An oil spill has reached the shores of a pristine Persian Gulf island in Iran surrounded by clear turquoise waters that provide refuge for endangered sea turtles and dolphins, according to videos circulating on social media.

The tiny, uninhabited island of Shidvar is one of Iran’s most important protected nature reserves. It is home to large coral reefs and a breeding ground for more than 80,000 birds.

The videos, verified by The New York Times, show large dark ribbons of oil snaking along the island’s pristine white sand beaches. Birds, turtles and crabs can be seen trapped inside mounds of tar.

“It is known as the Maldives of Iran — a beautiful place,” said Kaveh Madani, director of the U.N. University Institute for Water, Environment, and Health.

The videos have provided some of the first evidence of the environmental toll the war has taken on the area. Iran has been under an internet blackout since the United States and Israel started a war in late February, severely limiting visibility into the impacts of the conflict.

In one of the videos, a small boat plies through waters darkened from an oil slick, as the men on board point to smoke billowing up from the oil refinery at the nearby island of Lavan.