How do you count more than 60,000 sea turtles?

More than 64,000 endangered sea turtles are gathered in the world's largest nesting area near Raine Island, Australia, but who's counting? The Great Barrier Reef Foundation, that's who. Their researchers used harmless white paint to mark around 2,000 turtles and then flew a drone overhead. By determining the ratio of marked to unmarked turtles, they could then accurately estimate the total population. From BarrierReef.org:

“We’re taking action to improve and rebuild the island’s nesting beaches and building fences to prevent turtle deaths, all working to strengthen the island’s resilience and ensure the survival of our northern green turtles and many other species," [said Great Barrier Reef Foundation Managing Director Anna Marsden...]

The research paper’s lead author Dr Andrew Dunstan from the Queensland Department of Environment and Science is excited to share his work.

“Trying to accurately count thousands of painted and unpainted turtles from a small boat in rough weather was difficult,” Dr Dunstan said.

“Using a drone is easier, safer, much more accurate, and the data can be immediately and permanently stored[...]”

“In the future, we will be able to automate these counts from video footage using artificial intelligence so the computer does the counting for us.”

"Use of unmanned aerial vehicles (UAVs) for mark-resight nesting population estimation of adult female green sea turtles at Raine Island" (PLOS ONE)