Monday, May 26, 2008 - 2:00 PM
61

Fine sediment invasion: A macroinvertebrate killer at a regional scale

Evan Harrison1, Richard Norris1, and Scott Wilkinson2. (1) Institute for Applied Ecology and eWater CRC, University of Canberra, Building 15 Bruce ACT 2601, Canberra, Australia, (2) CSIRO Land and Water, Private Mail Bag PO, Aitkenvale QLD 4814, Australia

Fine sediment accumulation (particle size: <4mm) is a major cause of degradation to ecological condition in many rivers throughout the world. Macroinvertebrates are indicators of river ecological condition that have been used for many years to understand the impacts of sedimentation on river health. However, there has been little research on the relationship between sediment accumulation and macroinvertebrate community composition at a regional scale (1000-1,000,000 km2). This is major concern given that the majority of funding allocations for river rehabilitation are commonly made at regional scales and the majority of previous research on sediment accumulation and macroinvertebrates has been conducted using study designs based on local reach scales (<250m). Therefore, the objective of this study is to understand the variability in macroinvertebrate community response to the amount of sediment accumulation at a regional-scale. Both macroinvertebrate and sediment samples were collected from sites with varying degrees of sediment accumulation throughout the Upper Murrumbidgee River Catchment in south-east Australia. The results so far show that there are clear differences in macroinvertebrate community structure and sediment infiltration between areas with high and low levels of accumulation.


Web Page: Macroinvertebrates, Sedimentation

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