Some species, such as brown pelicans, have rebounded, while long-lived species have been hindered for generations. Still, data is scarce.
NEW ORLEANS, LOUISIANAOn April 20, 2010, an explosion at the BP Deepwater Horizon oil rig released over 130 million gallons of crude oil into the Gulf of Mexico. It was the biggest oil spill ever in U.S. waters and remains one of the worst environmental disasters in world history.
Eleven rig workers lost their lives. So did untold millions of marine mammals, sea turtles, birds, and fish. While the world watched, helpless, oil gushed into one of the planet’s most biodiverse marine habitats for 87 long days.
A decade later, many species, such as deep-sea coral, common loons, and spotted sea trout, are still struggling, their populations lower than before. By contrast, a few Gulf inhabitants have shown a robust recovery—among them, menhaden fish and the brown pelican, Louisiana’s state bird.
Scientists say it’s still too early to tell definitively what the impact has been for longer-lived species such as dolphins, whales, and sea turtles.
Even so, “based on our science to date, if you were a marine mammal alive in the Gulf at the time of the spill, it doesn’t look good for you,” says Cynthia Smith, a veterinarian at the National Marine Mammal Foundation. “Animals that weren’t born yet, those are the hope,” says Smith, a marine mammal expert who traveled to the spill.
Smith is one of many scientists whose careers pivoted after this event. Funds from the Gulf of Mexico Energy Security Act, the Gulf of Mexico Research Initiative—and more recently, the $16 billion settlement between BP and the U.S. federal and state governments—have enabled a legion of researchers to undertake long-term projects investigating how the spill affected Gulf wildlife.
Many species have been difficult to study. But after a decade of close monitoring, Smith feels that she and colleagues have a clear picture of what is going on with that most gregarious of cetaceans, the bottlenose dolphin—and it’s grim.
About a thousand dolphins died in the months following the spill, after they ingested toxins from the oil. Many others apparently have been sick ever since.
What was a bust for birds turned into a temporary boon for some fish: Scientists think that the lack of birds in the skies over the Gulf of Mexico is one reason some populations of fish exploded after the spill.
There were twice as many Gulf menhaden, for example, in the years following the spill as in four decades before, likely because so many fish-eating birds were absent.
Other fish species have shown evidence of having been harmed by oil, including nearly two thirds of all Gulf sturgeon, a threatened species. Studies of the economically valuable spotted seatrout and red drum found that fish in oiled areas showed reduced reproduction, and that even years after the spill, oil remaining in the environment is still toxic to fish larvae.
Recent research that tested 2,500 different fish across the Gulf found evidence of oil exposure in all 91 species sampled, suggesting that the impacts of the spill are widespread and ongoing.
It could take decades to understand how oil affects the next generation of whales, coral, sea turtles, birds, fish, and more.
For Smith, Frasier, Etnoyer, and others involved in spill research, this event has become career-encompassing. Their research will be devoted to monitoring and understanding the Gulf for many years to come—particularly if these ecosystems remain vulnerable.