| 摘要: |
| 虾拖网是南海区常见的作业方式, 由于其网囊网目选择性差, 虾拖网作业常产生大量的副渔获物。为了优化虾拖网网囊结构, 提高其选择性, 2015年8月在南海北部渔场用方形网目与菱形网目混合网囊进行试验。结果表明: 虾拖网的渔获种类有34种; 渔获种类中, 康氏小公鱼(Anchoviella commersoni)、黑尾吻鳗(Rhynchoconger ectenurus) 、中线天竺鲷(Apogon kiensis) 和杂食豆齿鳗(Pisoodonophis boro)的尾数逃逸率均超过80%; 周氏新对虾(Metapenaeus joyneri)和刀额新对虾(Metapenaeus affinis的尾数逃逸率最低, 仅为6.18%和2.07%; 周氏新对虾和刀额新对虾的50%选择体长(L50)分别为50.79 mm和53.858 mm; 脊突猛虾姑(Harpiosquilla raphidea)的L50为62.51 mm; 丽叶鲹(Caranx kalla)、中华青鳞鱼(Harengula nymphaea)、中线天竺鲷(Apogon kiensis)、赤鼻棱鳀(Thrissa kammalensis)和黄斑蓝子鱼(Siganus oramin)的L50分别为53.77 、78.87、47.17、60.92 和60.55 mm; 混合网囊对鱼类副渔获的释放率较高, 但对幼虾的释放率较低。建议今后放大网囊菱目段的网目尺寸进行相应的试验, 提高混合网囊对目标种类的L50值, 使其在释放鱼类副渔获物的同时释放幼虾, 达到渔业资源的合理利用。 |
| 关键词: 虾拖网 方形网目 菱形网目 网囊 渔获性能 |
| DOI：10.11759/hykx20160107001 |
| 分类号: |
| 基金项目:公益性行业(农业)科研专项(201203018) |
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| Preliminary study of catching performance of a combined diamond- and square-mesh cod-end of a shrimp beam trawl in the northern South China Sea |
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YANG Bing-zhong,YANG Lin,TAN Yong-guang,YAN Lei,ZHANG Peng,LI Jie
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| Abstract: |
| Shrimp beam trawl has been an important component of fisheries in the northern South China Sea. Because of its poor selective cod-end, a lot of bycatch is often collected. To improve the fishing selectivity of the shrimp beam trawl, fishing experiments using a combined diamond-and square-mesh cod-end were conducted in August 2015. The results indicated that 34 species, including fish and shrimp, were caught. Among these species, the escape rates of four species Anchoviella commersoni, Rhynchoconger ectenurus, Apogon kiensis and Pisoodonophis boro were more than 80%. For target species, Metapenaeus joyneri and Metapenaeus affinis, escape rates of only 6.18% and 2.07%, respectively, were observed. The 50% retention lengths (L50) were 50.79, 53.858 and 62.51 mm for Metapenaeus joyneri, Metapenaeus affinis, and Harpiosquilla raphidea, respectively. L50 were 53.77, 78.87, 47.17, 60.92 and 60.55 mm for Caranx kalla, Harengula nymphaea, Apogon kiensis, Thrissa kammalensis and Siganus oramin, respectively. Although the combined cod-end had a good effect in releasing the fish bycatch, it failed to release the small shrimp that was unmatured. Therefore, to sustainably use the fishery resources, a larger mesh size in the diamond section of the combined cod-end was suggested to improve the L50 value of target species and release small shrimp. |
| Key words: Shrimp beam trawl square-mesh diamond-mesh cod-end catching performance |
