Simulations of fixed closure and real-time closure to manage migratory fish species for data-limited fisheries

Abstract

Fisheries closure has been used as a fisheries management tool to protect species that need to be conserved. A commonly used type is fixed closure (FC), which specifies the closure area and period in advance and does not change after that decision is made. It has been claimed that FC is not effective for the management of migratory species, because it is difficult for FC to respond to uncertainties in the predicted distribution of species. Recently, real-time closure (RTC) has been introduced to address this issue. However, the use of RTC is still limited, because its benefits compared with FC have not been evaluated sufficiently. In this study, we conducted simple simulations to evaluate the efficiency of RTC to respond to uncertainties in the movement of migratory species. In terms of the protection of migratory species, the mean performance index of RTC was generally higher than that of FC, and the mean performance index of FC tended to decrease with greater uncertainty of species movement. We also estimated the extent of the reduction of the closure period by applying RTC instead of FC. The results of this study indicate that RTC is an efficient method of fisheries closure, and provide quantitative information to guide the use of RTC instead of FC.