Ecological characteristics of macrobenthic communities in the chaohu lake basin and their relationship with environmental factors

Abstract

Researchers investigated the structural characteristics and the biodiversity of macrobenthic communities and their relationships with environmental factors in the Chaohu Lake Basin. From 59 grab samples, we obtained 23 macrobenthic species of which six species were annelids (26.1% of total species number), eight species were arthropods (34.8%), nine species were mollusks (39.1%). The researcher assessed abundance, biomass and the Shannon-Wiener, Pielou and Margalef diversity measures. We found the dominant species to be: Limnodrilus hqffmeisteri Claparede, Branchiura sowerbyi Beddard, Bellamya aeruginosa with distinctive differences in their distribution. Multivariate analyses (cluster analysis, multi-dimensional scaling) divided the samples into three communities which could be related to three regions. The biodiversity of the community of the upper reaches of rivers inside and out of Chaohu lake (community I) was the highest that of the lower reaches (community II) was the lowest that of Chaohu lake and its estuaries (community III) ranked in the middle. We also measured a suite of environmental variables. We employed canonical correspondence analysis to relate these with the macrofaunal community structure. Chlorophyll a and Nitrate levels were the most influential environmental factors. © Medwell Journals, 2011.