Resource Ecology Fisheries Management Report for Alaska Fisheries Science Center Quarterly Report for January-March 1999

STATUS OF STOCKS AND MULTISPECIES ASSESSMENTS: Pacific Whiting Assessment

AFSC scientists, working in collaboration with Canadian researchers at the Department of Fisheries and Oceans (DOF) Pacific Biological Station, completed an assessment of the coastal Pacific whiting stock. In summer 1998, NMFS and the DOF conducted a cooperative acoustic survey of Pacific whiting. Because information from the survey was considered essential for evaluating current stock status, the whiting assessment was delayed from the usual assessment cycle so that survey results could be used. To coordinate scientific advice, the 1998-99 assessment was submitted to a joint Canada-U.S. technical review that satisfied the requirements of both the U.S. Pacific Fishery Management Council (PFMC) and the Canadian Pacific Stock Assessment Review Committee (PSARC). The Review Group meeting was held in White Rock, British Columbia, during 17-18 February 1999.

The assessment indicated that the whiting stock is at moderate abundance. Stock biomass increased to a historical high of 5.7 million metric tons (t) in 1987 due to exceptionally large 1980 and 1984 year classes, then declined as these year classes passed through the population and were replaced by more moderate year classes. Stock size has been stable over the past 4 years at 1.7-1.8 million t. The mature female biomass in 1998 is estimated to be 37% of an unfished stock. Although 1998 stock size is near a historical low, it is close to average stock size under current harvest policies. The exploitation rate was below 10% prior to 1993, then increased to 17% during 1994-98. Total U.S. and Canadian catches have exceeded the ABC (allowable biological catch) by an average of 12% since 1993 due to disagreement on the allocation between U.S. and Canadian fisheries.

An evaluation of Pacific whiting harvest policy led to the recommendation that the 40-10 option, the default harvest policy of the PFMC, be considered for whiting. The 40-10 option results in similar harvest rates as the hybrid F policy used previously for whiting, and may improve economic performance of the fishery by dampening variability in harvests. An appendix to the assessment described a meta-analysis of whiting stock-recruit relationships. Results indicated that the genus Merluccius may be less resilient to fishing than other gadoids. A Bayesian decision analysis produced estimates of FMSY (fishery maximum sustainable yield) in the F40%-F45% range, depending on the degree of risk-aversion.

The 1999-2000 Pacific whiting OY (optimum yield) of 290,000 t coastwide (232,000 t for the United States) was adopted by the PFMC in March 1999. The OY was based on 1) an F40% SPR (spawning biomass per recruit) proxy for FMSY, 2) a 40-10 adjustment because mature female biomass is slightly below 40% of its unfished level, 3) the average of the OYs for 1999 and 2000, 4) and an 80% U.S. share of the total catch.

By Martin Dorn.

Stock Assessment Video

James Ianelli assisted Dr. Ray Hilborn of the University of Washington in teaching a week-long course on Bayesian Stock Assessment Methods. The 17 participants included 8 scientists from the AFSC, 6 from the NWFSC, and 3 graduate students from the University of Washington. The course emphasized hands-on application of Bayesian methods and modern approaches to the precautionary principle and risk aversion. The course was funded by the AFSC and the NWFSC. Due to the demand for this type of information, a set of video tapes from the course is being produced for distribution to interested parties.

Stock Assessment Software

The REFM Division continues to actively participate in developing and implementing software applications for analyses of North Pacific fish stocks. This work is partly funded by NMFS Headquarters as part of a national initiative to develop common software applications for fisheries stock assessments and is in coordination with members of the Northeast Fisheries Science Center (NEFSC) and the NWFSC. A key issue is to modernize software (C++ is at the core of the numerical methods) and encourage the use of models that adequately deal with uncertainty. These issues are critical to the success of conservation recommendations made to fishery management councils. One aspect of the work is to develop a common base model with a user-friendly interface that will be broadly applicable to many fisheries situations.

Other activities include adapting software developed in Iceland for the multispecies situation in the Bering Sea. This model allows for explicit details about fish growth through bio-energetic models in addition to linkages between species and different areas. During this quarter, Dr. Bjarte Bogstad visited the AFSC and gave a seminar to discuss the implementation. He is a leader in applying multispecies models to Barents Sea fish and marine mammal populations. This initiative requires different stratification schemes from the generally used INPFC statistical areas and involves recompiling both survey and fishery data along newly defined biological domains.

By James Ianelli.

U.S. Groundfish Fisheries Observer Program

During the quarter, 200 observers were trained, briefed, and equipped for deployment to fishing and processing vessels and shoreside plants in the Gulf of Alaska, Bering Sea, and Aleutian Islands region. They sampled aboard 226 fishing and processing vessels and at 17 shoreside processing plants. The observers were trained or briefed in various locations. The AFSC Observer Program in Seattle briefed 67 observers who had prior experience. The University of Alaska Anchorage (UAA) Observer Training Center briefed 98 observers, and another 30 first-time observers were trained there. At the field office in Dutch Harbor, two more observers were briefed; three were excused from briefing because they had just completed a cruise successfully and were returning immediately to the field. The first quarter 1999 observer workforce thus consisted of 15% new observers and 85% experienced observers.

The Observer Program conducted a total of 73 debriefings during the first quarter of 1999. One debriefing was held in Kodiak, 4 in Dutch Harbor, 18 in Anchorage, and 50 in Seattle. No debriefings are conducted at the UAA.

In 1999, implementation of the expanded Community Development Quota (CDQ) program and the recent American Fisheries Act (AFA) continued. The CDQ program was developed for the purpose of allocating fishery resources to eligible western Alaska communities to provide the means for starting or supporting regionally-based commercial fishery activities or related businesses. The CDQ program was initiated in 1992 with walleye pollock and expanded to include fixed-gear halibut and sablefish in 1995. In 1998, the program was further expanded to include multiple species (MS) of groundfish and crab (MSCDQ). NMFS is responsible for monitoring the groundfish (including pollock and sablefish) and halibut CDQs, and the state of Alaska is responsible for monitoring crab CDQs.

The AFA, enacted by Congress in late 1998, made changes to the pollock fishery in the Bering Sea and Aleutian Islands. These changes included reallocation of fish between industry segments, provided for the formation of fishing cooperatives, and increased observer coverage levels on some components of the fleet. The offshore component of the fleet has organized a fishing cooperative and is operating in a manner similar to CDQ. Vessels which participate in both CDQ and AFA cooperatives have been allotted specific amounts of fish by their management groups. Thus, individual vessels know their limits before they start fishing and can adjust their fishing and processing practices to maximize the return from those fish.

The MSCDQ and AFA catch-accounting for offshore processors is based entirely on data collected by observers and, unlike the open access fisheries where observer data is used to manage a fleet-wide quota, industry participants in the MSCDQ and AFA fisheries require individual accounting of fish harvested in each haul or set. This change has required Observer Program staff to develop special selection criteria and training requirements for observers, develop new sampling strategies and regulations to enhance the observers’ working environment, and develop changes for the program’s data collection and data management software systems.

By Bob Maier.

Socioeconomic Assessments Program

During this quarter, Center economists have been involved in activities supporting the Pacific and North Pacific Fishery Management Councils (PFMC and NPFMC, respectively) and in other cooperative efforts within the agency and beyond.

5. American Fisheries Act (AFA) - Center economists assisted the Alaska Regional Office in addressing AFA implementation issues and initiated efforts to assess the effects of the factory trawler cooperative that occurred as the result of the AFA. The Council will make recommendations to address different aspects of the AFA during the next 2 years.

6. Community Development Quota (CDQ) Program - The Center has initiated a study of the Alaskan pollock and groundfish CDQ programs to determine the amount and the form in which CDQ holdings provide value to CDQ groups and their partners. The study will include a comparative analysis of contractual arrangements that CDQ groups used to lease quotas. It will also examine the way that CDQ partners utilize quota to complement their other fishing and processing activities. The project is an integral part of the Center’s efforts to augment economic data on the groundfish fisheries, and it should also provide useful information to policy makers designing future CDQ programs both in the United States and abroad.

7. PFMC Groundfish Management - A Center economist:

Center economists have participated in the following cooperative activities:

The activities associated with the Alaska groundfish fishery cost, earnings, and employment data collection program include the following:

By Joe Terry.

Age and Growth Program

Estimated releases of production ages for January to March 1999 were 236 rex sole, 390 northern rock sole, 870 arrowtooth flounder, 1,091 Pacific whiting, 791 Pacific ocean perch for a total of 3,378. Also 978 were tested, 785 were updated, and 37 were examined and determined to be unreadable. The program has recently hired three new age-readers.

By Dan Kimura.

Resource Ecology and Ecosystems Modeling Program: Activities and Research Results

Stomachs collected totaled 13 for the eastern Bering Sea and 966 for the Gulf of Alaska. Fishery observers performed no at-sea scans of fish stomach contents in the Bering Sea. Laboratory analysis was performed on 1,101 stomachs from the Bering Sea, 541 from the Aleutian Islands area, and 720 from the Washington-Oregon-California coast areas. One observer returned with stomach samples collected from the Bering Sea. Three classes of observers were trained for stomach collection.

Ecosystem Considerations in Fisheries Management: Linking Ecosystem Management Goals with Ecosystem Research

The international symposium on Ecosystem Effects of Fishing was held by the International Council for the Exploration of the Sea (ICES) Scientific Committee on Ocean Research (SCOR) during 6-19 March 1999 in Montpellier, France (see Items section in this issue). The symposium provided an opportunity to present a poster (soon to be made available on the AFSC web site) describing the following proposal regarding linking ecosystem management goals and ecosystem research. This year we will begin to implement a revision of the Ecosystem Considerations document that provides information to the groundfish plan teams of the NPFMC. The revision will expand and standardize some of the content of the Ecosystems Consideration document to more clearly highlight the status of ecosystem-based management efforts and the status and trends of various parts of the ecosystem. These changes and additions would accomplish several goals:

As fishery management organizations incorporate more ecosystem-oriented thinking into management, there is a need for more clearly defined ecosystem-oriented management goals, as well as the tools necessary for managers to attain those goals. Parallel to this must be the expansion of the scientific advice to management beyond traditional single-species stock assessment advice. A broad spectrum of ecosystem research currently conducted by GLOBEC (Global Ocean Ecosystem Dynamics) and GLOBEC-like groups includes habitat research, ongoing trophic interactions work, and long-term monitoring of noncommercial species. Although the ultimate goal is to have quantitative predictions from this research to guide management, these research efforts already serve as indicators of ecosystem status and trends. The indicators can provide an early warning system for managers, signaling human- or climate-induced changes that may warrant management action. These indicators can also serve to track the success of previous ecosystem-oriented management efforts. The NPFMC has started to include some of this ecosystem research information in an ecosystem considerations document that accompanies the traditional stock assessment reports. The expansion of the document will include ecosystem status and trend information and will link management actions with ecosystem observations.

The NPFMC has explicitly stated the following ecosystem management goals:

The new ecosystems document will contain two classes of ecosystem indicators: ecosystem management indicators and ecosystem status indicators. The ecosystem management indicators will measure performance towards meeting the stated ecosystem management goals. These indices will have the advantages of providing early signals of direct human effects on ecosystem components that might warrant management intervention and will provide evidence of the efficacy of previous management actions, such as the efficacy of the Bering Sea bottom trawl closures in areas of increasing diversity of benthic fauna. Ecosystem status indicators will provide measures of ecosystem status and trends and serve the dual purposes of 1) bringing the results of ecosystem research efforts to the attention of stock assessment scientists and fishery managers, which will provide stronger links between ecosystem research and fishery management, and 2) bringing together many diverse research efforts into one document, which will spur new understanding of the connections between ecosystem components and the possible role that climate, humans, or both may have on the system.

Resource Ecology & Fisheries Management

Resource Ecology &
Fisheries Management