Post-release survival and physiology of angled luderick (Girella tricuspidata) after confinement in keeper nets in an Australian estuary

AbstractButcher, P. A., Broadhurst, M. K., Hall, K. C., and Cooke, S. J. 2011. Post-release survival and physiology of angled luderick (Girella tricuspidata) after confinement in keeper nets in an Australian estuary. – ICES Journal of Marine Science, 68: . The study was initiated in response to concerns about the post-release welfare of angled luderick (Girella tricuspidata) after protracted confinement in keeper nets. In all, 111 fish were angled and confined for 2–250 min before being released into holding cages (with 87 controls) and monitored for 4 d. Blood was taken from fish angled and brought on board immediately (n = 11), angled and held in keeper nets (n = 25), and angled and held in monitoring cages for 4 d (n = 12). Blood was also taken from controls held in monitoring cages for 4 d (n = 12). No controls and only one angled fish died. Compared with immediately sampled angled fish, those confined in keeper nets had significantly elevated cortisol, glucose, lactate, chloride, sodium, and aspartate aminotransferase. Most of the variables returned to pre-stress levels in caged fish after 4 d. Despite this recovery, the short-term stress associated with capture and keeper-net confinement has welfare implications and justifies avoiding such a practice and/or reducing the personal daily angling quota of the species.