Genetic assessment of a summer chum salmon metapopulation in recovery

Evolutionary Applications

Maureen P. Small²  Thom H. Johnson¹  Cherril Bowman² 

[1] Point No Point Treaty Council, Kingston, WA, USA;Washington Department of Fish and Wildlife, Molecular Genetics Laboratory, Olympia, WA, USA

关键词: conservation;    hatchery impacts;    microsatellites;    population structure;    recovery;    salmonids;    supplementation;   

DOI  :  10.1111/eva.12118

来源: Wiley

【 摘 要 】

Abstract

Programs to rebuild imperiled wild fish populations often include hatchery-born fish derived from wild populations to supplement natural spawner abundance. These programs require monitoring to determine their demographic, biological, and genetic effects. In 1990s in Washington State, the Summer Chum Salmon Conservation Initiative developed a recovery program for the threatened Hood Canal summer chum salmon Evolutionarily Significant Unit (ESU) (the metapopulation) that used in-river spawners (wild fish) for each respective supplementation broodstock in six tributaries. Returning spawners (wild-born and hatchery-born) composed subsequent broodstocks, and tributary-specific supplementation was limited to three generations. We assessed impacts of the programs on neutral genetic diversity in this metapopulation using 16 microsatellite loci and a thirty-year dataset spanning before and after supplementation, roughly eight generations. Following supplementation, differentiation among subpopulations decreased (but not significantly) and isolation by distance patterns remained unchanged. There was no decline in genetic diversity in wild-born fish, but hatchery-born fish sampled in the same spawning areas had significantly lower genetic diversity and unequal family representation. Despite potential for negative effects from supplementation programs, few were detected in wild-born fish. We hypothesize that chum salmon natural history makes them less vulnerable to negative impacts from hatchery supplementation.

【 授权许可】

CC BY   
© 2013 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.