论文部分内容阅读
为了养护和管理海洋渔业资源,对虾桁拖网网囊网目进行了选择性试验,以期找到最适网目尺寸,为今后立法和管理提供科学依据。经试验表明,随着网囊网目的加大,50％选择体长也随之增加。当网囊网目内径分别为35mm、40mm、45mm时,哈氏仿对虾50％选择体长分别为72.73、74.61、81.43mm;葛氏长臂虾50％选择体长分别为70.42、75.60、79.45mm;脊尾白虾50％选择体长分别为88.37、92.05、97.17mm。 三种虾类的50％选择体长(L_0.5)与网囊网目内径(Me)的线性回归方程如下: 哈氏仿对虾:L_0.5=469+0.8697Me R~2=0.9029 葛氏长臂虾:L_0.5=39.063+0.9024Me R~2=0.9927 脊尾白虾:L_0.5=57.325+0.8801Me R~2=0.9911 三种虾类混合:L_0.5=37.597+1.1470Me R~2=0.9996 将网囊网目尺寸由现在的20mm到25mm提高到35～40mm,则在此网目大小下,能释放掉大量70mm以下的幼虾,而捕获的商品虾质量有明显改善。根据试验结果和分析,建议对虾桁拖网加强管理,制定相应的法规,规定最小网目尺寸。
In order to conserve and manage marine fishery resources, selective tests were conducted on shrimp trawl trawl mesh in order to find the optimal mesh size and provide a scientific basis for future legislation and management. The tests show that, with the purpose of the network increased, 50% of the body length of choice also will increase. When the mesh diameter of the cysts were 35mm, 40mm and 45mm respectively, the body length of 50% of Hyphanmus pumila was 72.73, 74.61 and 81.43mm, respectively. The body length of 50% of the length of Gekko shrimp was 70.42, 75.60 and 79.45 mm; spine white shrimp 50% body length were selected 88.37,92.05,97.17mm. The linear regression equation of body length (L_0.5) and mesh diameter (Me) of 50% of three kinds of shrimp was as follows: L_0.5 = 469 + 0.8697Me R ~ 2 = 0.9029 Long arm shrimp: L_0.5 = 39.063 + 0.9024Me R ~ 2 = 0.9927 White tail shrimp: L_0.5 = 57.325 + 0.8801Me R ~ 2 = 0.9911 Three kinds of shrimp mixed: L_0.5 = 37.597 + 1.1470Me R ~ 2 = 0.9996 The mesh size increased from the current 20mm to 25mm to 35 ~ 40mm. Under this mesh size, a large number of juvenile shrimp under 70mm can be released, and the quality of the captured commercial shrimp is significantly improved. According to the test results and analysis, it is suggested to strengthen the management of shrimp truss trawls, formulate the corresponding regulations and stipulate the minimum mesh size.