Abstract

Marine Protected Areas (MPAs) are increasingly employed to manageresonrce use in the coastal zones of Caribbean countries, and are being promotedas effective tools for the management of coral reef fisheries. A fundamental tenet of reserve-based fisheries nianagement is that these refuges from fishing mortality export fish from within the MPA to adjacent fished areas. An expectation is that the yield outside a refuge will increase enough to offset the catch forsaken by the fishery as a result of relinquished access to the MPA. If this does not occur within an economically viable period, fishermen will experience a net loss in income, which may inhibit compliance with management regulations. Documented increases in reef fish abundance and individual size within well-managed MPAs suggest two mechanisms of export to fisheries: 1) Emigration of catchable fish across refuge boundaries in response to increased densities of conspecitics, competitors or predators within refuses, and 2) Dispersal of larvae produced at high rates by the increased abundance of large fish within the refuge. The first mechanism assumes higher rates of recruitment or survival within the refuge to sustain exported production, while the second assumes that increased larval production enhances recruitment in adjacent areas (i.e. a local stock-recruitment relationship). Neither assumption is well-supported by current knowledge of coral reef fish ecology, and there are no robust demonstrations that Caribbean MPAs actually produce increased yields of catchable fish. Well-designed experiments conducted over complete histories of MPA creation are required to test for the existence of these mechanisms, and to quantify their contribution to the catches of fishermen who participate in reserve-based management. A collaborative research effort in the Soufriere Marine Management Area of St. Lucia, involving the national Fisheries Department, local NGOs and marine scientists from two universities is attempting to quantify the effect of a newly declared set of marine reserves and fishing priority areas stretching along 11 km of fringing reef. Spatially and temporally replicated mark-recapture and recruitment experiments will be conducted in partnership with local fishermen. Here we present a detailed experimental design, and estimate the power of different monitoring options to unequivocally identify the effects of MPAs and their causes.

PDF Preview