Abstract
Using a nationwide sampling of small stream health and condition conducted by the U.S. Environmental Protection Agency (USEPA), a representative statistical model was created to understand which socioeconomic factors correlate significantly with biological integrity in small streams. The Shannon index for species diversity of benthic macroinvertebrates was used as the dependent variable since benthic macroinvertebrates are both sensitive to pollutants and physical habitat alterations. Several independent variables were investigated focusing on select components within the sociopolitical and built environments of streams. Percent of a state’s gross domestic product attributed to agriculture, was identified as the strongest predictor for reduced benthic macroinvertebrate population diversity within streams, suggesting the urgent need for a change in current agricultural practices in order for stream quality to improve.. In addition, until such changes in agricultural production methods are made, the study suggests the usefulness of using low-cost, rapid economic assessments of a region’s local economic output instead of field-intensive biological sampling as a potentially valid measure of stream condition in the United States.
