Date of Award

5-2014

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Environmental Toxicology

Advisor

Dr. Elizabeth R. Carraway

Committee Member

Dr. Stephen Klaine

Committee Member

Dr. Cindy Lee

Committee Member

Dr. Mark Scott

Abstract

Anthropogenic activities have been shown to have deleterious effects on aquatic habitats, and changes in land use/cover reflecting these activities could be indicative of changes in aquatic chemistry. At present, little is known about aquatic population and community level responses to low levels of pharmaceuticals and personal care products (PPCPs) in the environment. While describing effects at a community level are the ultimate goal of many researchers, often researchers extrapolate potential community effects based on exposures to small populations that may or may not be endemic to the system of interest. The objectives of this study are to quantify elemental and organic contamination in small streams in SC, to identify potential sources of elemental and organic contamination, to identify changes in aqueous and sediment borne contamination as a result of changes in land use/cover, and to assess the effects of the studied contaminants on fish communities in small South Carolina streams. South Carolina is a diverse state with two distinct geographical and ecological areas, the upstate and the coastal plain, and it contains seven US EPA ecoregions and seven major watersheds. Research in small, rural watersheds may have the benefit of lower background contamination and lower thresholds of effect than larger urbanized watersheds. However, the myriad biological, physical, and environmental stressors often confound determination of community level effects of individual chemicals, as well as the presence of mixtures of compounds. Data from over 200 small watersheds in both ecological areas of South Carolina and data from the entire reach of the Reedy River are presented here. The Reedy River is a Piedmont Stream in the Upstate of South Carolina that traverses the city of Greenville, SC before emptying into Lake Greenwood. National Land Cover Data Set was used to determine the land cover for each sampled watershed. Water and sediment samples were collected and analyzed using ICP-MS, ICP-AES, and LC-MS/MS. A partial list of the analytes of interest included aluminum, cadmium, chromium, copper, iron, lead, manganese, nickel, silver, zinc, estrone, atrazine, and caffeine. Regression analysis was used to compare contaminants with land cover activities in individual and grouped watersheds. The Reedy River was sampled under normal and low flow condition to assess the fate of organic contamination during drought events. Statewide fish communities were assessed to determine changes in community response to contaminants, and a toxic units approach was employed for toxicity of mixtures of metals and organic contaminants. Species richness, Simpson's Diversity Index and total fish density were assessed as community response metrics. Cadmium, copper, lead, nickel, zinc, ibuprofen, and caffeine all had positive relationships with increasing urban land cover, while many metals also exhibit negative relationships with increasing forest cover. Interestingly a positive relationship was observed with iron and forest cover in the Coastal Plain, which may be indicative of agro-forestry impacts in that region. These results indicated that changes in land cover could have a large impact on water quality in small watersheds. Fish communities in the Upstate declined with increasing atrazine concentrations, while Coastal Plain fish communities declined when approaching the theoretical one toxic unit threshold. These results indicated that fish communities are affected by anthropogenic contamination; however, chemical sources and fates leading to the effects were likely different in the two regions. Diphenhydramine and 17α-ethinylestradiol observations in the Reedy River decreased on a downstream gradient from two WWTP effluent discharges just south of the city of Greenville, SC, while caffeine was observed primarily above the WWTP and in tributaries to the river.

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