학술논문
单船桁杆拖网网囊网目尺寸对哈氏仿对虾和大管鞭虾的选择性 / Selectivity of different mesh size codends of beam shrimp trawl for Parapenaeopsis hardwickii and Solenocera melantho
Document Type
Academic Journal
Author
徐国强; 虞宝存; 张洪亮; 周永东; 朱文斌; 许柳雄; XU Guoqiang; YU Baocun; ZHANG Hongliang; ZHOU Yongdong; ZHU Wenbin; XU Liuxiong
Source
渔业现代化 / Fishery Modernization. 50(6):103-112
Subject
Language
Chinese
ISSN
1007-9580
Abstract
为探明东海海域单船桁杆拖网网囊网目尺寸对哈氏仿对虾(Parapenaeopsis hardwickii)和大管鞭虾(Solenocera melantho)的选择性,于 2018 年 12 月份和 2019 年 3-4 月份分别开展了不同网囊网目尺寸选择性试验,分析了试验阶段渔获物组成、主捕虾类体长分布以及不同网囊网目尺寸对两种虾类的选择性.结果显示:12 月份试验以捕捞哈氏仿对虾为主,其体长范围为 35～100 mm,平均体长 66 mm;3-4 月份试验以捕捞大管鞭虾为主,其体长范围为 30～140 mm,平均体长 60 mm.随着网囊网目尺寸的增加,哈氏仿对虾平均体长从71 mm增至74 mm,大管鞭虾平均体长从64 mm增至74 mm,网目尺寸对两种虾类体长影响明显.网囊网目尺寸为 25 mm、28 mm和 38 mm时,哈氏仿对虾 50%选择体长(L50)分别为 55.334 mm、57.396 mm和68.319 mm;网囊网目尺寸为 22 mm、25 mm、28 mm和 38 mm时,大管鞭虾L50 分别为 54.919 mm、62.734 mm、72.807 mm和 74.819 mm.哈氏仿对虾和大管鞭虾网囊网目尺寸与L50 的关系式分别为:L50 =1.023 m+ 29.331(R2 = 0.995),L50 = 1.134 m+34.280(R2 = 0.724).随着网囊网目尺寸增加(25～38 mm,22～38 mm),哈氏仿对虾和大管鞭虾选择性曲线均依次向右移动,选择性曲线均出现交叉现象,这与虾类体形特征密不可分.为释放体长小于70 mm的小虾,建议主捕哈氏仿对虾期间,网囊网目尺寸应不小于39.75 mm;主捕大管鞭虾期间,网囊网目尺寸应不小于 31.50 mm.本研究可为东海海域单船桁杆拖网渔具管理与两种虾类资源保护提供参考.
To clarify the selectivity of beam shrimp trawl for Parapenaeopsis hardwickii and Solenocera melantho,authors conducted the selectivity tests of different mesh sizes in December 2018 and March to April 2019,respectively.The results showed that:In December,the experiment mainly focused on catching Parapenaeopsis hardwickii,whose body length ranged from 35 to 100 mm,with an average body length of 66 mm;in the investigation from March to April,the main fishing was Solenocera melantho,whose body length ranged from 30 to 140 mm,with an average body length of 60 mm.With the increase in mesh size,the average body length of Parapenaeopsis hardwickii increased from 71 to 74 mm,and the average body length of Solenocera melantho increased from 64 to 74 mm.The mesh size significantly affected the body length of the two types of shrimp.When the mesh size for Parapenaeopsis hardwickii was 25 mm,28 mm and 38 mm,its L50 was 55.334 mm,57.396 mm and 68.319 mm;when the mesh size for Solenocera melantho was 22 mm,25 mm,28 mm and 38 mm,its L50 was 54.919 mm,62.734 mm,72.807 mm and 74.819 mm.The equations for the relationships between the mesh size of the codends and L50 for Parapenaeopsis hardwickii and Solenocera melantho,respectively,are as follows:L50=1.023 m+29.331(R2 = 0.995),L50 = 1.134 m+34.280(R2= 0.724).As the mesh size of codends increased(25-38 mm,22-38 mm),the selectivity curves of both Parapenaeopsis hardwickii and Solenocera melantho shifted sequentially to the right,and the selectivity curves both showed crossover phenomena,which were inseparable from the body shape characteristics of the shrimp.To release shrimps with body length less than 70 mm,it is recommended that the mesh size of codend should not be less than 39.75 mm during the main catch of Parapenaeopsis hardwickii;The mesh size of codend should not be less than 31.50 mm during the main catch of Solenocera melantho.The results of this study can provide a reference for the management of beam shrimp trawl and the protection of two kinds of shrimp resources in the East China Sea.
To clarify the selectivity of beam shrimp trawl for Parapenaeopsis hardwickii and Solenocera melantho,authors conducted the selectivity tests of different mesh sizes in December 2018 and March to April 2019,respectively.The results showed that:In December,the experiment mainly focused on catching Parapenaeopsis hardwickii,whose body length ranged from 35 to 100 mm,with an average body length of 66 mm;in the investigation from March to April,the main fishing was Solenocera melantho,whose body length ranged from 30 to 140 mm,with an average body length of 60 mm.With the increase in mesh size,the average body length of Parapenaeopsis hardwickii increased from 71 to 74 mm,and the average body length of Solenocera melantho increased from 64 to 74 mm.The mesh size significantly affected the body length of the two types of shrimp.When the mesh size for Parapenaeopsis hardwickii was 25 mm,28 mm and 38 mm,its L50 was 55.334 mm,57.396 mm and 68.319 mm;when the mesh size for Solenocera melantho was 22 mm,25 mm,28 mm and 38 mm,its L50 was 54.919 mm,62.734 mm,72.807 mm and 74.819 mm.The equations for the relationships between the mesh size of the codends and L50 for Parapenaeopsis hardwickii and Solenocera melantho,respectively,are as follows:L50=1.023 m+29.331(R2 = 0.995),L50 = 1.134 m+34.280(R2= 0.724).As the mesh size of codends increased(25-38 mm,22-38 mm),the selectivity curves of both Parapenaeopsis hardwickii and Solenocera melantho shifted sequentially to the right,and the selectivity curves both showed crossover phenomena,which were inseparable from the body shape characteristics of the shrimp.To release shrimps with body length less than 70 mm,it is recommended that the mesh size of codend should not be less than 39.75 mm during the main catch of Parapenaeopsis hardwickii;The mesh size of codend should not be less than 31.50 mm during the main catch of Solenocera melantho.The results of this study can provide a reference for the management of beam shrimp trawl and the protection of two kinds of shrimp resources in the East China Sea.