南海区单船有袖单囊拖网网囊网目对金线鱼的选择性研究  

Size selectivity of codend-mesh size in single boat bottom otter trawls for Nemipterus virgatus in South China Sea

作　　者：杨炳忠[1,2] 晏磊 李杰[1] 王腾[1] 张鹏 YANG Bingzhong;YAN Lei;LI Jie;WANG Teng;ZHANG Peng(South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences/Key Laboratory for Sustainable Utilization of Open-Sea Fishery,Ministry of Agriculture and Rural Affairs,Guangzhou 510300,China;College of Marine Living Resource Sciences and Management,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]中国水产科学研究院南海水产研究所/农业农村部外海渔业可持续利用重点实验室,广东广州510300 [2]上海海洋大学海洋生物资源与管理学院,上海201306

出　　处：《南方水产科学》2024年第3期1-7,共7页South China Fisheries Science

基　　金：中国水产科学研究院中央级公益性科研院所基本科研业务费专项资金资助(2019CY0303);国家重点研发计划项目(2020YFD0901205);农业农村部财政项目“渔具标准及管理制度完善”。

摘　　要：金线鱼(Nemipterus virgatus)是南海区拖网渔业的重要经济种类。为提高拖网对金线鱼的选择性,在南海区使用套网法对网目尺寸分别为30、35、40和45 mm的4组网囊开展了试验。使用双重拔靴法拟合网囊对金线鱼的选择性参数和选择性曲线,比较网囊间的选择性差异,并估算网囊的捕捞方式指数。结果显示,随着网目尺寸的增大,50%选择体长(L50)增大,选择性曲线的置信区间变窄,网囊对金线鱼幼鱼的渔获比例减小。试验网囊的L50均小于金线鱼的开捕规格(15.0 cm),网囊对金线鱼的抛弃率大于67%。研究表明,增大网目尺寸能够优化网囊的选择性,但选择性仍需进一步提升,才能更好地促进金线鱼拖网渔业的可持续发展。Threadfin bream(Nemipterus virgatus)is an important species in the trawl fishery of the South China Sea.In order to improve the size selectivity and exploitation pattern of single boat bottom otter trawls for N.virgatus,we tested four experi-mental codends with mesh sizes of 30,35,40 and 45 mm by applying the covered codend method in the South China Sea.We analyzed the catch data with double-bootstrapping technique to estimate the selectivity parameters,selectivity curves,delta se-lectivity curves and exploitation pattern indicators.The results demonstrate that with increasing mesh sizes in codends,50%re-tention length(L50)increased,confidence intervals of the selectivity curves became sharper,and retention fraction of under-sized individuals decreased.However,when considering the minimum conservation reference size of the target species(15.0 cm),the L50 values of codends tested were less than 15.0 cm,and their discarded percentages were all over 67%.Though the study shows that increasing mesh sizes will improve size selectivity,it should be further improved to achieve a sustainable trawl fishery for threadfin bream.

关 键 词：拖网 网囊网目 选择性 金线鱼 

分 类 号：S971.4[农业科学—捕捞与储运]