Spillover from marine protected areas on the pacific coast in Colombia: A bioeconomic modelling approach for shrimp fisheries
Marine protected areas are currently recognized as an alternative for the conservation of marine ecosystems. Although the protection reduces the area available for fishing, it has been argued that the spillover effect can increase resources in the adjoining areas. The purpose of this study is to calculate the value of the provision of fishing resources resulting from an increase in the system of marine protected areas in Colombia. To do that, a surplus-production based dynamic bio-economic model is developed for white shrimp (Litopenaeus occidentalis), a species important socially and economically in Colombia. The model includes a protected area with essential habitats, a nonprotected area, and mobility of species between them. Changes in biomass, catch, effort and the economic benefits of fishing through time, under different protection scenarios, are analyzed. Despite the reduction of the area available for fishing, in the mid-term, the protected areas generate increased levels of biomass and greater benefits associated to the fishing activity, because of the spillover effect. In that sense, the marine protected areas constitute a valid alternative for fishery conservation with the potential to generate economic benefits in the midterm.