Genetic structure of a collapsed sockeye salmon stock: Atnarko River sockeye, British Columbia, Canada

Molecular tools have transformed management of genetically diverse species such as Pacific salmon and their mixed-stock fisheries. Here, I applied a new Single Nucleotide Polymorphisms panel to understand population structure of a collapsed sockeye salmon stock. Atnarko River sockeye is a diverse and culturally significant stock found on the Central Coast of British Columbia that collapsed in 2005, likely due to various factors that may include changes to sockeye salmon biodiversity. I found multiple genetically different populations within the stock, however not all spawner collections were genetically unique. Two highly distinct genetic clusters were generally associated with juvenile life history ecotype, although not exclusively. In-river catch predominantly assigned to the current most abundant population across all three decades of the indigenous fishery, however proportional contribution declined after collapse. My research advances understanding of Atnarko River sockeye stock collapse to inform recovery actions and has broad lessons on stewarding salmon diversity.