黄海北部单船有翼单囊底拖网结构优化研究

Structure optimization of bottom trawls in the northern Yellow Sea

为解决单船有翼单囊底拖网作业时兼捕稚幼鱼比例较大的问题,增大了原生产网第五节网背网衣的网目尺寸,并将改进后的生产网作为试验网,在黄海北部海洋岛附近海域采用交替作业法进行原生产网和试验网各10网次的对比试验。结果表明:试验网的总渔获质量比原生产网减少69.87 kg;原生产网捕获27种渔获物,试验网捕获19种渔获物,比原生产网减少8种,兼捕现象得到缓解;相比原生产网,试验网中的各渔获种类体长分布范围向右偏移,说明体长范围偏小的渔获物得到一定释放。本研究结果可为中国拖网类渔具的结构优化和渔业资源保护提供参考。

The bottom trawls were modified by increase in network back mesh size in the original network of the fifth section of the bottom trawls in order to reduce bycatch and small juvenile fish in the operation of the bottom trawl, and tested 10 times in the waters near the Haiyang Island using alternating operations issued by the original production network. The results showed that there was 69. 87 kg of catch weight in the test network, less than that in the original production network, and that 27 species of fish were captured by the original production network. While 19 species were caught in the test network, 8 species less than by the original production network, and with less bycatch. Compared to the original production network, the body length of the main catch in the test network was shifted to the right in the body length frequency curve, indicating that the test network released the smaller cat-ches of the fish and protected the larvae resources. The findings provide a reference for the structural optimization of trawl fishing gear and the protection of fishery resources.