定置網漁業의 漁獲量變動에 관한 硏究

Fluctuation of the Catch by the Set Net Fishery

The catch by the set net fishery from 1971 to 1985 were ananIyzed in order to reveal its fluctuation characteristics. Generally, the catch increased from 16,787M/T in 1971 to 84,103M/T in 1985 and showed maximum in 1979 with 99.475M/T of catch. This trend was mainly related to the higher production of file fish which accounts for 64% of the total catch in 1979, and the change of catch statistical classificaiton according to the revising of fishery law in 1976. It was also closeIy related to the variation of the sea water temperature in coastal area. The main fishing period of the set net fishery appeared from October to November. Catch of the set net fishery was led by that in the southern coast before 1976 and by that in the eastern coast from 1977 to 1980, the tendency changed irregular from 1981. Three groups of fishes could be distinguished by principal component analysis of the annual catch. A group showing steady decreasing tendency was composed of the fishes such as whiting, sand fish, hair tail and anchovy. The another group composed of small alaska pollack, round herring, goby, gizzard shad, sand lance and file fish revaled an increasing tendency. The other fishes did not show any annual tendency.