The Impact of Urbanization on Macroinvertebrate Communities of Creeks Within Western Georgia
Urbanization is a major cause of stream impairment in the United States, altering stream ecological integrity in a variety of ways. While control of point source pollution has largely improved over the last twenty years, the control of non-point source pollution has proved to be more of a challenge. Urbanization in the area surrounding streams has been linked with elevated levels of sediment, heavy metals, organic matter, and nutrients within streams, as well as with other negative effects. Examining the macroinvertebrate communities within streams has proven to be an effective indicator of the effects of urbanization on water quality. This study used that concept to evaluate the health of nine sites on three tributaries of the Chattahoochee River around and within Columbus, Georgia, for the effects of such urbanization. The results of this study indicated that the sites on the less urbanized Upatoi Creek had the healthiest representation of benthic macroinvertebrates, and consequently they were classified as having good to fair water quality, an attribute that needs to be conserved. In contrast, the lower and upper sites on Standing Boy Creek, which is located in a developing urban area, had fairly poor water quality, and were most in need in remediation efforts. To a lesser extent, the lower and middle sites on Bull Creek, which had notably higher percent urban land use than all other sites, also had somewhat degraded aquatic communities within them as well. Despite the less urbanized Upatoi Creek sites having comparatively superior water quality, no significant correlation was found between percent urbanization and any changes in metric values. Presumably, many factors in addition to urbanization caused the differences in macroinvertebrate populations found between sites. Other factors that likely acted in addition to percent urban land use to affect the benthic macroinvertebrate communities were percent agricultural land use and an ongoing drought. The ongoing drought in the area appeared to affect biotic values the most, as those values increased as sampling continued throughout the year, indicating that water quality was decreasing. Comparisons between sites were further complicated by physical differences among sites and a lack of a significant gradient in percent land use between the majority of sites. Due to the many factors influencing the water quality within these nine locations, additional biomonitoring efforts are suggested to further specify the exact effects of the increasing urbanization and other factors on streams within the city of Columbus and its suburbs.
Stream Impairment, Pollution, Urbanization, Chattahoochee River Columbus Georgia, Upatoi Creek, Standing Boy Creek, Bull Creek, Earth Sciences, Environmental Monitoring, Environmental Sciences
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