2016—2020年太湖鱼类群落结构变化及对太湖水环境的响应

基于2016-2020年太湖10个鱼类采样站位和33个水环境站点监测数据,分析研究了近年来太湖鱼类群落结构变化及其对水环境的响应。调查结果表明,2020年共在太湖调查发现鱼类55种,主要优势种为刀鲚、鲫、鲤,相对重要性指数分别为9219.28、1698.78和1075.27。太湖87.9%的鱼类全长在200mm以下,88.2%的鱼类体重在50g以下。2016年以来,共在太湖发现鱼类67种,太湖水环境总体保持稳定,但鱼类群落结构发生了较大变化,优势种发生明显改变。统计结果表明,近年来太湖鱼类群落结构多样性指数与主要水环境指标之间无显著相关性,太湖外排水量、人工增殖放流对太湖鱼类群落结构具有重要影响。需结合太湖水环境状况建立太湖鱼类精细化捕捞方案及鲢鳙鱼增殖放流方案,引导太湖鱼类群落结构恢复并最大程度挖掘太湖鲢鳙鱼控藻潜力。

Community structure and diversity of fish in Taihu Lake from 2016 to 2020 and their relationship with water environment

Based on fish community monitoring data of 10 sites and water environment monitoring data of 33 sites in the Taihu Lake from 2016 to 2020, the fish community structure and diversity were investigated, as well as its relationship with main water environment factors. A total of 55 fish species were collected in 2020, and the dominant species were Coilia nasus, Carassius auratus and Cyprinus carpio,of which the index of relative importance were 9219.28, 1698.78 and 1075.27 respectively. Besides, the proportion of 87.9% fish full length <200mm, and the proportion of 88.2% fish mass body <50g. A total of 67 fish species were collected since 2016, and fish community structure changed greatly although the water quality remains stable. The results showed that there was no significant relationship between fish community diversity index and main water environmental factors and the water discharge of Taihu Lake and the artificial propagation and release were the key factors. A finer fishy program and the artificial propagation and release program of Chinese silver carps and bighead carps should be established based on the water environment situation of Taihu Lake , in order to restore the fish community structure and play the role of the Chinese silver carps and bighead carps in controlling algal bloom.