Multiple-Use Management Strategies and Marine Reserves

Using parameters from an actual fishery, a dynamic optimisation model is used to evaluate the economic payoffs from fishing between: (1) no-take reserve and harvesting outside of a reserve; (2) unrestricted spatial access fishery; and (3) positive harvest rate in a restricted access area, but at a rate less than in unrestricted access area. The results indicate that under a wide range of parameters representing fish dispersal, imperfect control of exploitation rate, fish growth rates, and stochastic shocks a restricted spatial access fishery provides higher economic benefits than an unrestricted spatial access fishery as well as a no-take reserve. Optimal harvest and the economic gain of a restricted spatial access fishery increase the higher is the growth rate, the larger is reproductive advantage of protected area, the greater are the magnitude and frequency of shocks that reduce fish stock in unrestricted access area. By contrast, the optimal harvest and economic gain decline the greater is the mobility of the species and the higher is the level fishing activities harm fish growth in restricted access area. A key finding is that spatial management of fish habitat that allows for differential rates of exploitation by area can increase the inter-temporal fisher profits.