邢彬彬,齐雨琨,马丁一,林仲帅,李 超,许传才
(大连海洋大学辽宁省海洋牧场工程技术研究中心,辽宁 大连 116023)
摘要:为了解盘锦海域桁杆虾拖网的网囊网目尺寸是否适宜当地渔业生产,使用套网法研究了该网具不同网目尺寸的网囊对葛氏长臂虾(Palaemon gravieri)和脊尾白虾(Palaemon carinicauda)的选择性。结果显示,试验网囊网目尺寸为20、25和33 mm时,葛氏长臂虾的50%选择体长L0.5分别为30.7、36和40 mm,选择范围SR分别为12.2、10.4和13.8 mm,选择性因数SF分别是1.5370、 1.4394和1.3310;脊尾白虾的50%选择体长L0.5分别为38.3、40.2和45.3 mm,选择范围SR分别为9.3、14.4和12.9 mm,选择性因数SF分别是1.913 1、1.608 2和1.372 7。两种虾类的 50% 选择体长(L0. 5) 和网囊网目内径(m) 的线性回归方程为,葛氏长臂虾:L0.5=0.686 9 m+17.691 8;脊尾白虾:L0.5=0.550 0 m+26.955 7。研究认为:盘锦海域常见的20 mm网囊网目的桁杆拖网会捕获大量的幼虾,对渔业资源造成巨大破坏;建议捕捞葛氏长臂虾可用网囊网目内径为33~38 mm的桁杆虾拖网,捕捞脊尾白虾可用网囊网目内径为24~30 mm的桁杆虾拖网。
关键词:桁杆拖网;网囊网目选择性;葛氏长臂虾;脊尾白虾
Study on cod-end mesh selectivity of beam shrimp trawl in Panjin sea area
XING Binbin, QI Yukun, LIN Zhongshuai, WANG Zhenwei, LI Chao, XU Chuancai
( Center for Marine Ranching Engineering Science Research of Liaoning Province,
Dalian Ocean University, Dalian 116023, China)
Abstract: In order to know whether the beam shrimp trawls are adaptable for fisheries productio in Panjin sea area, the selectivity tests of the beam trawl with different mesh-sizes of cod-end to Palaemon gravieri and Palaemon carinicauda were studied by the covered net method. The results showed that the 50% escapable body length ( L0.5) increased with the mesh size of cod end. When the mesh sizes of cod end were 20, 25, and 33 mm, 50% escapable body lengths (L0.5) were 30.7, 36, and 40 mm respectively for Palaemon gravieri, and 38.3,40.2, and 45.3 mm for Palaemon carinicauda. The Selection Ranges (SR) were 12.2, 10.4, 13.8 mm for Palaemon gravieri, and 9.3, 14.4, 12.9 mm for Palaemon (Exopalaemon) carinicauda. And the Selection Factor(SF) were 1.5370, 1.4394, 1.3310 for Palaemon gravieri, and 1.9131, 1.6082, 1.3727 for Palaemon carinicauda. The relations between 50% escapable body length and mesh size of the two species mentioned above can be described as follows: Palaemon gravieri: L0.5=0.6869 m+17.6918; Palaemon carinicauda: L0.5=0.5500 m+26.9557. Combied with study results and relevant documents, it showed that 20 mm-cod-end-mesh beam trawl could catch a lot of juvenile shrimp and cause a huge destruction of the fishery resources in Panjin sea area.
Keywords: beam trawl; cod-end mesh selectivity; Palaemon gravieri; Palaemon carinicauda
(来源:《渔业现代化》2015,42(1)57-60)