Faculty of Bioresources, Mie University, Tsu, Mie 514-8507, Japan
To evaluate the effectiveness of marine protected areas (MPAs), we analyzed an age-structured model. We estimated the possible range of migration parameters based on the seasonal change in CPUE distribution during 1954 and 1956, and we obtained the expected range of YPR and SPR as functions of the size of MPA, fishing mortality coefficient and age at first capture. As a result, we concluded that MPA is effective in reducing the decrease of YPR and SPR in a high fishing mortality regime at low age at first capture. The difference of migration rate of fish influences the effectiveness of MPA containing about half of the stock of both species all year round. Thus, the accurate estimation of migration of fish not based only on information of seasonal change in CPUE distribution is required to design an effective MPA.