Trip Limits, Catch, and Effort in the British Columbia Rockfish Trawl Fishery

Abstract

Trip limits (catch ceilings on individual fishing trips) have been used extensively in the management of groundfish trawl fisheries on the west coast of North America. Here, I describe some consequences of this management approach on the fishery for Pacific ocean perch Sebastes alutus off British Columbia. Before the implementation of trip limits, vessels regularly landed catches of over 50 metric tons (tonnes). In 1992, vessels on one fishing ground were restricted to Pacific ocean perch landings of less than 4.5 tonnes. Thus, trip limits have redistributed effort in the fishery, and a relatively constant annual catch is now attained through an increasing number of smaller trips. However, some catch in excess of the trip limit is known to be misreported as catch of other species; the discarding of excess catch at sea also occurs. Consequently, the catch and catch-per-unit-effort (CPUE) data required for stock assessment are underestimated. In particular, CPUE is positively correlated with the trip limit. Managers should consider the detrimental impact of trip limits on fishery-dependent abundance indices when new trip limits are implemented. Improved catch reporting and fishery-independent abundance indices could provide more accurate assessments.