, (Clu~easp.), mackerel! (Scomber sp.), sand launce, (Ammodvtes americanus~,squid, (Loiiao or sp.), buttefish, (Pe~rilustriacanthus), menhaden, (Alma sp.), and alewives, (Alosa pseudoharenqus) as well as zooplankton on occasion. Photographic identification studies (Agler, et. al. 1992, Sadove & Matlock- Cooley, 1992) have indicated this species also exhibits a high degree of site fidelity from year to year. Estimates of the numbers remaining within the Bight are approximately 400, however population counts at certain times of year have demonstrated a presence of over 800 animals.
Balaenoptera acufomstrata, Min ke whale
Based on sighting data the minke is the second most abundant mysticete in the New York Bight. It is found regularly near the coast and occasionally in the Peconic Estuary, the Long Island Sound, and the Great South Bay. The presence of this species in such enclosed bodies of water is infrequent and they are probably not viable habitats, even historically. Minke whales have been sighted in all months of the year with greater numbers in the summer. With the exception of young calves all age classes have been observed. Minkes also concentrate in one of the five areas off Long Island where fin whales are found. All of these localities are within 30 miles of the coast. They appear to be primarily found in the shallow shelf waters and only rarely seen at the continental shelf break or beyond. Minkes are usually found singly or in small groups, although when aggregations of prey species are massive there are larger groups of up to 20 individuals. Minke whales have been observed only feeding on fish. There is little data on the details of prey species, however, sonar tracings and strandings demonstrate a preference for herring, pollack, and sand launce. The estimates of the population of this species for the region are incomplete at this time. Based on sightings surveys there are a minimum of 300 found within the Bight waters. This estimate has a very large range (130-970) so the minimum given is probably exactly that, a minimum.
Balaenootera boreatis, Sei whale
During the early 1980's sei whales were found frequently in association with aggregations of fin whales. However, the species has been infrequently sighted in the last 8 years. Based on a preliminary analysis of historical anecdotal records and whaling records it appears that this species may possibly occur in the New York Bight on a cyclical basis. When present sei whales have been found within one of the previously mentioned 5 areas off Long Island only during July and August. They are usually found in small groups of up to 10 individuals. All sightings have been of adult size animals, most being above 9.5 meters in length. The animals sighted have been actively feeding with groups of fin whales. Based on these mixed species aggregations it is probable that the sei whale's prey species in this region are similar to the fin whale's. Except for the CeTAP surveys (Winn H.E., 1982) no sightings exist for this species along the continental shelf break so conclusions regarding its deep water occurrence cannot be made. Due to the limitation of sightings a population estimate is not possible. However, based on overall sightings it is likely that numbers of this species in the region are small, probably less than 150 individuals at a maximum. Bafaenopfera musculus, Blue whale
Blue whales are rarely sighted in the region. This may be in part due to the difficulty of firmly identifying this species as it is similar to both the fin and sei whales. However, the extensive ship time of the Okeanos Foundation has produced less than a dozen sightings in 15 years. All sightings have occurred at least 25 miles south of Montauk Point. These sightings have all been of single individuals associated with large groups of fin whales. Based on the behavior of the animals observed it is probable that they were feeding, however, this is not confirmed. All sightings have been of adults >19 meters in length. There are no sightings of individuals in water less than 30 meters deep. The population for the region of this species cannot be estimated.
Meyaptera novaeanciliae, Humpback whale.
The humpback whale is regularly found in the New York Bight, however, its abundance fluctuates widely. In some years it is very numerous with aggregations of up to 20 individuals being common. In other years only a few individuals are present. Humpbacks are one of the baleen whales regularly found in very shallow water and have been observed for extended periods of time (>Iweek) within Long Island Sound, Block Island Sound, and Gardiner's Bay. In some instances this species has also been observed moving in and out of some of the inlets along the south shore of Long Island (i.e. Shinnecock, Fire Island, New York Harbor) for extended periods of time. It is possible that these individuals would remain in these shallow regions for longer periods if allowed to. However, they are often chased out of these areas since they attract public attention and the increased vessel traffic places them at risk of injury. This species is also one of the few species that have been observed frequently in the western portions of Long Island inclusive of New York Harbor and the surrounding shore. Humpbacks appear to be found in areas where there is an appropriate abundance of food regardless of location. They do not necessarily concentrate in the areas where fin whales are found. Humpbacks are found in the greatest abundance between the months of June through September. During this time they are usually found to be feeding on shoats of small schooling fish. The major prey item in the area appears to be sand launce. This species is also found during the months of December through January, again the individuals seen are usually feeding. During the summer the sightings are of ail age classes with a number of sightings of cowlcalf pairs. The sightings in the winter are mostly solitary juvenile individuals, often in with groups of fin whales. The population estimates for this species by region are not relevant. The total population of humpbacks for the Western North Atlantic is estimated at approximately 9,000 animals. The New York Bight probably never has any more than 50 to 100 animals at any one time based on our surveys. Phvseter catodon, Sperm whale
This species is one of the most unique marine mammals for the region. Although in most areas the sperm whale is a very deep water species this is not totally the case in the New York Bight. Sperm whales are found with two types of distributions for the region. Most of the year sperm whales are seen in waters greater than 200 meters off the continental shelf. However, they are regularly seen in one location south of Montauk Point in less than 18 meters. Sperm whales are found in this area during late May through June and again in October. They have been regularly sighted here over the last 10 years and may have been there prior to that. Prior to 10 years ago the effort for sighting sperm whales was limited. In addition, the species is difficult to sight since submergence times often exceed 20 minutes. All sightings of sperm whales, both inshore and offshore have involved single animals or groups of up to 7 individuals. No calves have been sighted, however, both sexes and ail other age classes have been observed. Sex is possible to determine based on the ratio of head size to overall body size. The longest continuous sighting period for the inshore area was 7 weeks. In the areas of deep water this species is known to feed on squid. No direct observations of feeding have been made and it is still unknown what the animals are doing in the shallow water area. However, based on their natural history it is likely they are feeding to some degree. Prey species can only be guess at based on the stomach contents of two stranded sperm whales. In both instances the stomach contained squid beaks (filex sp.) A population estimate for the region for this species is questionable but, the inshore area has had 17 individuals identified and an estimate of 102 animals was developed,
Kogia brevj~~s,Pygmy sperm whale
The pygmy sperm whale is a species that is largely reported to be offshore in its distributions. There are few live sightings of this species for the region, all of which are in water greater than 30 meters and the majority are greater than 100 meters. These sightings usually occur around areas of significant submarine features such as Hudson and Block Canyons. The lack of sightings may not be reflective of the occurrence in the region since it is one of the five most often stranded species, It is probably fairly common yet the lack of sightings represents the difficulty of sighting a single small cetacean in deep waters. The few sightings that exist for the pygmy sperm whale in this region confirm that it is a solitary animal since all are of single individuals. Strandings and sightings have all been of either adult or juvenile individuals and no calves have been reported. The species has not been observed feeding however, stomach contents of stranded animals have been filled with squid beaks (L& sp.). A population estimate for this region is not reasonable based on the limited number of sightings. Tursiops truncatus, Bottlenosed dolphin
This species is very abundant in the waters surrounding Long Island and includes two subspecies; an inshore and an offshore (Perrin, W, personal communication). The offshore subspecies seems to be a year-round resident distributed beyond the 50 fathom contour, largely concentrated around significant submarine features such as Hudson and Block Canyons. The inshore subspecies is far more seasonal. During the months of June, July, August, and into September it is found in Gardiner's Bay, Block Island Sound, Long Island Sound, and along the south shore of Long Island. Groups of both subspecies are usually small with a mean number of 20. However there have been larger groups of over 200 sighted. There is little information on the bottlenosed dolphin's feeding activities in this region and what there is exists largely from stranding data. Based on that data it appears that they feed mainly on squjd (Loljuo sp.) and sometimes on herring, (Clu~easp.) Historially, these dolphins may have been found in Long Island Sound in large numbers. The total population estimates of this species is somewhat questionable since the 1987 die-off. This region's population probably does not exceed 500 individuals.
Debhinus debhis, Common dolphin
This species is very abundant in the New York Bight during all months of the year. Common dolphin are rarely found very close to shore and there are no records of live healthy groups within any enclosed estuaries. The majority of sightings of this species are found in water depths greater than 10 meters along the south shore of Long Island. There are several stranding records in very unusual inshore locations, including 2 miles up the Carmans River and in the Peconic Bay, In these instances the animals were clearly debilitated for an extended period of time, therefore, the behavior was aberrant. Common dolphins are found closest to shore during the months of March through June, while during the rest of the year they are usually sighted offshore between the 100 to 200 meter contour. They are also found frequently around significant submarine features such as Hudson and Block Canyons. Aggregations around these canyons tend to be very large with up to 10,000 individuals. The usual group size appears to be around 50-200 individuals comprised of all age classes with young calves more prevalent in May and June. This species is highly mobile and as a result different groups may be found at different times of the year. Common dolphins have been found feeding on herring, mackerel, and squid depending on their abundance rather than any preference on the part of the dolphins. Population estimates for this species in the region are between 5,000- 10,000.
Stenella coeruteoatba , Striped dolphin
Striped dolphins are numerous on a seasonal basis. Although the striped dolphin is often thought of as a more tropical species (Hammond P.S. 1990) its presence in the New York Bight is largely in the late winter and spring. They are rarely found in waters less than 100 meters, probably associated with Gulf Stream or near Gulf Stream waters. Sightings of this species are of groups of usually 200 or more individuals, and similar to the common dolphin involving all age classes. They have never been sighted in any enclosed bays nor within 10 miles of shore. Striped dolphin do not seem to stay in one area for any extended period of time as many of the other dolphin species do which leads us to suspect their presence here is of a migratory nature. There are no direct observations of feeding for this species, however, stranding records for this area indicate they feed on squid (Loijao sp.) atmost exclusively. Population estimates are not locally relevant and the animals here are probably a part of the overall Western North Atlantic stock.
Stenella ~/a~iodon/atte#~ata,Spotted dolphin
There are two species of spotted dolphin within the New York Bight. Since identification of individuals in the wild is difficult this discussion will refer to both unless noted. This species is quite numerous when found in our waters, although it is very seasonal with both sightings and strandings restricted to late spring and summer. AH sightings of this species have been in offshore waters greater than 50 meters in depth. Spotted dolphins seem to follow the Gulf Stream waters, occurring in a broad band along the continental shelf. Two areas where the most frequent shallow water sightings are made are south of Montauk Point and at the shelf valley of Hudson Canyon. All sightings of this species have been of groups of 20 to 100 individuals and have included all age classes. It may be there are fewer juveniles sighted than for the other delphinid species, however, this could be a result of effort. Few observations of feeding exist but the stranding records indicate that the favored prey item is squid (f-o/iqoj\/\ex sp.). The populat~onest~mate for this species is not possible due to its seasonal status.
This species is very abundant in its normal range in the Arctic, but, it is rare in the New York Bight. In spite of its rarity, there are numerous sightings of beluga whales along the south shore of Long Island and in Long Island Sound. Over the last 15 years there have been several individual beluga whales observed taking up residence in various locations such as Fire Island Inlet, Norwalk Harbor and Port Jefferson Harbor. These have been for extended periods of time, in some instances years. All of the sightings have involved individuals that remained in specific locations apparently feeding on whatever prey was available. In some instances these animals were fed all sorts of human food items, including hamburgers, bologna, etc. There is no resident population so an estimate is not relevant. There have never been more than two individuals reported at any one time. Phocoena phocoena, Harbor porpoise
The harbor porpoise is a species whose presence was once very rare during the last 10-15 years, however, recently their populations appear to be increasing in local abundance. There are anecdotal indications that this species was once very numerous in Long Island Sound and the Peconic Bay system. Anecdotal reports of large schools of "dolphin" were reported prior to 25 years ago in Long Island Sound on a regular basis. Based these descriptions it is the authors' opinion that some of these sightings were of harbor porpoise. Presently the species is found in eastern Long Island Sound, Peconic Bay, Block Island Sound, Gardiners Bay, and rarely in the Great South Bay. Sightings within the bays are usually of single animals or small groups of up to three individuals. Sightings in Long Island Sound are of somewhat larger groups of up to five animals. When observed in the open ocean group size is more variable with single individuals and large groups (>12) seen often. All sightings of this species are concentrated between the months of December through June. There are differences for locations of the sightings based on time of year and to some degree upon group size. The larger groups in the ocean are seen during March and April and are usually located further out to sea (>I2 miles). Single individual sightings are more common in the ocean during March through June and these are usually closer to shore. Sightings in Long Island Sound are greatest from January through March while the sightings in the eastern bays and the Great South Bay are more frequent during April and May. Stranding records are consistent with this trend with no strandings occurring during the months of July through November. Sightings of this species have largely been of adults or juveniles and only in two instances have calves been observed, both in Long Island Sound. Since many of the sightings in the Sound and in the ocean have been repeats in similar locations the animals are suspected to be feeding. Since this species is very small, observation at sea is difficult. Therefore, it is not surprising that no direct observations have been made of feeding. Stranded individuals show either squid or herring to be probably the major prey items in this region. Populations estimates are crude at present, however, there appear to be at least 50 individuals present inshore during the winter months.
La~enorhvnchusacutus, Atlantic White-sided dolphin
The white-sided dolphin is a very common and abundant species within the New York Bight. The species is found near the coast during almost all months of the year. White-sided dolphin seem to concentrate in a few local groups that on occasion aggregate together. Although they are found around the submarine canyons offshore they seem to be most abundant in other areas usually located in less than 70 meters of water. This species is not often found in any of the bays or Long Island Sound unless it is a single debilitated animal. They are most numerous from March through July when they are found in large groups of 50-150 individuals, although larger (5,000) and smaller (3) groups have been observed. These groups seem to involve all age classes with very young calves seen in the spring. Occasionally these dolphins are seen with common dolphins, fin whales and or humpback whales. Estimates of the population of this species in the region are approximately 3,000.
La~enorhvnch~Salbirostns, White-beaked dolphin
The white-beaked dolphin is an abundant species, although its incidence in New York waters is highly variable. During years that it is present it is commonly seen, while it is infrequently seen during other years. The species is found generally on the continental shelf waters, primarily during the winter and spring. AH sightings of have been in depths greater than 30 meters. Groups of 30 to 50 individuals are most often observed. No sightings of calves have occurred and all groups seem to be comprised of juveniles or older individuals. When observed they have either been traveling or on a few occasions have been observed feeding on schools of mackerel (Scomber sp.). A population estimate is not relevant on this species.
Giobiceohata melaena, Long-finned Pilot whale
The long-finned pilot whale is a very abundant and common species in this region. Sightings of this species are seen in at1 months with their distribution in the Bight changing seasonally. Fewer sightings occur in summer months white spring has the greatest number. During the spring pilot whales seem to be distributed in two bands along the coast. One band is a more inshore distribution around the 30 to 40 fathom contours, particularly between the area south of Shinnecock Inlet east to south of Block Island. The second band is along the 100 fathom contour around Hudson Canyon, the Dip, and Block Canyon. During the fall and winter pilot whales seem to be distributed more in the offshore band. Group sizes are highly variable ranging from several thousand to 4 individuals. Pods of several hundred are more common and there appears to be some separation of these pods into sub-groups of 30 to 50 individuals. Sightings involve all age classes with both sexes present. Newborn calves, determined by the presence of fetal folds, are often seen in the larger groups. The overall social structure observed appears to match that previously reported for this species in other regions. They have been reported to follow local fishing vessels feeding on the trash fish discarded over the side and even taking some from nets. All observations of feeding and examination of stomach contents from stranded animals indicate that they feed largely on squid (Loljgo or & sp.). Pilot whales are a highly mobile species with telemetry studies indicating that movements throughout the Northeast are common. hence a population estimate is somewhat meaningless. Based on existing data there are clearly over 2,000 animals present in the Bight throughout much of the year.
O#ctnus orca, Killer whale
Although this species is globally abundant Orcas are only rarely seen in the Bight with occasional sightings mainly in late summer, fall or winter. There is only one stranding record for the region during the 1930's. AH sightings of orcas have been of groups of 1 to 20 individuals. Age and sexual structure of these groups is largely unknown, however, there are no sightings of very young animals. All sightings are in water depths greater than 30 meters and usually greater than 50 meters. Historically, there are sighting reports in the eastern Peconic Bay system around the turn of the century. Only one direct observation of feeding was ever made. This was of a group of approximately 20 animals in the fall feeding on Atlantic Bluefin Tuna, Thunnus thvnnus, southeast of Montauk Point. There are reports of this species also feeding on bluefish, Pornatomus saltatfix, locally. Based on orca behavior in other areas, it is likely that they feed on larger fish species when present. Population estimates are not relevant.
Mesoptodon densimstris, Dense-beaked whale
The dense-beaked whale, as is the case with all species of beaked whales, is poorly understood and their populations, distributions and status are largely unknown. This species, and all the other beaked whales, may be more common than sightings of them indicate. There are no confirmed sightings of this species in New York waters. Based on the lack of sightings here, and the sighting record for the CeTAP surveys it is likely this species is located well offshore beyond the continental shelf. There have been two recorded strandings for this area, of which one was live. Both animals were adults and stranded in the winter. Squid beaks were found in the stomach contents of both animals. A population estimate is impossible.
Meso~lodunmirus, True's beaked whale
As above for distributions and natural history.
Mesoolodon eurooaeus, Gulf Stream Beaked whale
As above for distributions and natural history
Ziphius cavimstfis, Goose-bea ked whale
Although knowledge of this species and its distribution is similar to the other beaked whales there are two sightings of this species confirmed in inshore waters in depths of less than 30 meters. Both sightings were of single individuals during the summer. There was no indication of any feeding activity, although stranding records indicate that this species feeds largely on squid. No population estimate is possible.
Grampus ariseusus, Grampus
The grampus is a very common abundant species in the New York Bight. It is found in this region during all months of the year with some seasonal variation. It is not usually seen in water less than 50 meters in depth, although in some years pods have been observed along the south shore of Long Island. There have also been strandings of this species within Long Island Sound and some of the bays of Long Island. Sightings of this species are usually located around significant submarine features such as Hudson Canyon and Block Canyon. Grampus are usually in groups of 30-1 00 individuals although large aggregations of over 1000 animals have been reported. All age classes are present with newborn individuals also being seen. There are no direct observations of feedingl however, based on its pelagic distribution and the stranding records for the area it appears to feed mainly on various species of squid. One interesting record shows an individual swimming for some time in Long Island Sound feeding on portun~dcrabs. A population estimate is presently vev crude, but over ZlO0O animals may inhabit in the Bight at any time.
Pboca vitu/jna, Harbor seal
The harbor seal is the most common seal species in the region. This species is very abundant and its populations for the region as well as in its temporal occurrence. During the last four years harbor seals have been reported to remain in the Long Island region on a year-round basis. All age classes are seen in the area with a large juvenile presence. Largest numbers of animals are obsewed during the months of November through May. Their distribution is very clearly tied to certain areas where they haul-out. There are 25 major haul-out sites located in the region, the largest of which has over 350 animals while the smallest has approximately 20 animals. There are also a number of minor haul-out sites where either the period of occupancy is not constant or the number of animals is less than 20. As mentioned before all age classes are observed including pups. During the last three years there have been 4 confirmed pupping events in the area and this is probably under-represented. These sites were Fishers Islandl Great Gull Island and Wading River Creek. Harbor seals in the region are found to feed on a variety of species. Although a much greater study is needed on prey itemsl they have been observed eating herring, mackerel, squid, flounder! green crabsl mussels, cod, and whiting. The winter population of harbor seals is presently estimated at 1,890, although this may be an underestimate.
Phoca hjs~jda!Ringed seal
The ringed seal has been sighted each winter for the last 5 years although it is most likely an extralim~nalspecies, All sightings have been of single animals not associated with other seal species. The species has only been seen during the months of January through April, mainly in the months of Februav and March. Most of the [ndividuais sighted or stranded have been juveniles. Vev few observations exist for this species feeding in the area, however, based on stomach samples of stranded animals they appear to feed on whatever small schooling fish are available. Sardines appear to be a favored prey item. Populat~onestimates are irrelevant.
Phoca ameniandica, Harp seal
The harp seal is becoming a more common species in the region. This is probably due to the increasing population numbers in its core range, the arctic. Prior to 6 years ago this stranding or sightings incidence of this species was rare. However, presently they are the second most common stranded species of seal and sightings of live animals are comparable to grey seals. They are always s~ghtedin one of the areas prev~ouslydocumented for harbor seals and are usually in with a group of this species. Wth the exception of one stranded adult, all strandings or sightings are of juvenile individuals w[th no more than two ever seen in one location, They occur in the region seasonally, arriving in late November and departing by mid May. The limited obsetvations of feeding indicate a preference for herring or squid. The North Atlantic population is extimated over 2,00U,OOO.the regional occurrence is probably not more than 100 indiv~dualshowever this estimate is only based on an incomplete analysis.
Ha~icboemsgwpus, Grey seal
The grey seal is one of the more abundant species for the region. Mainly pups and juveniles are observed, although there have been a few adults sighted on a occasional basis. Grey seals occur seasonally with animals first appearing in January. They remain in the area through April with the greatest numbers seen in Februaty and March. Sites where grey seals occupy are areas where harbor seals are also found There have been no sightings of this species in the western half of Long Island. The species has often been sighted by fishermen along the coast feeding on cod. During the last few years the number of grey seals sighted and stranded have shown a gradual increase. This is probably related to an overall population increase. A population estimate for the region is unrealistic, although there are certainly a few dozen an~rnalsin the area each season.
C~sto~horacnstata, Hooded seal
The hooded seal is similar to the ringed seal jn most aspects for this region. It is an extraliminal species regularly found here from January through April. One of the most significant differences from the ringed seal is in the age classes observed. No adult hooded seals have either stranded or been observed in the area. SEA TURTLES
L~DI~OC~~~VSkem~i,Kempls ridley sea tu~le
The Kemp's ridley sea turtle is an abundant sea turtle in the region. Although it is an extremely endangered species globally they are found here regularly evev June through October. Individuals are also found into December, but these are animals that are cold-stunned and would not normally survive. Although they do not occur in large aggregations in any one area there are a number of areas that are clearly significant habitats. Certain areas in Long Island Sound, Block Island Sound, Gardiners Bay and portions of the Peconic Estuary are critimlly important with larger numbers of ridleyls observed there than elsewhere in the region. Jamaica Bay, lower New Yurk harbor and to some extent Great South Bay are also important habitats. The Kemp's r~dley utilizes this region as a part of its developmental l~fecycle. All are juveniles of 2-5 years of age and approximately 27 an in standard carapace length. Studies conducted by the Okeanos Foundation have indicated that these turtles remain here for one season and do not return in subsequent years, Ridley's have been found to feed primar~lyon spider crabs and green crabs. During their time here animals consume large quantities since their growth rates in the region are substantial, with some animals doubling their weights in over 4 months. Popuiation estimates are approx~matelyAOO-300 individuals each season, which is a significant poriion of the surviving population.
Carretta carreffa, Loggerhead sea turtle
The loggerhead has a similar distribution pattern to the ridley with a somewhat greater number of individuals found in this region. They also occupy a slightly greater time frame w~thturtles appearing in the area as early as late May. Loggerheads have two types of distributional presence. The first is a more restricted age group of mainly juveniles in the bays and Long Island Sound. These animals average 45 cm in standard carapace length and are largely from the same year class, although not as restricted as the ridley. The second group are individuals more oceanic in their distribution and generally found along the south shore of Long Island up to 40 miles or more offshore. These individuals are much larger represent~nga wider range of age classes including adults. Based on limited tagging data this group probably indudes animals that return to the area over a number of years. This species also demonstrates a slightly greater variety of prey species. Although the spider crab is still a dominant prey item$ it is far less dominant than with the ridley. Loggerheads have been found to feed on horseshoe, green, and portunid crabs. Although vev large numbers are found here population estimates are incomplete at this time. There are approximately 800 animals (568-1021) in the Bight based on existing data. Che/o#ia mydas, Green sea turtle
The green sea turtle is common~yfound in the New York B~ghtbut with an apparent iesser abundance than the other species of sea turkles also found here. This lesser abundance may partly relate to effort. The species is usually found in shallow water bays and to some extent Long Island Sound. Its distribution is probably tied to submerged aquat~cvegetation such as U/va SD., and Codium SD.. However, comprehensive study of this turtle's food items has not been undertaken and it is presently poorly understood when compared to the ridley or loggerhead. Green turtles are found in this region from June through October with cold-stunned individuals recovered during the months of November through December. Although a few adult size animals have been recovered there is a wide range in size of individuals. Thereforel this species probably does not have a clearly defined single age class migration into the region. Rather it is probably representative of several year classes. There have not been any repeat recoveries beyond one year. Smali turtles may represent one nesting population of greens, while larger animals may represent a different nesting population. The estimate for populatians for green turtle is poor at the present time. There are at least I00 turtles in the region each year based on existing data.
Dermochelvs conacea, Leatherback sea turtle
The leatherback sea turtle is one of the most abundant species of sea turtle in the New York Bight. It is a common species present in these waters with animals arriving in May and remaining into November. Leatherbacks are found along the south shore of Long Island and Long Island Sound but rarely in the bays. There are clearly concentration areas where prey species are more prevalent, Leatherbacks have been found to feed largely on various soft bodied invertebrates such as Ctenophores and jelly fish. Large juveniles or adult sized animals are found in the reg~on.Aithough very few animals have been tagged one animal that was flipper tagged off French Guiana was recovered here. Clearly the leatherback is predominantly a pelagic species. The population est~matesare presently very roughl however, there may be approx~mately 500-800 animals present each year.
Eretomocheivs imbflcata, Hawksbill sea turtle
This species is rare and probably only an anomalous visitor to the area. There is only one record of the species for the region in Long Island Sound shortly after the 1938 hurricane. MARINE MAMMALS AND SEA TURTLES OF NEW YORK STATE
SPECIES FEDERAL STATUS CODE BWCODE
CETACEANS Balaenoptera physalus E A BW5/BWl,E Balaenoptera acutorostrata P A BW4 Balaenoptera borealis E A,S BW3 Balaenoptera musculus E R,S BW2 Megaptera novaeangliae E C1S BW Eu balaena glacialis E R,S BW1 Physeter mtodon E C%S BW4 Kogia breviceps P C,UNK BW? Mesoplodon densirostris P UNK BW Ziphius cavirostris P UNK BW? Mesoplodon mirus P UNK BW? Mesoplodon europeaus P UNK BW? Tursiops truncatus P A,S BW4 Delphinus delphis P A BW5/BWl Sienella coeruleoalba P A,S BW4/BW? Stenella plagiodon/attenuata P A,S BW3/BW? Detphinapterus leucas P R BWl Phocoena phocoena E 1,s BWIBW? Lagenorhynchus acutus P A BW5 Lagenorhy nchus albirostris P A,S BW4/BW? Globicephala melaena P A BW5lBWt Orcinus orca P R BWl/BWH Grampus griseus F A 8W5iBWl
Phoca vitulina Phoca groenlandica Phoca h~spida Haiiochoerus grypus Cystophora cristata
SEA TURTLES Lepidochelys kernpi E Carretta carretta P Chelonia mydas E-P Dermochelys coricea E Eretomochelys im bricata E
A=Abundani, C=Common, l=lncreasing in presence, R=Rarel UNK=Unknownl S=Seasonal, €S=Extend Seasonal
* CONCLUSIONS
Based on the material presented here it is dear that the New York Bight has one of the highest diversities of marine mammals and sea turtles reported anywhere in the United States. This region is dearly important for a wide range of species, many of which are endangered or threatened species. Studies by the Okeanos Foundation have demonstrated that the area is a critical developmental habitat for the highly endangered Kemp's ridley sea turtle, as well as a major feeding area for leatherback, green and loggerhead sea turtles. This is a significant winter habitat for the harbor seal, while other northern Atlantic seals such as greys come ashore in smaller numbers. Fin, minke and humpbacks utilize these waters frequently, with sperm whales regularly sighted in late spring. The critically endangered right whale at least utilizes the New York Bight for migration, if not remaining here to feed on occasion. Several dolphin species, including common, bottlenosed, white sided and striped dolphin and pilot whales can be found often. One of the most important features of the New York Bight is the enormous amount of human impact. This region is one of the most heavily used, if not the heaviest, coastal regions in the United States. There are over 20 million people living near the coast of this region and the impact on the marine environment is dramatic. Marine mammal and sea turtle populations should be monitored closely for future signs of stress from anthropogenic sources, while historical studies should continue in depth to assess impact so far. Acknowledgements
The compilation of data and information for this report represents the work of a large number of people over many years. It would not be possible to list all of them here. The studies of the Okeanos Foundation would not be possible without the support of the New York State Department of Environmental Conservation and Robert Miller. The review of the manuscript was provided by Giilian Lankshear and Eileen Gerle. Numerous samples were also collected by the stranding team, the crew of the Finback and the numerous volunteers who assist Okeanos. We appreciate their tireless efforts. References
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