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Wetlands and Aquatic Research Center - Florida
Deep-sea Cruises 2010
DISCOVRE Involvement in Deep Gulf of Mexico Research since the Deepwater Horizon Event
The USGS DISCOVRE team has been actively involved in assessing the impacts of the Deepwater Horizon oil spill on deep-sea coral habitats in the Gulf of Mexico. Our varied scientific expertise (including benthic ecology, microbiology, genetics, vertebrate and invertebrate taxonomy, food-web interactions, and coral reproduction) plus our valuable pre-impact data sets from 2004 - 2009, have positioned our team as both scientific leaders and key participants in examining the potential short and long term effects of the oil spill on vulnerable deep-sea ecosystems.
DISCOVRE scientists have been onboard four deep-sea coral research cruises in the Gulf of Mexico since the oil spill:
The first three cruises primarily visited deep-sea coral habitats along the edge of the continental shelf, at water depths of 300-500 meters. An area of particular concern was Viosca Knoll, a site approximately 20 miles from the Deepwater Horizon oil rig that hosts the largest known concentration of the cold-water coral, Lophelia pertusa, in the Gulf of Mexico. All visits to this site and similar areas revealed no obvious physical impacts. The number and types of corals were consistent with photomosaic images collected the previous year. Furthermore, the corals appeared healthy and there was no visible evidence of acute effects; the corals were behaving normally and had no signs of distress. These sites are being monitored for sub-lethal effects, such as reduced reproductive cycles. However, we are awaiting test results to confirm whether these areas were exposed to the oil from the Macondo well. Note that these coral habitats are much shallower than the site of the oil spill. Volatile compounds that reached the surface passed hundreds of meters above these corals. After the dispersant was added at depth, the oil appeared to form plumes or settle on the bottom; in both cases this oil was at depths of approximately 1400 m, well below the continental shelf break where Viosca Knoll is located.
The most recent cruise sponsored by the National Oceanographic Partnership Program and funded by the Bureau of Ocean Energy Management, Regulation and Enforcement and NOAA OER on the R/V Ronald H. Brown, discovered an area of deep-sea corals (gorgonians and Madepora, not Lophelia) that were visibly damaged. These corals were approximately 7 miles from the oil spill source at a depth of 1400 m. Visible damage included bare skeleton where coral tissue had sloughed off and was often covered with what appeared to be decaying tissue. Some coral skeletons had no live tissue visible. Even the behavior of the associated invertebrates, such as brittle stars, appeared impaired. None of the scientists, many of whom have worked in the Gulf for over a decade, have ever seen anything like this.
USGS DISCOVRE scientists will be on-board the next deep-sea cruise, in December 2010, using the deep-diving submersible Alvin to further assess any impacts to corals and chemosynthetic ecosystems in the Gulf of Mexico, particularly areas below 1000 m in the vicinity of the spill source.
Links to recent coverage of deep-sea corals in the Gulf of Mexico
Concerns about the deep-water corals in the Gulf - New York Times, June 2, 2010:
Reports after the September & October Cruises:
Penn State - photos of damaged corals:
Media Inquiries: Amanda Demopoulos, (352) 264-3490, firstname.lastname@example.org
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