OK, so now you've brought us up to speed on acid rain, the hole in the ozone layer, and the Amazon rain forest. Here's another hot-button environmental issue from the past I'd like an update on: the Exxon Valdez spill. Is everything up there copacetic or what?
Now's a good time to take stock of the situation, since this year marks the 20th anniversary of the environmental disaster Time magazine once called "a Greek tragedy updated by Murphy's Law." Though you might not have spared a thought for Prince William Sound in the past two decades, researchers haven't been so negligent: The spill-affected area continues to be a subject of active study—and controversy.
As you may recall, the oil tankerExxon Valdez ran aground on Alaska's Bligh Reef just after midnight on March 24, 1989. Nearly 11 million gallons of crude oil—about 17 * Olympic swimming pools' worth—spilled into Prince William Sound,fouling 1,300 miles of shoreline, killing scores of animals, and forging a generation of enviros with pictures of cute, oil-slicked otters.
Two decades later, the vast majority of water in the sound is oil-free, as are the beach surfaces. That's all thanks to a massive cleanup effort in the early 1990s, in combination with the natural action of winter storm waves. The otters are doing somewhat better, too: In its latest annual report, the Exxon Valdez Oil Spill Trustee Council—which coordinates the government's research and restoration efforts—classified the overall otter population as "recovering," though the animals living in more heavily soiled areas are lagging behind.
Otters are just one item on the Trustee Council's official list of resources and services injured by the spill, which includes both animal species and thingslike the subsistence activities of Alaskan Native communities. Judging by that list, the post-spill sound is indeed improving, but it's still got a ways to go. Ten items out of the 31 total are considered "recovered," including bald eagles, harbor seals, and common loons. Meanwhile, 14 itemsare making "substantive progress" toward recovery, though exactly how much progress differs in each case: For example, killer whales are classified as "recovering," even though that description applies to just one of the two orca pods observed in the sound; there isn't much hope for the other. Finally, two species—the Pacific herring and the pigeon guillemot—are barely showing any improvement, and for five items on the list there's inconclusive evidence to make a call either way. It's important to note, though, that factors other than the spill may be hampering progress for these animals and resources. In the case of the herring, for example, disease and predators seem to be far more of a problem than oil pollution.
On a positive note, a number of new spill prevention and response tactics have been established in the aftermath of the Exxon Valdez tragedy. For example, tankers passing through the sound are now accompanied by two escort vessels, which monitor the bigger ship and carry emergency response personnel, containment booms (water-borne fences that can corral oil spills), and equipment to skim spilled oil from the water's surface. The Trustee Council also reports that it has protected more than 647,000 acres of habitat in the affected area.
The issue of lingering oil remains a major topic of controversy, as Lila Guterman detailed in this 2004 Chronicle of Higher Education story and in a 2009 follow-up for Science. A series of studies in 2001 and 2003, conducted by researchers from the National Oceanic and Atmospheric Administration, discovered pockets of crude oil lingering below the beach surface in some intertidal areas (the parts of the shoreline that are submerged only during high tide). The NOAA team concluded that about 21,000 gallons of oil remain buried in the beaches along Prince William Sound. Though Exxon-funded scientists disputed the studies at first, they eventually came to accept the findings; however, they questiongovernment claims that this lingering oil poses a threat to wildlife (PDF). A recent statement on the Exxon Mobil Web site argues that "based on the studies of many scientists who have worked extensively in Prince William Sound, there has been no long term damage caused by the spilled oil."
A good chunk of change hangs on the outcome of this debate. As part of the $900 million civil settlement reached between Exxon and the Alaskan and federal governments in 1991, the government retained the right to claim an additional $100 million from Exxon if unexpected damages from the spill were discovered within 15 years. The government exercised this "reopener" option just before the deadline in 2006 and requested an additional $92 million to locate all the remaining oil and restore the affected sites. Negotiations are now on hold, pending the release of further studies from government researchers. (Meanwhile, a $5 billion lawsuit brought against Exxon by a group of Alaskan natives, fishermen, and business owners has had its own long, drawn-out legal saga.)
And what's happened to the infamous vessel itself? The Exxon Valdez has since been rechristened the Dong Fang Oceanby its new Chinese owners (the fourth name change since the spill) and as of March of this year was being retrofitted to carry ore, not oil. Under the Oil Pollution Act of 1990,however, the ship is no longer allowed to enter the Prince William Sound. The same goes for any tanker that's spilled more than 1 million gallons of oil since March 22, 1989—two days before the Exxon Valdez ran aground.
Is there an environmental quandary that's been keeping you up at night? Send it to email@example.com, and check this space every Tuesday.
Correction, May 11, 2010: The original sentence erroneously stated that 11 million gallons would fill about 125 Olympic swimming pools. (Return to the corrected sentence.)