“My eyes were watering from the oil fumes even at 1,000 feet,” recalled Rick Steiner, who flew over the Exxon Valdez oil tanker on March 24, 1989, only hours after it had plowed into a cold-water reef. “Oil was all over the deck, and it was everywhere in the water,” said Steiner, who was the University of Alaska's marine advisor in the Prince William Sound region at the time.
The Exxon Valdez was the worst oil spill in U.S. waters until the Deepwater Horizon oil spill in 2010. Within days oil from the Exxon Valdez spread some 1,300 miles along the coast of what was pristine wilderness. In the first days of the spill there was no oil recovery or clean-up equipment in the water, said Steiner, who is now a marine conservation consultant at the “Oasis Earth” project.
Eventually, massive clean-up efforts involving thousands of people were undertaken. The final death toll included 250,000 seabirds, almost 3,000 sea otters, 300 harbor seals, 250 bald eagles, 22 killer whales, and billions of salmon eggs. Populations of pacific herring, a cornerstone of the local fishing industry, collapsed. Fishermen went bankrupt.
It’s impossible to fully clean up an oil spill in the ocean, said Steiner, who’s been involved in many spills since 1989. And the impacts of these disasters can linger for decades. Thirty years later, local populations of killer whales and some seabirds in Prince William Sound have still not recovered, he said.
Some of the oil is still there, too. Recent sampling along the coast revealed pockets of oil buried four to eight inches under sand and gravel, often topped by stones. It’s likely to remain there for decades to come, according to a 2017 study by Jacqueline Michel, a geochemist specializing in oil spills, and president of Research Planning Inc.
A powerful storm or earthquake could potentially put that oil residue back into Prince William Sound, Michel said. However, digging up those residues to remove them would likely do more harm than good, she added.
Stricter laws reduce spills
In the wake of the Exxon Valdez disaster, the U.S. Congress passed a law, in 1990, that required oil tankers in U.S. waters to have double hulls (unlike that fateful ship) and increased penalties for spills. Today, all of the world’s fleet of 12,000 to 14,000 tankers for oil, liquefied natural gas (LNG), and chemicals are double hulled.
Combined with tougher regulations and better navigation equipment, oil spills releasing more than seven tons from tankers plummeted from a high of 79 spills per year in the 1970s to six per year over the past decade, according to ITOPF, an association of shipowners that responds to oil spills.
The decline in large spills greater than 700 tons was even more dramatic, falling from 24.5 per year to just two per year.
The biggest spills in history
Perhaps surprisingly, given its notoriety and impact on the shipping industry, the Exxon Valdez spill was only the 36th worst tanker oil spill yet recorded. The biggest between 1970 and 2018 happened in 1979, off the coast of Tobago in the West Indies when the Atlantic Empress lost 287,000 tons of crude in a collision with another tanker. For comparison, the Valdez lost 37,000 tons. (There is roughly 305 gallons in a metric ton of oil.)
The worst tanker accident in the past 25 years occurred in January 2018, when two tankers collided off the coast of China. An Iranian oil tanker, the Sanchi, lost 117,000 tons of highly toxic natural gas condensate. None of Sanchi's 32 crew members survived.
By far the biggest accidental spill into the ocean was from the Deepwater Horizon oil drilling platform in the Gulf of Mexico. At 35,000 feet, it was the deepest well ever drilled until the blow out that killed 11 workers. Over nearly 90 days the broken well pumped 680,000 tons (approximately 5 million barrels) of oil into the Gulf. The spill cost oil company BP an estimated $61.6 billion, and they still couldn’t contain or recover all the oil that was spilled, said Michel, who worked on the project to assess some of the impacts.
Marine oil spill containment and recovery technology improved tremendously after the Valdez, but not much has changed for at least the last decade, the experts say. Spills can be located faster and their movements modelled more accurately, but full containment and cleanup remains, impossible Michel said.
It can also be difficult to prevent an undersea oil well from leaking. In 2004, Hurricane Ivan destroyed an oil platform in the Gulf operated by Taylor Energy. It’s still leaking 15 years later. Taylor is reported to have spent over $400 million working alongside the U.S. Coast Guard to contain and clean up the spill, but it’s been an ongoing challenge.
More and more oil drilling is being done offshore in deepwater off the U.S. and around the world. Last year, the Trump administration proposed opening up far more offshore areas to drilling.
“Oil platform drilling in deeper water is the new paradigm of risk for oil spills in the marine environment,” said Michel.