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Signs of oil spill pollution might be hiding underwater

The signatures of such a disaster — grimy beaches and dead seabirds — haven't materialized, but the oil may be affecting the bountiful sea life below the surface.

May 16, 2010|By Bettina Boxall and Alana Semuels, Los Angeles Times

Reporting from Los Angeles and Venice, La. — Biologist Dennis Takahashi-Kelso peered into the cobalt waters of the Gulf of Mexico 20 miles off the Louisiana coast. The only sign of pollution was a plastic bag floating beneath the surface.

More than three weeks after the Deepwater Horizon rig exploded, resulting in a leak spewing 210,000 gallons of crude per day into the gulf, the fouled beaches and dead seabirds that are the hallmarks of catastrophic spills have yet to materialize.

But Takahashi-Kelso, who was Alaska's commissioner of Environmental Conservation at the time of the Exxon Valdez disaster, warned: "It's going to be bad."

Even as the spill breaks into separate strands, a nasty environmental storm is brewing below the surface, in deep columns of water teeming with life, from shrimp and fish eggs to dolphins and whales.

Last week, researchers from the National Institute for Undersea Science and Technology reported on their website that they had found what they believe are large plumes of oil far beneath the surface.

Experts don't know what the oil is doing to the complex web of offshore life. Most of their experience is with shallow-water spills that quickly bleed black goo onto beaches that are cleaned up relatively quickly.

The BP well blowout, 48 miles off the Louisiana coast, is different. Oil is gushing from a tangled, broken pipe lying on the seafloor nearly a mile beneath the surface. The leak will be a month old this week, and if it is not stanched by then, it will have spilled about 6.3 million gallons.

"We have no idea where the oil that isn't reaching the surface is going," said James Cowan Jr., an oceanography professor at Louisiana State University. "It could go everywhere."

Tar balls have washed ashore in three Gulf Coast states, strips of slick ribboned Louisiana's Chandeleur Islands, and the whiff of petroleum has permeated the morning breeze. But most fishermen and residents haven't seen any signs of the spill, aside from the media trucks parked in marinas and military helicopters whirring overhead.

They sit in dark bars and talk about possible solutions to the disaster, or fix parts of their boats, waiting for oil to reach land or go away.

"Everybody's just waiting," said Daniel Camargo, who was hanging out with friends on his boat, the Christian Louis, moored on a canal in St. Bernard Parish, La. Red and yellow crab traps were stacked nearby, unused.

The rust-tinted light crude, meanwhile, sloshes around a part of the gulf that is a major pathway for marine life, where the nutrient-filled waters of the Mississippi River mix with the ocean.

"It's a significant ecosystem that goes from the bottom to the top waters," said Roger Zimmerman, a marine biologist who directs the Galveston Laboratory, part of the National Oceanic and Atmospheric Administration's Fisheries Service. "This is a rich area in terms of biological productivity and diversity of animals. There's a lot of reproduction."

Red snapper, red drum, gulf menhaden and other fish use offshore waters east and west of the Mississippi Delta as nursery and spawning areas.

A big part of the country's commercial shrimp catch comes from the waters on either side of the undersea Mississippi Canyon, the site of the BP blowout. The canyon, which cuts through the continental shelf, harbors deep sea coral.

Pelicans and other seabirds that dive into the slick to catch prey will bathe in the oil and carry it back to their nests, where eggs can absorb it, possibly killing the chick developing inside. Sea turtles and dolphins, which surface twice a minute to breathe, will inhale harmful fumes as they swim through the slick.

"This is such sticky oil in its emulsified and dispersed form that there are mechanisms of harm that we don't usually look at," said Charles Peterson, a professor of marine sciences at the University of North Carolina who studied the effects of the 1989 Exxon Valdez spill on Alaska's Prince William Sound. The oil might clog the feeding organs of species such as jellyfish, he speculated.

What happens on the surface also affects the deep-sea creatures living far below, where they are nourished by the rain of plankton particles from above. "If that productivity is eliminated or if it's contaminated, all of that will go to the seafloor," said Gilbert Rowe, a professor of oceanography and marine biology at Texas A&M.

The light nature of the crude spouting from the leak is both good and bad. Rather than the thick, viscous pancake of oil that Takahashi-Kelso remembers floating on the ocean in the Exxon Valdez spill, the BP oil is rising to the surface as a mousse.

That means it could decompose more quickly. But it also floats through the water in snow-like bits that increase exposure to the oil's toxins. "That's all suspended in the water column where the organisms are found," Peterson said.

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