A multi-agency comparison of aquatic macroinvertebrate-based stream bioassessment methodologies

Sharing ecological data can increase the amount of information available to state and federal agencies to manage water resources. Because state agencies in the US use different methods to assess biological water quality, the quality and comparability of data must be understood before data can be shared. The documentation of data quality objectives and performance characteristics has been recommended as a way to compare biological data collected using different methods. To address this issue, five state agencies conducted a pilot study on methods comparability and performance characteristics of their methods and assessments (i.e. precision and sensitivity) at two streams located in the coastal plain of the southeastern US. Taxa richness and North Carolina Biotic Index (NCBI) results were not directly comparable among agencies using different sample processing, collection, and analysis methods, although these results often produced similar site rankings. Comparison of performance characteristics across methods suggested that assessment information could be shared among some agencies despite differences in methods and metric results.