As oil seeps into the sands of the beaches on the Gulf of Mexico, it’s a race against the clock to keep the oil and other chemicals from getting into the groundwater. And it’s a race against the clock for Florida State University scientists to figure out what happens to that oil once it starts seeping into the sand.

With the help of a (RAPID) (Rapid Research Response) grant from the National Science Foundation, oceanographers Joel Kostka and Markus Huettel have been busy studying samples from beaches from Louisiana to Florida. In addition, they are studying the oil dispersant Corexit. “Through contacts in the field, my laboratory has acquired Corexit and source oil from the MC252 (Deepwater Horizon) well head for use in our experiments,” Kostka said.

“Crude oil is a natural component that constantly seeps out of the Gulf of Mexico sediments—obviously in much smaller quantities than those now caused by the drilling accident—so native microbes have evolved that consume this oil and thereby degrade it,” Kostka said. “These microorganisms include bacteria and also some microalgae that live in the water column and the sediments of the Gulf of Mexico.”

While oil on top of the sand can be scraped off, oil that has seeped into the sand must be removed by microbial degradation, Kostka said. The microbes work faster when they get air, so oil degrades faster when it is in the upper layers of beach sand than it does in the deeper sediment layers of the beach where there’s no oxygen.

“Unfortunately,” said Huettel, “crude oil contains such harmful substances that even small amounts can kill fish larvae—which means that oil stored in deep layers of beach sediment present a potential source of toxins to near-shore waters and groundwater.”

Ultimately, the professors hope their research will also help them find out how to make the oil degrade faster.

Kostka is an environmental microbiologist and microbial ecologist, and Huettel is a biological oceanographer with expertise on biogeochemical processes in coastal sediments. Both are professors in the Department of Earth, Ocean and Atmospheric Science. To read more, go to http://www.fsu.edu/news/2010/07/01/oil.microbes/