Green lamps as visual stimuli affect the catch efficiency of floating cod (Gadus morhua) pots in the Baltic Sea

Abstract

This study compared catches in numbers (catch per unit effort, CPUE) and biomass (weight per unit effort, WPUE) of Atlantic cod (Gadus morhua) in two-chambered floating cod pots equipped with and without a green lamp as a form of visual stimuli in two areas. A green lamp inside the pot increased the CPUE and WPUE of cod above the maximum legal size (>38cm) by 74 and 80%, respectively. There were no differences in CPUE and WPUE of small (<38cm) cod caught in pots with and without a green lamp. By increasing the catch efficiency of cod green lamps could consequently be highly beneficial for the Baltic commercial cod pot fishery.