Northeast Fisheries Science Center Reference Document 01-07
Proceedings
of the 14th Canada-USA Scientific Discussions,
January 22-25, 2001, MBL Conference Center, Woods Hole, MA
by S. Clark and
R. O'Boyle, Convenors
National Marine Fisheries Serv.,166 Water Street., Woods Hole MA
02543
Print
publication date April 2001;
web version posted August 16, 2001
Citation: Clark S, O'Boyle R, Convenors. Proceedings of the 14th Canada-USA
Scientific Discussions, January 22-25, 2001,
MBL Conference Center, Woods Hole, Massachusetts. Northeast Fish Sci Cent Ref Doc. 01-07; 51 p.
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Abstract
This report provides a record of presentations and discussions at
the 14th Canada-USA Scientific Discussions meeting held
in Woods Hole, Massachusetts January 22-25, 2001. These informal
meetings are held every two or three years between Canadian and USA
scientists engaged in stock assessments and related research on transboundary
resources of the Gulf of Maine and adjacent regions. The goal of
these meetings has been to share information on ongoing research
projects and to explore options for cooperative work. This meeting
included both plenary sessions in which participants reviewed research
projects and developments since the previous meeting (October, 1996)
and working group discussions which focused on areas for future research
collaboration. This report includes summaries of presentations and
discussions in plenary and reports and recommendations of the working
groups.
Introduction
The Northeast Fisheries Science Center (NEFSC) of the National Marine
Fisheries Service (NMFS) hosted a meeting of experts from the Canadian
Department of Fisheries and Oceans (DFO) Marine Fish Division, the
Center, and other federal and state agencies and academic institutions
in Woods Hole, MA January 22-25, 2001. This was the 14th in
a series of informal meetings held between Center and DFO scientists
every two or three years to review research projects on transboundary
resources of mutual interest and to explore options for future collaboration.
Previous meetings largely focused on fish and invertebrate stock assessments
and related research, but recently, there has been increased emphasis
on protected species and habitat related issues.
The meeting was well attended, with over 70 participants. The meeting
was loosely organized into three theme sessions. The first session
provided an overview of organizational and legislative changes in both
countries and programmatic responses to these changes, and new directions
in peer review and management. The second session, entitled "Single
Species Science and Future Cooperative Research" was largely devoted
to new developments in fishery dependent and independent data collection
and analysis including systems for data entry at sea, web-based data
display, and the NMFS assessment "toolbox" under development at NEFSC
and elsewhere. The final session was entitled "Ecosystem-Based Management
and Future Cooperative Research" and included presentations on management
initiatives; ecosystems modeling, and habitat-related issues and research
activities.
One afternoon was devoted to working group meetings where important
issues were reviewed in detail and research recommendations made. Five
working groups were held on the following: assessment methods; marine
mammals and turtles; groundfish distribution and stock structure; Atlantic
herring, and sea scallops. These working groups provided opportunities
for intensive discussion of current research projects, problems of
mutual interest, and recommendations for future work. The Assessment
Methods Working Group provided a forum for review of data-based and
model-based approaches and their limitations and recommended the establishment
of a "Methods Review Group" to address local problems, to insure quality
control, and to incorporate ecosystems models into stock assessments.
The Marine Mammal and Turtle Working Group reviewed current research
progress on both sides and provided the groundwork for standardization
of data collection and research methods and future research collaboration
on population estimation, stock identification and other issues. The
Working Group on Groundfish Distribution and Stock Structure reviewed
information for transboundary species, identified research needs, and
recommended an overall strategy to meet these requirements, e.g. formation
of a steering committee to organize cooperative workshops on stock
structure. The Atlantic Herring Working Group reviewed research and
data collection activities for both countries including developments
in hydroacoustics programs and initiated planning for a joint assessment
which will be vetted through the Transboundary Resources Assessment
Committee (TRAC) process in 2002. The Sea Scallop Working Group reviewed
biology and recent recruitment trends for different populations and
identified several research priorities. An ad-hoc meeting
was also held to consider possible revisions to the TRAC process and
to develop terms of reference for the April 2001 meeting. Working group
reports were presented in plenary prior to the close of the meeting.
These reports, and summaries of the plenary discussions, are included
below.
Overview
Current
Organization
Steve Clark reviewed National Marine Fisheries Service
(NMFS) organizational changes since 1996. The NMFS, consisting of about
2,600 staff, is one of the five agencies within the National Oceanic
and Atmospheric Administration (NOAA). The other agencies are: the
National Weather Service (NWS); the National Environmental Satellite
Data and Information Service (NESDIS); the National Ocean Service (NOS);
and NOAA Research (also called the Office of Oceanic and Atmospheric
Research). See www.noaa.gov for
further details.
The 1995-1997 reorganization was in response to the National
Performance Review, directed by then Vice-President Al Gore. In it,
NMFS Headquarters was reorganized into five major offices: Operations,
Management and Information; Science and Technology; Protected Resources;
Sustainable Fisheries; and Habitat Conservation. The latter three have
corresponding divisions in the five regional offices, with the five
research centers operating in tandem with the Office of Science and
Technology.
In the Northeast Fisheries Science Center, the old Conservation
and Utilization Division and the Environmental Processes Division were
reorganized into four divisions, as follows: the Resources Evaluation
and Assessment Division (READ), including the Population Dynamics,
Protected Species, and Social Sciences Branches (Woods Hole); the Fisheries
and Ecosystems Monitoring and Analysis Division (FEMAD) including
the Ecosystems Surveys, Fisheries Sampling, and Population Biology
Branches (Woods Hole and Narragansett, R.I.); the Aquaculture and
Enhancement Division (two branches), in Milford, CT; and the Ecosystems
Processes Division (four branches) based in Woods Hole and Sandy
Hook, N.J. The NEFSC reorganization was designed to flatten organizational
structure, to increase the staff to supervisory ratio, and to eliminate
Deputy Division Chiefs. There are now no permanent units below the
branch level in the Center. For future information, refer to www.nmfs.noaa.gov and www.nefsc.nmfs.gov.
The question was raised as to whether the Center had
been able to maintain adequate staffing levels in recent years. It
was noted that the Center is now staffed by approximately 260 employees,
as compared to over 300 in the mid-1990s.
Legislative
Mandates
Oceans Act
Presenter: Faith Scattolon
Rapporteur: Joe Arbour
Before passage of the Oceans Act, Canada lacked clear
goals and accountability and a comprehensive national strategy which
could provide a management framework for future resource development
and environmental protection. Government's role in the oceans was determined
through the Fisheries Act which, although powerful, addressed only
fish and fish habitat protection. A great many issues related to Oceans
Management were not addressed. The Oceans Act responded to a number
of international agendas including the Law of the Sea, the Convention
on Biodiversity, and Agenda 21. Some 23 federal agencies, together
with provinces, territories and aboriginal groups, are involved with
oceans management in Canada; the Oceans Act respects the authorities
of other jurisdictions but gives overall responsibility for
Oceans Management to the Minister of Fisheries and Oceans.
Part I of the Oceans Act describes the maritime areas
in Canada and asserts authority over those areas. Part II outlines
Canada's approach to Oceans Management and DFO's responsibilities and
key authorities. It also defines the principles underlying these responsibilities,
i.e. sustainable development, integrated management, and the precautionary
and ecosystem approaches. Part III identifies the specific powers,
duties and responsibilities of the Minister of DFO as lead federal
authority. It also embeds the use of traditional knowledge in DFO's
approach to managing the oceans. The Minister will lead the development
of a national oceans management strategy in conjunction with other
federal departments, provinces and other interests.
Under the Oceans Act, the Minister will lead and facilitate
the development of integrated management plans in Canada's ocean areas.
Nested within integrated management is the designation of marine protected
areas (MPAs) and the development of guidelines to promote Marine Ecosystem
Health. To move these initiatives forward will require a solid science
base. The elements to this science base are: development of ecosystem
based objectives, the operational definition of the precautionary approach,
the development of benthic habitat classification and broader ecosystem
classification schemes.
Some of the major challenges facing the department are
(1) are existing management processes equipped to participate in this
integrated planning environment, (2) are revised and/or additional
indicators needed (e.g. human health), (3) scale of data collection
/ adequacy of existing monitoring programs, and (4) defining Oceans
Management Plan (OMP) level objectives vs. sectoral plan level objectives,
and how to fund.
A question was raised as to whether the system will allow
legal challenges; the reponse was that the process is voluntary at
the current time and would not evoke a legal challenge.
SFA and Current FMP Amendments
Presenters: Pamela Mace and Ralph Mayo
Rapporteur: Loretta O'Brien
The Northeast Multispecies Fishery Management Plan (FMP)
was implemented in 1986 and retained indirect controls from the previous
Interim Groundfish Plan as the primary management tools. These controls
included minimum mesh size, minimum fish size, and seasonal area closure.
Minor adjustments were made to the existing management measures in
Amendments 1-3 and were implemented between 1987-1989. Amendment 4
was implemented in May 1991 and included an overfishing definition
for most large mesh groundfish species based on percent maximum spawning
potential (MSP).
The objective of Amendment 5, implemented in 1992, was
to eliminate the overfishing of cod, haddock, and yellowtail flounder,
primarily by a 50% reduction in days at sea combined with limited access
controls. This amendment was in response to a Consent Decree issued
in 1991 giving the New England Fisheries Management Council (NEFMC)
until March 1992 to develop an FMP to eliminate the overfished condition
of cod and yellowtail flounder. The 18th Stock Assessment
Workshop issued a special Advisory in June of 1994 stating that the
stocks of haddock and yellowtail flounder were 'collapsed' and that
cod was close to a potential collapse and in addition, that projected
reductions of fishing mortality (F) implemented in Amendment 5 would
not be sufficient to allow stock rebuilding. Subsequently, Amendment
7 was implemented in 1996 to accelerate Amendment 5 mortality reductions
and to initiate rebuilding schedules for depleted stocks. Target TACs
were first introduced in this amendment.
Amendment 9 was implemented in November of 1999 to bring
the FMP into compliance with the Sustainable Fisheries Act (SFA) of
1996 (USA Magnuson-Stevens Fishery Conservation and Management Act).
The SFA had many significant changes from the previous USA Magnuson
Act including a redefinition of optimum yield, definitions of 'overfished'
and 'overfishing', the addition of 3 new National Standards, a moratorium
on ITQs and a requirement to identify 'essential fish habitat'. Guidelines
based on the Act state that status determination criteria for managed
stocks must specify both a maximum fishing mortality threshold and
a minimum stock size threshold with respect to maximum sustainable
yield (MSY) harvest control rules. Amendment 9 incorporated biological
reference points and harvest control rules established by the Overfishing
Definition Review Panel and defined target and threshold fishing mortality
and biomass levels. 'Overfishing' was defined in terms of Fmsy and
'overfished' was defined in terms of Bmsy.
Amendment 13 is under development to implement rebuilding
schedules to bring the FMP into compliance with the SFA. The objectives
are to specify rebuilding schedules for overfished stocks and to specify
maximum fishing mortality rates to promote rebuilding. Four options
are currently being considered to meet these goals: 1) retain existing
management measures, 2) 'fine tune' existing measures, 3) area management
and 4) sector management. Sectors could be defined by gear, target
species, or fishing community.
Species At Risk Act (SARA)
Presenter: Jerry Conway
Rapporteur: Joe Arbour
The Species At Risk Act died on the order table when
the election was called in autumn of 2000. However, the Minister of
Environment remains committed to passage of the Act. The next phase
of activity will likely see the non-government sector pushing for more
in-depth consultation on the Act. Of significance in the Act is that
it delegates the responsibility for the marine environment to DFO.
Canada already has a federal- provincial accord covering
endangered flora and fauna. This accord has established many of the
Act's provisions. Key steps are identified, which include the following
phases: Assessment; Legal Listing; and Protection, including prohibitions
and recovery plans.
The assessment process provides a description of the
terms and definitions used. In a listing action, the minister submits
a species to the governor in council for listing. Once listed,
automatic prohibitions kick in, as well as the requirement to initiate
recovery planning to develop strategies and action plans. Recovery
plans now in progress include those for the right whale and the beluga
whale. Action plans are being developed with multi-stakeholder participation
including First Nations.
Critical habitat is defined as that habitat which is
considered essential to survival of a given species. The definition
of critical habitat will prove to be problematic in marine areas. Species
range very widely and often in ways that are not yet understood. The
concept of incidental harm has been identified for some species such
as northern cod and wolffish. Incidental harm must not jeopardize survival
of a species and can invoke requirements for preventive measures.
The habitat stewardship program is currently a major
funding issue. This program has garnered significant interest from
communities and non-government interests.
In the ensuing discussion the question was raised as
to what criteria are used for defining endangered species. In response,
it was noted that initially, criteria developed by the Committee on
the Status of Endangered Wildlife in Canada (COSEWIC) were used, but
now there is movement towards using International Union for the Conservation
of Nature (IUCN) criteria as guidelines. The IUCN criteria would be
more applicable for marine species. COSEWIC has been very terrestrially
oriented. It was also asked whether whales and dolphins were under
federal control (they are, as is the leatherback turtle). Some other
species are under provincial control.
ESA and MMPA
Presenter: Richard Merrick
Rapporteur: Janeen Quintal
NMFS marine mammal legislative mandates fall mainly under
the Endangered Species Act (ESA) of 1973 and the Marine Mammal Protection
Act (MMPA) of 1972, supplemented by the Sustainable Fisheries Act (SFA)
and the National Environmental Policy Act (NEPA). NMFS goals under
these mandates are to recover and maintain protected species populations
and to reduce conflicts that affect them.
The ESA provides for conservation of
threatened or endangered species and their habitats. In the Northwest
Atlantic, these include loggerhead turtles (threatened) and leatherback,
Kemp's ridley, and green turtles; all large baleen whales and sperm
whales; and Atlantic salmon and shortnose sturgeon. After a species
is listed, a recovery plan is developed which generally prohibits takes
(with some exemptions). Section 7 requires consultation with NMFS concerning
potential effects by any Federal agency and applies to actions in US
waters and to US citizens in international waters.
The MMPA established a moratorium (with
some exceptions) on the take of marine mammals in US waters and by
US citizens on the high seas and also on importation of marine mammals
and marine mammal products. Its major goal is to allow populations
to rebuild to and remain at their Optimum Sustainable Population (OSP)
level.
The 1994 MMPA Amendments implemented
a comprehensive regime to reduce takes to levels approaching zero (zero
mortality rate goal or ZMRG). The following elements are included:
1) Introduction of a "harvest" control model known as
Potential Biological Removal (PBR) which addresses population growth
rate and quality of data collected;
2) Publication of annual stock assessment reports;
3) Establishment of independent Scientific Review Groups
to evaluate assessments;
4) Establishment of a framework for development of Take
Reduction Plans (TRPs) to reduce bycatch to below PBR and subsequently
to ZMRG (within a short time frame - usually 6 months); and
5) Production of an annual List of Fisheries (LOF).
Potential changes may occur with re-authorization of
the ESA and MMPA. Potential changes to the MMPA include the following:
- Management of recreational marine mammal bycatch;
- Enhanced co-management in Alaska;
- Non-lethal removal of "nuisance" pinnipeds; and
- Increased stranding network support.
Current issues under the MMPA and ESA are:
- North Atlantic right whale mortalities (from gear
entanglement and ship strikes);
- Gulf of Maine/Bay of Fundy harbor porpoise bycatch
in sink and drift gillnet fisheries; and
- Loggerhead and leatherback turtle bycatch in pelagic
longline and coastal gillnet fisheries.
North Atlantic right whales are declining
(abundance equals around 300 animals at present). This is the first
marine mammal species to be given a PBR of 0. A TRP is in place to
reduce entanglement through the use of gear modifications and some
fishery closures. More closures may be needed and ship strikes need
to be addressed further. NMFS is currently being sued for both entanglement
and ship strikes of right whales.
Gulf of Maine/Bay of Fundy harbor porpoise bycatch
in the drift and sink gillnet fisheries is an MMPA rather than an ESA
issue. The bycatch exceeded PBR (483 animals) through 1998. A TRP was
introduced in 1998, which included closures, gear modifications and
the introduction of "pingers". Since its introduction, takes have been
reduced to below PBR (less than one quarter of previous levels). Also,
the 2000 abundance estimate has increased, yielding a higher PBR (747).
Pingers have played an important role in the success of the TRP.
Loggerhead and leatherback turtles have
long been taken by pelagic longline fisheries. The USA pelagic longline
fishery on the Grand Banks was closed from October 2000 to April 2001.
NMFS is likely to be sued to reduce turtle takes, especially in the
gillnet fishery, and is developing a series of new biological opinions
with mitigating measures to reduce "jeopardy" to these species.
Future needs and challenges for the USA and Canada in
relation to protected species include:
- Joint research on bycatch reduction (e.g., reflective
net experiments in Gulf of Maine/Bay of Fundy); stock structure;
stock assessment techniques, and estimates of takes of transboundary
animals;
- Disentanglement of large whales; and
- Legal and political challenges over takes of endangered
species. There is currently a total of about 130 lawsuits directed
toward NMFS, several of which are for marine mammals, particularly
right whales, and questions concerning Canadian actions are being
raised.
In the ensuing discussion, the question was raised as
to the USA definition of a "take", and the response was that "takes" refer
to all interactions, including capture and release. It was also asked
whether listing decisions are made inside the agency, and the response
was yes, subject to public review and comment in the federal register.
It was also noted that there are some lawsuits now operative in Canada
- one is over seals.
Management
Processes and Initiatives
Objective-Based Management/Precautionary Approach
Presenter: Chris Annand
Rapporteur: Wayne Stobo
Objective-Based Management and the Precautionary Approach
were looked at as part of the larger Canadian government-wide initiative
of risk management which aims to develop systematic approaches as a
long term strategy to support the government's governance responsibilities.
In the context of fisheries and ocean resources management, the intent
is to identify and assess the level of risk associated with management
objectives and to develop operational strategies to manage those risks.
This process is partly the result of increasing public demands to participate
in decision-making and the concurrent need for imposing greater accountability
on government, and stakeholders, for decisions made.
The introduction of the Objective-Based Management approach
builds on DFO's Integrated Fisheries Management Plan Process, and seeks
to translate concepts like "conservation", "the Precautionary Approach",
and "ecosystem management" into explicit and measurable goals in fisheries
planning. In addition to setting goals, Objective-Based Management
includes risk analysis that incorporates strategies to avoid or otherwise
address potential obstacles to achieving these goals. A formal process
of post-season analysis rounds out the approach by developing measures
of performance against which to evaluate the success of the Plan.
DFO has only recently embarked on this initiative and
is currently in the process of elucidating and developing the various
components that need to be addressed in meeting these objectives.
SARC and Relevant Issues
Presenter: Terry Smith
Rapporteur: Russ Brown
Terry Smith described the fisheries stock assessment
review program employed by the NEFSC. The program uses a two-panel
system for completion of the peer review process. The first panel is
a working group, open to participation by members, other interested
scientists, industry representatives and other stakeholders. This group
is responsible for evaluating input data and performing analyses required
to meet assigned terms of reference. The working group prepares an
assessment report to be evaluated by the second panel, the Stock Assessment
Review Committee (SARC).
The SARC is an external review panel that includes 12+
members from the NEFSC and other NMFS facilities; scientists from other
regional, national, and international agencies; and industry representatives
and members from academic institutions. Recently, the SARC has included
1-3 representatives from the Center for Independent Experts, jointly
administered by the University of Miami and NMFS. The primary role
of the SARC is to provide an evaluation of tabled assessments and to
write management advice. The SARC produces two primary documents: a
SAW Advisory Report containing a brief and stylized summary of the
assessments, and a SAW Consensus Summary that contains detailed assessment
information, a summary of discussions occurring at the SAW and research
recommendations.
Positive aspects of the process include a detailed and
thorough review of assessments, high quality participation in the review
process, and an established, independent and accepted review process.
Negative aspects include questions regarding the actual independence
of the review process and high levels of demand for assessment review
that exceed the ability to perform such reviews.
The group discussed the issue of the perception of independence
of the review among stakeholders, noting that this is a commonly expressed
concern when stakeholders disagree with the scientific advice produced.
It was noted that distrust may arise when stakeholders have difficulty
understanding technical details, but note that both the assessment
personnel and reviewers appear to "speak the same technical language." It
was noted that two interventions are common in the Center's peer review
process: National Academy of Sciences reviews and lawsuits. It was
noted that the Northeast Center has been involved in four NAS reviews
in the past 6 years, and that a number of lawsuits have been filed
challenging the scientific integrity of stock assessments.
National
Stock Assessment Review and the TRAC Process
Presenter: Bob O'Boyle
Rapporteur: Wayne Stobo
Bob O'Boyle described the National Stock Assessment Review
now in progress and outlined the RAP and TRAC processes. As part of
DFO's ongoing evaluation of efficiencies, this review was intended
to help focus Science activities to priority areas, stemming from a
perception that allocation of Science resources may not be occurring
in proportion to stock importance. Objectives of the Review were to
describe a vision for 2010, to describe DFO's current situation, and
to investigate how the vision was to be achieved. The review process,
attributes of the analysis and the timetable of events were outlined.
The major conclusions were that the Science resources
were proportional to the importance of the stock, though the method
of ranking importance differed between regions. Also noted during the
review was that as resources allocated to stocks increased, knowledge
levels increased and uncertainty decreased, but the benefits of continuing
to increase funding tapered off after a certain point. On the down
side, it was noted that performance measures of success were inadequate.
It was also observed that there were gaps and imbalances in many areas
at both the single species and ecosystem levels.
The various areas which needed to be addressed to make
the stock assessment process more efficient included the need to develop
new technologies and methods for delivering advice to management bodies,
to address staffing levels and workloads, to provide for training staff
in new scientific methodologies, to improve data management and availability,
and to expand the suite of analyses used in evaluating stock status
including the use of models which are less data demanding. As well,
the need to improve and redefine the peer review process and the frequency
and nature of management advice from Science was highlighted. It has
been suggested that the assessment and advisory process could shift
to a system of intensive fishery assessments (IFAs) involving comprehensive
evaluations at a lower than annual frequency supplemented by updates,
scheduling to be determined by resource and fishery characteristics.
He also described essential features of the Regional
Advisory Process (RAP) and the Transboundary Resources Assessment Committee
(TRAC) process. The RAP considers many stocks, some being full-model
formulation or "benchmark" assessments, with most being updates. The
process includes both a scientist or working group preparing a draft
working paper on a stock, which is then peer reviewed in an open RAP
meeting; in the Maritimes, the latter reviews the full or benchmark
assessments but not the updates. Increasingly, the detailed technical
review is being undertaken in the pre RAP working groups, which are
generally not open to the public. This is because the open RAP meetings
are too short to allow major changes to assessments, and consequently
an "accept or reject" format is used. The National Stock Assessment
Review has proposed a new model in which full assessments become IFAs
on selected stocks and are conducted outside of the management cycle.
The updates being done would be done annually as part of the management
cycle.
The TRAC process was established in 1998 to deal with
transboundary resources and to date has considered Georges Bank stocks
of cod, haddock and yellowtail. The process includes a working group
(the Transboundary Working Group or TAWG) which produces the assessments
and other analyses as requested by the TRAC; and the TRAC itself, which
peer-reviews the assessments. There is limited time for revision. Both
update and benchmark assessments are reviewed by the TRAC. There may
be room in the TRAC process for an IFA type of approach.
Single-Species Science and
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Government
Survey Programs
Canada-Trawl Surveys and Hydroacoustics
Presenters: Joe Hunt and Gary Melvin
Rapporteur: Wayne Stobo
Joe Hunt summarized Canadian research vessel (RV) trawl survey time
series for the Scotian Shelf and Georges Bank, providing information
on vessels, areas covered and time frames. He included references
to additional cooperative industry surveys. Recent years have seen
expansion of existing RV surveys to greater depth ranges, additional
hydrographic sampling, and improved data audits and timeliness of
data availability through real-time at-sea editing.
The attempts to redefine the RV surveys from fish abundance surveys
to resource multi-tasking were described along with the challenges
and problems in achieving that objective.
He also described ongoing research on fish 'catchability' in the
Georges Bank survey. Over time, the mean date of the survey has progressively
moved earlier; and along with that shift, changes in mean bottom
temperature have been observed, along with changes in the maturity
status of cod. The study is examining if such changes could result
in changes in catchability of fish resources to the research trawl.
If catchability is modified, then does the time series, as currently
analysed, adequately reflect population status?
Gary Melvin reviewed the distribution of primary herring fisheries
and stocks in the Scotian Shelf and Bay of Fundy region and described
the use of hydroacoustics in herring assessment and management. In
response to concerns expressed by industry over the potential elimination
of local populations within overall catch restrictions for larger
stock areas, a process was initiated in 1995-96 to protect these
components. This process is a cooperative one between the industry
and DFO and involves real-time hydroacoustic assessment of biomass
levels in potential fishery areas prior to initiation of fishing
activity. Several herring purse seiners are now equipped with hydroacoustic
systems which are used to conduct multiple standardized surveys of
fishing grounds to assess the quantities of herring available to
the fishery. Once biomass estimates have been determined, the agreed
management strategy is to allow a 10% take of the estimated biomass;
this is considered a precautionary approach. The surveys are now
being conducted using standardized survey areas and procedures, providing
a time series of abundance estimates for multiple fishing areas.
USA Surveys- Recent Developments
Presenters: Tom Azarovitz, Holly McBride, Bill Michaels
Rapporteur:
Henry Milliken
Tom Azarovitz presented an overview of the NEFSC survey program.
Most bottom trawl survey cruises have been completed using RV ALBATROSS
IV; the autumn survey time series is now 35 years long with very
little change in vessels or gear used. The surveys sample inshore
and offshore waters to 200 fathoms from the Bay of Fundy to Cape
Hatteras. Conversion coefficients have been developed to account
for changes in vessels or gear.
The frequencies and the start dates for the various surveys are
as follows:
* Bottom Trawl
Autumn (1963), Spring (1968), Winter (1992), Summer (Intermittent)
* Surf Clam / Ocean Quahog
Summer, alternate years (1965, 1982)
* Sea Scallops
Summer (1975)
* Northern Shrimp
Summer (1983)
* Hydroacoustic - Herring
Autumn (1998)
* Hydroacoustic - Mackerel
Winter (2001)
* Ecosystem Monitoring, MARMAP (Ichthyo/zooplankton)
Seasonal, six annually (1977)
* Other, e.g. vessel/gear fishing power
Intermittent years
Recent developments include (1) a new data entry at sea system (the
Fisheries Scientific Computing System or FSCS) and (2) an acoustics
program to obtain abundance estimates on pelagic resources.
FSCS: Holly McBride reviewed the Center's FSCS
system, to be implemented during the Spring 2001 field season. The
Office of Marine and Aviation Operations (OMAO) and the NEFSC have
designed and developed this system over the past 2 years. It will
completely replace data entry on paper logs.
Hardware includes LCD touch screen displays with built in heaters,
SCANTROL electronic measuring boards, Marel digital scales, and label
printers and bar-code readers. The system is set up to run from a
server through a network, but can be run from an individual workstation
if necessary. The workstations and servers are backed up whenever
information is input to FSCS.
The software converts data to digital form; and built in audits
are included to check the data when entered. Bar codes attached to
age envelopes are utilized to record pertinent information for each
sampled specimen. The bar-coded envelope is permanently associated
with that individual fish. Upon completion of a station, data may
be loaded into an Oracle table and audited. With some minor post
processing, these files will be ready for archival to master data
immediately upon returning to dockside.
Hydroacoustics: Bill Michaels reviewed the NEFSC
hydroacoustics program. The Center now conducts annual hydroacoustic
surveys for Atlantic herring during autumn in the Gulf of Maine and
Georges Bank regions. These surveys employ EK500 echo-integration
(12, 38, 120 kHz), omni-directional sonar (64 kHz), midwater trawling,
CTD measurements, and underwater video operations. Acoustical biomass
estimates for offshore spawning stocks of Atlantic herring have closely
matched VPA estimates of 2 to 3 million metric tons. In-situ and
laboratory experiments have been completed to measure the individual
target strength of herring in an effort to refine the estimates.
Acoustical data are also being collected from other NEFSC surveys
(including bottom trawl and marine mammal surveys). A pilot survey
and in-situ experiment will be conducted in winter of 2001 in the
Mid-Atlantic shelf region to identify acoustic measurements from
other stocks (Atlantic mackerel, Loligo squid, silver hake,
and butterfish) to expand program capabilities.
Joint
Projects With Industry
Canada
Presenters: Paul Fanning, Steve Smith
Rapporteur: Don Clark
Paul Fanning described the Fishermen and Scientists Research Society
(FSRS) which promotes interaction among fishermen and scientists.
It has provided a forum for discussing cooperative work, which has
been useful in building and maintaining interest in such studies.
The Society now has 225 members (190 fishermen) and is involved in
a variety of studies ranging from diet and fish condition to surveys
of fishermen to identify historical spawning areas. It is involved
to some degree in many cooperative projects including the 4VsW fixed
gear ('Sentinel' survey); this is a stratified random survey, mostly
DFO funded. It extends into shallower water than the DFO RV survey,
with about double the sampling intensity.
Industry/science projects with other partners include the ITQ survey.
This is funded by industry from its pooled quota. The survey is conducted
by mobile gear, employs a fixed station design and, like the Sentinel
survey, has a higher sampling intensity and broader geographic coverage
than the DFO RV survey. Another example is the Halibut survey which
is a fixed gear stratified random survey focusing on halibut fishing
grounds from Grand Banks to the Hague line. A quota allocation is
used to fund this survey.
In the case of partnerships DFO has developed a process of Joint
Partnership Arrangements (JPAs). These are formal arrangements of
a contractual nature, specifying each partners' commitments and contributions
to a given project or process. These have become standard in the
case of emerging species fisheries. The policy on these fisheries
requires that a 5-year science evaluation be included prior to any
decisions regarding the eventual development of the species as a
fishery. JPAs have been routinely used to specify arrangements for
cooperative studies during the initial phase of fishery development.
Steve Smith described a number of cooperative surveys for invertebrates.
Offshore scallop surveys have been conducted using industry vessels
since the mid-1980s. The shrimp survey is done with industry participation
and vessels, as is the case for surf clam and rockweed surveys. Catch
sampling for these fisheries is also conducted (and paid for) by
industry. Industry has provided equipment and expertise for conducting
studies and designing surveys. These surveys have augmented resources
and sea time but cannot replace the long-term monitoring done by
government agencies.
Data from these surveys are archived in databases as for standard
data sources; one outstanding issue involves ownership of the data
in relation to access.
USA
Presenter: Steve Murawski
Rapporteur: Ann Richards
Steve Murawski gave an overview of joint research projects completed
or planned by NEFSC. These include research surveys to estimate distribution
and abundance for several species (clams, squid, scallops, monkfish),
tagging studies (e.g. cod) and use of study fleets to obtain high
quality commercial fishery data and bycatch information. Funding
for most of these projects has been made available from "disaster-relief" funds.
Steve discussed some specific programs in detail (scallops, monkfish)
and provided the following general observations: (1) using programs
from other regions as models may not always work, (2) teaching the
scientific method is possible, but difficult (3) communication is
best done in small groups (also at sea), (4) fishermen care about
gear, while scientists care about design, (5) peer review standards
must apply to the science which is produced, (6) fishermen can apply
political pressure to get money for projects they care about, and
(7) if the federal government doesn't become involved with joint
industry projects, others will (e.g. academia).
Databases
and Web-Enabled Data Display
Presenter: Jerry Black
Rapporteur: Don Clark
Jerry Black described the Virtual Data Centre, which is currently
an intranet website.
Data are generally archived in Oracle tables and the website is
designed around staff, projects or data sets, all of which are linked.
The site provides direct access to the data, and can produce standard
data products and maps and in many instances allows for customization.
Many products and maps are hot-linked so that the user may click
on them (drill-down) for further summaries. The capability exists
for linking otherwise disparate databases in some cases, so as to
provide linked summaries.
Data dictionaries are available for Oracle tables, which reflect
data structure. Survey data, including data from invertebrate (lobster,
shrimp and scallop) surveys, are available in the system, as are
commercial landings and commercial sampling data. An image gallery
is available with ~ 750 digital images catalogued on the site. The
data visualization package ACON is used for most of the mapping;
applications are run on an NT server and Oracle databases are accessed
on separate servers. Queries are made in SQL and PLSQL language.
SPLUS should be available for statistical analyses on-line shortly.
The developmental website
http://mfdvdc.bio.dfo.ca/mflib/plsql/mwmfdweb.splash
is currently available only from within the DFO firewall. A public
access version of this site will not be available until the last
quarter of 2001 at the earliest.
Pollock
Ageing Research
Presenter: John Neilson
Rapporteur: Don Clark
John Neilson gave a brief review of previous and current age validation
research on pollock. Age determinations for the first few years of
life have been validated through analysis of length modes, and chemical
marking has also been used to distinguish annuli in older fish. Juvenile pollock
of known age (based on modes) have also been tagged, providing definitive
ages when recovered after several years at large. Lengths at age
determined from these fish have been compared with lengths at age
determined from otoliths taken in commercial samples. Ages derived
from these otoliths were validated from the mark recapture data,
as the lengths at age matched those for known age fish. Differences
in growth among regions within the management area were also corroborated;
with lengths at age being higher in the west.
Assessment
Models and Software
Traffic Light
Presenter: Bob Mohn
Rapporteur: Stephen Smith
A common criticism of the population model approach to stock assessment
(e.g., VPA) is that relevant information on stock status (e.g., prey
abundance, condition factors) is excluded from the process. As well,
methods are needed for comparing and summarizing disparate indicators
when model-based approaches are not possible. Bob Mohn presented
the traffic light method as means of dealing with these situations.
The method consists of identifying potential indicators of stock
status such as biomass estimates from a population model, indices
from trawl surveys, trends in growth rates, etc. Levels for each
indicator corresponding to specific states of stock status (good,
intermediate and bad) are defined. The traffic light method then
presents the time series of each of these indicators color-coded
in a visual display as green, yellow and red, respectively. Indicators
that measure similar quantities are grouped and summarized as single
series referred to as characteristics. For example, trends in growth
rates, size at age and recruitment are grouped as the productivity
characteristic. The method also includes direct summaries that combine
indicators of various kinds or indirect summaries that combine characteristics.
Bob presented an example using software developed by MFD to visually
display trends for 4VsW cod.
One area of active work and contention involves methods for combining
different series and assignment of colors. The colors of the summaries
are intended to suggest a level of action as in red indicating that
a serious intervention is required because current fishing levels
are detrimental. Yellow may indicate that some adjustments to fishing
levels may be required and green would correspond to fishing not
having a detrimental effect. Concerns have been expressed that these
three states may be too coarse to allow for appropriate management
action. Methods for expanding on these three states such as using
fuzzy sets or a more continuous gradation from red to green have
been suggested. A workshop is planned for June/July 2001 to look
at these and other issues.
While the value of the traffic light method as a communication tool
was acknowledged, a number of participants noted that the method
was similar in its goals to methods such as expert systems, multi-attribute
utility analysis and decision analysis. Comparisons between these
methods and the traffic light method have not yet been done. It was
also noted that in its current state the method may not be capable
of evaluating alternative management strategies. More development
of the traffic light method is planned including evaluations of quality
and use of current indicators. Those who have experience with the
method felt that it was a useful tool for developing consensus for
a wide range of indicators of stock status.
Assessment Toolbox
Presenter/Rapporteur: Paul Rago
The Fisheries Assessment Computation Toolbox (FACT) is part of a
national program within NMFS to improve stock assessments. This national
focus has resulted in the incorporation of standard software from
within the USA and the UK. It has been under development at NEFSC
for the past three years.
The toolbox incorporates a variety of frequently used methods within
a common interface. File management and alternative model configurations
are easily implemented and self documenting. Hence the program both
facilitates the communication of methodology and results and provides
a degree of quality assurance. Diagnostic plots and other methods
are included as a means of testing model assumptions and performance.
An important feature of the toolbox is a comprehensive documentation
and help system. Each model that is incorporated into the toolbox
is documented with respect to the underlying theory and guidelines
on using the model. Textual hyperlinks aid understanding of the model
theory and a search engine allows one to search across documentation
for all models. The toolbox is designed to be flexible to allow incorporation
of new methods and can also serve as a baseline for comparison of
new methods with standard formulations.
At present, FACT contains software for age-based models (Adapt),
production models (ASPIC), and a stage-based approach (Modified Delury
or Catch-Survey Analysis). Two of the packages include stochastic
projection models (AgePro and ASPIC Projection) which allow for evaluation
of alternative management measures. In addition, techniques for estimation
of biological reference points (YPR and Precautionary Approach) have
been included. Via agreement with the Centre for Fisheries, Environment
and Aquaculture Science (CEFAS) the software package known as FishLab
is also included. This package contains models commonly used by the
International Council for the Exploration of the Sea (ICES), i.e.
Adapt, cohort analysis, the Extended Survivors Approach (XSA), the
Jones length-based model, a surplus production model with indices
and finally a separable VPA. Hence it is possible to rapidly compare
estimates from several different models and to gain additional insights
into resource dynamics. Various output options allow users to export
model outputs to statistical and graphics software packages for further
analyses.
Several areas of concern have also been addressed including problems
with pooled age groups in VPA assessments, alternative approaches
to bootstrapping and correction for bias, and incorporation of formal
theories for model building. These will be incorporated into future
versions of FACT. It may also be desirable to include a general simulator
which would allow tests of the ability of alternative models to recover
known parameters. Tests for robustness to noisy data and the ability
of model building strategies (e.g., information theoretic approaches)
to identify appropriate suites of candidate models could also be
included; and policy simulation methods could be developed to evaluate
management decision rules and effects of uncertainty. Longer term
considerations also include preparation for new and richer types
of data including real-time measures of fleet dynamics, catches and
bycatch, ancillary environmental data (e.g., bottom habitat typing),
improved biological information, and alternative management regimes
such as ITQs.
In response to questions from the audience it was noted that FACT
software is available for general distribution although installation
may be difficult on older computers and for Windows 95 and earlier
operating systems. Exhaustive debugging has not been done although
the models have performed well on test datasets. Incompatibilities
among models or difficulties in running a particular sequence of
operations may still exist but have been addressed via actual application
of FACT for assessments.
Stock
Definition Research for Transboundary Mammals
Presenters: Dave Potter,
Gordon Waring, Phil Clapham
Rapporteur: Janeen Quintal
Harbor porpoise.
Currently, fourteen putative stocks of harbor porpoise are recognized
as proposed by Gaskin (1984) based on summer distributions and
breeding times. This hypothesis has been supported by contaminant
studies and mtDNA and nuclear microsatellite data. Studies of organochlorine
and heavy metal contaminants published in 1995 both found significant
differences between the Gulf of Maine/Bay of Fundy, Gulf of St.
Lawrence and Newfoundland populations. Results of restriction fragment
length polymorphism (RFLP) analyses of mtDNA suggest the presence
of a weak cline in mtDNA genotype frequencies from Newfoundland
to the Bay of Fundy. Additional studies using mtDNA sequences and
nuclear microsatellite data including animals from west Greenland
have further supported the existence of different stocks. Movements
of tagged animals have also been used to support these genetic
findings. Life history parameters from the different putative stocks
indicate that the reproductive cycle is very seasonal and there
are slight differences, which may indicate stock differences between
the Gulf of Maine/Bay of Fundy and Gulf of St. Lawrence. Animals
from Newfoundland and W. Greenland have not been studied in as
much detail.
One 1999 study included
samples of 41 stranded harbor porpoises from the Mid-Atlantic states
(NY to NC) between December and May. The study revealed 8 haplotypes
that were unique to this Mid-Atlantic sample. That is, they were
not seen in any of the summer samples indicating either an unknown
stock or, more likely, inadequate sampling. Of the remaining 33
haplotypes, results indicate a mixture of individuals from the Gulf
of St. Lawrence, Gulf of Maine/Bay of Fundy, Newfoundland
and West Greenland stocks. There are still 145 harbor porpoise
samples from bycaught or stranded animals remaining to
be analyzed from the Mid-Atlantic region. By-caught animals were
healthy when captured and are probably representative of the animals
that normally inhabit Mid-Atlantic waters. Further studies to determine
the relative contributions of porpoises from the summer populations
to this larger Mid-Atlantic sample are needed as well as the collection
and analyses of additional samples.
Seals.
The four seal species found in New England and mid-Atlantic waters
are: harbor seal (Phoca vitulina), grey seal (Halichoerus
grypus), harp seal (Phoca groenlandica) and hooded
seal (Cystophora cristata). Harp and hooded seal populations
are centered in Canadian Atlantic waters, and there is no evidence
of pupping in U.S. waters. Harbor and grey seals are the most numerous
and are present year-round with pupping occurring in both U.S.
and Canadian waters. Following extirpation in the 1960s from bounty
removals, grey seals bearing Sable Island brands were re-sighted
in the 1980s around Nantucket Island and outer Cape Cod. They currently
have a year-round presence on the outer Cape and 2-3 documented
pupping sites in eastern Maine waters. Harbor seal breeding and
pupping continued in Maine coastal waters despite earlier bounty
programs and since passage of the MMPA (1972), the harbor seal
population has increased at least 5-fold. The current population
size of approximately 31,000 represents the largest and most widespread
seal population in U.S. Atlantic waters (Maine to Maryland). Stock
structure analysis will be used to improve our assessment reports
and to guide future abundance surveys. In spring 2001, the NEFSC
plans to tag seals using VHF and visual detection tags. While the
principal goal is to obtain a correction factor for the spring
abundance survey (pupping season), we expect that the visual tags
will provide new information on seal dispersal, particularly into
Canadian waters.
Right Whales.
The right whale population declined in the 1990s due to high mortality
and low reproductive rates. This year, however, 14 calves have
been counted to date. There is only one known calving ground. However,
while many mature females take their calves to the Bay of Fundy,
more than 20 do not, suggesting that there is a second undiscovered
nursery area (or that these animals scatter widely in summer).
Recent genetic studies suggest that Bay of Fundy and non-Bay of
Fundy animals represent two distinct sub stocks, but the evidence
is not conclusive. Much of the population is missing in winter.
Concerning distribution in historic habitats, it was noted that
eastern North Atlantic stocks were wiped out at the turn of the
century, but animals show up there occasionally. Also, some animals
seen occasionally in the western North Atlantic disappear for several
years at a time. Present research needs include: improved mortality
reporting for transboundary animals; rapid retrieval of dead animals;
improved disentanglement coordination and safety standards; and
continuation of the productive cooperation with DFO in aerial survey
fieldwork.
Humpback Whales.
The North Atlantic humpback population estimate was about 10,600
animals in 1992 and the population is probably growing. The Gulf
of Maine growth rate is estimated at 6.5%. A comprehensive
assessment will be undertaken by the IWC at its annual meeting
this year. The management unit used by the NMFS for stock assessment
recently changed from the North Atlantic stock to the Gulf of Maine
stock and a new abundance estimate and PBR calculation is needed.
There are stock boundary questions relating to the Scotian
Shelf and mid-Atlantic areas. Stock definition is being addressed
using vessel-based photo-ID surveys. Fifty-six individuals were
photographed on the Scotian Shelf in 1998 and 1999; 21% matched
to the GOM stock but there were no year-to-year matches, suggesting
that the population in this area is large. In the mid-Atlantic,
48% of the identified individuals were from the Gulf of Maine,
but 24% were Canadian Atlantic animals (four from Newfoundland
and one from the Gulf of St. Lawrence). Four of 16 dead animals
from the mid-Atlantic matched to the Gulf of Maine. Thus, this
area appears to have considerable mixing.
The question was raised
as to feeding habits. Humpbacks feed on herring, sandlance and
euphausiids.
Ecosystem-Based Management and Future Cooperative
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Ecosystem-Based
Management-USA Initiatives
Presenter: Pamela Mace
Rapporteur: Jon Brodziak
Pamela Mace described
eight USA initiatives relevant to ecosystem-based management of
fishery resources, including existing legal mandates, recommendations
of scientific groups, and ongoing legislative efforts.
The National Environmental
Policy Act of 1969 provides the most holistic initiative that encourages
an ecosystem-based approach. This legislative act requires environmental
impact statements and assessments. The NMFS has been sued for lack
of compliance with NEPA for failure to take account of ecosystem
effects of fishing, especially on forage species and protected
species.
The Sustainable Fisheries
Act of 1996 amendments require incorporation of ecosystem considerations
in fisheries management, including bycatch restrictions and essential
fish habitat requirements. The term "ecosystem-based management" (EBM)
is not explicitly used in this law, however. Another recent initiative,
the National Research Council's report (October 1998) on sustaining
marine fisheries, concluded that reducing fishing mortality was
the most comprehensive and immediate approach to rebuilding and
sustaining fisheries and marine ecosystems and that marine protected
areas should be established where fishing is prohibited. This report
also stated that, in general, more information and research on
ecosystem processes is required for effective ecosystem-based management.
Similarly, the Ecosystem Principles Advisory Panel was created
by Congress to report on EBM. In its April 1999 report, the panel
recommended that fishery ecosystems plans (FEPs) be developed and
also provided some guidelines for their preparation. As a first
step towards EBM, the panel recommended that one or more demonstration
FEPs be developed.
The 6th National
Stock Assessment Workshop (NMFS, March 2000) was focused on incorporation
of ecosystem considerations into stock assessment and management
advice. There were four subthemes in this workshop: ecosystem properties,
biological and technological interactions, effects of short and
long-term climate change, and the indirect or secondary effects
of fishing.
The NMFS stock assessment
improvement plan is an initiative that proposes three scenarios
of additional funding to improve assessments. The most ambitious
of these proposes to conduct next generation assessments that would
explicitly incorporate ecosystem considerations such as species
interactions and environmental effects, as well as socioeconomic
impacts.
The reauthorization of
the Sustainable Fisheries Act (2000) was not completed prior to
the USA presidential election and this legislation will likely
be revised in the future. Nonetheless, the House of Representatives
version did include a new section on conserving marine ecosystems
and requirements for FEPs. The Senate version included a requirement
for reports on ecosystem research priorities and also a requirement
that the "best scientific information" must be based on "a sufficient
statistical sample...such that any conclusions are reasonably supported." This
provision would presumably make the practical application of EBM
very challenging.
The Oceans Act of 2000
is the most recent USA initiative relevant to EBM. The main purpose
of this act was to establish a bipartisan commission to make recommendations
for a coordinated and comprehensive national ocean policy. The
report of this commission will be the first review of national
ocean policy since the one by the Stratton Commission in 1966 which
recommended the creation of NOAA and laid the groundwork for the
Magnuson Fisheries Conservation and Management Act of 1976.
Ecosystem
Models
Scotian Shelf Initiative
Presenter: Paul Fanning
Rapporteur: Joe Hunt
The Comparative Dynamics of Exploited Ecosystems in the Northwest
Atlantic (CDEENA) project was created in 1997 to collect and interpret
data for the dynamics of exploited ecosystems in the Newfoundland
area (northern cod), the Gulf of St. Lawrence, and the eastern and
western Scotian Shelf for three time periods - 1970s, 1980s and 1990s.
Objectives included descriptions of each system, demonstration of
differences between systems and evaluation of causes for lack of
recovery to pre-collapse conditions. Elements studied included trophic
interactions, system biomass and total production. Supplemental funding
from integrated management objectives has allowed progress on broad
scale objectives. Diet content and prey/predator interactions have
been the main focus of work in the eastern Scotian Shelf area including
new collections and recovery of historical data. Modeling of natural
mortality in cod using seal/cod interactions for 1980-1985 suggests
that M is variable both across age groups and across years.
Data collections from research surveys are an essential part of
the program and may require additional observations and expansion
of coverage to meet objectives. The project is presently supported
by non-core internal funds.
Georges Bank Modeling Initiatives
Presenter: Mike Fogarty
Rapporteur: K. Sosebee
Mike Fogarty presented information on ecosytem modeling initiatives
by the USA for Georges Bank over the last three decades. Several
approaches have been explored, including energy budget models, aggregate
biomass production models, age structured simulation models, multispecies
cohort models, donor control production models and delay difference
models. Species groups on Georges Bank have shifted historically
from a biomass dominated by groundfish and flatfish to one
dominated by pelagics and elasmobranchs. Total biomass on
the Bank has remained more stable suggesting interactions among components.
Energy budgets suggest that there is barely enough energy to account
for yields from the Bank. There seems to be an inefficient transfer
of energy from primary levels to secondary and tertiary levels.
Ongoing modeling efforts include energy budget modeling with information
from the GLOBEC project, including improved estimates of secondary
production and inclusion of the microbial loop. The Georges Bank
ecosystem appears to be loosely coupled with many links with low
interaction strength. Comparisons with more northern systems with
fewer species suggest that stronger predator-prey interactions may
be present in these simpler systems.
GLOBEC
Progress
Presenters: David Mountain, Jim Manning
Rapporteurs: Jim Manning,
Dave Mountain
The waters in the Gulf of Maine and on Georges Bank are a mixture
of two primary sources: cold, low salinity water from the Scotian
Shelf (SSW) entering in the surface layer around Cape Sable, and
warm, higher salinity Slope Water (SLW) entering at deeper levels
through the Northeast Channel. Direct measurements of these inflows
during the GLOBEC program (by Peter Smith at BIO) show a balance
of two parts SSW to one part SLW. Similar measurements in the late
1970s estimated about the same total transport, but with a reverse
proportion - two parts SLW to one part SSW. The increased contribution
of SSW can account for the generally lower salinities observed during
the GLOBEC period, compared to the 1980s. More importantly, the change
in the balance of the source waters to the Gulf system implies changes
to the inflow of nutrients, plankton and other characteristics, which
may have important consequences for the Gulf ecosystem.
The analysis of cod and haddock egg and larval data from the Broad
Scale Survey component of the GLOBEC program was described. Mortality
estimates through the early development of the year classes will
be determined and compared to physical forcing, food availability
and predation to gain understanding of the factors contributing to
recruitment variability. Early larval mortality for the 1995 and
1996 year classes of cod has been shown to range from 5-8 percent
per day. The 1998 haddock year class did not originate from an unusually
large egg production, but was characterized by high larval abundance,
implying that mortality rates during the egg and at least early larval
stages were low compared to other years sampled by GLOBEC.
Georges Bank GLOBEC process studies were conducted in three separate
field programs focused on 1) water column "stratification" in 1995,
2) "source, retention, and loss" in 1997, and 3) "cross-frontal exchange" in
1999. The effect of these processes on the distribution and abundance
of larval fish and their prey was examined on nearly a dozen cruises
each year. Larval distribution studies in 1995 revealed that cod
larvae were concentrated on the northeast peak of Georges in March;
the concentration then shifted to the central offshore edge of the
Bank in April and to Great South Channel in May. Examples of oceanographic
structures such as a slope water intrusion in May 1995 and an intensified
tidal-front jet in May 1997 were described in their relation to the
distribution of cod and haddock. The Dartmouth Circulation Model
(a good example of successful USA-Canadian collaboration) was used
to demonstrate the potential for larval advection on the southern
flank. The application of this model in "real-time" mode was noted
as one highlight of 1999 shipboard operations.
The transition from GLOBEC to more "operational oceanography" will
be the focus of the next few years. As an example of this effort,
the "Environmental Monitors on Lobster Traps" program has been introduced
to contribute to the long-term monitoring of the physical oceanographic
conditions in the Gulf of Maine. Further information on this program
is available from http://www.wh.whoi.edu/~jmanning/emolt.html.
The question was raised as to whether there was evidence for larval
swimming behavior, as modeling of larval retention would have to
consider this. The response was that earlier work has indicated an
on-bank movement by older larvae as they move toward the bottom.
There was also a question as to how cod and haddock eggs could be
separated for the purpose of estimating egg production by the two
species. The response was that the proportion of cod vs. haddock
eggs is determined for the older eggs, where species can be distinguished,
and applied to earlier stage eggs, on a station by station (or net
by net) basis.
The question was also raised as to the point at which cod begin
to exhibit schooling behavior. This sparked some discussion; the
conclusion being that there is no evidence for this at the larval
and juvenile stages. Direct observations of juvenile cod on the north
side of Georges Bank from submersibles show them to be scattered
in the gravel substrate, without any indication of schooling behavior.
Finally, there was a question as to whether there is any indication
of changes in the relative contribution of eastern vs western Georges
Bank to cod or haddock spawning; the response was that the GLOBEC
modeling group is actively investigating this question, largely from
historical data. In the synthesis phase of the program, data from
GLOBEC sampling will be included in this type of analysis.
A number of comments were made suggesting that 1998 was unusual
in the region for species other than haddock (e.g., redfish). This
may be a more general issue to be looked at. This was the first year
since the 1960s that slope water of Labrador Sea origin extended
far enough to the southwest to enter the Gulf of Maine, indicating
that there were other aspects of the physical environment that were
unusual that year, as well.
Early
Life History Modeling
Presenter: Dave Brickman
Rapporteur: Paul Fanning
Dave Brickman described results of a research program to study larval
retention on Browns Bank. In spring, the flow field would carry particles
from Browns Bank into the Gulf of Maine in approximately two months;
and the question may be raised as to what fraction of larvae produced
on Browns Bank is actually retained there.
An early life stage (ELS) model was constructed which includes flow
fields, particle tracking, egg production, and growth and survival
equations for both eggs and larvae. In southwest Nova Scotia diel
migration has not been seen and was not included in the ELS model.
The model has been 'tuned' to resemble the egg and larval distribution
data from the Fisheries Ecology Program or FEP.
For Browns Bank haddock, a retention survival index (RSI, Shackell et
al., 1999, CJFAS V.56, 1-12) was constructed. Since some larvae
are advected to the Bay of Fundy from Browns while others are retained
on Browns, the population is split early in life (egg or larval
stages) and the two components are segregated until about Age 2.
Examination of RV length frequencies of Age 2 fish showed two modes,
corresponding to faster growth in the Bay of Fundy and slower growth
on the Scotian Shelf. The RSI is simply the proportion of total
Age 2 numbers attributed to the Scotian Shelf component i.e. retained
on Browns. The ELS model was divided into the same areas and the
model RSI computed. There was a correlation of about 0.7 between
model and observed RSI but the model values are much lower, suggesting
the Bay of Fundy component has lower survival rates in spite of
faster growth.
To predict recruitment, an Age 1 recruitment model needs to have,
in addition to the ELS model, an improved egg production model, which
includes reproductive potential. This is an active research area
at this time. An important element is the treatment of mortality
to account for the fact that there are about 1e13 eggs
spawned, while Age 1 numbers are about 1e 7. This points
to the need to include predation by pelagic fish and invertebrates
if possible. As well, an 0-group survival model is needed including
density dependence, other species, and temperature and size dependence
effects.
From all of this, Age 1 abundance and distribution could be optimally
estimated using the RV and VPA age-1 data.
From looking at the average RV distribution of Age 1 captures, the
question may be raised as to why so many Age 1 individuals are to
be found upstream of the spawning grounds (Browns Bank) and next
to none in the downstream area offshore. This distribution can be
interpreted as a survivability map, and is consistent with low survivability
in the Bay of Fundy as indicated by the RSI. The particle model puts
no larvae in the upstream areas which show high abundance of Age
1, but FEP data showed large numbers of pelagic juveniles upstream
(at least in 1983). The flow fields in that area suggest that larvae
may be from the Western/Emerald spawners in (NAFO) Div. 4W. Thus,
Div. 4X haddock may be part of a metapopulation including Western
and Emerald Banks upstream. If this were the case, it appears that
Georges Bank is the end of a metapopulation conveyer belt, which,
given the warm water and high productivity, may explain the historical
stability of Georges Bank haddock production.
There are some 'hot spots' of settlement in Div. 4X but the greatest
concentration of drift suggests that most settle offshore and possibly
go to Div. 5Y but it is more likely that they don't survive at all.
Using a rough indicator of habitat (bottom sediment types), Age 1
survival appears highly correlated with sandy gravel bottom habitat,
and it is possible that this may be an important regulator of survival
to Age 1.
In the ensuing discussion it was noted that crossover of water masses
and presumably larvae from Browns Bank to Georges Bank is well documented.
Tagging results show that returns from downstream areas could be
by movement of adults upstream. This would provide a classic metapopulation
closure. It was noted that the large 1975 year class would be an
interesting case to examine.
SEAMAP
Presenter: Gary Rockwell
Rapporteur: Paul Fanning
Gary Rockwell described the Canadian Seabed Resource Mapping (SEAMAP)
initiative and gave examples of its capabilities and use. SEAMAP
is multi-departmental, including the Canadian Hydrographic Service
within DFO, the Geological Survey of Canada within Natural Resources
Canada (NRCan) and the Navy Route Survey Office from the Department
of National Defense (DND). The ultimate goal of this initiative is
the mapping of all the submerged lands of Canada. Increasing degrees
of detail are available through multibeam and sidescan sonar, seismic
surveys, and video and bottom sampling. The mapping efforts in Canada's
marine areas were originally based on the needs of safety of navigation.
This is still an important issue but other requirements have emerged
as well. These include marine geological processes and resources
and national defense issues such as mine countermeasures and submarine
warfare. The fishing industry has used new mapping information which
permits them to reduce expenses, fuel consumption and habitat impact.
Some of the new mapping capabilities were mobilized immediately after
the Swissair crash and contributed greatly to locating the debris
field.
SEAMAP objectives are to provide systematic mapping of bathymetry,
sediments, habitat, and benthic communities of the sea floor; to
provide basic information for decision making in areas of marine
management and policy; and to form partnerships with industry to
develop methodology and to complete surveys. (Many charts of remote
areas of Canada have little or no sounding data and in some cases
data are more than 100 years old).
A recently completed survey using multibeam and sidescan sonar provides
an example of SEAMAP's potential. Through this survey a vast amount
of highly detailed data on bathymetry was acquired. Analysis of backscatter
provided indications of the texture or composition of the seafloor
which was matched to surficial sediments. The resulting information
was used by scallop draggers to place their fishing effort precisely
on bottom areas most appropriate for scallops. They achieved a 2/3
reduction in their fishing effort with large savings in energy and
significantly reduced habitat impacts through use of lighter gear
and far fewer hours of dragging.
In summary, the technology and user community for SEAMAP exists
today; improved data and information is needed now for many applications,
and enhancing technologies are being developed. Accessible seabed
images are essential as a base for informed decision-making.
In the discussion it was noted that costs (per unit area) are highly
variable depending on area and depth surveyed as well as the degree
of detail (amount of additional ground truthing, sidescan, etc.),
type of hardware (e.g. multibeam), and bottom sampling intensity
needed. Mapping of Stellwagen Bank has cost about $4KK US for about
1000 km2.
Marine
Protected Areas (MPAs) and Habitat Impacts
Canadian MPAs
Presenter: Joe Arbour
Rapporteur: Paul Fanning
Joe Arbour reviewed recent developments with respect to MPAs for
Canada. The 1997 Oceans Act has been the driving impetus behind introducing
MPAs as ocean management tools. Over the last few years, DFO has
focused on a process of MPA identification, which involves a combination
of scientifically - based criteria and stakeholder input. The first
phase in this process has been the identification of areas of interest
(AOIs), which is a short list of areas that could become MPAs but
need closer examination. AOIs currently extend across Canada and
now the hard work of deciding which of these are to become MPAs is
at hand. Three AOIs mentioned in the Maritimes include the Musquash
AOI (an estuarine ecosystem), the Sable Gully AOI (an offshore submarine
canyon) and the Bay of Fundy AOI (part of the Gulf of Maine complex
of marine ecosystems). In the Gulf of Maine area, there are a number
of opportunities for a collaborative USA/Canada MPA approach. However,
this would require a jointly agreed-on approach to be effective.
This is potentially a very useful area for joint work.
In the ensuing discussion, it was pointed out that as part of the
Eastern Scotian Shelf Integrated Management (ESSIM) project, a project
has been initiated to first define the benthic ecosystem types in
the project area, and then to identify 10 percent of each type for
special protection. This raised the issue of benthic classification.
It was felt important that both countries use at least similar classification
schemes in order to avoid confusion on area designations. As a first
step, it was recommended that USA scientists be invited to participate
in the ESSIM benthic classification initiative.
The question was raised as to how stakeholders have responded to
the MPA initiative. While there has been some resistance, there is
a general recognition of the importance of safeguarding habitat from
all human activities (fishing, mining, oil & gas, etc). In this
respect, progress has been made.
USA MPAs
Presenter: Brad Barr
Rapporteur: Steve Clark
Brad Barr gave a brief review of the status of MPAs in the Gulf
of Maine (GOM) region. This is a very high activity area, contributing
more than a dozen of the more than 50 major MPA-related initiatives
currently ongoing in North America. The Gulf of Maine Council, which
includes states, provinces, and both federal governments is approaching
the subject in an ecosystem context and will be a major player in
the future. Specific activities of note include (a) the GOM MPA Inventory,
now being updated by the Center for Marine Conservation (CMC); (b)
the University of New Hampshire Gulf of Maine MPA initiative; (c)
the Wild Seas Report by the Conservation Law Foundation, describing
how the various units will function together as an ecological entity;
and (d) current updating of the management plan for the Studds-Stellwagen
Bank National Marine Sanctuary. Other possibilities for future action
include a proposed GOM "ocean wilderness" along the Hague Line and
a GOM Integrated Marine Protection Area (IMPAS) system which would
tie together existing areas for protection in a logical framework.
He stressed that GOM is a high priority area for MPAs and is a frequently
cited example of what can be done.
He then reviewed President Clinton's Executive Order #13158, which
was signed in May 2000. This order directs the Department of Commerce
(DOC), the Department of the Interior (DOI) and other federal agencies
to strengthen and expand the existing MPA system. Significant progress
has already been made. An advisory committee has been selected and
will initiate meetings in 2001; a website has been created (http://www.mpa.gov),
and preliminary work has been initiated on an MPA inventory. An MPA
Center has also been established which will develop and provide information
to stakeholders; and an Institute for MPA Science (in Santa Cruz,
CA) and an MPA Institute for Training and Technical Assistance (in
Charleston, SC) have been established. Other agencies, e.g. the EPA,
have supporting roles. This order is a significant development, which
is expected to greatly enhance MPA programs in USA waters.
As a result of this meeting, NOAA and DFO have begun to develop
plans for a workshop, to be held in autumn of 2001, to establish
transboundary agreements on identification of ecosystem boundaries,
strategies and methods for habitat characterization, and other related
issues for the Gulf of Maine, Georges Bank, and Scotian Shelf areas.
It will contribute to USA and Canadian efforts involving integrated
management and MPA network design and management.
Trawling and Dredge Impact Studies
Presenter: Frank Almeida
Rapporteur: Jason Link
Frank Almeida provided a review of some recent US efforts to examine
trawling/dredging impacts on Georges Bank closed areas and essential
fish habitat (EFH). When EFH was described for the 59 species that
the New England and Mid-Atlantic Fishery Management Councils regulate,
virtually the entire continental shelf was designated EFH. Recently,
all EFH designations have been overturned by the US court system;
more clarity in defining EFH is required. Current NEFSC research
has focused primarily on three closed areas: CA-I, CA-II, and the
Nantucket Lightship CA. These areas were closed in December 1994
primarily to protect and allow for recovery of groundfish stocks
but were re-opened to the scallop fishery for short periods during
1999 and 2000. There have been four research cruises into these areas
conducted both before and after the open seasons with a broad group
of collaborators. The main research objectives were to assess the
recovery of the habitat after the cessation of dredging/trawling
(from days to 5 years) and to quantify the impact of scallop dredging
on the bottom habitat after the open seasons. These cruises employed
a variety of sampling methods, including video transects and still
photographs, bottom grabs for benthos and chemistry, hydrography,
fish trawls, and sidescan sonar. Much of the data and samples are
still being processed but one main conclusion is that habitat type
is one of the biggest factors determining both impact and recovery
times from dredging/trawling.
Assessment
Methods and Modeling
Participants: Gerry Black, Jon Brodziak, Paul Fanning, Wendy Gabriel,
Chris Legault, Pamela Mace, Ralph Mayo, Bob Mohn (Co-chair), Bob O'Boyle,
Loretta O'Brien, Paul Rago (Co-chair), Gary Shepherd, Tim Smith
General Discussion:
Topics discussed ranged from specific, short term concerns to much broader
philosophical issues. Spirited debates of the philosophical issues consumed
most of the allotted time. While this reduced the number of topics that
could be addressed, it provided a basis for important future interactions.
A synthesis of these discussions is given below.
The dichotomy between data-based and model-based assessments served
to focus much of the discussion. Data-based approaches may be characterized
as the qualitative analysis of multiple time series of resource and fishery
attributes. These attributes may be observed quantities (e.g., survey
indices, catch data), derived quantities (survey-based estimates of Z),
or model estimates (e.g., F, SSB etc.). The underlying motivation for
such approaches is the synthesis of disparate pieces of information into
a coherent picture of stock status. For example, the traffic light approach
is data-based analysis while the ASPIC analysis would be model-based.
Regardless of whether formal modeling approaches are sufficient to identify
stock status, data-based methods have been proposed as a way of visually
depicting important attributes for management decisions. Data that may
not be incorporated in the formal assessment model can be introduced
to complement the deductions of model-based approaches.
It was noted that all data are interpreted via some model and it is
important to consider each time series carefully before ascribing a value
to a given data point. This is of particular importance in data-based
approaches. Examples include the average size or age of a population
over time, changes in condition factors and so forth. A small average
size may be "good" if it reflects a rapidly recovering stock dominated
by recent strong year classes. Alternatively, high fishing mortality
that removes larger individuals can also generate the same result but
the same value would be "bad". Thus the qualitative assignment of value
must also include alternative hypotheses that could generate the same
result.
The group also noted that use of indicator variables could improve communication
with user groups. Fishing mortality rates and SSB are abstract derived
quantities, whereas average size, low catch per tow, or thin fish are
observable quantities. By using a suite of such measures it is possible
to translate theoretical constructs into practical measurements that
are well understood. Nonetheless it is imperative that interpretations
of index data are based on a sound underlying theory.
The use of index measures to detect an "altered" state also implies
that a "normal" state can be specified. When measures of normal conditions
are dependent on historical data (e.g., using quantiles of data) the
problem of a moving baseline becomes an important consideration. Additional
years of data will generally improve our ability to interpret historical
trends but it may also alter decision thresholds. The working group noted
that the interpretation and analysis of index data might be facilitated
by drawing upon theory from other disciplines, notably decision theory.
Examples include utility theory for multi-attribute data, statistical
process control, and acceptance sampling. These approaches will probably
be necessary before index methods become fully functional in fisheries
management environments.
Index data complement more formal modeling approaches by providing a
context for the evaluation of historical conditions. For example, data
used in the fitting of more formal models may not cover the entire period
of available catch or survey data. Hence index data can be used to extend
the domain of inference to earlier time periods and prevent myopia associated
with an attenuated data set for modeling.
The working group also noted that many contemporary models might oversimplify
the richness of the underlying data. For example, concentration of landings
in either space (e.g., inshore vs offshore) or time (within season) may
be biologically important but not incorporated in most models. Errors
induced by model mis-specification are tolerable when stock abundance
is high, but become much more important when populations are reduced
by overfishing or other causes.
With respect to model selection, a number of formal approaches have
been applied beyond the contemporary variety, including information-theoretic
methods such as Akaike's Information Criterion (AIC) and various Bayesian
approaches. Methods for model averaging may also be useful when one or
more candidate models appear to fit the data equally well. It was noted
that tuning indices should be checked for internal consistency before
using them in model building.
More formal model building approaches are necessary for multi-index
models such as ASPIC and especially VPA models like ADAPT. ADAPT and
other VPA formulations rely on the assumption that catch at age is measured
without error. Reductions in the quantity and quality of biological sampling,
changes in discarding patterns, and changes in reporting systems have
resulted in gradual degradation of the catch at age data for many USA
assessments. (In contrast, catch data in Canada are probably improving
as regulations and scientist involvement has increased.) In some instances
statistical catch at age methods may be more appropriate for stock assessment;
but in all instances, the variability in estimates of catch at age should
be considered. Collectively, the group favored parsimonious models but
it was noted that the more highly parameterized models provide more explicit
depictions of underlying processes.
The Working Group noted that many of the ideas discussed were conceptual
and long range. At a more pragmatic level it was recognized that much
could be facilitated by simply exchanging existing software and data
visualization packages used in assessments. The Fisheries Assessment
Computation Toolbox (FACT) will be distributed to Canadian colleagues
and the ACON package for modeling and graphics has been distributed to
USA scientists. Access to the Virtual Data Center by USA scientists will
occur as soon as technical problems of external access to the DFO local
area network have been resolved.
Participants proposed the formation of a Methods Review Group. This
proposal recognizes the commonality of existing assessment issues between
the Atlantic labs in both countries and the reliance on common types
of data. The Group also recognized that existing review processes are
not an efficient way of providing sound critiques of new methodology,
since technical details of stock assessment, tight schedules and lack
of critical mass often impede the review, dissemination and implementation
of new methods. A methods review group could examine issues more thoroughly
and apart from the provision of management advice. The methods review
group would initially be a bilateral group and address pressing "local" concerns
in an informal working environment. Later, if the work is productive,
it is anticipated that the group would expand its remit and geographic
range. The group would also provide quality assurance and control and
would facilitate incorporation of ecosystem models into stock assessments.
The first meeting of the Methods Review Group would take place in 2001
and terms of reference will be a necessary precursor. The list of candidate
topics is large but a meeting to specifically address index based methodology
might provide timely input to current management needs. Other issues
might be the application of formal model building processes to assessments,
or the implications of stock rebuilding for VPA model formulation (e.g.,
influence of closed areas, use of plus groups, "dome-shaped" partial
recruitment patterns, etc.)
Recommendations:
- Continue exchange of software programs currently in use (e.g.,
ACON) and under development (FACT), and provide access to data
visualization software such as the Virtual Data Center.
- Form a bilateral Methods Review Group in 2001 to evaluate
and review methodology related to stock assessments. Candidate
topics for initial review include index-based qualitative assessments,
model
building strategies, and selected VPA topics.
- The bilateral Methods Review Group should meet once in 2001
to review the efficacy of such a group and its products,
and to advise on establishment of a permanent working group.
Plenary Discussion:
Participants supported the concept of a group to explore these and other
related issues, in a free thinking environment. It was noted that there
is a SARC Assessment WG but it has not been active; and a similar Canadian
body has also been moribund. ICES has a Methods WG, but there was general
sentiment for an independent initiative. It was agreed that this Working
Group on Assessment Methods would provide the initial focus for discussion
on assessment techniques. It would be a 'bottom - up' driven group which
would meet sometime within the year. It was noted that the TAWG is tentatively
planning to meet in September 2001. The group could meet in conjunction
with this meeting.
Terms of Reference for the Group are as follows:
- Evaluate the use of index measures of abundance and resource status
for the assessment of fishery resources. Focus on the use of ranking
scale measurements and visualization techniques and their utility for
communicating assessment results. Consider applicability of multi-attribute
decision theory.
- Compare and contrast current methodologies used in USA and Canadian
versions of ADAPT and recommend modifications to existing software
as appropriate.
- Review diagnostic methods and model-building approaches for sequential
population analysis and recommend further work.
Marine Mammals
and Turtles
Participants: Kathryn
Bisack, Phil Clapham, Tim Cole, Jerry Conway, Harold Foster, Richard
Merrick (co-chair), David Potter, Richard Pace, Janeen Quintal,
Marjorie Rossman, Cheryl Ryder, Fred Serchuk, Tim Smith, Gary Stenson,
Wayne Stobo (co-chair), Gordon Waring.
Canadian representatives were from DFO, Maritimes (Conway and Stobo)
and Newfoundland (Stenson). Other DFO invitees from Quebec (Hammill)
and Nova Scotia (Bowen) were unable to attend due to fieldwork commitments.
USA participants were from the NEFSC, Resource Evaluation and Assessment
Division and the Protected Species Branch.
Discussion and Recommendations:
The morning session was devoted to a discussion of the organization
of protected species-related activities within the NMFS (focusing on
the NE Region), and at DFO (including contemplated changes under SARA).
DFO activities have been heavily impacted by the overall program review
in the mid-1990s. Implementation of an expanded Protected Species responsibility
under SARA or its final derivatives will have equally profound impacts;
in many ways, similar to those within NMFS resulting from 1994 amendments
to the MMPA. Each of the DFO Regional offices is expected to add:
a. Two staff members to "Science" to deal with SARA sciences issues
(especially small and large cetaceans); and
b. Up to three staff to "Science" or "Fisheries Management" (varying
by Region) to support the management component of SARA.
The organization of DFO for protected species will be remarkably like
that at NMFS. One difference is that permitting of science activities
will be from the Regional SARA offices, rather than from a national office.
Funding will also change. Under this new regime funding for new staff
will be available immediately. Additional funds will then be available
competitively, which can be used to fund staff, field work or additional
programs (increasing from $3.5M at present to $12.5M in 5 years). Funds
will also be available for some projects under the Habitat Stewardship
Fund, though these funds are not meant for "science" and require a 50%
match.
Science practiced by the DFO and NEFSC groups are similar in some ways
(both focus on abundance estimation), and dissimilar in others (DFO staff
focus heavily on ecological issues, while the NEFSC focuses on mortality
estimation and bycatch reduction).
Marine Turtles
The USA longline fishery on the Grand Banks was closed during October
10, 2000 through April 9, 2001 as a result of takes of leatherback and
loggerhead turtles. NMFS is now developing a revised set of Reasonable
and Prudent Alternatives (RPAs) as part of the ESA Section 7 review of
the USA fishery. A workshop was held with USA fishers to attempt to develop
a list of gear modifications that would serve as RPAs. Similar changes
may be useful in the Canadian fishery. A meeting will be hosted by DFO
in March to consider this issue.
Data are collected on marine mammal and turtle bycatch in various USA
and Canadian fisheries, although differences in types of data collected
and methods used exist. It would facilitate communication of bycatch
results and data usage if data collection were standardized. The
group recommended that NEFSC and DFO staff in the Maritimes and Newfoundland
Regions collaborate to address this issue.
The USA is initiating a leatherback turtle disentanglement network.
Similar efforts may begin in Canada. The group recommended that
the NMFS and other USA participants in this network coordinate their
efforts with their Canadian counterparts.
Harbor Porpoise
Gillnet fishery takes for the Bay of Fundy/Gulf of Maine stock of harbor
porpoise have been reduced below PBR. This is due partly to the Harbor
Porpoise Take Reduction Plan, and partly to changes in the commercial
fishery. Results from the 1999 NEFSC abundance survey indicate that the
population is stable or increasing, thus increasing PBR. Issues remain,
however, on stock identification and abundance for other stocks. These
appear to be important issues for both DFO and NMFS. The group
recommended that the two agencies collaborate on additional stock identification
studies and on abundance surveys.
Specifically, the NEFSC invited DFO participation in its summer 2001
survey. This will provide field training for DFO's new cetacean biologists.
Further, NMFS and DFO should coordinate harbor porpoise surveys planned
for summer 2002 or 2003, if these surveys are funded. NMFS will
participate in the DFO workshop on harbor porpoise biology planned for
Halifax in March 2001. Should DFO hold a second workshop later in 2001
on survey methods, NMFS would be willing to participate if requested
to do so.
DFO expects to continue its experiments with reflective nets as a means
for reducing harbor porpoise bycatch during summer 2001 in the Bay of
Fundy. The NEFSC expects to begin experimental work with these nets in
2001-2002 in New England waters. Continued Canadian work and collaboration
in this area was encouraged.
NEFSC staff agreed to provide reprints of various manuscripts on bycatch
estimation to their DFO counterparts.
Large Whales
The status of large whales in USA waters and of the Atlantic Large Whale
Take Reduction Plan was reviewed, as well as the roles of the ESA related
NE and SE Implementation Teams. The group then discussed the various
surveys being used to support large whale take reduction in the Bay of
Fundy and in USA waters. The use of zooplankton data to focus aerial
surveys was also discussed, and the NEFSC agreed to provide data to DFO
on prey distribution in the Roseway Basin and elsewhere.
The difficulties of photo-identification were considered, which led
to discussion of various forms of automated pattern recognition. It was
suggested that these procedures and available software be further researched.
USA and Canadian protective measures were discussed. DFO pointed out
that lobster gear is not a significant source of right whale interactions
in the Bay of Fundy (BOF) as the area is closed to lobster fishing from
April to November. Gillnet gear could continue to be a problem.
Disentanglement gear caches will soon be in place on both sides of the
BOF, which will allow quick response to entangled large whales. Fisheries
officers in the BOF area have all had Level 1 training for disentanglement,
and it is possible that two Fishery Officers will be designated solely
to respond to right whale events.
The collection of data on entanglements, serious injuries, and mortalities
will be discussed further on a staff to staff level; and NEFSC will provide
materials and data sheets currently being used by the USA for collection
of these data to DFO. The NEFSC will also provide copies of the report
from the NMFS workshop on defining serious injuries, and will also work
with the Canadian stranding network to standardize data collection procedures.
Peer Review of Science
DFO has historically participated in an ex-officio capacity on NEFSC
Take Reduction Teams and on the Atlantic Scientific Review Group. The
group recommended that this relationship continue and perhaps be expanded.
The group also recommended that NMFS and DFO consider a joint
meeting of the two nations' marine mammal scientific review groups.
Next Steps
The group recommended another meeting in either November 2001
or February 2002. This meeting could also include planning
for the 2002 joint harbor porpoise survey. The NEFSC extended an invitation
for new DFO staff to visit the Center to exchange ideas and to explore
the data available on marine mammals and turtles in Canadian waters.
Plenary Discussion:
It was asked whether listing criteria had been discussed. The ESA has
no criteria and Canadian COSEWIC criteria appear inappropriate for marine
resources. The PBR provisions of MMPA appear to be the most useful ones
at present for quantifying impacts of takes. It was noted that, as many
of these resources are transboundary, PBR would need to be allocated
between both nations. It is therefore important to have agreed-on criteria.
It was recommended that this issue be discussed further to coordinate
with current discussions of listing criteria for marine species occurring
within the IUCN, CITES, and the ESA community.
There was only limited discussion on joint work on seals, but interactions
have been occurring between the two countries at a high level for some
time, and will continue.
It was recommended that the USA and Canada collaborate more closely
on monitoring ship traffic in the Gulf of Maine, to be better prepared
for International Maritime Organization action.
Groundfish
Distribution and Stock Structure
Participants: Steve
Cadrin (co-chair), Don Clark (co-chair), Joe Hunt, Steve Murawski, John
Neilson, Stacy Paul, Mark Soboil, Kathy Sosebee, Sue Wigley.
General Discussion and Recommendations:
The Working Group focused on general stock ID issues for principal transboundary
groundfish resources (i.e., those currently assessed through the Transboundary
Resources Assessment Committee (TRAC) process: cod, haddock and yellowtail)
and secondary groundfish resources as determined by the expertise in
the group. Many other transboundary groundfish resources were not discussed
due to time restrictions.
Introductory statements identified the need to consider many aspects
of stock structure such as movements, geographic variation, and environmental
signals to evaluate the suitability of current management units for conserving
spawning components and optimizing yield. Stock identification studies
for many species-stocks in the region are transboundary in nature, and
will require close cooperation between Canada and the U.S. to insure
their ultimate success.
One recurring theme was the need for updated summaries of stock structure
information. Perhaps the most valuable source for transboundary groundfish
is a Canadian report of a 1986 workshop (CAFSAC Res. Doc. 87/21). However,
many specific contributions and advances in stock identification methodology
have been made since that workshop. Participants agreed that management
areas should be re-evaluated through cooperative Canada-USA workshops
to draw on specific expertise from both countries and to promote consistent
evaluations. The group felt that a series of iterative workshops might
be required to achieve successive goals. A diverse scope for workshops,
including pelagic, invertebrate and marine mammal species may strengthen
the ability to develop effective evaluations.
Recommendation #1: Establish a Steering Committee to organize
cooperative workshops on stock structure of transboundary resources.
The
Steering Committee, comprising experts on stock identification from
Canada and the USA, should establish a time frame, and facilitate a
series of workshops. A series of goals should be considered for successive
workshops, such as 1) development of approved criteria for
stock identification decisions, 2) summarization and dissemination
of information in the form of review papers authored by species experts
from both countries, 3) application of approved criteria to
comprehensive summaries for consistent conclusions on stock structure
of transboundary resources, and 4) development of cooperative research
priorities.
The group considered tagging studies to be of primary importance, because
adequate observations on movements are lacking for most stocks. Conducting
tagging studies through binational efforts will greatly increase the
power of tagging studies for transboundary resources. Simultaneous tagging
of fish in all areas where returns are expected, and cooperation of fishermen
from both countries will reduce the effect of reporting bias. Expanding
cooperative tagging research to multiple species may also lend efficiency.
However, each species presents slightly different problems and may require
unique considerations.
Recommendation #2: Consider expanding cooperative tagging studies
to include multiple species.
Distributional analyses provide
another primary source of information for stock identification decisions.
The development of geographic information
systems and advances in quantitative techniques for describing spatial
distributions greatly expand the capacity of distributional studies for
contributing to stock structure research. For some groundfish species,
stock identification information is lacking and decisions may be based
solely on distribution patterns. However, most distributional studies
are currently limited to the spatial extent of national research surveys.
For many species with continuous distributions across survey areas, distributional
analyses should include survey data from both countries.
Recommendation #3: Allow easy access of survey data to researchers
from both countries.
Specific Discussions and Recommendations:
Cod - Participants reviewed developments in cod stock
structure research including proposals for tagging work through the DFO
Strategic Research Program and NMFS cooperative work with the fishing
industry. The Group concluded that such proposals should be coordinated
to maximize returns and minimize bias.
Recommendation #4: Coordinate national tagging initiatives for
cod so that design features are complementary and results can be easily
compared and combined.
The group also discussed the need to consider current management restrictions
in the interpretation of tag returns. Trip limits and rolling area closures
may affect return patterns. The need to implement mechanisms of recapturing
tagged fish within closed areas was discussed.
Yellowtail flounder - Recent progress in studying yellowtail
stock structure was reported, including a brief summary of DFO tag returns
on Georges Bank and USA MARFIN research on genetic and phenotypic patterns.
While information to date suggests only localized movements in comparison
to other groundfish, yellowtail tagging studies are needed to address
smaller-scale issues e.g. quantifying movements from the "yellowtail
hole" to other portions of Georges Bank, movements from Closed Area II,
and ontogenetic movements in the Cape Cod area.
Recommendation #5: Coordinate tagging initiatives for yellowtail
to ensure adequate reporting rates from all fisheries.
Considering the small scale of yellowtail tag recaptures, mixing of
early life history stages may be more important for identifying self-sustaining
geographic groups. The approach used in the GLOBEC project for understanding
the dynamics of gadid eggs and larvae may be also valuable for yellowtail
research. However, models and field sampling would require modification
to account for later spawning of yellowtail as compared to cod and haddock.
Recommendation #6: Investigate application of GLOBEC models
for studying dispersion of yellowtail eggs and larvae.
Haddock - Recent research developments were reviewed,
including genetic sampling and ongoing microconstituent work. It was
noted that a recent publication (Begg 1998; Marine Fisheries Review)
summarizes historical and recent research and may provide a model for
review papers for the recommended cooperative workshops. Recent DFO tagging
efforts confirm earlier observations of low survival of tagged haddock.
Perhaps alternative capture techniques could increase survival. Failing
this, distributional studies may be the most fruitful approach to studying
haddock stock structure.
Recommendation #7: Explore spatial patterns of haddock distribution
over time using quantitative geostatistical techniques.
Witch flounder - In contrast to cod, haddock and yellowtail,
witch flounder presents a more "data-poor" resource with respect to stock
identification studies. There have been technical recommendations to
include Scotian Shelf data in the USA assessment. Similarly, Canadian
assessments have considered including Gulf of St. Lawrence data in the
Scotian Shelf (4VWX) assessments. The extremely long pelagic stage of
witch ichthyoplankton suggests large-scale dispersal. The most effective
approach to witch flounder stock identification may be a cooperative,
broadscale distributional analysis.
Recommendation #8: Explore wide-scale spatial patterns of witch
flounder distribution using U.S. and Canadian survey data.
White Hake - Again, little stock structure information
is available. Although resources are assessed in separate jurisdictions,
white hake are continuously distributed from the Gulf of Maine to the
Scotian Shelf. Based on a comparison of length samples from the Scotian
Shelf and the USA age-based assessment, there appear to have been coincident
recent recruitment events.
Recommendation #9: Develop an exchange of data or otoliths to
investigate age structure of white hake on the Scotian Shelf.
Atlantic Halibut - The rarity of halibut eggs in USA
and Canadian ichthyoplankton surveys suggests spawning in deep water.
It appears that the USA resource is a fringe of a much larger population.
Participants felt that advances in assessing Canadian halibut resources
should be applied to the USA resource.
Recommendation #10: Develop a commercial hook survey of the
USA halibut resource in cooperation with U.S. fishermen to complement
Canadian surveys.
Redfish - The pattern of a relatively abrupt increase
in abundance of redfish at many ages in the Gulf of Maine suggests large-scale
movement among areas.
Recommendation #11: Explore wide-scale spatial patterns of redfish
distribution using Canadian and USA survey data.
Pollock - The difference in management units between
Canada and the USA was noted. The group agreed that DFO and NMFS should
consider cooperative assessments of pollock.
Recommendation #12: Cooperative research should be continued,
perhaps as a precursor to more formal assessments for review through
the TRAC process.
Plenary Discussion:
The list of topics discussed by the WG was reviewed. It was recommended
that the priorities of the recommendations be clearly outlined in the
proceedings. There was agreement that work on cod, haddock and yellowtail
is of high priority, although work on all species in the transboundary
area is ultimately needed.
There was a question on the accessibility of the 1987 CAFSAC Research
Document on stock structure. R. O'Boyle agreed to have it scanned and
placed on the Maritimes RAP Website.
There was a question on the reporting relationship of the Steering Committee.
It will report to the TRAC, which in turn reports to the line managers
of each country.
There was some discussion of Recommendation #3, relative to access to
the raw data of each country. It was noted that Canadian scientists now
have routine access to USA survey data and that the reverse is possible
through the website for Canadian data.
Atlantic Herring
Participants: Matt Cieri, Mike Jech, David Libby, Gary Melvin (co-chair),
Bill Michaels, Bill Overholtz (co-chair)
General Discussion and Recommendations:
2002 Assessment: Herring in the Gulf of Maine-Georges
Bank region will be assessed as a complex within the 2002 TRAC process.
However, there will be some attempts to disaggregate the components by
area by some of the methods used in previous assessments and by hydroacoustics
results.
Data Issues: Commercial sampling and timing for assembling
the 2001 catch at age were reviewed. Samples, landings and catch at age
for the USA will be completed by the State of Maine. Landings reporting
for the USA is via a phone-in system and biological sampling is relatively
good. Canada has very detailed dockside sampling of landings with all
ports and fleet components being sampled. The DFO will provide
Canadian catch at age for the 2002 assessment. The State of Maine has
reviewed sampling back to 1960 and will complete a historical revision
of the USA catch at age, possibly in time for the 2002 assessment. The
New Brunswick weir fishery will be included in the 2002 assessment, but
recent Canadian tagging information suggests that the appropriateness
of including this may have to be reviewed in the future.
Assessment Models and Methods: The current assessment
is a VPA tuned with USA spring and winter bottom trawl survey data. It
is a low precision assessment with some retrospective problems, but is
at present considered to be the best available approach. Log- transformed
survey indices will be investigated as tuning indices. The USA
has completed several surplus production (ASPIC) analyses, which will
be reviewed prior to the 2002 assessment. In addition, several biomass-based
models, e.g. DeLury, Delay Difference, or Bayesian models will
also be tested for their applicability prior to the 2002 assessment.
The State of Maine will update a VPA for the Gulf of Maine component.
Recommendation # 1: It was agreed that the group would try to
have an interim meeting sometime in late 2001 to review model results
and other issues prior to the TAWG meeting in 2002.
Hydroacoustics Issues: The USA will continue to survey
offshore spawning concentrations of herring on Georges Bank during autumn,
and a cooperative hydroacoustics survey is planned on the Bank with Canada
in October 2001. As well, the USA will be doing cooperative analysis
work with Dr. Pat Sullivan from Cornell University. This work will focus
on a geostatistics-based modeling approach for analysis of acoustics
data. Additional work currently being conducted by The Maine Aquarium
Development Corporation in Maine inshore waters was also discussed. Hydroacoustic
estimates of abundance and biomass will be included in the 2002 assessment
as well as attempts at using acoustics results to tune or anchor terminal
year biomass estimates.
Recommendation #2: A coordinated joint herring hydroacoustics
survey, conducted with vessels from both countries, will be completed
in early October 2001.
Predation Mortality: Recent work in the USA indicates
that herring are important in the diets of many predatory fish, including
cod, spiny dogfish, white hake, and silver hake. Herring consumption
has been quantified for the major predatory fishes during 1977-1998 and
work on M2s at age has progressed. Predatory fish diets follow herring
abundance fairly well and predation estimates could be included in the
catch-at-age matrix for 1977-2002.
Recommendation #3: The group agreed that including some information
and at least some qualitative advice on the impact of predation on
assessment results should be included in the 2002 assessment.
Plenary Discussion:
The question was raised as to stock structure assumptions for the 2002
assessment. The response was that the assessment would be of the complex
(Georges Bank, Nantucket Shoals and Gulf of Maine). Questions were also
asked relative to stock associations of the NB weir fishery, and the
reponse was that status quo associations would be assumed. It was pointed
out that until now, the joint assessment has been delayed due in part
to differing views in Canada and the USA on stock structure. The next
assessment should include a review of the components within the complex.
Given that the complex is being assessed for Canadian management purposes
as well, the Georges Bank component would need to be identified via acoustics,
egg and larval and/or bottom trawl surveys.
There was discussion on the recommendation for a joint USA/Canada meeting
in autumn of 2001 to review modeling approaches and related issues. It
was suggested that this could be conducted as part of the fall TAWG,
the exact timing of which needs to be established.
Concerns were raised on statistical aspects of the acoustic survey.
There has been substantial communication between USA and Canadian scientists
on acoustics, which will continue. However, joint survey work may not
be possible in autumn of 2001 due to funding problems in Canada.
Sea Scallops
Participants: Christina Annand, Dvora Hart (co-chair), Larry Jacobson,
John Quinlan, Ginette Robert, Stephen Smith (co-chair)
General Discussion:
Recruitment: The 1996 and 1998 year-classes have been
observed as being strong on both sides of the ICJ line. In particular,
the 1998 year class has also been observed as being the strongest in
years on Georges Bank and in the Bay of Fundy and approaches. While there
may be a relationship between higher scallop spawning stock biomass in
the closed areas and recruitment on the American side of Georges Bank,
there is little evidence of a stock-recruitment relationship on the Canadian
side or in the Bay of Fundy. Environmental factors that may be driving
these strong year classes have not been studied in detail and more work
will be directed to this area.
Growth: Research has shown that there are demonstrable
spatial and temporal changes in growth. Studies on both sides of the
ICJ line have shown that the strong 1996 and 1998 year-classes have grown
faster than expected. In fact, the 1996 year class appeared to be one
year older than expected in 1999 based upon historical growth models.
Canadian stock assessments have reported that all animals exhibited larger
meat weights at size in 1999 than has been observed in the past. Unfortunately,
there were no American observations of meat weights to compare with.
Spatial patterns in catch rates: American and Canadian
scallop vessels are required to carry vessel monitoring systems (VMS)
and participants were able to compare temporal/spatial patterns of fishing
and catch rates of scallop vessels on their respective grounds. The American
example was particularly interesting in that it showed the interaction
between market price, meat weight size and density with the location,
intensity and spatial distribution of fishing. These interactions make
it difficult to evaluate catch-rate trends in terms of changes in abundance.
Population models: There is a pressing need on both
sides of the border to develop a population model for scallops that incorporates
the spatial/temporal variability in growth and fishing mortality. It
is very important to take this information into account when defining
recruits by shell height ranges and predicting meat weight yields.
Reference points: There is a need on both sides of
the border to define reference points and overfishing in a way that takes
into account the spatial nature of these populations. Current definitions
were developed based on finfish population dynamics and are not suitable
for scallops. In addition, closed area management on the American side
creates special complications. At this time a project proposal has been
submitted to DFO's Strategic Science Fund for an international workshop
in 2001/2002 on developing reference points for sessile and sedentary
invertebrates.
Recommendations
1. Conduct a joint project to evaluate recent recruitment on
Georges Bank and the Bay of Fundy in terms of stock-recruitment relationships
and environmental factors. This evaluation has to be done with data
from both sides of the ICJ line. In addition, data and results from
GLOBEC will be used to describe larval transport.
2. Conduct a joint project to develop population models that
incorporate spatial patterns in growth, recruitment and fishing mortality.
Plenary Discussion:
There was discussion on recruitment estimates from US RV surveys in
relation to measured eggs/tow data. This led to discussion on the 1998
year class, which is the largest and most widespread ever observed. It
is not apparent what has caused this major event. It was queried as to
whether or not the strong year-classes observed in the Gulf of Maine
area have also been seen further south; some have, but not all. Evidently,
this is a fruitful area for further research. Questions were also raised
on ageing research, focusing on the relative differences of growth increments
between open and closed areas.
With respect to management, the impact of closed areas was discussed
and the efficacy of refugia considered.
TRAC Process
and Peer Review
Participants: Chris Annand, Steve Clark, Ralph Mayo, Bob O'Boyle, Loretta
O'Brien
An ad-hoc meeting was held to further explore issues relating to the
TRAC process. Overall, there was a desire to involve external experts
in the technical peer review, separate from public discussion on interpretation
and communication of assessment results. The Transboundary Assessment
Working group (TAWG) would conduct benchmark evaluations intersessionally
i.e. outside of the management cycle. The benchmarks would focus on ensuring
that the assessment models are the most appropriate. Canadian and USA
scientists, along with the external experts, would work in a workshop
environment to conduct the benchmark assessments. The TAWG would subsequently
update the benchmark with the latest data to provide annual advice as
part of the management cycle; and the TRAC would review the status reports
without getting into 'reruns'. It would also define when benchmarks would
need to be done. In essence, the majority of the technical peer review
would be undertaken in the TAWG, the activities of which would be overseen
by the TRAC, analogous to peer review structures elsewhere (ICES, CAFSAC).
TRAC planning for April 2001 included updates of the five Canadian and
USA management units, critical review of the methods used to calculate
biological reference points, and proposed changes to the TRAC process.
If accepted, benchmark assessments would be planned for cod and possibly
Atlantic herring in autumn of 2001. Then, in 2002, assessment updates
for cod, haddock, yellowtail and herring assessments would be completed
and peer-reviewed.
Plenary Discussion:
It was noted that a benchmark assessment on herring in the autumn of
2001 may not be possible due to time limitations. However, it was agreed
that it would be appropriate to do the cod and herring benchmarks through
the TAWG.
There was general acceptance that the detailed peer review could be
performed by the TAWG. However, it was not clear what level of peer review
assessment updates would receive. The proposal appeared to indicate none.
There was strong sentiment that the updates need to be peer reviewed.
Indeed, there was concern that the proposal overall did not meet the
standards of peer review, i.e. one independent team reviewing the results
of another team. These concerns were duly noted and it was agreed that
a new proposal, which addressed these concerns, would be prepared and
presented at the April 2001 TRAC.
To Appendices
