2021年度长江口江心青草沙水库鱼类群落结构

为了解长江口江心青草沙水库的鱼类群落结构，于2021年对该水库进行了鱼类资源调查和群落结构分析。共采集鱼类3 209尾，分属于9目13科36属46种，以鲤科淡水鱼类为主；鲢（Hypophthalmichthys molitrix）、鳙（Aristichthys nobilis）、花（Hemibarbus maculatus）、鲫（Carassius auratus）、刀鲚（Coilia nasus）、翘嘴鲌（Culter alburnus）、长蛇（Saurogobio dumerili）、花鲈（Lateolabrax japonicus）的IRI均超过1 000，为优势种；优势种生态位分析显示肉食性和杂食性鱼类在食物资源和生存环境存在较高的生态位重叠，这两种鱼类种群规模扩大受到食物、空间等资源的限制会比生态位重叠低的更大；鲢、鳙与其他鱼类生态位重叠较低，在水库内受到的食物、空间等资源的竞争较小。年度的Margalef种类丰富度指数（D）为5.70,Shannon-Wiener多样性指数（H’）为3.01,Pielou均匀度指数（J）为0.78, Simpson优势度指数（C）为0.81...

Fish community structure of Qingcaosha Reservoir in the Yangtze river estuary in 2021

In order to understand the fish community structure in Qingcaosha Reservoir in the Yangtze River estuary, the fish resources investigation and community structure analysis were carried out in 2021. A total of 3209 individuals were collected、identificated and classified 9 orders, 13 families ,36 genera and 46 species. The Freshwater carnivorous fish species are largest. The Index of Relative Importance，IRIof Hypophthalmichthys molitrix, Aristichthys nobilis, Hemibarbus maculatus, Carassius auratus, Coilia nasus, Culter alburnus, Saurogobio dumerili and Lateolabrax japonicus are more than 1000 and all belonged dominant species .The niche analysis of dominant species showed that carnivorous and omnivorous fish have higher niche overlap in food resources and living environments. The population expansions of the two groups of fish should be more limited by food, space and other resources than the low niche overlap groups. The niche overlap among Silver carp, Bighead carp and other fish is lower, and the competitions for food, space and other living resources in the reservoir are also lower. In 2021, the Margalef species richness index ( D ) was 5.70, the Shannon-Wiener diversity index ( H '' ) was 3.01, the Pielou evenness index ( J ) was 0.78, and the Simpson dominance index ( C ) was 0.81. Compared the results of fish diversity and the community structure with from 2015 to 2019 in the Reservoir , the diversity index is increasing significantly. The ABC curve analysis showed that the community structure was less disturbed by external factors.