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PMEL Programs and Plans
Accomplishments in FY 97 and Plans for FY 98

 

Accomplishments in FY 1997

FOCI, one of a few marine fisheries oceanography programs in the world predicting recruitment, made its sixth annual prediction of pollock year-class strength for Shelikof Strait: average recruitment for the 1997 year class. Developed in 1992, the Shelikof Recruitment Index (SRI) is based on process-oriented studies, field surveys, and numerical modeling experiments.  This index is used to predict the abundance of age-0 and age-1 walleye pollock that will survive to recruit to the Shelikof Strait, Gulf of Alaska, fishery as adults.  SRI incorporates environmental estimates such as rainfall, wind mixing, advection, and larval abundance, and predictions by SRI compare favorably with actual recruitment. Together with spawning biomass estimates also produced by FOCI, the index provides  fishery-independent information that helps National Marine Fisheries Service stock assessment scientists project future stock sizes.  These projections advise the North Pacific Fishery Management Council who establish fishing quotas for the Gulf of Alaska.  The 1995 year class, initially forecast to recruit in average to strong abundance, then downcast in 1996 to average abundance, is estimated from 1997 surveys to be recruiting in weak to average numbers.

Bering Sea FOCI concluded seven years of research for NOAA's Coastal Ocean Program.  Results from the project support a moratorium on walleye pollock fishing in the international waters of the central Bering Sea (the Donut Hole).  The observed scarcity of prey for larval pollock there, combined with historical documentation that juvenile pollock are rarely found in the basin, indicates that the juvenile nursery for basin pollock is located elsewhere.  Measurements of larval transport and studies of pollock genetics support the assumption that the juvenile nursery for basin pollock is on the eastern shelf in the U.S.Exclusive Economic Zone.  A final report that includes chapters synthesizing recruitment studies, stock structure, and new technology is in progress.

FOCI's observations in the Bering Sea led to the discovery and naming of a new current, the Aleutian North Slope Current (ANSC).  By measuring hydrography, trajectories of satellite-tracked drift buoys, and current velocities on the north side of the Aleutian Islands,  FOCI determined that there was a persistent, well-defined, eastward flow with significant  transport in regions that had been identified historically as only sometimes having weak, eastward flow.  The ANSC is made up of relatively warm, nutrient-rich water whose source is the Alaskan Stream, some of which enters the Bering Sea through the deep passes of the Aleutian Islands.  Water properties borne by the ANSC are important to the ecology of the eastern Bering Sea shelf, e.g, the spawning success of walleye pollock.

FOCI published a brochure that presents an in-depth look at the program for a wide ranging audience.  FOCI also supported the creation of a Bering Sea and North Pacific Ocean Theme Page.  The theme page provides pointers to information and images generated by NOAA, universities and other governmental sources and other information grouped by scientific discipline.  This page includes links to up-to-date satellite imagery, new research, and educational material related to the Northern Pacific Ocean and the Bering Sea.  Routines for the display of drifter data and for the overlaying of biological data on physical oceanographic properties are being developed.  The theme page includes a link to the Bering Sea Ecosystem Biophysical Metadatabase, a resource for locating data pertaining to the Bering Sea ecosystem, also developed with FOCI support.

Southeast Bering Sea Carrying Capacity (SEBSCC), a NOAA Coastal Ocean Program regional ecosystem study co-managed by PMEL, completed its first full year of research. SEBSCC focuses on two elements of the ecosystem: 1) cross-shelf transport and fate of nutrients, and 2) juvenile pollock as a nodal species.  First-year results include advances in monitoring and development of biophysical indices, circulation modeling, individual-based modeling of walleye pollock, the role of atmospheric forcing on the "cold pool" and ecosystem dynamics, and the influence of mesoscale eddies on the interaction of lower and higher trophic levels. 

Plans for FY 1998

• Conduct spring, summer, and fall research cruises to the North Pacific, Gulf of Alaska, and Bering Sea supporting physical and biophysical research for FOCI, SEBSCC, Arctic Research Initiative, and associated programs.
• Contrast the environment of the Bering Sea shelf and slope from observations made during 1996, 1997, and 1998 (as possible) to help understand the strong interannual variability in the ecosystem.
• Use model simulations to compare circulation, its effect on pollock survival, and upper-trophic-level interactions in the southeastern Bering Sea for warm and cold years (to help determine the influence of interannual variability in the ecosystem).
• Conclude Phase I SEBSCC research and contract for Phase II research.
• Publish a final report on Bering Sea FOCI containing synthesis information that contrasts  affects of slope and shelf habitat on survival of walleye pollock in the eastern Bering Sea, summarizes findings on pollock stock structure in the Bering Sea, and documents technological developments.
• Forecast recruitment of 1998 walleye pollock year class for Shelikof Strait.