We still don’t know the full impacts of the BP oil spill, 10 years later

The BP oil spill of 2010 started suddenly, explosively, and with deadly force. But the response has stretched out for years and scientists say there’s still much more we need to learn.

As a crew on the Deepwater Horizon drilling rig worked to close up an exploratory oil well deep under the Gulf of Mexico, a pulse of gas shot up, buckling the drill pipe. The emergency valve designed to cap the well in case of an accident, the “blowout protector,” failed, and the gas reached the drill rig, triggering an explosion that killed 11 crewmembers.

Over the next three months, the uncapped well leaked more than 300 Olympic-sized swimming pools of oil into the Gulf’s waters, making it the biggest oil spill in United States history. The leak pumped out 12 times more oil than the Exxon Valdez spill of 1989.

The spill opened many people’s eyes to the risks of drilling for oil in one of the most ecologically rich, culturally important, and economically valuable parts of the world. But 10 years and billions of dollars in cleanup efforts later, many of the same risks that allowed the disaster to occur remain.

“It took the better part of six to seven years [after the disaster] to get in place the inspection of blowout preventers and rules about making drilling plans safer and putting commonsense regulations in place, but those have been rescinded,” says Ian MacDonald, a scientist at Florida State University. “So basically we’re back to where we were in 2010, in terms of regulatory environment.”

And in some ways, more is known now than ever before about the Gulf and how the spill affected its ecosystems.

“We’re just to the point now where we have enough data to recognize things we missed earlier, and there’s still a lot we don’t know,” says Samantha Joye, a marine scientist at the University of Georgia. “This is a marathon, not a sprint.”

Can this kind of spill happen again?

About 17 percent of the U.S.’s total crude oil production comes from offshore projects in the Gulf. Pipelines—26,000 miles of them—connect wells to the processing infrastructure that lines the coast. Before plummeting demand from the coronavirus pandemic drove already-low oil prices lower, the Gulf of Mexico was producing as much crude oil as it had in years.

“Even in times of low prices like today, offshore just keeps going on,” says Gregory Upton, Jr., an energy economist at Louisiana State University.

And drilling for oil in deep offshore waters is inherently dangerous for the people working the platforms, as well as potentially for the environments they’re drilling in.

“Working on the ultra-deep stuff is pretty much like working in outer space,” say Mark Davis, a water law expert at Tulane University.

But conditions on the Deepwater Horizon rig were particularly concerning. After the spill, the commission created by the Obama administration to investigate the spill reached stark, damning conclusions. Many lapses in safety had contributed to the disaster, many of which traced back to a culture both within BP and the industry more broadly that did not value safety enough.

A new agency, the Bureau of Safety and Environmental Enforcement (BSEE), was created to track and enforce offshore drilling safety issues, something that had been handled by the same agency that approved leases to oil companies.

“Before Deepwater, there was this mentality that had set in in the 1990s and 2000s, that the oil and gas industry, as it was going farther offshore, was capable of self-regulating,” says Matt Lee Ashley, a researcher at the Center for American Progress. “Then Deepwater happened and burst that set of assumptions.”

BSEE announced a new set of safety rules for offshore operations in 2016. Among those rules was one that required blowout protectors—the piece that had failed at Deepwater Horizon—to be inspected by a third party, rather than self-certified by the drilling companies. But many of those rules, as well as other safety practices put in place after the disaster, have been weakened in recent years. Most notably, in 2019 the Trump administration finalized rollbacks of several components of the 2016 rules, including the independent safety certification for blowout protectors and bi-weekly testing.

Inspections and safety checks by BSEE have also declined some 13 percent between 2017 and 2019 and there have been nearly 40 percent less enforcement activities in that time compared to previous years, according to Lee Ashley’s analysis.

Today, more than 50 percent of Gulf oil production comes from ultra-deep wells drilled in 4,500 feet or more of water, compared with about 4,000 feet for Deepwater Horizon. The deeper the well, the more the risk: A 2013 study showed that for every hundred feet deeper a well is drilled, the likelihood of a company self-reported incident like a spill or an injury increased by more than 8 percent.

Terry Garcia, former deputy administrator of the National Oceanic and Atmospheric Administration and a member of a major safety commission convened after the Deepwater Horizon disaster, worries that the safety changes in the years after the disaster didn’t extend broadly enough, either.

“We have this tendency to fight the last war, to prepare for the last incident that occurred,” he says. After the 1989 Exxon Valdez spill, for example, new laws and regulations were enacted to deal with future tanker spills. But that focus on the future didn’t happen for oil rigs, and the next disaster is unlikely to look exactly like Deepwater.

Another concern, says Scott Eustis, the science director at the Louisiana-based Healthy Gulf, a group that focuses on marine protection, comes from the ever-increasing pressures of climate change. Louisiana, which has the most comprehensive climate adaptation plan in the region, is expecting the number and intensity of major hurricanes to increase within the next 50 years. Each storm that blows through the Gulf threatens offshore drilling infrastructure.

“Since Deepwater Horizon, we’ve taken two steps forward and one step back, and that one step back is worrying because we could very much end up in a similar situation,” says Lee Ashley.

What we know about the spill’s effects

After the spill, BP agreed to pay out more than $20 billion in penalties and damages, with around $13 billion directed toward restoration and a vast research effort in the region.

But scientists realized they lacked much of the basic background science necessary to predict where, when, and how the oil would spread or what its impacts on the region would be.

At first, it was difficult even to assess how much oil spilled from the well. Early initial assessments were low—but satellite imagery revealed that there was much more oil than had been reported. The final tally showed that the spill dumped more than 200 million gallons of oil.

Oil continued to sink to the ocean floor for more than a year, a recent study shows. It changed the amounts of sediment collecting on the bottom of the sea for years afterward and choked them of oxygen. Immediately after the spill, the 1,300 miles of contaminated coasts saw oil concentrations 100 times higher than background levelsl even eight years later, concentrations were 10 times higher than before the spill. And In February of this year, a study showed that the footprint of the oil spread some 30 percent wider than previously estimated, potentially contaminating many more fish communities than previously thought.

Scientists are still figuring out exactly how the oil impacted the biology of the Gulf, but the immediate effect was to turn the seafloor near the well site into a “toxic waste dump,” one study said. Studies are also showing that reef fish changed drastically after the spill; that fish absorbed some of the oil-sourced contaminants; and that ecological communities throughout the water column, from tiny bacteria to deep sea corals to arthropods, could take decades to recover.

(Read about how the effects of the spill are still reverberating in dolphins).

“It’s astounding,” says Joye. “We underestimated so many of the impacts when we were first looking.” Only after a decade of sustained observation, she says, have the true impacts of the spill started to become clear.

(Read about how pelican habitat on the Louisiana coast is being restored after the spill).

What we learned about the Gulf

The paradoxical effect of the spill is that scientists know more about the Gulf of Mexico, as well as the physics, ecology, and chemistry of oil spills, than they ever would have otherwise.

It was clear from the moment the spill began that there were many basic science questions that were unknown about this area of the world, like ocean currents and wind patterns, knowledge gaps that hindered the recovery process.

“The first fundamental issue we faced in 2010 was a chronic lack of baseline data,” says Joye.

For example, no high-resolution map of the seafloor existed, information that would have helped scientists understand where the bottom-dwelling creatures of the Gulf might be affected. Driven by the disaster, federal scientists produced a map in 2016.

“It was crucial to be able to detect and predict where the oil would go,” says Oscar Garcia Pineda, a satellite expert. In 2010, it took days to get satellite images downloaded and processed; today the response time is about 20 minutes, he says. In conjunction with studies that used drifters, boats, drones, and other techniques, scientists have deepened their understanding of the Gulf’s restless movements.

But there’s much more still to learn, say Joye and MacDonald; it’s crucial to set up long-term monitoring programs so scientists can be better prepared for the inevitable next disaster.

“We need much better oceanographic data,” says MacDonald, “so we’re not trying to model after the fact whether Florida is going to get hit by this oil spill, or if it’ll go the other way.”

And other knowledge gaps also engender risk. For example, a 2004 hurricane triggered underwater landslides at another drilling site in the Gulf. The mudslide broke the drilling rig away from the well, leaving it leaking hundreds of barrels a day. But the mudslide risk across the Gulf hasn’t yet been thoroughly mapped out.

“There was a dearth of knowledge. It’s that old adage, ‘you can’t manage what you don’t understand’—well, you can’t protect what you don’t understand,” says Garcia.