THURSDAY, APRIL 27, 2006

Topic: A Pilot Study to Evaluate the Potential for River Water Toxicity to Increase Following Dam Removal
There has been a precipitous decline in anadromous fish populations, with Atlantic salmon (Salmo salar) populations in 8 Maine rivers listed as endangered in 2000. Dam removal has been identified as the most important strategy for restoring salmon populations in Maine and two dams on Penobscot River, Great Works Dam and Veazie Dam, have been designated for removal. Dam removal can result in release of contaminants from riverine sediments into overlying waters, potentially increasing water toxicity to resident species, including anadromous fish. Because dams will be removed as part of the Penobscot River Restoration Project, there is a need to evaluate the toxic potential of Penobscot River sediments prior to dam removal. We are using a simple laboratory-based, sediment resuspension design and two well-established aquatic toxicology models, fathead minnows (Pimephales promelas) and zebrafish (Danio rerio), to evaluate if resuspension of Penobscot River sediment significantly elevates the toxicity of river water as measured by fish survival, hatch success, development, and immune competence, whether bioactive metals and/or endocrine disrupting substances are present, and to provide preliminary information on the types of chemicals likely to desorb during resuspension.

Speaker: Adria Elskus, USGS/Dept. of Biological Sciences, UMaine
Adria Elskus received her AB in Biochemistry from Mount Holyoke College and spent 2 years working as an environmental consultant at Energy Resources Company in Cambridge, MA as a bench chemist. Her experiences there with oil spills and their chemical and biological fate led her to seek a MS in Biological Oceanography from the Graduate School of Oceanography at the University of Rhode Island. To support herself financially during her MS, she simultaneously worked at the Environmental Protection Agency Narragansett laboratory conducting aquatic toxicity tests and as analytic organic chemist. Her MS research on CYP1A, an enzyme that responds to organic pollutants, led her to the Woods Hole Oceanographic Institution where she pursued a PhD in Biology in the laboratory of Dr. John Stegeman through the Boston University Marine Program. Her doctoral research explored the effects of hormones on the response of fish to pollutant exposure, peaking her interest in endocrinology. To learn more about the endocrine system of vertebrates, she did a postdoctoral fellowship in reproductive neuroendocrinology with Dr. Neena Schwartz at Northwestern University.

From there, she joined the Marine Sciences Research Center at SUNY Stony Brook as a research professor, then took a tenure-track position with the Biological Sciences Dept at the University of Kentucky. In 2004 she resigned from UK to take a Research Fishery Biologist/Toxicologist position with the U.S. Geological Survey and became their ‘One Person Field Station’ at the University of Maine. At UMaine she is responsible for providing toxicological research support for partners working on anadromous fish issues in the Eastern Region of the US.

Her main research area is aquatic toxicology, with a specific focus on the effects of pollutants on fish. Adria is interested in how pollutants affect the development, reproduction, metabolism and physiology of fishes. Her research projects include studies of endocrine disruption in fish exposed to wastewater effluents and flame retardants, the developmental effects of PCBs, and the ability of fish to develop genetic resistance to the toxic effects of these compounds. Her current projects include developing non-lethal bioassays to evaluate pollutant exposure in endangered fish species, mercury accumulation in salamanders and sculpins in Maine, and correlating contaminant body burdens with biochemical markers of contaminant exposure in fish. Today she will present the results of a collaborative project at UMaine whose goal is to evaluate changes in water quality following a simulated dam removal.