NOAA Technical Memorandum NMFS NE 120
Marine Mammal Research
Program
of the Northeast Fisheries
Science Center
during 1990-95
by Janeen M. Quintal and
Tim D. Smith
National Marine Fisheries Serv., Woods Hole Lab., 166 Water St., Woods
Hole, MA 02543
Print
publication date September 1999;
web 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.
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Preface
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.
ABSTRACT
We 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.
INTRODUCTION
In
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 ACTIVITIES
INTRODUCTION
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 DIRECTIONS
Priorities 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.
ACKNOWLEDGMENTS
We
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
CITED
Blaylock, 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
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Acronyms
|
ESA |
= |
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 |