OYSTER RESEARCH

Apalachicola Oyster Research

Laura Petes, Ph. D.
Petes Home Page

As a postdoctoral associate at the FSUCML, I am studying how anthropogenic alterations to freshwater input affect downstream estuarine oyster reef communities. Water allocation issues are current and pressing in the U.S. Southeast, particularly under drought conditions. Georgia is withholding fresh water from the Apalachicola-Chattahoochee-Flint (ACF) River Basin due to drought-related water shortage. The ACF River Basin flows directly into Apalachicola Bay downstream, a productive ecosystem that supplies 90% of the oysters for the commercial oyster industry in the state of Florida. Reduced freshwater flow can lead to increased water temperature and high salinity in estuarine environments. In this context, I am studying how temperature and salinity affect Apalachicola oyster survival, growth, condition, and disease. Dermo disease, caused by the protozoan parasite Perkinsus marinus, thrives in warm water at high salinity. Typically, this parasite is kept at low levels due to freshwater input, but when salinity stays high for prolonged periods of time, disease-related oyster mortality can be high.

Through my research, I work closely with the Apalachicola National Estuarine Research Reserve (ANERR), as well as commercial oyster harvesters, conservation organizations, and water managers to foster cooperation and to inform water allocation policy with science. My research involves a combination of field and laboratory studies. I perform monthly field surveys of oyster bars in ANERR to determine how Dermo disease prevalence and severity fluctuate with temperature and salinity. I am also conducting laboratory tank experiments at FSUCML to study the effects of temperature and salinity on oysters. My results indicate that disease-related mortality of oysters is high due to the interaction of warm water temperatures and high salinity. In addition, mortality tends to be size-specific, with large oysters dying at a much more rapid rate than small individuals. These results have important implications for both oyster population dynamics and water allocation policy in the Apalachicola River watershed.