Oil Invades Coral Communities of the Deep

On the deep seafloor of the Gulf of Mexico, ecosystems made up of fish, corals, sea stars, anemones and other invertebrates flourish. Since the sun’s rays don’t reach the deep sea, coral communities rely on nutrients making their way to them from surface waters, dropping down in the form of marine snow.

After the Deepwater Horizon spill dumped 3.19 million barrels of oil into the Gulf of Mexico, the nearby deep-sea environment changed. Oil, gas and dispersant spilled out from the site of the leak, some 5,000 feet below the sea surface. Cloud-like plumes of oil and dissolved gas formed at a variety of depths, and a mixture of oil, dispersant, microbes, and mucus (sometimes called “sea snot”) clumped together, raining down on the seafloor from above.

Not knowing is the nature of working in the deep. Because these ecosystems are so difficult to reach, not a great deal is known about the life histories of deep-sea organisms and how they interact with one another, let alone how they may be affected by a large influx of oil and dispersant. How do you study the impacts of an underwater disaster when you don’t know much about the ecosystem you are studying to begin with?

This is the challenge facing a group of chemists, biologists and physical oceanographers who are studying the impacts of the Deepwater Horizon oil spill on deep-sea communities. The ECOGIG (Ecological Impacts of Oil and Gas Inputs to the Gulf) team, made up of researchers from 14 different institutions and funded by the Gulf of Mexico Research Initiative (GoMRI), is meeting the task head-on with long-term monitoring of sites throughout the Gulf and a multitude of ongoing lab experiments. Dr. Charles (Chuck) Fisher from Penn State University is an ECOGIG researcher who focuses on deep-sea corals, asking questions about how the oil and dispersant associated with Deepwater Horizon impacted coral species that live in the cold and dark of the deep.

Follow some of the expeditions that ECOGIG has made to coral sites in the Gulf of Mexico in our slideshow. See what they are looking for and what they have found.


The Ocean Portal receives support from the Gulf of Mexico Research Initiative (GoMRI) to develop and share stories about GoMRI and oil spill science.

The Gulf of Mexico Research Initiative (GoMRI) is a 10-year independent research program established to study the effect, and the potential associated impact, of hydrocarbon releases on the environment and public health, as well as to develop improved spill mitigation, oil detection, characterization and remediation technologies. For more information, visit