Nagasaki Prefectural Institute of Fisheries, Nagasaki 851-2213, Japan
This study evaluated the stocking effectiveness of hatchery-produced ocellate puffer by sampling surveys at fish markets in Ariake Sound where young-of-the-year (YOY) puffer are landed. The recapture rate of released seeds (3-100 mm in total length) for each annual release in the three areas Shimabara coast, Isahaya Bay, and the innermost area of Ariake Sound was estimated at between 0.01 and 22.3%, and was found to increase with increasing release size and showed a tendency that the recapture rates of seeds released at Isahaya Bay and the innermost area are higher than that at Shimabara coast. The contribution rate of the released puffer to the total landings in number was estimated to range between 6 and 52%. Stocking effectiveness was shown in Fukuoka, Saga, Kumamoto and Nagasaki prefectures and the ratios of landing number and value differed among the release sites. It was suggested that 75 mm in total length is the optimal size for release and Isahaya Bay and the innermost area in Ariake Sound are the best sites for release in terms of the ratio of landing cash value to the cost of seed.