Sockeye salmon (Oncorhynchus nerka) return after an absence of nearly 90 years: A case of reversion to anadromy

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

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Abstract

We document the recent reappearance of anadromous sockeye salmon (Oncorhynchus nerka) that were thought to have been extirpated by the construction of hydroelectric dams on the Coquitlam and Alouette rivers in British Columbia, Canada, in 1914 and 1927, respectively. Unexpected downstream migrations of juveniles during experimental water releases into both rivers in 2005 and 2006 preceded upstream return migrations of adults in 2007 and 2008. Genetic (microsatellite and mitochondrial DNA) markers and stable isotope (??34S and 87Sr/86Sr) patterns in otoliths confirm that both the juvenile downstream migrants and adult upstream migrants were progeny of nonanadromous sockeye salmon (kokanee) that inhabit Coquitlam and Alouette reservoirs. Low genetic diversity and evidence of genetic bottlenecks suggest that the kokanee populations in both reservoirs originated from relatively few anadromous individuals that residualized after downstream migration was largely prevented by the construction of dams. Once given an opportunity for upstream and downstream migration, both populations appear capable of reverting to a successful anadromous form, even after 25 generations.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Sockeye salmon (Oncorhynchus nerka) return after an absence of nearly 90 years: A case of reversion to anadromy
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/f2011-089
Volume 68
Issue 9
Year Published 2011
Language English
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Canadian Journal of Fisheries and Aquatic Sciences
First page 1590
Last page 1602