サンゴ海南西部におけるシロカワの漁場,漁期,釣獲率の年変化

Abstract

I studied on the differences of fishing grouds (Fig. 1) of white marlin in each year from the distributions in respective year and period (Table 1, Fig. 2), on those differences of fishing seasons (Table 1) and rate-of-catches (catch number per hundred hooks ) of the fish for each year from the annual and periodical distributions (Fig. 2) and periodical variations of mean rate-of-catch. Consequently, it was presumed that a trend of decreasing product of 1957 and 1958 may not be attributable by a deviation of the fishing grounds or the seasonal change, but would be caused by falling of the rate-of-catch itself in the whole fishing grounds and seasons.