Mitochondrial DNA variation and genetic population structure of chum salmon Oncorhynchus keta around the Pacific Rim.

A survey of mtDNA variation among populations of chum salmon Oncorhynchus keta around the Pacific Rim revealed four large population groups: Rim of the Sea of Japan, the Rim of the Okhotsk Sea and West Bering Sea, North-west Alaska and Gulf of Alaska. The observed population structure appears to reflect isolation by distance with limited gene flow between regions and larger amounts of gene flow between populations within these four regions. [ABSTRACT FROM AUTHOR]