The impact of fine sediment accumulation on benthic macroinvertebrates: implications for river management

Fine sediment accumulation (particle size: <4mm) is a major cause of degradation to instream habitats and ecological condition in many Australian rivers. Benthic macroinvertebrates are commonly used indicators of river ecological condition that can be adversely affected by fine sediment accumulation. Sedimentation can change the suitability of the substrate for some taxa, increase macroinvertebrate drift and affect respiration and feeding activities. Only a few studies have focussed on the responses of individual taxa to sedimentation and many have not disentangled its impact from other associated land-use impacts. This paper describes current understanding of the ways in which fine sediment accumulation affects benthic macroinvertebrates. The paper then outlines the research needed to provide methods for assessing how fine sediment accumulation affects benthic macroinvertebrates at a regional scale. Such research is important for ongoing efforts to maintain and improve river health.