National Wildlife Federation
The gusher damaged the hearts of fish and the lungs of dolphins, fouled beaches where birds and turtles nest, and killed marsh plants that provide food and shelter for other animals.
Deforestation in Mexico and habitat destruction in the US have led to a 90 percent decline in the butterfly's population since 1996.
Federal officials and environmentalists have praised the deal, the largest environmental settlement in US history, which will help cover the costs of Gulf Coast restoration.
A new report by the National Wildlife Federation says dolphins continue to die, while the recovery of sea turtles has stalled and corals continue to show signs of damage from exposure to oil.
Underneath the Straits of Mackinac, a 60-year-old pipeline carries 23 million gallons of oil per day. That has environmentalists, politicians, and residents worried.