Sperm Whales

A bloated and burned juvenile sperm whale that had been found dead on June 15, 2010 in the Gulf Of Mexico. (Courtesy of Greenpeace)

It's difficult to measure just how many sperm whales were affected, but one arresting photo of a rotting, burnt sperm whale carcass circulated widely after researchers saw the animal from a ship about 77 miles from the Deepwater Horizon site in June 2010. A 2013 study of sperm whale skin samples found higher than usual levels of genotoxic metals in Gulf of Mexico whales after the spill, with the whales closest to the site of the spill with the highest levels.The genotoxic metals, including nickel and chromium, are capable of damaging DNA, causing lasting genetic impacts on generations of whales. In the short term, even a few whale deaths can affect an entire population as sperm whales, already an endangered species, give birth to very few calves."As soon as we get to the level of three deaths caused by human interaction -- and this would include the oil spill -- that would jeopardize that particular sperm whale population," Celine Godard-Codding, an environmental toxicologist at Texas Tech University, told National Geographic