长江口近海鱼类多样性的年际变化  

Analysis on annual change of fish diversity in Yangtze estuary offshore water area

作　　者：李建生[1] 李圣法[1] 丁峰元[1] 程家骅[1] 

机构地区：[1]农业部海洋与河口渔业重点开放实验室中国水产科学研究院东海水产研究所,上海200090

出　　处：《中国水产科学》2007年第4期637-643,共7页Journal of Fishery Sciences of China

基　　金：科技部公益性项目-东海区渔业资源动态监测网(2005-2006)

摘　　要：以1960年和2004年各3个季节长江口近海的渔业资源调查资料为基础,通过网具标准化之后对该水域的鱼类优势种组成和多样性的长周期年际变化进行分析。结果表明,该水域2004年的鱼类种类数和资源密度指数与1960年相比均出现了较大幅度的下降;虽然仍以底层鱼类的生物量占绝对的优势,但鱼类群落中的优势种的种类组成却发生了较大的更替,由1960年以底层优质鱼类为主变为2004年以中上层种类和小型低值杂鱼为主,群落的多样性趋于简单化,稳定性更加脆弱。高强度的捕捞和近海环境污染是引起鱼类多样性降低的主要原因,因此,从提高长江口近海鱼类群落结构的多样性和恢复海洋生态系统的稳定性方面考虑,当前最主要的措施应该是降低该水域的捕捞强度以减小对鱼类的捕捞压力,同时还需要减少近海的水环境污染。The paper analyzed the dominant fish composition and annual diversity change after standardized investigating fishing gear based on the data about fishery resource pooled from the investigations in 1960 and 2004 in Yangtze estuary offshore water area. The result indicated that in the water area, the number of species and index of fish resources density in 2004 have a great decline compared with 1960; the species numbers in spring and autumn decreased by above 20% except little change in summer, and that total occurrence and average species numbers of three seasons have above 25% decrease; the CPUE＇s decrease of spring and autumn and seasons average and total index of the three seasons are above 88 % except summer with comparatively low value（66.32% ） in 2004 compared with 1960. Although the demersal fish also had absolute dominance in biomass, the dominant species composition presented great subrogation in 2004 compared with 1960 that the main dominant fish had 11 species which were Larimichthys crocea , Dasyatis bennetti, Dasyatis sinesis , Larimichthys polyactis , Platyrhina sinensis , Ilisha elongata , Muraenesox cinereus, Trichiurus japonicus, Mǖchthys mfiuy and Sillago japonica in 1960, but it had 6 species which were Trichiurus japonicus , Larimichthys polyactis , Setipinna taty , Pampus argenteus , Engraulis japonicus and Psenopsis anomala in 2004. The top 21 species＇ biomass cumulative percentage was above 90% in 1960, but the top 5 species＇ biomass cumulative percentage was above 90 % in 2004. Each diversity index of 2004 had a great decline compared to 1960;the decreasing value of D was the most in autumn and the sec- ond in spring and the lest in summer; the decreasing value of index H＇ was the most in autumn and the second in summer and the lest in spring. The primary fish community composition was demersal and with high quantity in 1960,but it had shifted to give priority to pelagical and minitype and low value fish in 2004. Now the community diversity has tended to simplification and it

关 键 词：长江口 鱼类 多样性 年际变化 

分 类 号：S931[农业科学—渔业资源]