伏休前后舟山渔场单拖船低值杂鱼渔获物组成比较分析

Comparative Analysis of Species Composition of Low Value/Trash Fish Caught by Single Otter Trawl in Zhoushan Fishing Ground before and after the Closed Fishing Aeason

随着捕捞加剧和资源衰退,低值杂鱼在渔获物产量中所占比例也越来越高。最初渔获物中的这些低值杂鱼并没有引起足够的重视,到2005年亚太渔业委员会专门发布关于亚太地区低值杂鱼的捕捞情况的报告,才第一次正式提出该问题,对大量捕捞低值杂鱼的生态后果表示了担忧。如何正确认识低值杂鱼的捕捞,了解其资源利用现状是资源持续发展面临的关键问题之一。本文根据2014年5月和9月6艘在舟山渔场作业的单拖渔船渔获物资料,分析低值杂鱼渔获组成的情况。重点比较伏季休渔前后,低值杂鱼种类组成和体长、体重等生物学特征。通过分析发现,5月份共出现低值杂鱼28种,9月份共出现鱼类29种,仅在5月份出现的共18种,仅在9月份出现的共19种。5月份单一种类比例较9月份高,这主要是受到鲐鱼幼鱼产量的影响,可能与主捕鲐鱼的围网渔船在5月份开始禁渔有关。但5月份的经济种类比例低于9月份,这体现了伏季休渔对于经济种类资源恢复所起到一定的效果。

The proportion of low value/trash fish in catch is increasing with the increase of fishing effort and the decline of fisheries resources. At first, people did not pay more attention to the low value/trash fish un-til the report released by Asia-Pacific Fishery Commission Secretariat（APFIC）, which firstly formally put for-ward this issue, and expressed worry about the ecological consequence of the catch of low value/trash fish.Thus, how to understand the catch of low value/trash fish and the current situation of its resource utilization is one of the key problems in the sustainable development of resources. In this study, species composition was analyzed based on catch data from 6 single otter trawls fishing in Zhoushan fishing ground in May and September. The composition of low value/trash fish and body length, body weight were compared before and after closed fishing season. The results showed that 28 species of low value/trash fish were observed in May, and29 species in September. Eighteen species were observed only in May, while 19 species were observed only in September. The proportion of single species was higher in May than that in September, which was affected by the catch of juvenile of chub mackerel（Scomber japonicus）, and this may be the reason of the closed fishing season of purse seines start in May 1st. However, the proportion of economic species in May was lower than that in September, which indicate the effect of closed fishing season for the recovery of economic species.