Detection of Fishing Grounds, Fishing Season, and Size Distribution of Stocked Barfin Flounder Verasper moseri in Southern Tohoku, the Pacific Coast of Eastern Japan

摘要

Barfin flounder Verasper moseri, a rare pleuronectid flatfish, is a target species for stock enhancement programs in Hokkaido (42。N) and Iwate (39。N) prefectures in northern Japan. To elucidate the fishing grounds, fishing season, and size distribution of stocked barfin flounder in southern Tohoku, on the Pacific coast of eastern Japan, fishery data and daily fishery records of offshore bottom-trawl vessels in Fukushima Prefecture were analyzed during 2000-2006. The size distributions in the largest fish market in Fukushima were investigated in 2006. Annual landings increased from lower levels to the highest 1.1 t in 2006，which probably related to the increase of released seedlings in Hokkaido and Iwate prefectures. The main fishing areas evaluated by quantitative assessment of fishery records were found in southernmost Tohoku (35°40'-36 deg 35'N) at depths of around 300 m (mean 278 +- 83.9 m). Remarkable seasonality of the landings was detected: over 92% were caught during January-April, withthe peak period during February-March (68% in total). The two size modes detected in the landings presumably comprised males (ca. 43 cmTL, n = 361) and females (ca. 60 cm TL, n = 42).