浙江南部外海头足类种类组成和数量分布

根据2006年5月、8月、11月和2007年2月浙江南部外海底拖网渔业资源调查资料,用渔获率作为资源分布的数量指标,对浙江南部外海头足类种类组成、数量分布、季节变化趋势作了定量分析。结果表明:浙江南部外海调查海域头足类种类有36种,其中:群体数量较大,经济价值较高的常见种有杜氏枪乌贼、剑尖枪乌贼、中国枪乌贼、长蛸、针乌贼、真蛸、神户乌贼、珠乌贼、罗氏乌贼、短蛸、椭乌贼、太平洋褶柔鱼、多钩钩腕乌贼等13种。调查海域以夏季头足类资源密度较高,数量分布主要集中在100~200 m水深的外侧海域;秋季和冬季尽管头足类资源数量在下降,但其数量的地理分布与夏季相近;而春季分布较密集的区域则在80~200 m水深海域。年间不同水深海域的头足类资源密度是80~100 m水深海域低于100~200 m水深海域。与近海渔场相比,浙江南部外海调查海域头足类种类多而且资源较丰富,其渔获量仅次于鱼类,是浙江南部外海底拖网的主要捕捞对象,特别是枪乌贼科的种类是今后可供底拖网作业开发利用的主要渔业资源之一。

Species composition and quantitative distribution of cephalopod in the offshore waters of southern Zhejiang Province

According to the bottom trawling surveys in the offshore waters of southern Zhejiang Province during May,August,November of 2006 and February of 2007,the species composition,quantitative distribution and the seasonal variation of Cephalopod have been analyzed by means of using relative fishing rate as the abundance index of the resources distribution,it came to the results that there were 36 species caught in four investigations in the sea areas mentioned above.Among them 13 species such as Loligo duvaucelii,Loligo edulis,Loligo chinensis,Octopus variabilis,Sepia andreana,Octopus vulgaris,Sepia kobiensis,Sepia torosa,Sepia robsoni,Octopus ocellatus,Sepia elliptica,Todarodes pacificus and Abralia multihamata were the main commercial species caught in the investigations.The highest catch rate appeared in summer and mainly distributed in the outside of the water areas with depth ranged from 100m to 200m.The trend of quantitative distribution both in autumn and winter was similar to that of summer,though the abundance index of summer was higher than that in other two seasons.Cephalopod appeared in a wider waters with depth ranged from 80m to 200m in spring.The abundance index was higher in the waters with depth ranged from 100m to 200m.In the offshore waters of southern Zhejiang Province,there were more species and quantity of Cephalopod as compared with those in the inshore waters.The Cephalopod resources only after the fishes resources become the main target caught by bottom trawl in the sea areas of southern Zhejiang Province,especially the species of Loliginidae could be caught by the bottom trawl and create more commercial value.