沿岸における小型刺網漁業とその資源-VI

Abstract

In this paper, the author presents the characteristics of the catch and fishing ground on the stopping-net (Egiri-ami) fishery, based on the records of commercial catches and the results of the research from 1957 to 1960 at Tomioka, Amakusa Islands. 1) The stopping-net is chiefly used to catch the Mugilid fishes in winter. The resources of this fishery is rapidly decreasing (Fig. 1). 2) The type of frequency distribution curve of the catch per fishing for a year resembles logarithmic distribution (Fig. 2). The average catch is about 20 in kg. and the coefficient of variation is 1.66. 3) The fish community at the outer bay is similar to that of the inner bay in winter, but the degree of similarity decreases in summer (Table 1 and Fig. 3). 4) Leiognathus nuchalis, Gerres japonicus and Acanthogobius favimanus live largely in the inner bay, while Gerres oyena lives only in the outer bay (Fig. 3). 5) The outer bay is superior to the inner bay in that the amount of catch is not only larger but more stable (Fig. 4).