1Wakayama Research Center of Agriculture, Forestry, and Fisheries, Marine Fisheries Experimental Station, Kushimoto, Wakayama 649-3503, 2Ocean Research Institute, University of Tokyo, Nakano, Tokyo 164-8639, Japan
We studied the optimum management policy for shirasu fisheries in the eastern waters of the Kii Channel using Y/R and evaluated the effect of the prohibition of fishing from March 26 to April 7 in 2004. Y/R is the future yield of an individual at the age of recruitment and two cases of Y/R, under non-fishing and fishing, were compared. In the actual case that fishing was opened on April 8, the effect of the prohibition of fishing was 1.60 times in comparison with the case of non-prohibition. The ideal case can be attained by opening on April 9, for which the effect is 1.61 times, which almost corresponds with the actual case. It is effective to continue this fisheries management.