On 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.

We found that the spill likely harmed or killed about 82,000 birds of 102 species; about 6,165 sea turtles; as many as 25,900 marine mammals; and a vast (but unknown) number of fish — from the great bluefin tuna to our nation’s smallest seahorse — plus oysters, crabs, corals and other creatures.