Preliminary estimation of chum salmon stock composition in the Bering Sea and North Pacific Ocean using polymorphic microsatellite DNA markers

Variation at the three microsatellite (ms) DNA loci in chum salmon was applied to estimate preliminarily the stock composition using a conditional maximum likelihood method in more than 700 fish collected from 14 stations in the Bering Sea and adjacent North Pacific Ocean during September 2003. Regional stock assignment accuracy with these msDNA markers was nearly the same as the previous estimation with mitochondrial (mt) DNA for the Japanese and North American stocks, but decreased for Russian stocks. The temporal stock estimation with msDNA gave a nonrandom distribution pattern of chum stocks, in that the Japanese and Russian stocks increased in the western to central Bering Sea, and the North American stocks were abundant in the eastern Bering Sea and near the Aleutian Islands. However, predominance of the North American stocks in nearly all of the surveyed area was different from the previous mtDNA estimation.