A study of mitochondrial DNA variation in populations of chum salmon Oncorhynchus keta Walbaum from rivers of Primorye and the Sakhalin Island

Mitochondrial DNA (mtDNA) variation was studied using restriction fragment length polymorphism (RFLP) in chum salmon populations from three rivers in southern Primorye and one river in Sakhalin Island. Significant differences were detected between the samples from Primorye and Sakhalin Island. No di fferences were found between the samples from the rivers of Primorye, which can be explained by a high rate of gene flow due to transplantation of spa wn from one river to another. The effect of fish breeding on the chum salmo n populations correlated with the indices of haplotype and nucleotide diver sity (h and pi, respectively). The lowest diversity was found in the comple tely artificial population from the Ryazanovka River; the highest, in natur al populations from the Narva and Naiba rivers. Frequencies of haplotypes i n consecutive generations were significantly different, which confirms the effects of genetic drift on the small-size chum salmon populations of Primo rye.