单桩张网菱形、方形网目网囊选择性研究  

Size selectivity of diamond and square mesh codends in single-stake stownet fisheries

作　　者：张健[1] 张鹏[2] 石建高[3] 陈小康[1] 

机构地区：[1]大洋渔业资源可持续开发省部共建教育部重点实验室,上海海洋大学海洋科学学院,上海201306 [2]农业部渔业生态环境重点开放实验室,中国水产科学研究院南海水产研究所,广州510300 [3]农业部海洋与河口渔业重点开放实验室,中国水产科学研究院东海水产研究所,上海200090

出　　处：《海洋渔业》2011年第2期213-220,共8页Marine Fisheries

基　　金：国家自然科学基金(NSFC31001138);国家科技支撑计划(2006BAD09A05);上海市教育委员会科研创新项目(11YZ156);农业部渔业生态环境重点开放实验室基金项目(2007-3);上海市重点学科建设项目(S30702)

摘　　要：近年来,一种利用帆布作为扩张装置的新型单桩张网渔具在吕四渔场得到了快速发展。为了改善这种张网对主要渔获对象的尺寸选择性,进而评价其渔获性能以及对渔业资源的影响,使用套网试验法开展了不同网目尺寸(25 mm、35 mm和45 mm)的菱形和方形网目网囊尺寸选择性试验。通过对黄鲫(Setipinnataay)和小黄鱼(Pseudosciaena polyactis)渔获体长数据的选择性分析,结果显示,无论是菱形还是方形网目网囊,其50%选择体长L50和选择范围SR都随着网目尺寸的增大而增大(L50呈线性增长)。对比菱形和方形网目的选择性发现,对于黄鲫,50%选择体长L50差异不大,但菱形网目的选择范围SR大于方形网目;对于小黄鱼,方形网目具有更好的选择特性,即具有较大的L50(8%)和较小的SR(52%),但差异均不显著。菱形和方形网目对于不同体型鱼类的选择性差异以及渔民对方形网目网囊的抵触情绪等都使得在张网渔业中推广方形网目网囊值得商榷。A new style single-stake stownet fishery,in which canvas device took the place of traditional beam as expansion devices,has been developed in the Lvsi Fishing Ground.In order to improve size selectivity of stownet and assess its fishing efficiency and effect on fishery resources,traditional diamond mesh and square mesh codends with 25mm,35mm and 45mm mesh size were tested on a commercial stownet using the covered codend technique.Selectivity analysis on hairfin anchovy Setipinna taty,little yellow croaker Pseudosciaena polyactis catch composition showed that 50% retention length L50 and selection range SR increased with mesh size（increase of L50 was significantly linear）,irrespective of mesh shape.Comparison with size selectivity of different codends demonstrated that,for hairfin anchovy,L50 of diamond mesh codend was insignificantly different from that of square mesh with the same mesh size whereas SR of diamond mesh codends was higher than that of square mesh.As for little yellow croaker,the square mesh codend gave a better selection than diamond mesh codend,that is,with higher L50 value（8%） and narrower SR（52%） than diamond mesh codend.Different selection characters of diamond and square mesh codends for target species with different body shapes and resistance from fishermen made the promotion of square mesh codends in stownet fisheries debatable.

关 键 词：单桩张网 方形网目 菱形网目 选择性 黄鲫 小黄鱼 

分 类 号：S972.12[农业科学—捕捞与储运]