Dartmouth researchers, working with scientists from the State University of New York at Stonybrook, have been awarded a $1.4 million grant from the Department of Defense's Strategic Environmental Research and Development Program (SERDP). The funds will support a three-year study on how the metals arsenic, mercury, cadmium and lead move through the food web in estuaries, the areas where fresh water meets the ocean.
"Metal contaminants can adversely impact estuarine communities," said Celia Chen, one of the principal investigators and a Research Associate Professor of Biological Sciences. "In addition, there is a heightened concern because humans can be exposed through the consumption of seafood that comes from these habitats."
Estuaries provide important habitats for organisms that are a food source for commercially harvested fish and shellfish. The researchers are learning how the organisms, like algae and invertebrates (snails, mussels, zooplankton), accumulate and transfer the metals to animals higher in the food web.
"Estuarine environments become the repositories for these toxic elements that are transported from watershed via rivers and streams," said Chen. "And estuaries are important habitats for many invertebrate and fish species. We're trying to better understand how metals move from the sediment, through the food web and ultimately into the fish."
Chen and her co-principal investigators, Joseph Shaw, a research associate in the department, and Nicholas Fisher, a professor at the Marine Sciences Research Center at SUNY Stonybrook, comprise a multidisciplinary team that includes expertise in community ecology, metal biogeochemistry, ecotoxicology and applied genomics. Chen, no stranger to collaborating with researchers from different disciplines, is one of the original members of Dartmouth's ten-year-old Toxic Metals Research Program that is dedicated to the multidisciplinary study of these elements and their impact on human health and the environment.
With this project, they hope to learn more about how the metals transfer from sediments to intertidal food webs and determine the food web variables, like species diversity and food-web complexity, that are sensitive to biological exposure and bioaccumulation. They also aim to better understand the processes that regulate how metals accumulate in animals and to develop a predictive model of metal bioaccumulation in estuarine organisms representing different functional groups (deposit feeder, filter feeder and omnivore/predator). Finally, the team hopes to produce a set of genomic biomarkers that are predictive of the site-specific hazards posed by contaminated sediments.
By SUSAN KNAPP
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Last Updated: 12/17/08