Comparison of Macroinvertebrate Bioindicators to Ecosystem Function Across a Gradient of Agricultural Impairment

Elaine Langone Center, Terrace Room

The ability to assess stream health efficiently and accurately is vital for predicting the overall impact of land use on aquatic systems within their watershed. This can be done in a variety of ways, including the examination of various ecosystem functions as well as the use of structural attributes such the resident macroinvertebrate community. For this study, the effects of stressors associated with agriculture was assessed on the macroinvertebrate community as well ecosystem functions. This was done with goal of establishing a link between both parameters, thus allowing for more efficient and effective assessment of water quality. The study sites included 19 streams across central Pennsylvania, with varying intensities of agriculture within the catchment area. The functional parameters we studied include extracellular enzymes, ecosystem metabolism, and nitrogen and phosphorous uptake. These were compared to structural indicators examined through the benthic macroinvertebrate community. We collected macroinvertebrates through kick netting, and then quantified steam health using a calculated index of biotic integrity (IBI) to assess water quality across samples. Preliminary findings indicate that both ecosystem function and macroinvertebrates reflect similar impairment to land alterations from agriculture.