Pollock Conservation Cooperative Research Center
2005 Awarded Research Projects
Developing DNA Markers for the Analysis of Chum Salmon Bycatch in Alaskan Trawl Fisheries (Phase 1)
A.J. Gharrett and M. Garvin
Overview
Chum salmon bycatch in the Gulf of Alaska and Bering Sea creates problems for the groundfish fisheries, particularly the
Bering Sea trawl fisheries. Salmon returns to western Alaskan systems, which have declined in recent years, are critical
to the livelihood and culture of rural Alaskans.
In addition, chum salmon are the focus of a number of other issues including
allocation among Alaskan users and between the U.S. and Canada. Central to bycatch questions is the origin/destination
of intercepted fish.
Substantial effort has been (and continues to be) devoted to genetic studies of North American chum salmon stocks,
the objective of which is to resolve mixtures to their contributing components. An extensive allozyme baseline has been
developed to address those questions.
Unfortunately, because of the logistics required to sample tissues for allozyme analysis
and the increasing costs of storing and processing the samples, most labs are ceasing their allozyme operations. In addition,
for chum salmon, allozymes may not provide the fine-scale resolution needed to address some questions.
An alternative approach is the use of DNA variation; however, there are as yet no baselines for DNA markers. In this project,
we are developing DNA markers, particularly single-nucleotide polymorphism (SNP) markers, for application to the trawl fishery
chum salmon bycatch problem. The challenge is to discover the variation, design the specific molecular tool, and verify its utility
in separating stocks. In this phase of the project, we are developing markers.
In the next phases, we will survey the variability
in substantial portions ofthe geographic range of chum salmon and evaluate the success that the markers can be expected to have
in resolving populations in mixtures, for example, between or within the Yukon and Kuskokwim drainages.
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