Humboldt-Universität zu Berlin - Albrecht Daniel Thaer-Institut für Agrar- und Gartenbauwissenschaften

Increased timidity is a behavioral response to exploitation caused by a combination of learning and fisheries-induced selection favoring shy fish. In our study, the potential for angling-induced change in fish behavior was examined in two marine coastal fishes exploited by boat recreational fishing in the Mediterranean (Mallorca, Spain). It was expected that the mean vulnerability to capture of surviving individuals would differ across a gradient of previous exposure to recreational angling and that this effect would be present in multiple species. The prediction received partial empirical support. Recreational angling intensity was correlated with enhanced gear-avoidance behavior in only one of the two study species, the carnivorous painted comber (Serranus scriba). By contrast, the omnivorous fish species in our study, the annular seabream (Diplodus annularis), did not differ in its behavior towards hooks in exploited compared with unexploited sites. These results suggest that recreational angling may contribute to patterns of hyperdepletion in catch rates because of increased timidity and associated reduced vulnerability to fishing gear in some exploited species. Such effects would lead to erroneous interpretations about the status of the fish stocks when assessed by fishery-dependent data and would negatively affect catch rates and quality of the fishery in the affected species.