南海北部灯光围网渔获组成分析

Analysis on the catch composition of light-purse seine in the northern South China Sea

灯光围网是南海区海洋捕捞业的主要渔具之一。在这一渔业中,幼鱼渔获比例长期居高不下,这一问题已经引起渔业管理部门和渔业科学工作者的关注。为了查明灯光围网渔获中幼鱼比例及其对渔业资源的影响,2006年5月和10月在广东阳江沿海进行了海上渔获组成调查和分析。研究结果表明,渔获种类多,主要是中上层种类,如带鱼Trichiurus haumela、蓝圆鲹Decapterus maruadsi、枪乌贼属Loligo spp.、竹筴鱼Trachurus japoni-cus、长体圆鲹D.macrosoma、羽鳃鲐Rastrelliger kanagurta和脂眼凹肩鲹Selarc rumenophthalmus等;幼鱼比例高,许多种类的幼鱼渔获均超过法定比例;该渔业对南海北部的渔业资源造成较大损害。笔者建议尽快制定南海北部主要捕捞种类最适开捕规格;制定围网取鱼部最小网目尺寸;规定最适灯光强度;加强渔具优化和管理。

A light-purse seine is one of the main fishing gears in the marine capture fisheries of South China Sea. The proportion of the catch of juvenile species in this fishery has long been high, which has arrested the attention of fishery administrations and scientists. In order to find out the proportion of the catch of juvenile species in the light-purse seine fisheries and its effects on fishery resources, an investigation and analysis was conducted on the fishing ground along the coast of Yangjiang, Guangdong, in May and October, 2006. The results showed that there was a diversity in species and a high percentage of juveniles in the catch. The catches were mostly pelagic species, such as Trichiurus haumela , Decapterus maruadsi , Loligo spp. , Trachurus japonicus , D. macrosoma , Rastrelliger kanagurta and Selar crumenophthalmus, etc. The catch of the juveniles in many species had exceeded the minimum legal percentage of allowable catch. The fisheries tended to damage the marine fishery resources in the northern South China Sea. It is recommended that the optimum length at first capture be established as early as possible for the main fishing species in the northern South China Sea, that the minimum mesh size be established for the bunt of the purse seine, that the optimal light intensity be regulated and that the optimization as well as management of the fishing gear be strengthened.