Undersea Oil Adrift in Gulf May Create Oxygen ‘Dead Zones’
Share Business ExchangeTwitterFacebook| Email | Print | A A A
By Jessica Resnick-Ault
June 1 (Bloomberg) -- The millions of gallons of oil leaking from a broken well a mile under the Gulf of Mexico may create oxygen-depleting dead zones below the ocean, killing sea life and upsetting the region’s ecology for decades, scientists say.
BP Plc’s oil spill, the biggest in U.S. history, has been sprayed with 950,000 gallons of chemicals on the surface and near the seabed to dissolve the oil into water. The amount of dispersants used is unprecedented and the behavior of the dissolved oil unknown, Environmental Protection Agency Administrator Lisa Jackson has said.
“There is great, great concern of the subsurface nature of this event, of the amount of dispersants and what this means to the entire ecosystem,” Roger Helm, Chief of the U.S. Fish and Wildlife Service Division of Environmental Quality, said at a press conference. “This is going to be groundbreaking science.”
A government team appointed by the Coast Guard estimates oil has been spilling from the well at a rate of 12,000 to 19,000 barrels a day. That could increase as much as 20 percent when BP makes its next attempt to control the leak by sawing off a damaged pipe. Within the week, BP plans to reconnect the pipe and funnel oil to a ship on the surface.
Long-Term Damage
Even if BP succeeds, long-term damage to the Gulf ecosystem is unavoidable, said Rick Steiner, a marine biologist and consultant who has worked with governments and the United Nations on oil spills.
“This much oil in a productive marine environment will cause substantial environmental damage,” he said.
Marine biologists are worried the oil will kill off fragile organisms, such as shrimp and fish larvae and plankton, a critical part of the offshore food chain, Steiner said. Fish can also suffocate if their gills are coated with crude.
Microbes in the sea that feed on oil seeping from the seabed are expected to consume most of the underwater oil from the leak, said Frank Muller-Karger, professor of biological oceanography at the University of South Florida.
With such a big oil spill, that may bring its own problems, he said. Populations of oil-gorged microbes could expand rapidly, consuming oxygen needed by other sea life and creating “dead zones.”
Underwater Spread
“You end up with a transformation of the chemistry of the water, and we are not clear on what that is,” Muller- Karger said.
Universities and federal agencies are dispatching boats to search for oil deep within the sea, where it remains unseen and more difficult to measure than the oil floating atop the water or washing ashore.
Oil from the spill may have spread underwater for 22 miles toward Mobile, Alabama, researchers aboard a University of South Florida vessel reported May 27. Initial tests aboard the Weatherbird II show the highest concentrations of “dissolved hydrocarbons” were 1,312 feet (400 meters) below the surface.
Research crews dispatched to study the spill include expeditions funded by the Louisiana Universities Marine Consortium, the National Oceanic and Atmospheric Administration, and the National Science Foundation.
As of yesterday, the Unified Area Command in Robert, Louisiana, reported oil along 100 miles of Louisiana coastline. Nearly 100 birds and five sea turtles have been found dead or visibly oiled, according to the Command’s latest report. Hundreds more birds and turtles may have been affected, the report says.
Coastal marshlands, which are breeding grounds for a rich variety of sea life, will take years to recover from the toxic effects of crude, scientists say.
The environmental effects of oil spreading beneath the sea are less certain.
“We are now entering a different phase of this disaster,” said Samantha Joye, a researcher at the University of Georgia who is part of a group gathering data about the spill.
“Everybody has been focusing on the surface impacts, which is normal, but now we’ve got to switch gears and start thinking about the deep water,” said Joye, before setting out on a new research mission funded by the National Science Foundation. |
