Oil Plumes Threaten Deep Gulf Reefs

From Microcosm Aquarium Explorer

While heart-wrenching images of sea turtles and pelicans smothering in oil leaked from the out-of-control BP underwater oil well dominate the media, marine biologists are predicting possibly horrific consequences for large expanses of deep reefs in the Gulf of Mexico.

Sprawling underwater plumes of emulsified, microscopic oil droplets from the runaway BP deep-water well in the Gulf of Mexico have marine scientistics and oceanographers on high alert and fearful that the worst consequences of the massive spill are yet to come. "Plumes that run deep in the water column would actually pose more of a threat than surface oil slicks," says Billy Causey, NOAA southeast director for the Office of National Marine Sanctuaries.

“If these plumes are toxic, it could be far more catastrophic than anything that happens to the coastal wetlands,” says Larry McKinney, chairman of the Flower Garden Banks science advisory committee in Texas. While the floating oil slicks and tarballs are not likely to pose a threat to the Flower Garden Banks reefs, 300 miles west of the blowout, drifting undersea plumes are of potential great concern.

While BP CEO Tony Hayward has asserted that "oil floats" and that the plumes are non-existent, researchers from a number of universities have been documenting the presence of phantomlike clouds of underwater oil in the Gulf. McKinney told The Houston Chronicle that one of the plumes had a volume of 82-cubic miles or half the size of Lake Erie.

Little is known about the toxicity of these plumes, which can vary significantly in their concentration of oil, but marine biologists believe the effects on the plankton in the Gulf, including fish and invertebrate eggs and larvae, could be lethal. Causey is also concerned about the unprecedented amounts of oil disperants used by BP to break up the slicks, as various studies have shown the dispersants to be much more toxic to corals than oil itself.

Death for Deep Corals

According to researchers at the Rosenstiel School of Marine & Atmospheric Science at the University of Miami, the massive plumes of suspended oil offer significant threats to delicate corals and other marinelife in the Gulf and beyond.

According to Drs. Gregor Eberli, Mark Grasmueck, and Ph.D. candidate Thiago Correa of the Marine Geology & Geophysics division of the University of Miami (UM), the drifting rivers of suspended oil present serious risk for the planktonic and benthic (sea floor) life throughout the region, including the deep-sea reefs they study.

“The deep water communities within the Gulf of Mexico and in the Straits of Florida are well hidden from us, but they include many species of cold-water corals that live in water at depths of 600 – 1500 m. (1969 -4921 ft.) in waters as cold as 3° Celsius (37.4°F),” said Eberli.

“It is most likely that the delicate cold-water corals are not able to digest these oil-laden food particles and will perish in large numbers,” said Eberli. “We are especially concerned because the migrating oil plumes have the potential to destroy or greatly diminish these deep-sea coral communities as they are carried by the currents. These corals are important because they are the foundation of a diverse ecosystem that at last count includes over 1,300 marine species, according to Dr. Thomas Hourigan at NOAA.”

There is also a danger that these plumes are carried by the Loop Current from the Gulf of Mexico to the Atlantic Ocean. Deep-sea coral ecosystems are common at numerous sites in the path of the Loop Current, from the eastern Gulf of Mexico through the Straits of Florida and northward to the Blake Plateau off North Carolina.

Scientists studying Cuba's marine life also fear that the oil may impact wide tracts of some of the Caribbean's most-pristine reefs, where large stands of healthy Acropora palmata still exist.

"The catastrophic oil spill in the Gulf of Mexico presents a potentially grave and unprecedented threat to Cuba’s marine life and coastal areas," says Dr. David E. Guggenheim, president of 1Planet1Ocean in Washington, DC. "Not only would this be devastating to Cuba’s marine life, but given the biological connections present in the Gulf of Mexico, such an impact could affect a myriad of species, including fish, sea turtles, dolphins, manatees, sharks, corals inhabiting the waters of the U.S., Mexico and beyond." --- FURTHER READING:

Currents Oil-Spill Modeling Map (Video)

Ocean Explorer: Gulf of Mexico Deep Sea Habitats

Watercrunch: Southeast's Secret Deep-water Coral Reefs

Crude oil dispersants profoundly increase the toxicity of crude oil to coral reefs

Cuba Could Be Impacted by Gulf Oil Spill