The use of minisatellite DNA variation for stock identification of chum salmon, Oncorhynchus keta

Geographic variation in minisatellite DNA was examined in 42 stocks of chum salmon, Oncorhynchus Keta, from the eastern and western Pacific by restricting genomic DNA with HaeIII and hybridizing it with two minisatellite probes. Regional differentiation in allelic frequencies at the two minisatellite loci was observed; Japanese stocks were distinct from Russian and Yukon River stocks, and stocks from those two regions were distinct from stocks in southeast Alaska and British Columbia. No significant annual variation was observed in allelic frequencies at the two loci for three stocks. Simulated mixed fishery samples of 100 Japanese chum salmon were resolved with a baseline of nine Japanese stocks with an average error of 0.5% per mixture stock. Similarly, simulated mixtures of Yukon River chum salmon resolved with a baseline of five stocks resulted in an average error of 0.6% per mixture stock. Fraser River chum salmon mixtures were resolved with an average error of 3% per mixture stock. With Asian and North American stocks pooled into two groups, accuracy of classification for individual fish to continent of origin was 78% for 323 Asian fish, and 94% for 797 North American fish. Minisatellite DNA variation can be successfully applied to problems of stock discrimination in chum salmon.