Homogeneity of Chinook in Trawls

This project genotyped 1,620 Chinook salmon samples from the spring salmon excluder device test that was conducted in the Bering Sea in 2009. This included 1,318 Chinook salmon samples from the Pacific Prince collected between January 26, 2009 and February 28, 2009. These samples were taken from 34 hauls, of which 4 hauls had samples from over 97 Chinook salmon. The analysis also included 302 Chinook salmon samples from the Starbound collected between March 9, 2009 and March 15, 2009. These samples were taken from 19 hauls, of which 3 had more than 50 samples. All samples were genotyped for 43 single nucleotide polymorphisms (SNPs) using a MALDI-TOF genotyping protocol. Of the 1,620 samples, 1,610 were successfully genotyped (missing 8 or fewer loci). While the statistical analysis of the samples will be part of future proposals, a preliminary stock composition of the sample mixture suggests that the majority of samples were derived from Coastal Western Alaska stocks. In addition to the SNP genotyping, the 1,620 samples were also genotyped for the 13 GAPS microsatellite markers and 1,459 were successfully genotyped (missing 4 or few loci). This genotyping was included to increase the power of the ongoing statistical analysis.

This project will complete the genotyping of 1,621 samples necessary to determine the genetic uniqueness of Chinook salmon taken in particular hauls and areas in the Bering Sea north of Unimak Pass. This information is vital to the development of an implementable sampling regimen for future genetic analyses of the Chinook salmon bycatch. It will help fisheries managers understand how Chinook salmon are distributed and whether taking many Chinook salmon in a limited number of trawls would have the same effect as taking the same total number of Chinook salmon over a larger number of hauls.