摘要
本文根据“东方”号船在东海大陆架外缘和大陆坡深海渔场所测定的38个渔获物种类的尾数、体重的选择率资料,讨论了影响选择率和选择域的诸因素、囊网内渔获物的阻碍效应以及套网网目的适当尺寸。并认为今后开发利用该渔场时,囊网的最小网目内径25.0毫米是合适的。
During the period of October-November 1981, eleven operations of trawl mesh selectivity experiments were carried out on the deep sea fishing grounds of East China Sea (28°10′～29°13′N、126°15′～127°15′E; 125-376m depth). The trawl adopted for tests was the bottom trawl (538meshes x 135mm) using in R/V 'DONG FANG'.Under the cases of codend (mesh opening 77.4/48.7mm) with the cover net (mesh opening 25.0mm), 38 specific selection rate in number were obtained as varied from o to 1. In addtion, in order to correct the catch of exploratory fishing corresponding specific selection rate in weight were obtained too. The escape from the square and the baiting of trawl was very little, so that it is negligible.In the paper, the factors affected on the selection rate and selection range, the block effect of catches held in codend, as well as the appropriate mesh size of cover net are discussed.It is pointed out that for furture exploitation and ultilization of these fishing grounds, choosing 25mm as the minimun mesh opening of codend is recommendable.
