The Effect of Substrate Size On Macroinvertebrate Distribution in Little Niagara

Abstract

Our research objective was to investigate how rock substrate size influences macroinvertebrate species richness and abundance within Little Niagara Creek of the University of Wisconsin--Eau Claire campus. A restoration project of Little Niagara took place during the construction of the university's new Davies Center in 2012. Rocks and sediment were added to the stream during this time to enhance habitat and increase stream flow (Knight 2012). We predicted that medium-sized substrate would promote the greatest richness and contain the highest numbers of macroinvertebrates because the size of the interstitial spaces created would be large enough for organisms to find refuge from predators (e.g., crayfish), but not so large as to allow access to predators.