Imagine you’re at your favorite seafood restaurant. You peruse the menu: tuna, shrimp, scallops, crude oil… oil?!
It may be hard to imagine, but for some of the smallest organisms in the ocean oil is one of their main meals. What’s more, these single-celled microbes digest food the same way we do, except instead of producing enzymes that break down milk or gluten, their digestive enzymes are able to break down chains of hydrocarbons the building blocks of oil.
It’s well known that oil is formed from the decomposition of plant and animal material called plankton that has been heated deep under the earth for millions of years. A recent study also suggests that hydrocarbons could also be formed abiotically from the compression and heating of methane. Regardless of how it’s created, oil has been drilled by man for centuries.
Did You Know?
The first oil wells were drilled by the Chinese in 347 AD using bamboo poles.
You may think that human activity is responsible for oil pollution in the oceans, but naturally occurring oil seeps have existed on the ocean floor for hundreds of millions of years. Oil-eating microbes have existed nearly as long, evolving to consume this otherwise toxic substance. Most are bacteria but some algae and fungi can also consume oil. When an oil spill or natural seep occurs, microbes multiply and flock to it like an all-you-can-eat buffet. But no single microbe can produce all the enzymes required to break down all oils, so it requires many different species to break down an oil plume.
Did You Know?
About half the oil that enters the Earth’s oceans each year comes from natural oil seeps; the other half comes from human activities.
Scientists are using microbes to clean up oil spills, a process called bioremediation. This method helped break down oil from the 1989 Exxon-Valdez spill in Alaska, where clean-up crews released large numbers of microbes near the oil spill. When the Deep Horizon spill released massive amounts of oil in 2010, scientists were encouraged that a large number of naturally occurring microbes had appeared and seemed to be quickly consuming the oil. But a year later, researchers are discovering that microbes have not eaten nearly as much oil as they thought, and instead have only broken much of it into millions of microscopic droplets. There is now a strong scientific debate about how useful microbes can be in oil spill recovery; this just goes to show how much we have yet to learn about these organisms.
Meanwhile, oil-eating microbes will continue drifting in the ocean, awaiting their next all-you-can-eat oil buffet.
The Mystery of the Missing Oil Plume
Oil Biodegradation and Bioremediation: A Tale of the Two Worst Spills in U.S. History
New Oil-Eating Microbe Found in Gulf
Slick Solution: How Microbes Will Clean Up the Deepwater Horizon Oil Spill
How Oil is Made
Slick Science: The Science of Oil Spills and Effects on Water Quality
Article first published December 2, 2011