Nearly four years after the BP Deepwater Horizon explosion dumped more than 200 million gallons of crude oil into the Gulf of Mexico, the slate has been largely cleared for BP -- the EPA ban on federal contracts has been lifted, and the company is free once again to bid on federal oil and gas leases.
But as a new study published this week makes clear, we're only beginning to understand the spill's devastating long-term implications for the region's sea life.
Released on the 25th anniversary of Alaska's Exxon Valdez oil spill, the National Oceanic and Atmospheric Administration-led study found that young bluefin tuna and amberjack exposed to oil samples collected during the Gulf skimming operations after the spill are showing a range of disconcerting abnormalities.
The exposed fish suffered from finfold deformities, dramatic reductions in eye growth and, most concerning of all, heart defects likely to limit the open water food-catching abilities key to their survival.
The study's findings are significant, but hardly surprising. There's no doubt that for years to come we'll be learning the spill's true cost to wildlife in one of our world's most important spawning grounds for imperiled bluefin tuna.
Four years after the spill, officials have no idea how many fish were killed or the extent of the long-term damage to the Gulf. But with only 25 percent of the spilled oil recovered and nearly 2 million gallons of toxic oil dispersants sprayed into the Gulf's waters, we know the toll on wildlife will be measured in decades, not years.
An analysis projecting the true wildlife toll based on documented strandings suggests the spill likely harmed more than 80,000 birds, 25,000 marine mammals and 6,000 sea turtles as well as doing untold damage to marine invertebrates such as coral lobsters, crabs, oysters, clams, zooplankton and starfish.
Despite the ongoing carnage, little has been done to tighten oversight necessary to prevent similar spills in the future.
The name of the agency overseeing offshore drilling changed, but little else. Environmental review is still waived for many drilling projects in the Gulf. And though there are already nearly 4,000 offshore oil and gas operations in the Gulf, the expansion of risky deepwater wells continues.
While the government proposed to raise the oil spill liability cap to $134 million, that is woefully inadequate to cover the costs of an offshore oil spill. To date, there's been no thorough scientific review of the short-term and long-term impacts of oil dispersants on marine life.
As this new study demonstrates, we have much to learn yet about the costs of oil spills.
But what we know with great certainty is that oil spills and the far-reaching damage they cause will continue until we leave dirty fossil fuel sources behind and commit fully to a clean energy future.