link to AFSC home page
Mobile users can use the Site Map to access the principal pages

link to AFSC home page link to NMFS home page link to NOAA home page

NOAA Technical Memorandum NMFS-AFSC-222

Publications Overview
Pubs Database
New Publications
Poster Presentations
Processed Reports
Quarterly Report:
Current Issue
Archives
Index
Feature Articles
Feature Archives
RACE Cruise Archives
Reports to Industry
Stock Assessments
Tech Memos
Yearly Lists

Genetic stock composition analysis of chum salmon bycatch samples from the 2008 Bering Sea groundfish fisheries

Abstract

A genetic analysis of samples from the chum salmon (Oncorhynchus keta) bycatch of the 2008 Bering Sea walleye pollock (Theragra chalcogramma) trawl fishery was undertaken to determine the overall stock composition of the sample set. Samples were genotyped for eleven microsatellite markers and results were estimated using the current chum salmon microsatellite baseline. In 2008, genetic samples were collected opportunistically as part of a special project, but sample biases have the potential to affect stock composition analysis results. Consequently, stock composition estimates apply to the sample set and may not represent the entire chum salmon bycatch. Based on the analysis of 629 chum salmon bycatch samples collected throughout the 2008 Bering Sea trawl fishery, North Asian (27%), East Asian (35%), and Eastern Gulf of Alaska/Pacific Northwest (24%) stocks dominated the sample set, with smaller contributions from western Alaska (7%) and Upper/Middle Yukon River (6%) stocks. The estimates for the 2008 chum salmon bycatch sample set were similar to the 2005, 2006, 2007, and 2009 chum salmon bycatch estimates, suggesting consistency of the regional stock contributions across years. Analysis of temporal groupings within the groundfish “B” season revealed changes in stock composition during the course of the season with decreasing contribution of Eastern Gulf of Alaska/Pacific Northwest stocks over time, but leaves unanswered whether these changes are due to temporal or spatial differences in the sample set.



View Online  (.pdf, 1.28 MB).


            | Home | Site Map | Contact Us | FOIA | Privacy | Disclaimer | USA.gov | Accessibility | Print |           doc logo