State Water Resources Research Institute Program
Project Id: 2010GA234B
Title: Assessment of endocrine disruption in fish and estrogenic potency of waters in Georgia
Project Type: Research
Start Date: 3/01/2010
End Date: 2/28/2011
Congressional District: GA-010
Focus Categories: Surface Water, Wastewater, Water Quality
Keywords: Intersex,wastewater,reproductive fitness,surface water
Principal Investigators: Bringolf, Robert (UGA); Jennings, Cecil A. (US Geological Survey/University of Georgia)
Federal Funds: $ 18,000
Non-Federal Matching Funds: $ 36,000
Abstract: Recent reports of intersex fish in water bodies around the world (including Georgia) have stimulated widespread concern about the effects that chemicals are having in the environment. Intersex is a term used to describe the presence of both male and female characteristics in individual fish, most commonly, the presence of oocytes (eggs) in testicular tissue, a pathological condition that is not routinely observed in most fish species. The intersex condition has been associated with a component of municipal wastewater effluent discharge and this condition has been demonstrated to reduce reproductive fitness, i.e., intersex fish have been shown to have decreased sperm (milt) production, decreased sperm motility and decreased fertilization success compared to histologically normal male fish. These findings generate numerous ecological questions and have human health implications as well. To date there has been only one published study documenting intersex fish in Georgia; however, a systematic evaluation of the severity and extent of this condition as well as the causes has not been completed. Therefore, our objectives are to: (1) assess intersex condition in fish collected from rivers and lakes across Georgia; (2) determine spatial and temporal trends in estrogenic potency (a measure of the estrogens and estrogen-like substances) of surface waters downstream from municipal effluent discharges which are commonly associated with intersex fish; (3) compare the sensitivity of in vivo and in vitro assays to detect estrogens in river water.
Study sites will include the Oconee River and its major tributaries, the Ocmulgee River, the Savannah River and the Broad River as a reference (no major wastewater effluent discharges). We will also assess lakes across Georgia in all major physiographic regions of the state. Fish will be collected upstream and downstream of municipal wastewater effluent discharges and examined histologically for evidence of the intersex condition. Blood samples from the male fish will be assessed for vitellogenin, the egg yolk protein which has become the standard biomarker for estrogen exposure in fish. In vitro assessment of the estrogenic potency of Georgia's surface waters will be performed with a reporter gene assay in which yeast cells have been transfected with human estrogen receptors and lux genes. Compounds that bind the estrogen receptors activate the lux gene and result in bioluminescence. Spatial and temporal variation in estrogenic potency of Georgia surface waters will be determined by comparing vitellogenin induction in caged male fish at sites upstream and downstream from municipal effluent discharges. In addition to the fish vitellogenin (in vivo) assay, we will use the reporter gene assay (in vitro) to quantify the seasonal and spatial variation in estrogenic potency of Georgia waters.
The goal of the proposed work is to begin systematic characterization of the estrogenic activity in Georgia Rivers and the incidence of intersex in fish across the state. We hypothesize that estrogens in Georgia waters are linked to the incidence of intersex condition in fish.
This study will provide the first investigation of estrogens in Georgia's surface waters and intersex fish in many of Georgia's rivers and lakes. The results are crucial for understanding the spatial and temporal distribution of estrogens in surface waters, particularly those receiving substantial municipal wastewater effluent. Use of two independent assays to detect estrogenic compounds in the water will allow us to determine which approach is best suited for a larger, region-wide sampling effort.
Progress/Completion Report, 2010, PDF