Skidaway Institute of Oceanography
10 Ocean Science Circle
Savannah, Georgia 31411
Telephone: (912) 598-2494 or 2487
Fax: (912) 598-2310

B.A. Chemistry, California State University at San Diego 1964
M.A. Chemistry, California State University at San Diego 1966
Ph.D. Marine Biology, Scripps Institution of Oceanography, University of California, San Diego 1970

• DNA Damage and Embryo Developments in Grass Shrimp Exposed to Contaminants
  We use a rapid and sensitive assay for DNA damage, the Comet assay, to assess the presence of genotoxic agents at several contaminated estuarine sites. The presence of these genotoxic agents, e.g., mercury, toxaphene, and chromium at these sites are linked to both DNA damage and embryo development effects. Laboratory studies, where suspect contaminants are added to food, water, or sediment, are used to verify field results. The presence of genotoxic agents in sediment are determined by adding female grass shrimp to contaminated sediments, allowing reproduction to occur, followed by DNA strand damage assays and embryo development bioassays of the embryos produced by the females.
  
• Prevalence and Intensity of a Blue Crab Disease in Coastal Georgia
  The blue crab, Callinectes sapidus , supports an important fishery along the Atlantic and Gulf coasts of the U.S.  This fishery has suffered a significant decline in recent years with Georgia blue crab catches decreasing from 9.3 million pounds in 1995 to 1.8 million pounds in 2002.  The cause of this sudden and dramatic crash is the subject of intense investigation.  The decrease  in crab population has been coincident with an increase in the prevalence and intensity of a disease in blue crabs caused by a parasitic infection of a dinoflagellate, Hematodinium sp.  A focus of our work has been on development and use of molecular gene based diagnostic test for Hematodinium sp. that is very sensitive and can be used to detect Hematodinium sp. in the water as well as in crab hosts.  A combination of field and laboratory studies are being used to study the transmission and life history of  Hematodinium sp .  
  View a photomicrograph of muscle sections of a Hematodinium infected blue crab (photo taken by A. Walker at Mercer University Medical School)
  
• Mariculture of Black Sea Bass for the Sushi Market
  Our group has been developing a greenhouse based recirculating system to grow larval sea bass to 2 pound adults in one year. Instead of pellets, the black sea bass are fed live tilapia juveniles. Tilapia are reared in separate heated tanks with reproduction taking place every two weeks so there is a constant supply of tilapia fry and juveniles for the black sea bass.  For further details, please see our mariculture webpage.

• Coastal Oceanography - Skidaway Institute of Oceanography
• Ecotoxicology - Georgia Southern University