Community structure of macrozoobenthos and its relationship with environmental factors in Lake Gehu, Jiangsu, China.

Abstract

A survey on macrozoobenthos was conducted seasonally and 14 aquatic physicochemical parameters were monitored monthly to reveal the community characteristics of macrozoobenthos and their relationship with aquatic environmental factors at 20 sampling sites in the Lake Gehu from July 2013 to December 2014. A total of 25 macrozoobenthos species including 3 species (12% of total) of Mollusca, 12 species (48%) of Chironomidae, 4 species (16%) of Oligochaeta, 4 species (16%) of Crustacean were identified. The dominant species were Limnodrilus hoffmeisteri, Branchiuras owerbyi, Tanypus chinensis, and Propsilocerus taihuensis. Density and biomass of Chironomid larvae and Oligochata had significant spatial and seasonal changes. The state of aquatic environment was mainly affected by the nitrogen, phosphorus and water temperature in the Lake Gehu, and TN, NO3--N and DO changed significantly with space and season. The Spearman correlation analysis indicated that TN and NO3--N played a key role in the community structure characteristics of the macrozoobenthos in the Lake Gehu. The environmental variables could well explain the changes of main macrobenthic species.