Comparison of catch per unit effort of invasive European green crab (Carcinus maenas) across four bait types

Abstract

Restoration of marine ecosystems impacted by invasive, non-native species usually depends on reducing the density of the invader through a targeted cull. The effectiveness of these programs depends, in part, on using a selective fishing gear that maximizes catch per unit effort (CPUE). In this study, we examine how using different types of bait affects CPUE of European green crab (Carcinus maenas), an invasive species impacting ecosystems on the south and west coasts of the island of Newfoundland, Canada. We compared both CPUE and mean body size of green crabs caught in Fukui traps baited with Atlantic herring (Clupea harengus), short-fin squid (Illex illecebrosus), blue mussels (Mytilus edulis), and Atlantic cod (Gadus morhua). We found that squid and cod produced substantially higher catch rates, and also caught larger-bodied crabs. Despite green crabs being generalist predators, our results show that bait choice affects capture efficiency, and thus managers should preface removal programs with controlled studies designed to identify locally-effective and ecologically-appropriate baits.