- Ph.D. in Systems Ecology, Emory University, Atlanta, Georgia, U.S.A., 1978
- M.S. in Marine Ecology, University of Miami, Florida, U.S.A., 1971
- B.S. in Biology, Emory University, Atlanta, Georgia, U.S.A., 1969
Dr. Harwell is an ecosystems ecologist with expertise in ecological risk assessments and ecosystem management. He (with colleague Dr. Jack Gentile) was a leader in the development of the US EPA ecological risk assessment framework, and has led several large ecological risk assessments, including on Tampa Bay, Apalachicola Bay, Biscayne Bay, the Coeur d'Alene River basin, and the Bay of Fundy. He and Dr. Gentile presently are assessing the ecological significance of residual exposures and effects in the Prince William Sound ecosystem from the Exxon Valdez oil spill. He chaired the US Man and the Biosphere Human-Dominated Systems Directorate, and led its project on ecological sustainability, ecosystem management, and an ecosystem integrity report card framework.
He served for over ten years as a member of the US EPA Science Advisory Board (SAB), including two terms as Chair of the Ecological Processes and Effects Committee and member of the SAB Executive Committee. He chaired the ecological risk committee of the US EPA Unfinished Business Project, and was a member of the US EPA SAB Reducing Risk project. He led the Scientific Committee on Problems of the Environment (SCOPE) 5-year international study to assess the global environmental consequences of nuclear war (ENUWAR), emphasizing ecological effects of climate change. He directed the PANEARTH Project, case studies on the ecological effects of climate change on Venezuela, India, Japan, China, and Sub-Saharan Africa. He was a member of the US Global Change Research Program's National Assessment working group on coastal resources effects, and he continues to serve as an Expert Reviewer for the International Panel on Climate Change (IPCC).
Dr. Harwell lead a series of interdisciplinary studies on human interactions with the South Florida environment, including field, mesocosm, and modeling studies in Biscayne Bay and the
Florida Keys National Marine Sanctuary. He served on the National Academy of Sciences panel on ecological risks in the US and Poland, and was a member of the NAS panel on risk communications. He was the NOAA Distinguished Professor of Environmental Sciences, leading interdisciplinary studies on National Estuarine Research Reserves, developing conceptual models of coupled human-environment systems, and conducting ecological risk assessments. Dr. Harwell was a member of the National Academy of Sciences Board on Environmental Studies and Toxicology, and was elected a Fellow of AAAS.