Evaluation of the advantage of marine protected areas over the reduction of the fishing mortality coefficient

ABSTRACT:   In the present study, we compared the advantage of marine protected areas (MPA) to the reduction of the fishing mortality coefficient ( F ). We accomplished this by comparing the yield per recruitment (YPR) and spawner biomass per recruitment (SPR) under two controls. This was accomplished using a mathematical model. We used the following five measures as comparisons: (i) the condition of the fishery where the increase in YPR is possible; (ii) the increase in YPR or SPR obtained by allocating half the fishing ground as an MPA and by reducing F by half; (iii) the maximum YPR obtainable when the fishing mortality coefficient or the proportion of MPA in the fishing ground is completely controlled; (iv) the proportion of the MPA and the reduction ratio of F required for attaining 30% SPR; and (v) the YPR obtainable while maintaining 30% SPR. Our results show that the MPA has a minor disadvantage in terms of the first measure. The MPA is advantageous in increasing SPR in the second measure, with a low migration rate of fish. The MPA is also advantageous in increasing YPR in the second measure, with some intermediate migration. The MPA is disadvantageous in the third measure. The MPA is advantageous in the fourth measure, with a low migration rate. The MPA is disadvantageous in the fifth measure.