Distribution of Walleye Pollock Theragra chalcogramma off Southwestern Hokkaido in the Japan Sea in Spring

• Main Authors: 髙木, 省吾, 前田, 辰昭, 亀井, 佳彦, 中谷, 敏邦, 髙津, 哲也, 高橋, 豊美
• Format: Journal Article
• Language: Japanese
• Published: 日本水産学会 = The Japanese Society of Scientific Fisheries 1996
• Subjects: Theragra chalcogramma; スケトウダラ; 北海道南西部沖合; 対馬暖流; 索餌期初期

In order to elucidate the distribution pattern of walleye pollock Theragra chalcogramma off southwestern Hokkaido in the Japan Sea, trawling and acoustic surveys, and hydrographic observations were conducted in early April from 1989 to 1993. In 1991 and 1993, the Tsushima Warm Current Water was widely distributed in the coastal area of Aomori Prefecture, and a large number of walleye pollock were collected in the southwestern area off Hokkaido. In contrast, this water was observed only in a restricted coastal area of Aomori Prefecture in 1989 and 1990, and walleye pollock were found distributed in a coastal area 20-30 miles off Aomori Prefecture. Although an annual change in the distribution of walleye pollock was observed, they were concentrated in the area of the horizontal thermal front between the Tsushima Warm Current Water and the Japan Sea Proper Water every year. From these observations, it appears that the migration of walleye pollock in early spring is closely related to the behavior of the Tsushima Warm Current Water in the Japan Sea off Aomori Prefecture.