The development of biological indicators for assessing ecological conditions in streams and rivers is
urgently needed in China, particularly in heavily impacted regions. The aim of this study was to develop
and apply benthic macroinvertebrate-based multimetric indices (MMIs) for the assessment of streams
andriversinthewesternhillandeasternplainaquaticecoregionsof theTaihuBasin.MMIswerebasedon
samples collected fromOctober16 to November 8 2012 at 120 sites in streams and rivers. Least disturbed
sitesdefinedthereferenceconditions