Priority Effects in Commercial Traps for Black Sea Bass (Centropristis striata)

Structure-oriented fish species, such as black sea bass (BSB, Centropristis striata), are challenging to assess by trawl survey because it is impractical to trawl over reefs, wrecks, or other structured habitats. Trap surveys have been proposed as an alternative strategy for assessing structure-oriented fish species, but it is not known whether traps can be used to accurately measure abundance. One crucial and unanswered question is whether priority effects – the effects of previous fish in a trap on subsequent fish entries into that trap – have an impact on abundance measured by traps. To test the role of priority effects in traps, we compared catch per unit effort (CPUE) of BSB caught in traps seeded with males, females or no fish on the continental shelf of NJ. Mean CPUE for both male and female BSB was highest in traps seeded with female BSB, followed by CPUE in control traps, with CPUE in male-seeded traps lowest of all three groups. Our results suggest that priority effects do impact trap catch rates, and need to be taken into account when analyzing trap data.