The Effect of Commercial Geoduck (panopea Abrupta) Fishing on Dungeness Crab (cancer Magister) Catch Per Unit Effort in Hood Canal, Washington

Résumé du livre

Recreational crab pot fishers in Hood Canal, Washington sometimes complain that their catch rates for Dungeness crab, Cancer magister (Dana 1852) decline drastically following commercial geoduck clam Panopea abrupta (Conrad, 1849) harvest by divers. To test this assertion, we sampled crabs during a 4.6-year period with baited pots before, during, and after commercial geoduck fishing at a treatment site in Hood Canal. We also sampled crabs at a nearby unfished control site during the same time period. We tested whether significant changes in crab catch-per-unit-effort (CPUE) occurred following geoduck fishing in the treatment site, and if such changes could be attributed to geoduck fishing. Mean CPUE at the treatment site increased from 1.70 crabs/pot prior to fishing to 2.96 crabs/pot after geoduck fishing began. CPUE at the nearby unfished site during the same two time periods was 4.79 and 4.85 crabs/pot. Based on the results of an unpaired t-test of CPUE before and after geoduck fishing at the treatment site, we concluded that there were no significant effects on crab CPUE that could be attributed to geoduck fishing. A high level of natural variability in crab CPUE reduced the statistical power of the experiment, but such variability would likely affect the recreational pot fishery to an even greater degree. We therefore conclude that anecdotal reports which allege drastic declines in crab catch rates following geoduck fishing cannot be given much credence.