Overview Academic/Research Interest Areas

Environmental Toxicology

Trace Metal Biology

Marine and Freshwater Ecology

Recent Projects and Results

" Environmental Toxicology: One of my primary research interests involves understanding the cellular and physiological effects of environmental toxins (metals, oil products, algal toxins, etc.) on estuarine and marine invertebrates, and the development of these systems as biomedical models for understanding the effects of toxins on basic cellular processes. While the primary model organisms for these studies have been bivalve mollusks (oysters, clams, mussels, scallops), studies have also been conducted using a variety of invertebrate species (e.g. shrimp, crabs, cnidarians, sea urchins), with developmental stages as well as adults.

" Trace Metal Biology: Some trace metals (Zn, Cu, Mn, Cr, etc.) are essential for normal function of many important enzymes and proteins (including DNA polymerase, carbonic anhydrase, alkaline phosphatase). Others (such as Pb, Hg, Cd) have no known biological function and are highly toxic; it is important to realize that all metals, even essential trace metals can also be toxic at high concentrations. I am particularly interested in the mechanisms (e.g. metal binding proteins such as metallothioneins) associated with regulation of essential and toxic trace metals, especially with regards to developmental processes, calcification processes, and hepatic function.

" Marine and Freshwater Ecology: The distribution and success of animals that live in various aquatic habitats are often related to many natural environmental variables (temperature, salinity and alkalinity, dissolved oxygen, etc.). Often these factors vary over a 24 hr period as well as seasonally. Using real-time in situ water quality monitors that periodically collect data over days or weeks, we have begun to characterize the impacts of variable environmental conditions on the biota, and to understand species-specific tolerances. Sessile organisms or organisms with low motility (such as marine bivalves and barnacles, fresh water mussels) are especially valuable for these kinds of studies since they are forced to deal with the conditions, they must adapt or die.

Recent Publications

Ringwood, A.H. , S. Khambhammettu, P. Santiago, E. Bealer, M. Stogner, J. Collins, K. E Gonsalves. 2006. Characterization, Imaging and Degradation Studies of Quantum Dots in Aquatic Organisms, in Life-Cycle Analysis Tools for "Green" Materials and Process Selection, edited by Stella Papasavva, Vasilis Fthenakis (Mater. Res. Soc. Symp. Proc. 895, Warrendale, PA, 2006), 0895-G04-06-S04-06.

Keppler C.J., A.J. Lewitus, A.H., Ringwood, J. Hoguet, T. Staton. 2006. Sublethal cellular effects of short-term raphidophyte and brevetoxin exposures on the Eastern oyster Crassostrea virginica. Mar. Ecol. Prog. Series. 312: 141-147.

Cherkasov, A.S., P.K. Biswas, D.M. Ridings, A.H. Ringwood, I.M. Sokolova. 2006. Effects of acclimation temperature and cadmium exposure on cellular energy budgets in the marine mollusk Crassostrea virginica: linking cellular and mitochondrial responses. J. Exper. Biol. 209: 1274-1284.

Jenny, M.J., G.W. Warr, A.H. Ringwood, D.A. Baltzegar, R.W. Chapman. 2006. Regulation of metallothionein genes in the American oyster (Crassostrea virginica): Ontogeny and differential expression in response to different stressors. Gene (In press).

Keppler, C.J, J. Hoguet, K. Smith, A.H. Ringwood, A.J. Lewitus. 2005. Sublethal effects of the toxic alga Heterosigma akashiwo on the southeastern oyster Crassostrea virginica. Harmful Algae 4: 275-285.

Educational Background

B.A., Biology, Wake Forest University

Ph.D., Zoology, University of Hawaii

Postdoctoral Fellowship, Pacific Biomedical Research Center, University of HI.

Postdoctoral Fellowship Duke University Integrated Toxicology Program, Duke University Medical School and Marine Laboratory.