ST. PETERSBURG, FLA. -- A decade after the nation's worst offshore oil spill, dolphins, turtles and other wildlife in the Gulf of Mexico are still seriously at risk, according to a report released Tuesday.

The fact that the Gulf hasn't fully recovered is 鈥渉ardly surprising given the enormity of the disaster,鈥� said David Muth, director of the Gulf of Mexico Restoration Program for the National Wildlife Federation, which authored the report.

The April 20, 2010, explosion on the Deepwater Horizon drilling rig killed 11 workers and spewed what the non-profit environmental organization Ocean Conservancy estimated to be 210 million gallons (795 million litres) of oil before it was capped 87 days later.

What followed, Muth said, was the largest restoration attempt ever in the world, with billions invested or committed to projects to help restore the Gulf and its ecosystem, and another $12 billion to be spent through the year 2032.

鈥淚t's an opportunity we cannot afford to squander,鈥� he said, adding that the projects create jobs.

In the report, the NWF said it believes a large portion of the money should be spent on estuary restoration, where freshwater mixes with the saltwater of the Gulf.

鈥淧rojects that restore wetlands, rebuild oyster reefs, protect important habitats from development, and recreate natural patterns of water flow and sediment deposition will help many species harmed by the oil. In addition to helping wildlife, many of these projects will help protect coastal communities from rising seas and extreme weather,鈥� the report said.

During a telephone news conference Tuesday, NWF experts highlighted the plight of a few species of wildlife that were affected by the spill:

  • Dolphins. They are still struggling, with many living in oiled areas still ill. About 55 per cent had worsening lung disease, 43 per cent exhibited abnormal stress responses, 25 per cent were underweight, and 19 per cent were anemic, the report said. Dolphins born after 2010 aren't as sick as those that were exposed directly to oil, but they also aren't as healthy as dolphins born in unoiled areas. Scientists say it could take affected dolphin populations decades to recover.
  • Kemp's Ridley Sea Turtle. Once facing extinction in the 1960s, the sea turtles were largely saved by conservation efforts until the oil spill, which killed as many as 20 per cent of adult females. Nesting in the post-spill years has fluctuated.
  • Birds. About 12 per cent of brown pelicans and 32 per cent of the laughing gulls in the northern Gulf died in the oil spill. Approximately 1 million offshore and coastal birds perished.

Scientists estimate the oil killed or seriously hurt 鈥渂illions, if not trillions鈥� of animals, according to a lawsuit filed by environmental groups in 2019. The government declared a fisheries disaster. BP says its costs have topped $60 billion.

In June of last year, environmental groups sued to challenge a decision by President Donald Trump's administration that they say weakened critical safety rules created after the spill.