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Resource Ecology &
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In area 541, no
prescribed movement of the fishery outside of critical habitat has been mandated, but the
20-nmi trawl exclusion zones around Seguam and Agligadak rookeries that have been in place
only for the walleye pollock A-season will operate for the Atka mackerel B-season as well.
These changes are proposed to take effect in 1999.
Changes in the management of the
Atka mackerel fishery were necessary to address the possibility that the fishery creates
localized depletions of Steller sea lion prey (Atka mackerel) and adversely modifies
Steller sea lion critical habitat by disproportionately removing prey. Leslie
depletion analyses conducted on 37 time-area Atka mackerel fisheries in the Aleutian
Islands region since 1986 revealed that significant declines in fishery
catch-per-unit-effort (CPUE) occurred when catches from an area were large (in 17 of 37
cases). Using the Leslie-derived estimates of initial biomass, the local harvest
rates of Atka mackerel in times and areas which showed significant declines in CPUE may
have ranged between 40% and 94%. Furthermore, harvest rates in all the fished areas
in 1996 and 1997 may have been 56% and 37%, rates which were approximately five and three
times higher, respectively, than the target harvest rate of 12% on the Aleutian-wide Atka
mackerel population. Temporal and spatial dispersion of the fishery increasingly
into areas outside of Steller sea lion critical habitat could decrease the likelihood that
the fishery creates localized depletions of sea lion prey or adversely modifies critical
habitat.
While it is unlikely that catches of Atka
mackerel over the last 20 years in the Aleutian Islands have caused the Steller sea lion
population to decline, the current fishery could be an impediment to their recovery.
The Steller sea lion population has declined approximately 80% over the last 25
years, with the steepest rates of decline observed from 1985-89. Since then, the
population has continued to decline, but at reduced rates of between 0% and 10% per year
(depending on the area). Of all the groundfish fisheries off Alaska, the Atka
mackerel fishery has typically caught the greatest percentage of its target species catch
within areas now designated as Steller sea lion critical habitat.
By Lowell Fritz.
Shellfish
Assessment
Earlier analysis of the statistical
distribution of survey catch rates for Chionecetes bairdi and C. opilio
for the 1980-96 period demonstrated a mild degree of skewness. However,
distribution tail weights were not heavy enough to warrant alternative estimation of mean
density. Prior results obtained from a similar analysis of survey catch rates for
red king crab indicated distribution tail weights were of a magnitude to require an
alternate estimator. In order to gain insight into these differences between
species, Visual Basic coding of the statistical estimation process has been developed.
By Jerry Reeves.
Flatfish Stock
Assessment Review
A review of the REFM Divisions
flatfish stock assessments was conducted from 18 to 21 May 1998. The review panel,
consisting of fishery scientists from the NMFS Woods Hole Laboratory, the International
Pacific Halibut Commission, the Department of Fisheries and Oceans (Canada), and the
University of Alaska School of Fisheries and Ocean Sciences, was tasked with critically
reviewing the current status of the flatfish stock assessments as well as providing
recommendations on how these assessments could be improved. Center scientists gave
presentations on flatfish stock assessments to the review panel focusing on the quality
and quantity of the data used, the general nature of the assessments, the modeling
constructs, and how the results were communicated to fishery managers and decision makers.
They also presented information on the:
flatfish fisheries and current management
trawl surveys in the Bering Sea, the Aleutian Islands, and the Gulf of Alaska
the Observer Program and catch estimation procedures and problems
bottom-typing studies
flatfish trophic studies
maturity research
catchability studies
flatfish species growth rates during a period of increasing growth of the flatfish population in the Bering Sea.
The report submitted by the review
panel addressed four general areas of research: fishery independent data collection
programs; fishery dependent data collection programs; biological and ecological
research; and stock assessments and assessment methods. The review team was
impressed with the scope and direction of work being performed and indicated that the data
collection procedures and supporting research were appropriate and that the methods used
were sound. The review team report provided recommendations that will help Center
scientists produce improved flatfish stock assessments.
By Jack Turnock.
Socioeconomic
Assessment Task
During the past quarter, the
Socioeconomic Assessment Task has been heavily involved in activities in support of the
Pacific and North Pacific Fishery Management Councils (PFMC and NPFMC, respectively), the
implementation of the Magnuson-Stevens Act, and other cooperative efforts within the
agency and beyond.
Inshore Offshore Allocation III - The current allocation of Bering Sea-Aleutian Islands (BSAI) and Gulf of Alaska (GOA) walleye pollock and GOA Pacific cod between inshore and offshore processors expires at the end of this year. Therefore, establishing the allocation for 1999 and beyond has been a high priority for the NPFMC this year. Task members assisted in preparing and presenting the draft analysis for the April council meeting and assisted in revising the analysis for public and council review prior to the June council meeting. At its June meeting, the NPFMC recommended that the current allocation in the GOA be extended for 3 more years and that the BSAI pollock allocation to inshore processors be increased from its current level of 35% to 39%.
Cost Recovery Program for the IFQ and CDQ Programs - The Magnuson-Stevens Act requires the Secretary of Commerce to implement a program to recover the management and enforcement costs of the Alaska Individual Fishing Quota (IFQ) and Community Development Quota (CDQ) programs. A Task member assisted in revising a draft proposal for the cost recovery program and presenting the proposal to council committees.
Aleutian Islands Atka Mackerel Management - In response to the concern that the Atka mackerel fishery could cause localized depletion of Atka mackerel stocks and, therefore, adversely affect Steller sea lions, several alternative methods of preventing localized depletion were developed. Task members assisted in revising the draft analysis of alternatives for council and public review prior to the June council meeting. In June, the council recommended a combination of seasonal allocations and limits on the amount of the Atka mackerel quotas that could be taken in Steller sea lion critical habitat.
Bycatch in the BSAI and GOA Groundfish Fisheries - The 1996 revisions to the Magnuson-Stevens Act included three new national standards. One of them, national standard nine, requires that fishery management plans contain conservation and management measures that will, to the extent practicable, minimize bycatch and bycatch mortality. In response to this new requirement, the council has begun to address additional methods for reducing bycatch. A task member has assisted in developing a proposal to apportion the halibut and crab bycatch quotas to individual vessels and the preliminary analysis of two other proposals to reduce bycatch: the halibut mortality avoidance program and the vessel checklist program. A council committee met in May to discuss all three proposals.
PFMC Groundfish Management - A task member prepared and presented analysis to the PFMC on the viability of an industry-funded buy-back of limited-entry permits, developed new models for projecting in-season catch rates for several limited-entry and open-access fisheries, presented the new models and their results to the council, and provided technical support for the PFMCs allocation committee.
The Task contributed to
Magnuson-Stevens Act implementation activities in a renewed and successful effort to use a
broad definition of bycatch in the NMFS Bycatch Plan. The
Magnuson-Stevens Act defines bycatch as fish which are harvested in a fishery, but
which are not sold or kept for personal use, and includes economic discards and regulatory
discards . . . This definition explicitly includes discarded fish and
implicitly includes unobserved fishing mortality. The latter is the mortality of
fish that are not captured by a fisherman, but die as the direct result of an encounter
with fishing gear. It does not include indirect mortality resulting from changes to
the environment as a result of fishing activity. Unobserved fishing mortality is
included because it consists of fish which are harvested (i.e., caught, taken, or
harvested) in a fishery but which are not sold or kept for personal use.
In order to meet fully the
agencys conservation and management responsibilities as defined principally by the
Magnuson-Stevens Act, the Marine Mammal Protection Act, and the Endangered Species Act,
NMFS expanded this definition in two ways. First, all living marine resources other
than fish as defined in the Magnuson-Stevens Act (i.e., marine mammals and
seabirds) were included to consider all species taken in marine fisheries. Second,
the retained catch of nontarget species (i.e., retained incidental catch) was included.
Task members participated in the following cooperative activities:
development of programs to collect and model economic data for the Pacific Coast and Alaska commercial fisheries
development of the Alaska Fisheries Information Network (AKFIN)
preparation of a report on Task research for the Technical Subcommittee of the U.S.-Canada Groundfish Committee
participation on the PFMC Groundfish Management Team
preparation of information for Senate Bill 1221, the American Fisheries Act
the preparation of papers for the International Institute for Fisheries Economics and Trade.
By Joe Terry.