广东硇洲岛周围水域虾拖网副渔获组成分析

根据2005年渔业资源监测船的生产调查资料和现场取样数据，运用数理统计方法分析了广东硇洲岛周围水域虾拖网副渔获组成及其月变化等。结果表明：硇洲岛周围水域虾拖网副渔获种类多，主要为沿岸性底栖种类，组成结构存在明显的月变化，其中蟹类和鱼类是影响副渔获组成结构和月变化的优势类群；副渔获海上抛弃率很低，兼捕现象严重是现阶段虾拖网的主要问题，副渔获与目标虾类的平均重量比为6．8：1，平均产值比为2．5：1。为了合理利用渔业资源和促进虾渔业的可持续发展，应根据鱼、虾、蟹等的生活习性和行动差异开发适宜广东沿海虾拖网的选择性捕捞技术，减少副渔获的兼捕量。

Composition of by-catch in shrimp beam trawls in waters surrounding Naozhou Island in Guangdong province

The composition and monthly variation of by - catch were analyzed on the basis of production investigation and data collected by fishing vessels in 2005 by Microsoft Excel. The results showed that there were many coastal and epibenthile species, dominate fishes and crabs with significant monthly variation in composition, in the by -catch of shrimp beam trawls in waters surrounding Naozhou Island had. The average ratio of by - catch to shrimp was found to be 6.83：1 in weight and 2.5：1 in value, indicating that relatively high percentage of by - catch and less by - catch discards were the main problems in shrimp trawls. A great number of by - catch should be reduced and released largely using trawl separating devices and techniques based on behavior and characteristics of shrimp, fish and crabs to exploit rationally fishery resources and to improve sustainable shrimp fishery development.