Advantages and Disadvantages of Rotating Spatial Closures for Managing Fisheries

Abstract

Marine protected areas are becoming an increasingly important tool in fisheries management. Particularly for species with relatively sedentary adults, the basic approach taken is to permanently close areas to fishing, which allows species to recover inside the reserve and export larvae to outside of it that can eventually be harvested. Two key issues posed are ensuring the movement of larvae outside the reserve to support fisheries and the sociological and economic impact of marine reserves. An alternative approach that addresses these issues is rotational zoning systems, which have been implemented for some fisheries. What has been missing is an analysis of the relative impact of marine reserves versus rotational zoning systems on fisheries yields that could be used to provide important principles to guide management. Using a simplified model with clear assumptions, we show that rotational zoning systems are inferior in fisheries management targeting low-fecundity species or species with a low proliferation rate, especially when the fraction of the coastline protected is relatively small (approximately less than 20%) and the rotational fraction results in landings far below optimal fisheries yields. These results are tested with hypothetical species, providing quantitative guidelines in cases where decisions must be made with limited data as well as a framework for more detailed analyses in cases where more data are available.