The baby dolphin rolled over on its side, floating on the surface. Its mother repeatedly nudged its head above the oily waves in a lagoon in Mauritius, where environmentalists are demanding an investigation into the deaths of dozens of dolphins following an oil spill.
The footage - obtained by Reuters from a fisherman who tried to help rescue the dolphins - showed the last desperate moments of the mother and her calf before they both died.
At least 40 dolphins have been found dead in Mauritius - 38 who washed ashore, as well as the mother and her baby - since Monday, when a Japanese ship was scuttled after running aground in July and leaking oil.
The death toll may rise: Yasfeer Heenaye, the 31-year-old fisherman who filmed the mother and baby, said he saw nearly 200 dolphins inside the reef Friday morning, 25-30 of them dead.
"Some were injured and some were just floating," Heenaye said. Fishermen were trying to herd the dolphins out of the lagoon into the open seas.