Stunning footage shows hundreds of thousands of sea turtles swimming in the Pacific Ocean off the coast of Central America.
The images, captured with a drone, were taken by marine biologist Vanessa Bezy in Costa Rica.
The massive gathering of the aquatic reptiles was part of the animals birthing season, during which female turtles lay eggs on the sandy beaches at Ostional National Wildlife Refuge.
Ms Bezy, who saw the phenomenon in 2016, told National Geographic: "I immediately knew there was something special going on.
"To this day I’m still blown away by the video. They look like bumper cars out there.”
She added she is releasing the footage now because the turtles are under threat from tourists crowding beaches and developments.
The Olive Ridley Sea turtles, which tend to live for around 50 years and weigh around 45kg, are designated as vulnerable.
Research has shown the animals gather at a density of 250 turtles per square kilometre, with more underneath the surface.
