Developing methods to evaluate vitality of Pacific salmon bycatch from marine commercial fisheries to improve post-release survival

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While targeting abundant species, commercial Pacific salmon fisheries inadvertently capture less abundant species that must be released (termed bycatch). Recently, vessels in the northern BC fleet owned by Canfisco, an industry leader in commercial Pacific salmon fisheries, have been targeted by ENGOs and other groups as employing poor release practices for bycatch species. This has led to some confrontation and economic uncertainties for these fisheries. Canfisco wishes to improve on live release approaches used by its fleet and develop a reliable and scientifically defensible method to estimate bycatch condition at capture to better predict survival of released fish. We propose a simple technique for observers or others on-board to quantify bycatch condition using rapid reflex assessments with little interference to the fishers' normal routine, an approach previously validated by our group in freshwater Pacific salmon fisheries. This technique could be used to identify vessels or handling methods that cause the most harm to released fish and enable better practices to be developed. There is a strong run of pink salmon expected in 2015, providing an opportunity for the approach to be tested under realistic conditions with chum salmon as a bycatch species. The research activity would occur aboard a northern BC commercial purse seine vessel (industry in-kind vessel contribution of $50K for 10 days) operating under a scientific research permit. As chum bycatch are encountered, we would immediately evaluate their condition and reflexes, then release most of them. All pink salmon will also be immediately released. A subset of chum salmon bycatch will be assessed for vitality and held captive for monitoring in nearby near shore net pens to determine vitality measures predictive of mortality. A subset of fish will also be assessed for vitality and blood sampled post-capture to understand the physiological stress underlying various levels of impairment. The goals of the study are to estimate post-release mortality following typical bycatch handling approaches, determine the predictability of reflex measures for post-release survival, and use physiological information to understand impairment and mortality.