(Tallahassee.com) - In some respects, the Gulf of Mexico may be less fragile than many people feared in the aftermath of the 2010 Deepwater Horizon oil spill.
A team of scientists from Florida A&M and Florida State universities, joined by graduate students at each school, has been examining the methane released during the oil spill, which made up about one-third of the hydrocarbon issued from the well head in the summer of 2010. The methane, or natural gas, could have been expected to pour into the atmosphere where it could have polluted the air over the Gulf.
Their initial findings, however, indicate that the ocean absorbed and digested the methane, thanks to millions of tiny bacterial particles. These bacteria are called methanotrophs, or methane eaters.
"The thing that's cool about this, there was a large amount of methane released in the oil spill and none of it made it to the surface of the ocean," FSU oceanographer Jeffrey Chanton said. "All of it was consumed by these methane-eating bacteria. They serve as a bio-filter."
FAMU environmental scientist Jennifer Cherrier was the lead author on their paper, published in the premier issue of a new journal, Environment Science & Technology Letters. It reports that the methane has entered the food web because they are finding it in the tiny particles resulting from bacteria and can trace it as far as the plankton.
"That's actually a good thing," Cherrier said. "It keeps the methane from getting into the atmosphere. It means that the methane got absorbed."
The paper is the highlight of a number of published studies following three years of research in the Gulf, funded by an initial $5 million from BP to the Florida Institute of Oceanography which was dispersed to a number of Florida Institutions. Chanton subsequently was awarded a portion of a second $20 million grant through the Deep-C Consortium, a group of 10 universities and research institutions. It is also funded by BP, to do further studies in the Gulf.
One of the challenges for the scientists working in the Gulf of Mexico is they don't have established baselines for what the Gulf was like prior to the oil spill.
Methane seeps on the sea-floor are common in the Gulf, making it difficult to know how the ecology of the sea was influenced by the more massive BP oil spill.
While methane is a relatively benign compound in the water, Chanton said, it is a powerful greenhouse gas once it makes its way into the atmosphere.
"The good news is that the bacteria saved the atmosphere from getting a big dose of this greenhouse gas and it fed the plankton which are then eaten by pinfish which are then eaten by grouper and other seafood we enjoy," Chanton said. "It's a good news story"