Gulf Oil: Booms and Bonanza

Helen Brandt, Ph.D., is a writer interested in marine topics. She also provides math-prep sessions for students in grades 3-5. helenbrandt@comcast.net

Pictures of oil-coated pelicans from the Gulf of Mexico, graphically demonstrate the toxic effects of oil. Meanwhile, scientists report oil plumes stretching toward Florida. For both humans and many creatures the Deepwater Horizon oil well blowout is a disaster. Have we finally dealt a mortal blow to an entire ecosystem?

Oil rigs may lack backup systems, but biological systems do have them. Scientists have known for at least 25 years that the Gulf of Mexico has gas and oil seeps that occur along natural faults and fissures on the ocean bottom.

In 1993, satellite photographs showed slicks extending miles over deepwater areas where there had been no oil production. By 1996 over thirty natural oil seeps had been identified off the Gulf Coast from Texas to Florida.

Recent surveys using satellite remote sensors indicate there are about 350 constant seeps that produce perennial slicks at constant locations. An estimated 70,000 tons of oil seep yearly into the northern Gulf from faults and fissures in the oceanfloor. A 2003 study concluded the entire Gulf of Mexico oceanfloor seeps about 165,346 tons of crude oil each year. By comparison the Exxon Valdez spill was 37,000 tons

In order to assign environmental damage from the Deepwater Horizon blowout, it will be necessary to distinguish oil from natural sources from oil flowing from the damaged well. The molecular composition of the oils can be compared to that from the well. This takes time and will require sampling of oil from many locations in the Gulf, both surface and subsurface. Oil sheens identified from satellite sensors might be from natural seeps or from a particular well.

So can anything live in seawater permeated with oil and gas? Turns out the answer is, yes. Organisms have adapted over thousands of years. There are thriving communities living around oceanfloor seeps in the Gulf. Bacteria take oxygen and carbon from oil or gas and reassemble them into food for their neighbors. There are clams, the size of your hand, that have red “blood.” Yard-long tube worms that can live hundreds of years live in tangled mounds. Crabs crawl over the assemblage. Snails, mussels, echinoderms and crustaceans may join the community.

So what has been a disaster for humans and many animals in the Gulf, can be a bonanza for particular bacteria and animal communities. Oil- and gas-loving bacteria and their companions will likely migrate to the oil spill. Natural processes will allow them to begin to transform the oil and gas for their own benefit. The very slow process of natural cleanup can begin. §