Sewanee Faculty Member Named a Fulbright Scholar

Sewanee faculty member Thea Edwards has been named a Fulbright Scholar for the 2015–16 academic year. She has been teaching courses and directing student research in the University’s biology department since August 2014. 

In January 2016, Edwards will travel to Botswana for eight months to study the effects of aquatic pollution on fish health in the Okavango Delta. The Okavango is an inland freshwater delta that floods with rainwater draining south from mountains in Angola. This great natural event is the life spring for magnificent herds of southern African wildlife that migrate annually to the flooded Okavango.

At the Okavango Research Institute (ORI), Edwards will collaborate with research scholars, other ORI scientists and students from the University of Botswana, collecting tilapia fish along a growing pollution gradient in the Okavango. The pollution originates from a variety of sources, including agricultural and mining runoff, aerial deposition from coal burning and bioaccumulation of persistent pesticides.

Edwards will use tilapia like “canaries in a coal mine” to study the environmental impacts of pesticides, heavy metals and nitrogen pollution on fish reproductive health. Some pollutants, like DDT and nitrate, mimic or block animal hormone signaling. When tilapia are exposed to hormonally active pollutants, their reproductive development can be delayed or impaired. Edwards’ results will provide new information about how human-made pollution and changes in land use are affecting the reproductive health of Okavango wildlife.

Another important group of pollutants in the Okavango ecosystem are heavy metals. Using equipment recently purchased by the University of the South, Edwards will measure heavy metal concentrations in Okavango tilapia tissues. This is important because heavy metals accumulate in fish and are transferred to people who eat those fish. Metal bioaccumulation causes a variety of adverse health effects in both fish and people. 

Edwards will also map nitrate pollution across portions of the flooded Delta. The loss of oxygen caused by this pollution kills fish and other aquatic animals.

While evaluating how pollution affects health and ecology in the Okavango, Edwards will mentor ORI students who will join in field sample collections, tissue analyses, data collection and publication of results. The team will gather a range of tilapia tissues to facilitate student research projects at both Sewanee and the University of Botswana.

Edwards is currently working with Sewanee sophomore Robert Corey on a related project using tilapia caught in South Africa. Corey’s project is a collaboration with doctors at the Medical University of South Carolina and the University of Pretoria in South Africa.

The Fulbright Program is America’s flagship international exchange and diplomacy program funded by the U.S. Department of State and partner countries. Each year, 800 faculty and experienced professionals are selected by review panels and the Fulbright Foreign Scholarship Board. Fulbrighters receive teaching and/or research grants to work in any of 130 countries worldwide. Nine current Sewanee faculty members have been selected for this prestigious program.