NPR logo Underwater Oil Plumes Alarm Scientists

Underwater Oil Plumes Alarm Scientists

BP CEO Tony Hayward raised eyebrows last week when he said his company's broken oil well was releasing a relatively "tiny" amount of oil and dispersant into the vast volume of water that is the Gulf of Mexico.

That comment stands in stark contrast to reports over the weekend that scientists have discovered giant oil plumes under the waters of the gulf. Scientists are worried about what the potential impact of so much oil, and the chemical dispersant being used to keep it from coming ashore, on marine life. Much of that life is unseen and not well understood.

Scientists are speculating that the plumes, one that's at least 10 miles long under the surface, could account for the differences between the official estimates of how many barrels of oil are pumping into the gulf, with Coast Guard and BP using the figure of about 5,000 barrels and some scientists saying the flow could be 10 times that or more.

Especially troubling to scientists are the effects the oil and dispersants could be having on dissolved oxygen levels in the water. Scientists fear the oil will make it difficult for marine animals to obtain the oxygen they need to survive. Scientists have already observed some dying fish.

As the Associated Press reports:

Researchers Vernon Asper and Arne Dierks said in Web posts that the plumes were "perhaps due to the deep injection of dispersants which BP has stated that they are conducting."

These researchers were also testing the effects of large amounts of subsea oil on oxygen levels in the water. The oil can deplete oxygen in the water, harming plankton and other tiny creatures that serve as food for a wide variety of sea critters.

Oxygen levels in some areas have dropped 30 percent, and should continue to drop, Joye said.

"It could take years, possibly decades, for the system to recover from an infusion of this quantity of oil and gas," Joye said. "We've never seen anything like this before. It's impossible to fathom the impact."

"Meanwhile, the Washington Post's Joel Achenbach has a piece that gives a small glimpse of what's at stake.

In total darkness at the bottom of the Gulf of Mexico lives a creature with many scuttling legs and two wiggling antennae that jut from a pinched, space-alien face. It is the isopod, Bathynomus giganteus, a scavenger of dead and rotten flesh on the mud floor of the gulf.

"If you think of a giant roach, put it on steroids," said Thomas Shirley, a marine biologist at Texas A&M University. "They can be scary big."

There is beauty in the lightless deep as well. Fan corals, lacylike doilies, form gardens on the seafloor and on sunken ships. The deep is full of crabs, sponges, sea anemones. Sharks hunt in the dark depths, as do sperm whales that feed on giant squid. The sperm whales have formed a year-round colony near the mouth of the Mississippi River, and have been known to rub themselves on oil pipes just like grizzlies rubbing against pine trees.

This is the unseen world imperiled by the uncapped oil well a mile below the surface of the gulf. The millions of gallons of crude, and the introduction of chemicals to disperse it, have thrown this underwater ecosystem into chaos, and scientists have no answer to the question of how this unintended and uncontrolled experiment in marine biology and chemistry will ultimately play out.

The leaking gulf well, drilled by the now-sunken rig Deepwater Horizon, has cast a light on a part of the planet usually out of sight, out of mind, below the horizon, and beyond our ken. The well is surrounded by a complex ecosystem that only in recent years has been explored by scientists. Between the uncapped well and the surface is a mile of water that riots with life, and now contains a vast cloud of oil, gas and chemical dispersants and long, dense columns of clotted crude.

"Everybody fixates on the picture of the cormorant or the bird flailing around all covered with oil, and while that's obviously sad to see, no one should assume there's not similar things occurring in the open ocean," said Andy Bowen, an oceanographer at Woods Hole Oceanographic Institution in Massachusetts. "It's not like the open ocean is irrelevant."