Benthic macroinvertebrate community structure in Lake Taihu,China: Effects of trophic status,wind-induced disturbance and habitat complexity

Lake Taihu, the third largest lake in China, is subjected to severe eutrophication and cyanobacterial blooms as a result of development and urbanization. However, little is known about the macroinvertebrate assemblages and their relationship with eutrophication and other environmental factors in this lake. To characterize the community structure of macroinvertebrates and to examine the benthos-environmental relationships in Lake Taihu, a quarterly investigation was conducted from February 2007 to November 2008. A total of 42 taxa was recorded; Limnodrilus hoffmeisteri, Rhyacodrilus sinicus, Corbicula fluminea, Bellamya aeruginosa, Tanypus chinensis and Gammarus sp. dominated the community in abundance and biomass. Cluster analysis and one-way analysis of similarity (ANOSIM) identified three groups of stations that had significantly different macroinvertebrate communities. Stations in the north bays and three river mouths had the lowest diversity and were dominated by pollution-tolerant species such as L. hoffmeisteri and R. sinicus while Gonghu Bay, the Central Region and the Western Region contained intermediately diverse communities mainly dominated by C. fluminea. Diversity and evenness were highest in the East Bays where aquatic macrophytes were abundant; the zoobenthos were characterized by gastropods. One-way ANOVAs revealed that environmental characteristics differed significantly among the three groups of stations. Canonical correspondence analyses showed that community structure and spatial patterns of macroinvertebrates in Lake Taihu were strongly correlated to three ecological factors—trophic status, wind-induced disturbance and habitat complexity. Our results could provide valuable information that could be used by managers and policy makers to evaluate and modify restoration practices.