Evaluating the Impacts of Wastewater on Aquatic Biota in the Red River Basin
Abstract
The capture and reuse of wastewater is a promising strategy for increasing water
availability, but the environmental benefits and costs are poorly quantified. In water-limited river
basins, wastewater outfalls are an important component of stream flows and may buffer
ecosystems from drought. How does wastewater influence the biodiversity of fish and
macroinvertebrate communities? We investigated two competing hypotheses. First, we
hypothesized that if wastewater flows buffer aquatic communities from drought, then measures
of biodiversity should be higher at sampling sites near wastewater outfalls than at sites not near
wastewater outfalls. On the other hand, if wastewater outfalls negatively impact water quality or
homogenize flow regime, then measures of biodiversity may be lower at sites near wastewater
outfalls. To test these competing hypotheses, we calculated a suite of biodiversity indices at 320
biological sampling sites in the Red River basin and analyzed for significant differences in
communities based on proximity to wastewater outfalls. We found that wastewater outfalls had
varied impacts on biodiversity in fish and macroinvertebrate communities, and in most cases the
effects were not significant. Findings from this study could be used to provide insight to
management decisions on wastewater reuse initiatives in beneficial subbasins while minimizing
harmful ecological impacts.
Collections
- OU - Theses [2098]