NOAA Technical Memorandum NMFS-NE-120
Marine Mammal Research Program of the Northeast Fisheries Science Center during 1990-95
Janeen M. Quintal and Tim D. Smith
National Marine Fisheries Serv., Woods Hole Lab., 166 Water St., Woods Hole, MA 02543Web version posted August 16, 2001
Citation: Quintal JM, Smith TD. 1999. Marine Mammal Research Program of the Northeast Fisheries Science Center during 1990-95. US Dep Commer, NOAA Tech Memo NMFS NE 120; 28 p.Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report. These predissemination reviews are on file at the NEFSC Editorial Office.
Preface
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Marine mammal research conducted and supported by the Northeast Fisheries Science Center through 1989 was summarized in Waring et al. (1994). The present paper extends that summary through 1995, as the focus and scope of research expanded substantially. This paper was unfortunately delayed in press for more than 3 yr during administrative reorganization, the manuscript having been completed and accepted for publication in early 1996.
Marine mammal research conducted and supported by the NEFSC since 1995 is reported in the NEFSC Protected Species Branch website - http://www.nefsc.nmfs.gov/psb. That website includes: this paper and its predecessor, reports documenting the status of all marine mammal populations off the northeastern United States, reports of marine mammal surveys and research cruises, and a bibliography of publications. The website, however, does not include budgetary details as included here.
ABSTRACTWe summarize marine mammal research supported by the Northeast Fisheries Science Center (NEFSC) from 1990 through 1995, extending the earlier description of NEFSC-supported research conducted during 1980-89 (Waring et al. 1994). The studies are classified into four broad research areas: ecological roles and habitat requirements, human interactions, optimum sustainable population size, and research planning and archiving. Each of these four research areas is then further classified into several research topics for a total of 19 topics. In the 1990-95 period, research on marine mammals intensified over that in the 1980s (Waring et al. 1994). In particular, population-level studies moved from population description (e.g., distribution, migration) to population assessment (e.g., abundance, bycatch) as definition and implementation of specific management approaches evolved to meet the changing requirements of the U.S. Marine Mammal Protection Act. Approximately 100 contracts, grants, and in-house projects in the amount of $9.1 KK were supported during 1990-95, and these expenditures are summarized by fiscal year. Research results that have emerged in the form of formal publications, reports, and oral presentations are organized into a series of appendices and are numerically sequenced to relate each one to a specific research topic described in the text. Those projects that appear to fall into more than one research area are classified according to where the most important results were obtained. The implications for future research directions are discussed.
INTRODUCTIONIn the northeastern United States, marine mammals are a subject of historical and ecological significance. After decline of the Northeast’s American whale fishery in the late 1800s and early 1900s, concern for systematic scientific study of marine mammal species declined. However, in the 1940s, following taxonomic studies undertaken by Remington Kellogg at the Smithsonian Institution and William Schevill at Harvard University, cetacean biology began to be investigated more thoroughly. In the early 1970s, several researchers began studying marine mammals in this region. With passage of the Marine Mammal Protection Act (MMPA) in 1972, this effort expanded. In 1979, the U.S. Marine Mammal Commission (USMMC) sponsored a workshop to address ongoing cetacean studies and to help in defining research needs for U.S. East and Gulf Coast marine mammals (Prescott et al. 1980). The National Marine Fisheries Service (NMFS) responded to these needs by funding a variety of projects on marine mammals and their interactions with commercial fisheries. The program expanded further as a result of information needs mandated by the 1988 amendment of the MMPA (Waring et al. 1994).
Waring et al. (1994) summarized research on marine mammals conducted and sponsored by NMFS in the northeastern United States in the 1980s. They organized this research into four broad areas, and within each area organized contract, grants, and in-house activities into several related topics. For each topic, they described the main results of the several research activities, and related those results to the expenditures and resulting publications.
NMFS marine mammal research activity during the first half of the 1990s was substantially broader and more intensive than that in the 1980s. The focus and conduct of this research effort began to change following the 1988 amendment to the MMPA. Increased funds became available, and NMFS staff became increasingly involved in both contracted and in-house research activities. In 1990, the Marine Mammal Investigation (MMI) was formed within the Northeast Fisheries Science Center (NEFSC) of NMFS. Initially, the MMI included five members, but by 1995 it had expanded to a staff of 10 and was renamed the Protected Species Branch (PSB). In addition, the need for information on bycatch of marine mammals in fishing gear resulted in the expansion of a program placing observers aboard fishing vessels. These at-sea observations were conducted as part of a more general program within the NEFSC by a separate unit, the Sea Sampling Investigation (SSI), beginning in 1989.
Research effort shifted again following the 1994 reauthorization of the MMPA, as increased emphasis began to be placed on information needed to implement the specific management approaches defined therein. In addition, the PSB became increasingly involved in the work of the Scientific Committee of the International Whaling Commission (IWC), especially in areas of expertise initially developed to address domestic research needs.
ORGANIZATION OF RESEARCH PROJECTS We summarize the research conducted in the six fiscal years of 1990 through 1995, that is, from October 1989 through September 1995. This research effort was focused by the information needs identified under the 1988 amendment to the MMPA, especially those needs relating to fishery bycatch, and by several other more specific information needs. Planning for this research effort was formally organized into the four broad areas, the same identified by Waring et al. (1994) from retrospective analysis of the work in the 1980s (Table 1). Theses areas are: 1) ecological roles and habitat requirements, 2) human interactions, 3) optimum sustainable population size, and 4) research planning and archiving. While the four major research areas remained, specific research topics changed somewhat from those in the 1980s. Of the 18 original research topics, five were dropped and six were added for a total of 19 (Table 2).
The research area of ecological roles and habitat requirements continued its focus on distribution and abundance of humpback and fin whales, and also on habitat requirements of the right whale in the North Atlantic. The focus of study on harbor and gray seals shifted entirely from this area into that of optimum sustainable population size. The biological research related to samples and data provided by the NEFSC Sea Sampling Program (SSP), the successor to the SSI, was included within the ecological roles and habitat requirements area under the topic of biological sampling of fishery bycatch. Humpback biopsy sampling was included under the North Atlantic humpback and fin whales topic. The oceanographic correlation to spatial distribution topic contains research information previously listed under the energetic requirements of East Coast cetaceans topic. The satellite tagging and tracking topic was added as development and testing of this technology continued to expand.
The human interactions research area added a more topic on bycatch reduction. Methods are being developed to study the effect of time/area fishing restrictions on harbor porpoise bycatch and fish catch, and also to study the usefulness of deterrent devices attached to fishing gear to prevent marine mammal entanglement.
The optimum sustainable population size research area focuses mainly on the distribution and abundance of harbor and gray seals, harbor porpoise, large marine pelagics, and the right whale, and on the photographic identification of North Atlantic humpback and right whales. Research under the topic of bottlenose dolphin distribution and abundance along the Virginia Capes was taken over by the NMFS’s Southeast Fisheries Science Center, and our focus expanded to include a more general topic of large marine pelagic distribution and abundance. The topic of population dynamics and assessment of status was added to address potential management issues implied by increased information resulting from current research, especially on levels of abundance and bycatch. Stock assessments for all marine mammal populations in the region were completed (Blaylock et al. 1995) as required under the 1994 reauthorization of the MMPA.
The research planning and archiving research area has one additional topic on the IWC Scientific Committee. This topic was added as U.S. involvement in IWC Scientific Committee issues continued to expand.
SUMMARY OF RESEARCH ACTIVITIESINTRODUCTION
During 1990-95, approximately 100 contracts, grants, and in-house projects in the amount of $9.1 KK were supported. Expenditures for each research topic within each of the four areas of research are summarized by fiscal year (Table 3). These values reflect all costs to NMFS and the NEFSC (exclusive of SSP contracts), including equipment and supplies, staff, salaries and related costs, contracts, charters, and travel. Salary expenditures for staff members were distributed proportionately among those topics according to the level of work responsibility. Results of this research were communicated in many forms, including formal publications, research reports, contract reports, cruise reports, and oral presentations to scientific bodies. These communication products have been organized in a series of four appendices depending on the degree of formality. Primary peer-reviewed scientific papers are listed alphabetically by author in Appendix A. Contract reports, working papers, and unpublished manuscripts are listed alphabetically by author in Appendix B. Oral presentations at scientific conferences are listed in Appendix C, alphabetically by author within conference. Finally, brief summaries of ship and aerial sighting surveys are listed chronologically in Appendix D.
The individual research results listed in the four appendices relate to one or more of the specific research topics. This relationship is summarized in Table 4, where the sequence numbers from each of the four appendices are tabulated for each research topic. From this table, it is apparent that the research results pertaining to each specific topic appear in several types of publications and reports.
ECOLOGICAL ROLES AND HABITAT REQUIREMENTS
Oceanographic Correlation to Spatial Distribution
Beginning in 1990, research surveys along the Gulf Stream wall and associated warm-core rings and in several major canyon areas were conducted, focusing on the associations of these features with the sperm whale and pelagic delphinid and beaked whale species. GIS techniques were used to analyze spatial and temporal data to determine overlap between the Mid-Atlantic/New England delphinid complex and its potential pelagic prey resources. Such studies were augmented by expansion of the scope of shipboard sighting surveys to include additional measurements of the water column’s oceanographic regime and biological community.
Similar analyses were undertaken to determine better the seasonal habitat of harbor porpoise.
Considerable effort was devoted to developing more powerful statistical methods for analyzing spatial distribution patterns. As support for this work, GIS procedures were developed to describe the bathymetry and sea surface temperatures of the region. These procedures will allow researchers to develop habitat models for cetaceans and their prey, based on oceanographic features.
North Atlantic Humpback and Fin Whales
Beginning in 1984, researchers conducted transect surveys to document seasonal distribution and abundance of both fin and humpback whales in Cape Cod Bay and the Provincetown Slope. These surveys later expanded to the Great South Channel and the northern ridge of Georges Bank.
The YONAH Project began in January 1992 with a large-scale study of the humpback whale in its principal West Indies breeding range. The project continued in summer 1992 with sampling in all known North Atlantic feeding grounds from the Gulf of Maine to Norway. Sampling continued in 1993, and upon completion of the project’s field work, the project had photographically identified approximately 4,000 humpback whales, and biopsied almost 2,600. While matches between areas (notably breeding and feeding grounds) will inevitably reduce these totals, these sample sizes remain unprecedented for a marine mammal study. The third year of the YONAH Project, 1994, was devoted to analysis of the huge volume of photographs, data, and tissue samples. All photographs were submitted to the College of the Atlantic (Bar Harbor, Maine) where they were compared and matched.
DNA has been extracted from virtually all YONAH tissue samples by the Institute of Population Biology at the University of Copenhagen, and sex determinations (using a molecular technique) were completed. Principal genetic analyses included an assessment of population structure using mitochondrial DNA and microsatellite systems. A variety of analyses of this data set are underway, including estimates of abundance, genetic relationships, and behavior patterns.
Biological Sampling of Fishery Bycatch
Marine mammals taken incidentally in directed fishery operations were collected by observers aboard U.S. East Coast foreign fishing/processing vessels beginning in 1986, and by observers aboard domestic fishing vessels beginning in 1989. These specimens provided new information on food habits, morphometrics, reproductive biology, physiology, and parasitology.
Bycaught animals continued to be collected by observers under the SSP for use in NEFSC necropsy sessions. These sessions, conducted in cooperation with other organizations such as the U.S. National Museum of Natural History and Woods Hole Oceanographic Institution, serve to train new observers and also to provide a wide variety of information for studies of life history of small cetaceans. All biological samples collected by the SSP and stored at NEFSC were processed and cataloged.
Northern Right Whale Habitat Requirements
The NEFSC has administered an integrated research program on the northern right whale since the mid-1980s which has yielded findings on the species’ abundance, distribution, stock structure, and behavior. Methods have included vessel and aerial surveys, radio-satellite tagging, photographic identification, and genetic analysis.
As a result of a Congressional initiative supporting northern right whale research, the NEFSC increased ongoing research on habitat requirements in 1987. Five major habitats were identified: 1) coastal waters of the southeastern United States, 2) Great South Channel, 3) Cape Cod Bay, 4) Bay of Fundy, and 5) Scotian Shelf.
Genetic analysis, based on mitochondrial DNA, suggests that the population is based on three “matrilines,” or distinct lineages, stemming from reproductive females.
The population is estimated to number between 300 and 350, and is thought to be recovering at a rate of 3-4% annually. The “Final Recovery Plan for the Northern Right Whale” was released in spring 1992. Science and management workshops were held in April 1992 and October 1994 to review research and to identify recovery plan implementation priorities. Recent observations of a drop in calf counts, a possible increase in the average calving interval, longer calving intervals on average than for the southern right whale, and a proportion of apparently nonreproducing mature females, give cause for concern.
Satellite Tagging and Tracking
Beginning in 1992, the NEFSC, working jointly with the Office of Naval Research, supported contract studies to develop and test application of satellite tags to large and small cetaceans. Studies included biocompatibility of attachment materials, hydrodynamic aspects of tag design, and the dorsal fin’s morphology and role in temperature regulation.
Increased field testing of satellite tags on harbor porpoise occurred during summer 1995 on Grand Manan Island at the mouth of the Bay of Fundy. Six harbor porpoise were tagged with ARGOS transmitters redesigned for a lower profile. Data were collected on movement and diving patterns as these animals undertook their annual migration.
HUMAN INTERACTIONS
Marine Mammal - Fishery Interactions
Marine mammals in New England and Mid-Atlantic waters are taken incidentally in several fisheries. These fisheries are described in the “List of Fisheries” published annually by the NMFS Office of Protected Resources.
Data were collected by the SSP and other programs on bycatches of marine mammals, and were used with fishing effort information to estimate total annual bycatch levels. Scientific workshops reviewed data collection techniques for use by the SSP, and sought to optimize data collection by changing from random sampling to sampling proportional to fishing effort.
Focus of this work involved the harbor porpoise because of its high incidental take relative to its potential biological removal (PBR) in the Gulf of Maine sink gillnet fishery. The initial focus on harbor porpoise was gradually replaced by an emphasis on all species. Trawl fisheries for Atlantic mackerel and squids and drift gillnet fisheries for swordfish and tunas also take marine mammals in the western North Atlantic. Twenty-one species of marine mammals have been reported as bycatch in these fisheries. These bycatch data are included in the “U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments” published annually by NMFS (Blaylock et al. 1995). Bycatch and abundance data from these assessments classify stocks as strategic or nonstrategic as defined by the MMPA.
Whale - Vessel Interactions
The northern right whale population is threatened by human impacts, specifically ship strikes and gear entanglement. In 1992 and 1993, the NEFSC participated in a multi-agency mitigation effort with the states of Florida and Georgia as major participants. The effort included an assessment of vessel traffic, education of mariners, development of an early warning network to alert vessel operators in and near shipping areas, and research on right whale distribution, behavior, and habitat. A Southeastern U.S. Implementation Team for the Recovery of the Northern Right Whales became active and based much of its effort on work from the 1992 and 1993 wintering seasons.
Funding was also provided for modeling the dynamics of interactions between cetacean size and ship hull design in order to determine the likelihood of ship strikes of marine mammals, especially large whales.
Bycatch Reduction
The high incidental take -- relative to PBR -- of harbor porpoise in the Gulf of Maine caused much concern about the status of this species. As a result, the NEFSC investigated bycatch reduction methods during 1992 and 1993. To investigate the effect of time-area fishing restrictions on harbor porpoise bycatch and fish catch, a computer program was developed that uses GIS and the 1990-92 sea sampling and commercial weighout databases. The program was designed to link at-sea observer and fisheries port sampling data to estimate the proportion of harbor porpoise bycatch that may be associated with different seasons and areas in sink gillnet fishing operations in the Gulf of Maine. In September 1993, the NEFSC hosted a bycatch reduction workshop which considered net modifications that might make the nets more detectable or otherwise less likely to entangle harbor porpoise. The NEFSC also supported or participated in several experiments to test acoustic deterrent devices for use in the sink gillnet fishery. The 1994 definitive experiment by Kraus et al. (1995) was supported with SSP observer coverage.
OPTIMUM SUSTAINABLE POPULATION SIZE
Harbor and Gray Seal Distribution and Abundance
Two major species of pinnipeds occur in New England waters. The harbor seal is a year-round inhabitant of coastal waters of Canada and Maine, and occurs seasonally in Southern New England. The population is subject to influenza outbreaks and incidental mortality in several fisheries. Since 1972, harbor seal abundance along the New England coast appears to have more than tripled, and range has expanded southward. Pupping ledges along the Maine coast have increased in number and expanded further offshore. An aerial survey was conducted during pupping season in 1993 along the coast of Maine. The number of harbor seal counted was more than double that counted in a 1986 aerial survey.
The gray seal has established breeding colonies on islands in Nantucket Sound and off the Maine coast in recent years.
Harbor Porpoise Distribution and Abundance
In the Northwest Atlantic, harbor porpoise are found from North Carolina to Labrador. The simultaneous timing of reproduction in widely separated geographical areas suggests that there are four populations in the Northwest Atlantic: 1) western Greenland, 2) Newfoundland-Labrador, 3) Gulf of St. Lawrence, and 4) Gulf of Maine (Gaskin 1984). Populations, seasonal movements, and the degree of mixing between putative populations are largely unknown.
To document seasonal distribution of harbor porpoise in the Gulf of Maine region, researchers began by using harbor porpoise sightings made aboard whale-watch and research vessels. In 1982, a shipboard survey was conducted along the Maine coast to estimate coastal distribution patterns and to estimate population size using line-transect methods. After survey methodology experiments that began in 1987, NEFSC researchers conducted aerial and shipboard line-transect surveys from the Gulf of Maine to Florida to improve documentation of seasonal distribution, the southern edge of summer range, and the northeastern distribution pattern of the species. Shipboard surveys were conducted during each August of 1990-93, March 1995, and July-August 1995. Aerial surveys were conducted during October 1991, December 1992, February 1993, April 1993, November 1993, and August-September 1995. Large numbers of harbor porpoise were seen in the Gulf of Maine - lower Bay of Fundy region in summer, but nearly none in the same region in winter. Winter distribution is largely unknown, except that some harbor porpoise have been found stranded on beaches from New York to North Carolina in winter and spring. There is little information on distribution of harbor porpoises in nonsummer months in Canadian waters off Nova Scotia and Newfoundland, and within the Gulf of St. Lawrence.
The best available estimates of population size based on summer survey work are 37,500 (95% confidence interval of 26,700-86,400) animals for 1991, 67,500 (32,900-104,600) animals for 1992, and 74,000 (40,900-109,100) animals for 1995.
Harbor Porpoise Survey Methodology
In 1987, the NEFSC conducted an experimental line-transect survey for harbor porpoise in the Gulf of Maine. Results indicated that harbor porpoise elicited a negative response to the vessel, that a large fraction of animals along the survey track were missed, and that observer elevation above sea surface had little effect on sighting rate.
Another experimental sighting survey for harbor porpoise was conducted during August 3-23, 1993, to test for vessel avoidance. The analysis of survey data suggested that, although harbor porpoise do appear to avoid survey ships, this does not occur at distances greater than can be detected by observers searching with the unaided eye.
In March 1995, a hand-held, pen-based computer system for at-sea data entry of line-transect data was developed and successfully tested at sea.
During August-September 1995 line-transect surveys, a comparison study was conducted of sighting rates, distribution, and estimated abundance of harbor porpoise as detected by an airplane versus a ship sighting platform. Also, methods were used to further study the calculation of g(0), the probability of detecting a group of animals on the track line.
Studies were started on an adaptive sampling design in which a planned transect line is diverted in order to explore an outside area where animals seem plentiful. With development of a proper accountability for bias, this method may be more useful than the systematic sampling method used thus far.
Large Marine Pelagics Distribution and Abundance
Shipboard surveys of pelagic delphinids were conducted along the shelf edge and slope waters from the southern edge of Georges Bank to the Scotian Shelf. Surveys were conducted in August 1990, June-July 1991, March-April 1992, June-July 1993, August-September 1994, and July-August 1995. These surveys investigated beaked whale and pelagic delphinid fine-scale distribution in shelf edge and Gulf Stream warm-core rings. These distribution studies are essential for accurate determination of population abundance as required by the MMPA. Line-transect survey data were also collected and photographic identification studies were done using a rigid-hulled inflatable boat.
Humpback Photographic Identification Catalog
During the 1980s, mark-recapture methods were used to derive population estimates for the five Northwest Atlantic substocks of the humpback whale. Also, researchers conducted a study on the stability of humpback fluke patterns over time using a time series of archived photographs. The study supported the validity of using fluke patterns for long-term studies of individual animals.
Several organizations were funded in the 1980s to conduct song recordings and photographic identification studies which provided information on breeding behavior, stock intermixing, individual identification, and habitat use.
Since 1976, the College of the Atlantic has curated the “North Atlantic Humpback Whale Catalog,” the central collection of photographs of the flukes of humpback whales obtained from the North Atlantic region. The collection contains material on more than 4,500 cataloged humpback whales from 1952 to 1992.
Northern Right Whale Photographic Identification Catalog
Beginning in 1987, as a result of a Congressional initiative supporting northern right whale research, individual identification photographs were taken and integrated into a single database. This effort resulted in an improved count of individually known animals in a published catalog and an ongoing system for archiving new photographs. The New England Aquarium (Boston, Massachusetts) maintains the “North Atlantic Right Whale Photographic Identification Catalog.” The catalog contains 6,795 photographed records of 340 right whales taken between 1935 and 1994. One component of this catalog documents scars and wounds resulting from human impacts, principally ship strikes and net entanglement.
Northern Right Whale Distribution and Abundance
During the 1980s, the NEFSC administered funding for several northern right whale studies focusing on photographic identification, calving rates, population estimation, demographics, and habitat use. Studies for documenting historic right whaling activities along the southeastern U.S. coast were also supported. Through the earlier-mentioned Congressional initiative, an integrated study of the North Atlantic right whale was implemented in 1987 through a cooperative agreement with the URI with the overall goal of detecting changes and causes of changes in population distribution and size.
In 1992, an airship donated by Sea World, Inc., surveyed winter nursery grounds off the Florida and Georgia coasts and observed distributional overlap between whales and U.S. Navy submarines. A similar project was conducted in 1993, and included ship traffic characterizations in two shipping channels and an education and awareness program for mariners. In August 1993, airship research flights were conducted using airship-mounted, high-resolution camera equipment for studying whale behavior and sightability relative to abundance estimation correction factors.
Population Dynamics and Assessment of Status
Throughout the 1980s, marine mammal research supported by the NEFSC focused on determining basic biology, distribution, and migration of cetaceans, and on primary human impacts. There was a broader emphasis in the 1990s as information increased, especially relative to levels of abundance and fishery bycatch. Research shifted more towards population dynamics and assessments of stock status and associated management implications.
An initial focus on harbor porpoise resulted in identification of possibly unsustainable levels of bycatch for this species. Subsequently, the status of other species was determined by comparing estimates of bycatch and abundance. PBR levels were computed for all species and compared to annual estimates of incidental take. These comparisons identified several species of concern, including harbor porpoise, long-finned pilot whale, shortbeaked common dolphin, whitesided dolphin, bottlenose dolphin, and five species of beaked whales (Mesoplodon spp.).
Studies of the population dynamics of pilot whales, in conjunction with the International Council for the Exploration of the Sea (ICES), were also conducted.
Assessments of the status of all marine mammal populations in the region were conducted as mandated under the 1994 MMPA reauthorization (Blaylock et al. 1995).
Studies of the performance of management procedures were also undertaken to meet information needs of the IWC Scientific Committee.
RESEARCH PLANNING AND ARCHIVING
IWC Scientific Committee
U.S. scientists have been involved in the work of the IWC Scientific Committee since its beginning in the 1950s. In recent years, scientists from the Alaska, Southwest, and Northeast Fisheries Science Centers, NMFS headquarters, and from several academic institutions have been involved. NMFS scientists were involved primarily because their research was relevant to issues being addressed by the IWC Scientific Committee.
Beginning in 1992, U.S. scientists began to conduct research which directly addressed some Scientific Committee issues, and NEFSC involvement expanded to include: 1) coordination of U.S. research interaction with the Scientific Committee, 2) preparation with other U.S. scientists of an annual progress report for the Scientific Committee, and 3) specific research on population dynamics, management methods, and methods of estimating abundance.
Workshop Support
A harbor porpoise workshop was hosted by the NEFSC during May 5-8, 1992, to evaluate the status of harbor porpoise populations in eastern North America. Information was reviewed on population structure, reproductive rates, population size, bycatch levels, and ecological relationships. The NEFSC also hosted a follow-up harbor porpoise workshop during February 23-25, 1994, where scientists from the United States, Canada, and England assessed the status of harbor porpoise by reviewing information on population structure, as well as estimates of abundance, bycatch, and population growth rates. Also, habitat requirements were hypothesized by investigating physical, biological, and anthropogenic factors correlated with the distribution and abundance of harbor porpoise.
A workshop on tagging and tracking technology, supported by the NEFSC, was held during February 11-13, 1992, in Warrenton, Virginia. The workshop was jointly sponsored by the Office of Naval Research, Minerals Management Service, NMFS, and USMMC. Participants included researchers from the United States, Canada, Great Britain, Norway, and Japan, and representatives of engineering and consulting firms involved in developing radio tags. The meeting provided a forum to review past approaches, to describe state-of-the-art technology, and to identify further research and development requirements.
A workshop was hosted by the NEFSC during September 20-23, 1993, to identify possible modifications to sink gillnet fishing gear to reduce harbor porpoise bycatch rates. Participants included representatives from the gillnet fishing industry and research scientists and statisticians from Japan, New Zealand, Great Britain, Canada, and NMFS. The workshop considered modifications which might make nets more acoustically detectable and less likely to entangle animals.
“Right Whales in the Western North Atlantic: A Science and Management Workshop” was conducted on April 14 and 15, 1992, in Silver Spring, Maryland.
In October 1994, an independent peer review of North Atlantic right whale research supported by the NEFSC was conducted in Woods Hole, Massachusetts. A five-member international panel reviewed and evaluated past right whale research and made recommendations for future research and a long-term monitoring program.
Documentation and Archiving
A database documenting right whales in the Northwest Atlantic is kept by URI. Humpback whale photo and biopsy samples from the YONAH Project are being documented and stored in a comprehensive YONAH archive.
Data transfer from a VAX computer to an ORACLE database management system was begun at the NEFSC in 1995. Included in this exercise was the entering of marine mammal bycatch data from the sink gillnet fishery collected by the SSP.
SUMMARY OF RESEARCH RESULTS The 16 yr of research on marine mammals documented here and in Waring et al. (1994), in conjunction with other research programs sponsored by other agencies (e.g., U.S. Army Corps of Engineers, Minerals Management Service, State of Massachusetts), have established a broad general understanding of the distribution, abundance, and ecological roles of the 34 species using the waters off the Northeastern United States. This research has addressed and gone well beyond recommendations of the initial USMMC research planning workshop in 1979 (Prescott et al. 1980; see Table 1 of Waring et al. 1994).
The spatial scale of the research has expanded to cover more of the ranges of most of the species which are more than intermittent visitors to the region. Sighting and individual identification surveys have been conducted south to the northern wall of the Gulf Stream, east along the southeastern coast of Nova Scotia, and north well into the Bay of Fundy. Further, for selected species, international efforts have been developed which effectively expand the geographic area of research coverage across the Atlantic. These efforts have been facilitated by increased involvement internationally. For example, the geographic scope of harbor porpoise studies has been expanded to address issues of population discreteness through the IWC Scientific Committee and the “Agreement on the Conservation of Small Cetaceans of the Baltic and North Seas.” Studies of pelagic delphinids have also been expanded in scope under auspices of ICES. Less formal international efforts have been conducted bilaterally, with both government and academic Canadian researchers focusing on harbor porpoise, and with researchers in Canada, Greenland, Iceland, Norway, Great Britain, and Puerto Rico working on the YONAH Project.
Research activities have involved the application of existing methods and the development and adaptation of new techniques. The 1885 recommendation of Frederick True (True 1885) of collecting and analyzing stranded animals has been generalized to include samples collected by trained observers from fishery bycatch, and has become a well organized and critically important basis for the study of marine mammals in this region. Through such programs, tissue samples have been made available routinely to researchers around the world for a variety of basic research studies. Increasingly sophisticated methods for field collection and for laboratory analysis of these samples have been applied, providing valuable information on population discreteness and vital rates.
Related information has been obtained from individual animal identification studies of some species. These have become a mainstay of studies of humpback and northern right whales. Long-term investments have been made in the annual sampling required for these methods, and in establishing and supporting photographic catalogs and their associated field sampling databases. This effort has provided an improved understanding of movements and improved estimates of vital rates.
Additional information has been obtained from tissue samples using biochemical and molecular genetic analyses. Collection of a variety of tissue samples for this purpose has become routine, both from stranded and bycaught animals and from biopsy samples collected with increased frequency during photographic identification studies. Such methods have begun to allow strong inferences about population genetic structure and ecological roles.
Aerial and shipboard sighting survey methods have been applied since 1979, first in a major study to determine overall distribution patterns and subsequently for other purposes. These methods have been markedly improved and have received increasing interest in the United States and elsewhere in managing cetacean populations based on abundance estimates derived from fishery-independent data. At-sea data collection methods have been improved through use of better electronics for data collection and automated recording. In addition, the scope of the data collected during sighting surveys has been expanded in this region to include various forms of oceanographic and fishery-related data. This expansion has allowed more specific study of habitat requirements and correlated factors.
Development of increasingly sophisticated electronic tags, communicating radio frequencies, has been matched with a strong effort at development of methods of attaching these tags to cetaceans. Focus has been on methods of attaching tags to captured living animals such as rehabilitated stranded animals (e.g., pilot whale) and fishery-caught animals (e.g., harbor porpoise), and of directly implanting them in larger cetaceans, especially northern right whales. This research effort has increased information on individual animal movement patterns and ecological behavior.
Over the past 16 yr, a large amount of data on a wide variety of aspects of marine mammal biology have been collected. Although the data were collected to answer specific questions, they have also become very useful for new research applications, including identification of longer-term patterns. Spatial aspects have increasingly been addressed using GIS technology, especially in linking the data with other data collected by other elements of NMFS and by other agencies. The application of this technology has been made more effective by developing improved statistical methods for analyzing spatial data.
Focus of the research conducted within each of the four areas has shifted over time as our understanding has increased and as priorities and questions have shifted. The level of activities related to research planning and data archiving has varied over the 16 yr. Initially, general long-term plans were developed, followed in the 1980s by implementation of those plans. More specific long-term planning was undertaken in the late 1980s, followed in 1993 and 1994 by very specific assessment, methodology, and species-oriented planning. A new role began in coordinating the scientific work done by several elements of NMFS in support of the Scientific Committee of the IWC. Strong emphasis was given towards archiving the developing photographic identification and sighting survey databases.
Research on ecological roles and habitat requirements have focused on cetaceans, and increasingly (in the 1990s) on spatial distribution patterns. The long-term focus on the endangered northern right whale and humpback whale has continued, and there has been increased focus on the laboratory analysis of samples obtained from fishery bycatch. In 1992, a major effort to develop methods for satellite tagging and tracking was begun, culminating with the successful tagging of harbor porpoise in 1994 and 1995.
Research on human interactions with marine mammals has been expanded since the early 1980s in response to the increased focus on fishery bycatch in the 1988 and 1994 amendments of the MMPA. Data collected under the NEFSC observer program were used to estimate levels of bycatch, focusing initially on harbor porpoise, but gradually expanding to include all species of marine mammals. This bycatch estimation effort was associated with an increase in emphasis on bycatch reduction methods in response to the identified high bycatch levels for some species. Human impacts on large whales were also studied and research was supported to mitigate ship strikes on right whales through mathematical modeling of ship hulls, with such modeling serving as a tool for evaluating the potential for collisions with right whales on their calving and wintering grounds in the coastal waters of the southeastern United States. This study addressed an issue first identified in the mid-1980s.
Research on optimum sustainable population size increased markedly for harbor porpoise, and was continued for humpback and northern right whales. Surveys to document the expansion of pinniped abundance were repeated in the 1990s. The ecology of pinnipeds has continued to receive little or no attention. The abundance of other cetacean species, especially in the southern portions of the areas, has received increased attention in recent years. The 1994 reauthorization of the MMPA increased the focus on determining the status of all marine mammal populations. This population status work included both preparation of routine summaries of abundance and bycatch estimates, and more basic research into population dynamics of cetaceans. Work was also done here in conjunction with ICES and the IWC.
The results of this research have been used to provide information within NMFS and to other management and scientific bodies, including the New England and Mid-Atlantic Fishery Management Councils, Atlantic States Marine Fisheries Commission, USMMC, ICES, and IWC.
IMPLICATIONS FOR FUTURE RESEARCH DIRECTIONSPriorities for research in the 1990s increased the focus on a selected set of issues, especially the impacts of fishery bycatch and the status of endangered large whales. During the process of conducting this research, substantial data sets have been accumulated and many new methods have been developed and applied. This is especially true relative to the areas of human interactions and optimum sustainable population levels. We are in a position to be able to answer many questions that are likely to arise in these areas.
To ensure our ability to respond efficiently to future management needs, it is essential that several sets of data collected over the past 16 yr be made more easily accessible. The progress made in working up the Cetacean and Turtle Assessment Program sighting data, and more recently the bycatch and photographic identification data, needs to be continued in order to access efficiently many other sets of data, many collected with evolving field methods.
Many aspects of the ecology of marine mammals remain to be addressed. The need for understanding the ecological role of marine mammals, especially in relation to the heavily exploited fisheries in this region, can be expected to increase. To address such questions will require integration of what we have learned over the past 16 yr, and the development and application of additional new research methods.
Other areas in need of additional attention are feeding ecology, habitat use, and population migration and genetic patterns. These areas are difficult to study, and will require more intense field studies using increasingly sophisticated research methods. The issue of feeding ecology, especially, must be jointly conducted with studies of the principal prey species involved. This will clearly require increasing interaction with other elements of the NMFS, and with other agencies and institutions. It is less clear, however, how priorities for this additional research should be determined. For example, much needs to be learned about feeding ecology of pinniped populations, but determination of the proper balance between dedicated studies of pinniped distribution and abundance and dedicated studies of pinniped feeding ecology will be difficult. Similarly, both direct observation of movements and genetic analyses will be useful in studying population migration and genetic patterns, but the best balance between these issues will be difficult to determine.
The priorities and direction of marine mammal research in the northeastern United States were initially determined by the 1979 workshop (Prescott et al. 1980). Beginning in the late 1980s, the priorities were increasingly determined by questions in support of the management of these populations. The management issues have been determined by the focus of successive amendments to the MMPA and the ESA. Those priorities ensure that the most pressing management questions are addressed, but will not necessarily ensure that the knowledge base required into the next century will be developed. To ensure a proper balance in future research activities, it would be timely to once again develop a broad general research agenda, much like that developed in 1979. Such a broad agenda could be used, in conjunction with the likely changing management priorities, to determine the best mix of research programs over the next decade. The scope of the research required and the problem of balancing competing research priorities make developing such an agenda difficult. Obtaining an agreed agenda can most easily be done in the context of a workshop, with broad representation across disciplinary lines. Without the development of such an agenda, the focus of research in this region will tend to drift with management priorities, and the long-term studies required to understand fully the ecological role and human interactions of marine mammals will be difficult to carry out.
ACKNOWLEDGMENTSWe acknowledge all of our co-workers in the NEFSC Protected Species Branch (formerly known as the Marine Mammals Investigation) who, from the beginning, have devoted countless hours to the success of this program. These co-workers include Kathryn Bisack, Mark Bravington, Solange Brault, Jim Hain, Joanne Harrington, Nan Logan, Mike Maxwell, Simon Northridge, John Nicolas, Debbie Palka, Tom Polacheck, Dave Potter, Sue Schell, and Gordon Waring. We also acknowledge and thank all of the crews and scientific observers aboard the various research vessels and aircraft that have supported us in our extensive field work, and the commercial fishermen who have participated and cooperated in the Marine Observer Program. They have all been an integral part of our research. We also acknowledge and thank the many graduate students, volunteers, contractors, fishing vessel observers, and all our scientific colleagues, both national and international, whose collaboration has always been with a spirit of cooperation, determination, and integrity. The authors also wish to thank Jon Gibson for his expertise with the final editing and publication of this paper. This publication and its predecessor, Waring et al. 1994, summarize the hard work and commitment of all these people over the last 15 yr.
REFERENCES CITEDBlaylock, R.A.; Hain, J.H.W.; Hansen, L.J.; Palka, D.L.; Waring, G.T. 1995. U.S. Atlantic and Gulf of Mexico marine mammal assessments. NOAA Tech. Memo. NMFS-SEFSC-363; 211 p.
Gaskin, D.E. 1984. The harbour porpoise Phocoena phocoena (L.): regional populations, status, and information on direct and indirect catches. Rep. Int. Whaling Comm. 34:569-586.
Kraus, S.; Read, A.; Anderson, E.; Baldwin, K.; Solow, A.; Spradlin, T.; Williamson, J. 1995. A field test of the use of acoustic alarms to reduce incidental mortality of harbor porpoises in gillnets. Int. Whaling Comm. Pap. SC/47/SM17; 28 p.
Prescott, J.H.; Kraus, S.D.; Gilbert, J.R. 1980. East Coast/Gulf Coast cetacean and pinniped research workshops. U.S. Mar. Mammal Comm. Rep. No. 79/02; 142 p.
True, F.W. 1885. Suggestions to keepers of the U.S. life-saving stations, light-houses, and light-ships, and to other observers, relative to the best means of collection and preserving specimens of whales and porpoises. Rep. U.S. Comm. Fish & Fish. 11(App. F):1157-1182.
Waring, G.T.; Quintal, J.M.; Smith, T.D. 1994. Marine mammal studies supported by the Northeast Fisheries Science Center during 1980-89. NOAA Tech. Memo. NMFS-F/NEC-103; 27 p.
AcronymsESA = Endangered Species Act GIS = geographic information system ICES = International Council for the Exploration of the Sea IWC = International Whaling Commission MMI = [NEFSC’s] Marine Mammal Investigation [predecessor to the NEFSC’s PSB] MMPA = Marine Mammal Protection Act NEFSC = [NMFS’s] Northeast Fisheries Science Center NMFS = [NOAA’s] National Marine Fisheries Service PBR = potential biological removal PSB = [NEFSC’s] Protected Species Branch [successor to the NEFSC’s MMI] SSI = [NEFSC’s] Sea Sampling Investigation [predecessor to the NEFSC’s SSP] SSP = [NEFSC’s] Sea Sampling Program [successor to the NEFSC’s SSI] URI = University of Rhode Island USMMC = U.S. Marine Mammal Commission WCR = [Gulf Stream] warm-core ring YONAH = Years of the North Atlantic Humpback Project
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