Indicators of status and benchmarks for conservation units in Canada’s Wild Salmon Policy

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The goal of Canada’s Wild Salmon Policy (WSP) is to restore and maintain healthy and diverse salmon populations and their habitats for the benefit and enjoyment of the people of Canada in perpetuity. To achieve that goal, the WSP requires that biological status be assessed for all geographically, ecologically, and genetically distinct populations, or Conservation Units (CUs). One component of that assessment is identifying quantifiable metrics of biological status and benchmarks along those metrics. Here, we provide a toolkit of metics of biological status and benchmarks of status, which will set the stage for future CU assessments. Specifically, we propose a multi-criteria approach for assessing status that uses information on current abundances, trends in abundance over time, distribution of spawners, and fishing mortality relative to stock productivity. That approach captures the multiple dimensions of population status that will be important to achieve WSP goals better than assessments based on abundances alone. Futhermore, any redundancy in information content among criteria may allow for increased flexibility when assessing stocks that differ widely in data quantity and quality. Here, we identify quantifiable metrics and candidate benchmarks drawn from the scientific literature and previous management experience. Using a simulation model, we further evaluate a subset of those benchmarks on two performance metrics: the probabilityod extirpation over the long term and the probability of recovery to a target. Finally, we apply those metrics and candidate benchmarks to two example CUs, Takla/Trembleur sockeye salmon (Early Stuart run-timing group of the Fraser River) and Hecate StraitLowlands pink salmon (odd year).