长江口海域夏季大型底栖动物群落结构分析

Analysis of summer macrozoobenthos community structure in the Yangtze River estuary

本研究基于2011—2014年夏季对长江口大型底栖动物的调查,对其种类组成、丰度和生物量进行了年际变化分析。4年间分别采集到大型底栖动物60、58、78和83种。平均丰度和平均生物量在2011—2013年间呈现出逐年递减趋势,长江冲淡水区的平均丰度和平均生物量明显高于长江口内。2014年平均丰度和平均生物量均显著回升。生物多样性指数(H')、丰富度指数(D)和均匀度指数(J')基本稳定,2012年略低,而之后呈现整体回升的趋势。优势种包括丝异须虫、双形拟单指虫和钩虾,2013年未出现优势种,其余年份则以多毛类为主。年际间群落结构变化较大,且群落组成呈逐年丰富的趋势。本研究为进一步研究长江口环境变化和该海域大型底栖动物群落演替提供了基础资料。

Based on the survey of macrozoobenthos from the Yangtze River estuary in summer during 2011—2014,this paper analyzes inter-annual variation of species composition,abundance and biomass. The results showed that a total of 60 species were collected in 2011,58 species in 2012,78 species in 2013,and 83 species in 2014. During 2011—2013,the mean abundance and the mean biomass decreased year by year. M eanwhile,the mean abundance and the mean biomass in the diluted water region of the Yangtze River estuary were noticeably higher than those of the Yangtze River estuary. Both the mean abundance and the mean biomass,however,rose again significantly in 2014. The biodiversity index（ H＇）,richness index（ D） and evenness index（ J＇） were basically stable,slightly lower in 2012 and exhibiting an overall recovery trend later. The dominant species were Heteromastus filiformis,Cossurella dimorpha,and G ammarus sp. Polychaetes were the dominant group every year except in 2013,in which no dominant species was detected. The inter-annual variation in community structure was relatively large and the community components showed a trend of increasing abundance year by year. The results of this paper provide a scientific basis for further study of environmental change and macrozoobenthos community succession in the Yangtze River estuary.