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
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Published source details
Cook K.V., Hinch S.G., Watson M.S., Patterson D.A., Reid A.J. & Cooke S.J. (2018) 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. Fisheries Research, 206, 96-108
Published source details Cook K.V., Hinch S.G., Watson M.S., Patterson D.A., Reid A.J. & Cooke S.J. (2018) 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. Fisheries Research, 206, 96-108
Actions
This study is summarised as evidence for the following.
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Reduce the duration of exposure to air of captured fish before release Action Link |
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Reduce the duration of exposure to air of captured fish before release
A replicated study in 2015–2016 in two areas of pelagic water in the Gulf of Alaska off British Columbia, Canada (Cook et al. 2018) found that shorter durations of air exposure reduced levels of injury and improved physical condition of unwanted chum salmon Onchorynchus keta caught in purse seine nets. In both areas, salmon injury was lower and physical condition was better for shorter durations of air exposure during handling than longer (data reported as statistical model results). In addition, shorter holding times in the purse seine before retrieval were associated with improved physical condition (data reported as statistical model results). Experimental purse seining was carried out on two fishing trips targeting Pacific salmon Onchorynchus spp., in July-August 2015 and 2016. The effects of air exposure (1–12 min) and experimental holding times (4–43 min) on discarded chum salmon were investigated. Injury was scored based on scale loss, skin loss, wound depth and fin damage. Fish physical condition was scored according to the number of reflexes (e.g. burst swimming, orientation, eye movement, fight response and ventilation) that were impaired.
(Summarised by: Leo Clarke)
