The importance of social and ecological context factors for the sustainability of stock-enhancement schemes in recreational fisheries: insights from a coupled social-ecological model

Stocking of fish into wild fish stocks is one of the most popular measures in recreational fisheries management to enhance stocks and associated angler welfare. Stocking decisions by managers are based on, and influenced by, a variety of social and ecological factors, e.g. degree of peer pressure by anglers, ecological state of the water body, and availability and certainty of monitoring information about the fish stock. To examine likely scenarios of the long-term development of stocking measures and their impact on wild fish stocks, we developed a coupled social-ecological model. In the model stocked and wild fish interact through ecological competition and genetic hybridization. Stocking decision making is informed by monitoring information as well as social factors. We test the impact of these factors on the sustainability of the fisheries under stochastic natural recruitment. We find that the rate at which stocking decisions are revised and the weights of social and ecological factors prompting action by managers jointly determine the outcome of stocking programs. The results provide robust hypotheses about likely stocking outcomes in real systems under varying ecological and social contexts. They will inform an empirical data collection campaign whose results will be used to further refine the model.