Contrast between the Core and Periphery of the Range: Demographic, Historical, and Environmental Factors Determining the Genetic Uniqueness of Sockeye Salmon (Oncorhynchus nerka) Peripheral Populations

A study of the population-genetic structure of sockeye salmon (Oncorhynchus nerka) in the Asian part of its range was conducted, with special attention paid to peripheral, including island, populations, assessing their genetic diversity and adaptive potential against the background of global climate change in the North Pacific and increasing anthropogenic pressure. Both original and previously published data on variability of 45 SNP loci in sockeye salmon, obtained by TaqMan PCR in 44 samples from 18 key spawning watersheds of this species in Asia, were analyzed. Trends towards reduced genetic diversity and high levels of divergence in peripheral sockeye salmon populations compared to populations from the central part of the range were revealed. Conclusions are drawn about the necessity of conserving island sockeye salmon populations to maintain the biodiversity of unique island ecosystems.