Unanticipated declines of major stocks of Chinook salmon in Western Alaska prompt interest in the marine migratory patterns and survival. Variable survival in the context of the changing marine environment confounds our ability to forecast run strength and manage these stocks. Additionally, record numbers of Chinook salmon were harvested as bycatch in the Bering Sea walleye pollock fishery in 2005. What impact might this bycatch have on returns to AYK drainages? We propose a run reconstruction model that may offer critical insight into marine survival of AYK stocks of Chinook salmon, ultimately providing a forecast tool for improved management. First, National Marine Fisheries Service marine surveys will provide age 1.0 Chinook salmon in the eastern Bering Sea collected during the summers of 2002-2006; we will use stock composition analysis and abundance estimates to approximate relative year class strength of contributing stocks. We will then perform stock composition and abundance estimates of subadults (by age class) in the Bering Sea trawl bycatch. The reconstruction model will use a cohort analysis to test the utility of the juvenile data and bycatch data to forecast run strength of AYK stocks.
The primary goal of this study is to initiate a time series of data of stock composition and abundance of juveniles in NMFS BASIS cruises, coupled with stock composition and abundance of subadults (by age class) in trawl bycatch, to estimate marine survival and look for a linkage to subsequent adult returns to AYK drainages. To accomplish this goal the following objects will be completed: Develop a comprehensive and standardized baseline for Chinook salmon from western Alaska by adding approximately 25 populations to the existing Pacific Rim standardized DNA baseline. Identify a set of genetic markers that provide useful resolution for Bering Sea mixture analyses. Determine the stock composition of samples from the NMFS BASIS cruises 2002-2006 using markers from the standardized baseline. Determine the stock composition of Chinook salmon from the 2005-2006 bycatch by age class to facilitate possible forecast model and to provide immediate insight into the number of AYK Chinook salmon in bycatch. Evaluate if scales archived from historical bycatch collections can be used to lengthen the stock-composition time series. Develop run reconstruction methods to forecast western Alaska Chinook salmon runs based on stock-specific information originating from collections from juvenile surveys and the trawl bycatch.
Wiiliam Templin
A Project Authorization Statement is available for this project: Click to view First Year Funding: $472,700.00
bill.templin@alaska.gov
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Fields of Expertise
Biological Science
Genetics - 9 Other Projects
Physical Science
Socio/Economic
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Field research and Data Collection - 37 Other Projects
Ecosystems
Freshwater – Rivers/Streams - 45 Other Projects
Marine – Nearshore - 7 Other Projects
Ecosystem Components
Fish - 51 Other Projects
Species Groups
Anadromous salmonids - 51 Other Projects
Chinook - 22 Other Projects
Specific research issues
Genetics and stock identification - 13 Other Projects
Geographic Regions
Bering Sea - 11 Other Projects
Technological Expertise/Lab Methods
Lab Methods
Genetic analysis - 11 Other Projects
Technology
Modeling
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Type
Physical Science Specialties Areas
Management/Policy/Social
Bycatch - 2 Other Projects