A fisheries management success story: the Gisborne, New Zealand, fishery for red rock lobsters (Jasus edwardsii)

Abstract

After individual quotas were imposed in 1990, the fishery for Jasus edwardsii in the Gisborne area showed continuing declines in catch and catch rate to 1993, and the total quota could not be caught in this area. There were few legal-sized but many sublegal-sized lobsters. Pots caused mortality of sublegal lobsters through handling, pot-related Octopus predation, and thefts from commercial pots.

The industry, in conjunction with recreational fishers and Maori, developed a scheme to address these problems. The aim was to increase landed value to compensate for quota reductions, and to do this by landing more lobsters in winter (when prices were higher) and landing smaller lobsters (which had a higher unit price). A shortened season was designed to reduce pot-related mortality.

Part of the scheme—a proposal to reduce the minimum legal size of male lobsters—caused controversy. However, the package was evaluated with a simple model and then accepted by the Minister of Fisheries. Results were substantially increased catch rates since 1993, a successful shift to a winter fishery, and a shift in length frequencies toward larger sizes. A simple size-structured model fitted to the fishery data and used to evaluate future management options is also described.