LONG-TERM EFFECTS OF REGULATORY FISHING INSTRUMENTS: THE PACIFIC JACK MACKAREL CASE (TRACHURUS MURPHYI) IN THE CENTRAL SOUTHERN CHILE

Abstract

Chilean Pacific jack mackerel (Nichols, 1920) fishery yields about 90% of the Eastern South Pacific catch. The Southern Central region is the one that concentrates the major abundance of this resource. The objective of this study is to test which of the regulation fishery systems is the most efficient for this fishery from a bioeconomic approach. Based on catch and effort data, the behaviour of the T. murphy stock and the fishing fleet was simulated over time under three regulatory scenarios: open access, total allowable catch and individual transferable quotas. The behaviour of the fish stock, and the dynamics of fishing vessels coming in and going out over time from the fishery, were represented by equations of the model. The results indicate that when the fishery operates in open access, the biomass and economics benefit diminished, whereas the number of fishing vessels increased (mostly small and middle-sized ones). Upon imposing the total allowable catch, biomass increased and maintained over time, while the size fleet decreased (middle-sized and large vessels). Within the individual transferable quotas view, the fish stock behaves in a similar way to the total allowable catch measure. However, significant differences in terms of fleet size (reduction of only 10% of the initial size), as well as structure (remaining only large vessels in operation) and economic profits obtained (maximum in this regulation), arise from this framework modelling. In conclusion, from the fishery bioecomic point of view the individual transferable quotas was the best management scenario for the Southern Pacific Jack Mackerel.