Just how hard is it to clean up a big oil spill? Here's one pessimistic take: Charles Wohlforth, who covered the Exxon Valdez spill back in 1989 for the Anchorage Daily News, says the lesson from the Alaska disaster is that massive slicks can be nearly impossible to clean up, for the most part:
More than 10,000 workers worked for a summer to wash glue-like oil from cold rocks. After spending more than $2 billion and inflicting untold additional environmental damage through their efforts, the cleanup recovered, at most, 5 to 7 percent of the oil. Some oil still remains in the beaches.
Eventually I realized I had covered the wrong story. The important point wasn’t that Exxon couldn’t clean up its oil spill. The point was, no one could clean it up. ...
The truth is that when large amounts of oil go into the ocean, it’s a huge success to recover as much as 10 percent. More than that is rarely possible. Oil spreads too rapidly and reacts too quickly with the environment; and the ocean is a challenging place to work, especially considering the logistics of speedily gathering up a blob the size of a small state.
To make things worse, the effects of a big spill that never gets cleaned up can linger around for a very long time: One 2003 study in Science, led by Charles Peterson of UNC Chapel Hill, found that even a decade after the Exxon Valdez accident, the leaked oil was still killing off species, stunting the growth of salmon, and poisoning fish eggs.
So the follow-up question: Is anything different this time around? Not a whole lot. BP's cleanup tactics are still pretty similar to what Exxon was doing back in the 1980s. Both companies lowered booms into the water to keep the spill from hitting the shore—a strategy that can work moderately well if the wind and tide cooperate (and they don't always). Second, as happened in Alaska, the Coast Guard and BP have been trying to burn off oil on the surface of the water. But this wasn't very effective in Prince William Sound and it's not yet clear how well it will work in the Gulf.
Maybe the big difference is that BP is using far more chemical dispersants to try to break up the crude and sink it to the bottom. But, as in Alaska, those dispersants can be toxic in their own right, and the oil that settles on the seafloor can cause havoc on shellfish and other small-but-key-to-the-food-chain organisms there. (Okay another big difference is the big containment domes that BP is trying to place over the leak, but that hasn't worked so far…) Indeed, all told it's surprising how slowly cleanup technology has advanced since the 1980s—especially since, as Wohlforth notes, so little of the Exxon Valdez spill actually got mopped up.