Effectiveness of Conditioning Strategies in Improving Fish Fitness‐Related Traits

ABSTRACT Although conditioning strategies are widely used to increase fish post‐release adaptability in stock enhancement projects, their effectiveness has not been systematically evaluated. Using a global‐scale meta‐analysis, we demonstrate that three major conditioning strategies, including environmental enrichment, life skills training and release tactic, can significantly improve fish fitness‐related traits, with the fitness indicator and developmental stage being the most important moderators for interpreting the high heterogeneity among cases. The effect size of approximate fitness indicators was marginally lower than that of post‐release behavioural traits. Our findings indicate the necessity of conditioning procedures and highlight the need to enact context‐dependent strategies in practical conservation projects.