Experimental capture and handling of chum salmon reveal thresholds in injury, impairment, and physiology: best practices to improve bycatch survival in a purse seine fishery.

摘要: Abstract Recommendations and regulations regarding handling of non-target fish (i.e. bycatch) are often vague subjective in commercial fisheries. Identifying how different components capture influence the condition discarded can help develop specific guidelines best practices. Using an experimental approach, we modified severity stressors purse seine fisheries for Pacific salmon monitored indices injury reflex impairment chum (Oncorhynchus keta), a species commonly from these Study were held 5 or 10 days. Modeling changes sought to disentangle latent effects role sex maturity. Thresholds physiological responses times (i) pursed net (ii) air exposed on deck also evaluated. Injury progressed throughout holding, was more extensive females, accelerated faster less mature fish. Both crowding set size estimated number caught) increased impairment, that exacerbated with time pursed. Physiological indicators exhaustion 15 min identified as important transition point, potentially representing temporal limit anaerobic exercise. The between 1 3 min exposure being survival, after 6 min exposure, endogenous energy stores may have become exhausted. Resulting recommendations include keeping nets loose during sorting, releasing prior pursed, within range 1–2 min, less. Additionally, females appear be susceptible injurious capture.