The Effects of Sediment and Nutrient Loading on Aquatic Organisms in Nails and Ellejoy Creeks, Blount County, Tennessee

The health of an entire ecosystem is influenced by its water supply. Nonpoint source pollution, such as sediments and nutrients, cause impairment of water quality and harm aquatic diversity. This study was designed to assess the impacts of excess sediment and nutrients on aquatic health in the Nails (HUC12, 060102010105) and Ellejoy (HUC 12, 060102010104) Creeks, subwatersheds of the Little River (HUC10, 0601020101) watershed and the Watts Bar Lake watershed (HUC8, 06010201) in Blount County, Tennessee. Previous research has shown a negative correlation between these pollutants and benthic indicator species. In 2002, the 303(d) list indicated that both streams were partially supporting. There have been no studies of these streams since 1998, which categorized them as impaired water bodies. A total of 12 sites were sampled 12 times, beginning in June of 2003 and continuing through February of 2004. Parameters tested included Total Kjedahl Nitrogen (TKN), total phosphorous (TP), nitrate (NO₃^-), nitrite (NO₂^-), phosphate (PO₄^3-), soluble reactive phosphorous), total solids (TS), total suspended solids (TSS), total dissolved solids (TDS), turbidity, biochemical oxygen demand (BOD-5 day), total organic content (TOC), and ammonium (NH3-N). Benthic macroinvertebrates data were collected in August of 2003 and added to available benthic data for some of these streams from previous years. General Linear Mean procedure was performed on all water quality data. The individual streams showed small positive correlations between TSS, TDS, TS, TKN, NO₃^-, NH3-N, TP, and PO₄^3-. A mean separation test was performed to look for differences among sites. Two tributaries on Ellejoy Creek exhibited nitrate differences (P<0.05). The lesser nitrate contributor (1.71 mg/L) was surrounded by forest, and the greater one (4.05 mg/L) was agricultural. Benthic macroinvertebrates showed more diversity than anticipated, attributed to the cool, wet conditions of the season. All 3 sites on Nails Creek, and 3 of the 5 sites sampled on Ellejoy were classified by use of the TN State metric system as fully supporting, the remaining 2 being partially supporting. However, Principle Component Analyses of all samples across all sites showed separation between the prolific nutrient tolerant and the few nutrient intolerant species, indicating that high NO₃^- levels are influencing low species diversity. They also showed correlations between poor bank conditions and poor benthic habitat, indicating that aquatic life is influenced by land use. Both streams will remain on the 304(d) list, though some tributaries on Ellejoy will likely be removed. Data from this study will contribute to the eventual development of Total Maximum Daily Loads for both streams.