UF Oyster Recovery Team issues findings: Drought and salinity major issues, not oil

April 25, 2013

GAINESVILLE, Fla. — There is no evidence that pollutants from the 2010 Gulf of Mexico oil spill contributed to the “unprecedented” decline in recent Apalachicola Bay oyster populations, according to a report released this week by the University of Florida.

Instead, the report by UF’s Oyster Recovery Team cites drought, insufficient rainfall and increased salinity in the bay as factors contributing to the dramatic drop-off in oyster landings beginning in September 2012 and continuing through the year, said Karl Havens, task force leader and director of Florida Sea Grant.

“There was a whole chain of circumstances that led to this situation, some of which are beyond human control,” Havens said. “Our report makes recommendations for many things that can be done to help the oyster population through management and restoration.”

Havens and other recovery team members discussed the report and findings with a crowd of about 60 residents and seafood workers Wednesday at the Apalachicola Community Center.

The full report and a summary are available at the UF/IFAS Franklin County Extension office or its website, franklin.ifas.ufl.edu.

One concern locally is the lack of small oysters in the bay, which could mean reduced harvests of legal-sized oysters in 2013 and 2014, Havens said.

“Naturally, everyone would like to see oyster populations bounce back very soon,” he said. “We don’t know at this point whether there’s been a failure of mature oysters to reproduce, or if something has been killing larval oysters.”

The report recommends more research on the issue. A related finding: Computer modeling suggests it could take as long as a decade for the population to recover unless large-scale oyster-bar restoration projects occur.

“The task force will continue to work with the local community through grant proposals to fund further restoration, research and community-development efforts,” Havens said.

Other major findings from the report:

*The Apalachicola River and the two rivers that feed it have experienced exceptional drought during the past three years.

*Water quality data indicate that 2012 was a year of high salinity throughout the bay.

*Recent declines in oyster landings and juvenile oyster numbers are unprecedented for the bay, at least for the time detailed records are available: 1986 to the present.

*Numerous seafood species — including oysters, shrimp, crab and several popular finfish — tested clean when checked for polycyclic aromatic hydrocarbons, or PAHs, contaminants associated with crude oil.

Report recommendations include more research on oyster population dynamics and harvesting practices; expanded oyster reef monitoring; and strict observance of current harvest and sale regulations.

The report also suggests that alternative seafood products be evaluated that might diversify the local industry. One candidate species is the crown conch, a native mollusk recently approved for commercial development.

At the Apalachicola meeting, seafood specialist Steve Otwell, a professor with UF’s Institute of Food and Agricultural Sciences, displayed a crown conch shell and large pieces of fresh crown conch meat. He said test-marketing of the delicacy had been highly successful in restaurants.

Task force activities were supported by funding from UF/IFAS, Florida Sea Grant and the National Institute of Environmental Health Sciences.