Oil Spill Continues off Louisiana

The Coast Guard and BP are attempting to stop the leak that resulted from last week's drilling rig explosion. As of last night, their efforts were still unsuccessful, and oil continued to leak out of the pipes at a rate of 42,000 gallons per day. For now, they are trying to use robots to shut off a valve at the wellhead. If that fails, it may be possible to build an underwater dome to collect the oil or drill a relief well to take pressure off the original wellhead.

Plans are moving forward to design a dome that could be submerged over the leaks, which are coming from a 5,000-foot pipeline called a riser that ran between the wellhead and the rig. The riser is now snaking along the ocean bottom.

The dome would corral the oil and route it up to vessels to be collected. But Doug Suttles, the chief operating officer for exploration and production at BP, which was leasing the rig from Transocean and is required by law to pay for the cleanup, continued to emphasize the engineering challenges of such an operation at a news conference on Monday.

“I must stress that this is state of the art,” Mr. Suttles said, adding that the method had never been done at such depths. It would take at least two weeks to put into place, he said.

More than 1,000 people are working on the spill, including officials from the Coast Guard, the federal government and BP. BP is also mobilizing rigs that would drill one or more deep wells nearby to push mud and concrete into the gushing cavity, an operation made all the more expensive and complex in the deep waters. That would take two to three months.

Here are good diagrams of the leak and what might be done about it. So far the oil slick is not threatening the coastal wetlands because winds have pushed it eastward. If the wind direction changes before the leak is stopped, the slick could reach the coast relatively quickly. Even if the coast is not affected, the oil spill can still harm marine life.

Charlie Henry, the lead science coordinator for the National Oceanic and Atmospheric Administration, said that three sperm whales were seen swimming near the spill but that they appeared unaffected.

But other environmentalists warned of damage. "Oil spills are extremely harmful to marine life when they occur and often for years or even decades later," said Jacqueline Savitz, a marine scientist and climate campaign director at Oceana, an environmental group. She said spills could coat sea birds and limit their flying ability and damage fisheries by injuring marine organism's systems related to respiration, vision and reproduction.

Savitz said that the Gulf of Mexico is host to four species of endangered sea turtles and bluefin tuna, snapper and grouper. "Each of these can be affected," she said. "Turtles have to come to the surface to breathe and can be coated with oil or may swallow it." And, she added, the Gulf is one of only two nurseries for bluefin tuna, more than 90 percent of which return to their place of birth to spawn.

The event will raise questions about the Obama administration's plans to open more of the coast to offshore drilling. One accident does not necessarily mean that the policy is wrong. However, accidents like this one have human costs, environmental costs, and monetary costs for cleaning up the mess. Those costs need to be accounted in any decisions regarding increased drilling.