東海・黄海における底魚群集の研究 : I.トロールによる漁獲物組成の変遷

抄録

1. Twenty-three series of correlation coefficients obtained by the reciprocal treatment of catch in every year are classified to four types.(Refer to Fig. 1)2. Correlation coefficients of the association between the successive years are shown in Fig. 2. The depressions of the curve are equivalent to the turning points of the type in Fig. 1. 3. It is presumed that the fish composition which maintains the condition immediately before interruption of fishing failed to return to the beginning condition, because the series of correlation coefficients from 1952 to 1954 are similar to those from 1942 to 1943. 4. The fish species which have effect on the change of composition are, sea bream, white croaker, black croaker, sharp toothed eel, ribbon fish and butter fish, and they are distributed in main fishing ground and caught by trawllers. 5. Concerning the organizing process of the fish association, the law of geometrical progression can be applied in 1941,and such a linear relationship was not recognized in other years. I should like to consider that the demersal fish association in 1941 showed the maximum development.