The five species of sea turtles that live in the Gulf are all listed as threatened or endangered. About 500 have been found dead in the spill region every year since 2011. What’s unknown is how many turtles died at sea and were never recovered by scientists. ©Colby J. Brokvist

Just over five years ago, on the evening of April 20, 2010, the BP Deepwater Horizon oil platform exploded off the coast of Louisiana, rupturing the Macondo exploration well below it. For the next 86 days, until BP finally capped the well, at least 3.19 million barrels of oil gushed into the Gulf of Mexico and touched the shores of five states. It was the largest marine oil spill in history.

In the weeks following the spill, BP siphoned off 810,000 barrels of oil at the wellhead before it entered the Gulf, pumped 1.8 million gallons of chemical dispersant into the Gulf’s waters, lit 411 surface fires, deployed miles of absorbent floating booms, and enlisted tens of thousands of workers and volunteers to clean beaches. In all, the company is expected to spend $31.5 billion in restitution.

But where is the rest of the oil today? And now—even with stricter regulations in place—is it safe to green-light other offshore oil enterprises to help alleviate our rising energy demands?

The Deepwater Horizon oil spill was the largest marine oil spill in history. It was caused by an April 20, 2010, explosion on the Deepwater Horizon oil rig, located in the Gulf of Mexico, approximately 41 miles off the coast of Louisiana. ©John Masson, flickr

In the South: a lasting legacy of the worst kind?

It turns out that nature itself appears to have given BP a hand with the cleanup. Bacteria that evolved specifically to feed on the million or so barrels’ worth of oil that naturally seeps from the Gulf floor each year quickly consumed many of the alkanes (saturated hydrocarbons) found in the crude. Six months after the well was capped, the plume had disappeared.

But oil is a complex mixture, and other hydrocarbons were left behind. In the months following the spill, the toll on wildlife proved to be astounding: nearly 7,000 animals were found dead, including more than 6,000 birds, 600 sea turtles and 100 mammals. Just as the endangered Kemp’s ridley sea turtles were coming back from the brink of extinction, they may have been hit the hardest. Because the spill happened in a foraging area and migratory route for sea turtles, it’s estimated that tens of thousands of them may have encountered the oil. Roughly 500 sea turtle deaths were recorded in 2011, 2012 and 2013 in the northern Gulf, which is as many as five times more than normal.

The Mississippi River Delta is an area where countless numbers of birds, fish and other wildlife species feed and reproduce. The spill occurred in April, at breeding time, exposing vulnerable young and larvae to toxins from the oil and other chemicals. How this will affect marine life over a longer period of time is not yet known, but studies of how the toxins are working their way up the food chain are currently being conducted.

More than 6,000 birds died in the Gulf after the BP oil spill. ‬©Candice Gaukel Andrews

Five years later, people are suffering, too. Oil remains in the estuaries, marshes and ocean. Tens of thousands of coastal residents have developed symptoms associated with oil exposure, such as cardiovascular issues, memory loss, organ degradation and respiratory problems. Two big research projects are underway: the National Institute of Environmental Health Sciences is conducting a 10-year study, which will monitor 33,000 cleanup workers and coastal residents. It the largest such study in history. And a five-year project by a consortium of five universities is measuring polycyclic aromatic hydrocarbon (PAH) levels in subsistence-fishing communities. Of course, proving a link between such health issues and the BP oil spill could take years.

Yet, earlier this month the Obama administration granted conditional approval to Shell to begin oil drilling in the Arctic waters off the coast of Alaska.

In the North: a disaster waiting to happen?

According to World Wildlife Fund, the Arctic is estimated to hold the planet’s largest remaining untapped gas reserves and some of its largest undeveloped oil reserves. A significant proportion of these reserves lie offshore, in the Arctic’s shallow and biologically productive shelf seas. If a spill should happen here, the difficult conditions of the Arctic—and its distance from where response capacity is stationed—means it will take days or weeks to respond, even during ice-free periods. And, to date, we have no proven, effective method for containing and cleaning up an oil spill in icy water.


Shell is currently conducting exploratory oil drilling missions in Arctic waters.

However, on May 11, 2015, citing “rigorous safety standards” and a long review process, the Interior Department granted conditional approval to Shell to begin oil drilling off the coast of Alaska in the Chukchi Sea. Several environmental conditions still need to be met, including a sign-off from agencies assessing the impact on endangered species and approval from state agencies. It’s the first major exploratory drilling plan in the U.S. since the BP Deepwater explosion.

The New York Times states that President Obama has pursued the most ambitious environmental agenda of any president, but he has sought to balance those moves by opening up untouched federal waters to new oil and gas drilling. Shell claims that developing Arctic resources could be essential to securing enough energy supplies for our future, quoting a U.S. Geological Survey study that estimates that the Arctic could hold about 13 percent of the world’s undiscovered oil reserves. The Interior Department has significantly strengthened and updated drilling regulations since the BP spill and proposed new rules to tighten safety requirements on blowout preventers, the devices that are the last line of protection against explosions in undersea oil and gas wells.

The 2010 BP explosion was caused, in part, when a section of drill pipe buckled, leading to the malfunction of a blowout preventer. Some say the new regulations fix this problem and that while the challenges of recovering oil in the Arctic are many, allowing drilling to take place only in the summer months and in shallow waters not more than 140 feet deep (the Deepwater Horizon well was in water about 5,000 feet deep) will surmount them.

It’s a complicated question: is drilling for oil in the Arctic worth the risk? ©Ralph Lee Hopkins

Today, no one is really sure how much oil from the BP spill is still out there in the Mississippi River Delta. What we have learned is that Corexit, the dispersant pumped into the water shortly after the explosion, made the oil more edible to fish and plankton, which otherwise don’t consume it. And there is some evidence that the chemical actually hindered degradation, allowing more hydrocarbons to remain in the Gulf.

Perhaps all we know, five years after the Deepwater Horizon debacle, is that we still are gathering up the unknowns.

Do you think drilling for oil in the Arctic is worth the risk? Would you rather depend on foreign oil? Is getting the country off oil entirely in the next few decades realistic?

Here’s to finding your true places and natural habitats,