Understanding and predicting the effect of entrance cone diameters on the catch efficiency of snow crabs (Chionoecetes opilio) in conical pots

Abstract

Conical pots with a plastic entrance cone on the top are a type of fishing gear used to harvest snow crabs (Chionoecetes opilio) in Arctic regions. In this study, we assessed the effect of pot entrance diameter on the catch efficiency of snow crabs. We used catch data collected during sea trials of pots with different entrance cone diameters, and we conducted laboratory experiments where morphological characteristics of snow crabs were investigated to estimate the extent of the different body parts of the animal that are decisive for the catch efficiency of the pot entrance. The results show that body parts larger than the carapace affected pot entrance efficiency. We predicted that entrance diameter is a key factor determining catch efficiency and that the experimental pots used in this study would experience significant reductions in the catch of marketable size crab, compared to pots currently used in the fishery.