The river runs through it: Evaluation of the effects of agricultural land use practices on macroinvertebrates in Prince Edward Island streams using both new and standard methods

Thirty-seven streams representing reference and test sites were sampled for the benthic macroinvertebrate fauna and habitat characteristics during two seasons (summer and fall) in 2001. Several reference condition approaches were used to evaluate the streams. The BEnthic Assessment of SedimenT was used to group related streams based on the macroinvertebrate community composition (which was related mostly to size characteristics of the stream). Biological (taxa abundance) and environmental characteristics were considered simultaneously to produce a prediction model for a reference condition for PEI. The model was also used to predict the kinds and abundance of various taxa that should occur in a site, based on habitat characteristics. Eleven "'test" samples (from sites which were believed to be impacted by agriculture) were then compared to the reference sites with similar habitat characteristics to assess whether their macroinvertebrate fauna matched the predictions. The same groups of sites were compared using nine biological metrics, which compare the abundance or proportions of certain taxa or groups of taxa. These methods were also used to assess the Wilmot River after a catastrophic pesticide runoff event in the summer of 2002. (Abstract shortened by UMI.)...