Conditioning to predators improves survival of stocked Murray cod (Maccullochella peelii) fingerlings

Context Following recent major fish kill events, there is increasing interest in stocking Murray cod fingerlings to help stocks recover. Strategies that can increase post-release survival of stocked are important for conservation and may also have application other species.Aims The aim this work was evaluate whether pre-release predator recognition avoidance training conferred a advantage on (Maccullochella peelii) fingerlings. Predator-free release enclosures were evaluated as method improve survival.Methods Fingerlings trained by exposure predators skin extract. marked with visual implant elastomer (VIE) tags denote status strategy (trained, untrained, soft release, standard release). released at three sites the northern Murray–Darling Basin. Marked recaptured electrofishing 24h quarterly up 15months post-release.Key results Trained had higher relative than did untrained fish. mean recapture rate twice directly into waterbody significantly rates acclimated 90min predator-free enclosures.Conclusions Predator conditioning provides However, disadvantage.Implications Pre-release could be beneficial recreational-fish programs. We recommend receiving environment, rather soft-release enclosures, so maximise their chance survival.