Allozymes and mitochondrial DNA discriminate Asian and North American populations of chum salmon in mixed-stock fisheries along the south coast of the Alaska Peninsula

A representative baseline of allozyme allele frequencies of 69 stock groupi ngs covering the entire range of chum salmon Oncorhynchus kern was evaluate d for its ability to estimate stock of origin of Asian and North American c hum salmon in complex mixtures. We estimated the origin of 2,000 chum salmo n harvested incidentally in fisheries for sockeye salmon O. nerka slung the south side of the Alaska Peninsula in the northern Pacific Ocean in 1993 a nd 1994 using a maximum likelihood algorithm. Of eight major regions(Japan, Russia, northwest Alaska summer run, Yukon River fall run, Alaska Peninsul a-Kodiak Island, southeast Alaska, British Columbia, and Washington) report ed, northwest Alaska summer-run populations predominated in the fishery wit h estimates ranging from 0.52 to 0.72. A mitochondrial DNA (mtDNA) marker c apable of distinguishing the Japanese component from the rest of the Pacifi c Rim stocks was assayed in 400 of the 1994 samples. Estimates from the all ozyme and mtDNA data were similar. Monitoring of the fishery and expansion of the chum salmon baseline are continuing.