A comparison of claw removal methods on the post-release survival and claw regeneration of stone crab (Menippe mercenaria)

Commercial and recreational stone crab (Menippe mercenaria) fisheries primarily occur along the Gulf of Mexico and Atlantic coasts of the southeastern United States and the northeastern Caribbean. The fishery is unique in that only the crabs claws are retained and the animal is returned to the water alive. While the fishery is often regarded as sustainable because it is believed to exploit the crabs natural ability to voluntarily drop (autotomize) and regenerate lost claws, the post-release survival of de-clawed stone crabs is often low, especially when both claws are harvested. In this study, a controlled laboratory experiment was used to compare a new method of claw removal to the typical method currently used in the fishery. For the two different claw removal methods, we compared crab survival and start time to claw regeneration as a function of harvester and whether one claw or both claws were removed. Overall, we found a significant effect of the removal method, harvester, and whether one claw or both claws were removed on crab survival, but these factors did not influence the time to start of claw regeneration. Although our new method was several seconds slower in processing time than the typical method, it resulted in a 28% increase in survival (up to 92% survival throughout the study) compared to the typical method of claw removal (64% survival throughout the study). Overall, these results suggest that our new method of claw removal significantly increases post-release survival of stone crabs, and most notably does so independent of harvester and whether one claw or both claws are removed.