Study Shows Gulf Oil Spill Harmed Deep-sea Coral

The Deep Submergence Vehicle, Alvin, working at the coral site impacted by the oil spill in the Gulf of Mexico. (Photo: courtesy of Chuck Fisher of Penn State University and Timothy Shank of WHOI; deep-sea time-lapse camera system provided by WHOI-MISO)

New research suggests the 2010 Gulf of Mexico oil  spill did serious damage to deep sea corals. Communities near the Deepwater Horizon spill site show varying degrees of injury – from sick to dying to dead, according to research led by Penn State University Professor of Biology Charles Fisher.

The study finds that coral communities about 11 kilometers from the spill site, and approximately 1310 meters below the water’s surface,  are covered with a thick brown substance. It was found to be a mixture of dying tissue, oil, mucous excretions from the coral and other various adhering particles.

More distant coral communities examined by the research team show no signs of similar damage and appear mostly unharmed.

The multi-disciplinary research team included a number of specialists in sciences such as geology, biology, ecology and taxonomy.

The team also relied on geochemists, who were able to “finger-print” and identify the hydrocarbons found on the affected coral and in the surrounding ocean sediment.

The data gathered for this study came from two research cruises to the Gulf of Mexico.

The first cruise sailed in late October 2010, about six months after the Deepwater Horizon oil spill.  After finding initial evidence of coral damage, researchers planned a second trip to the gulf. They set sail again in December 2010, barely a month after the first cruise arrived home.

Researchers had a variety of sophisticated tools to work with.

The team used the remotely controlled vehicle (ROV) Jason II from the Woods Hole Oceanographic Institution (WHOI).

The three-passenger, robotic-armed, US Navy-owned and Woods Hole operated submersible, Alvin, provided researchers with a closer look at the deep-water coral on the mission’s second trip.

One of the impacted corals with attached brittle starfish. Although the orange tips on some branches of the coral is the color of living tissue, it is unlikely that any living tissue remains on this animal. (Photo: Lophelia II 2010, NOAA OER and BOEMRE)

Fisher considers their findings significant in several different ways. He says it’s the only study to document damage to big animals on the sea floor.

Fisher points out the study demonstrates that the Deepwater Horizon oil spill did impact a deep-sea community that harbors more than just coral some 11 kilometers away from the spill site, which he says is further than some of the other published estimates.

Also significant, says Fisher, is that the findings extended the range of the impact. He suggests continued research and investigation must be done to define the “footprint” of the spill’s impact.

Although the research looked at one close-in site, Fisher feels there are undoubtedly other deep-sea coral sites in the region that should be studied.

Fisher’s team is continuing its research and investigating similar coral communities.

On this week’s radio edition of “Science World”, Charles Fisher talks about the research expedition’s results. Tune in (see right column for scheduled times) or check out the interview below.

Other stories we cover on the “Science World” radio program this week include:

• Indonesian quake and resulting tsunami scare test region’s preparedness
• Are plants affected by a noisy environment?
• Cigarettes are bad for your health, menthol cigarettes may be worse
• Space Shuttle Discovery gets ready for final landing at Washington museum
• International Dark Sky Week brings attention to light pollution
• US physicist joins search for lost DaVinci mural