Researchers capture amazing drone footage of thousands of turtles waiting to lay eggs

The vision from Raine Island, on the Great Barrier Reef, shows about 64,000 endangered green turtles in the waters about 620km off Cairns.

It's all in the name of more accurately surveying turtle populations, scientists from Queensland Government's Department of Environment and Science (DES) explained.

Dr Andrew Dunstan said drones, or unmanned aerial vehicles (UAVs), were found to be the most efficient survey method.

"Previous population survey methods involved painting a white stripe down the green turtles' shell when they were nesting on the beach. The paint is non-toxic and washes off in a couple of days.

"From a small boat, we then counted painted and non-painted turtles, but eyes are attracted much more to a turtle with a bright white stripe than an unpainted turtle, resulting in biased counts and reduced accuracy.

"Trying to accurately count thousands of painted and unpainted turtles from a small boat in rough weather was difficult. Using a drone is easier, safer, much more accurate, and the data can be immediately and permanently stored."

The drone vision was analysed, frame by frame in the laboratory, reducing observer error and allowing accurate counts on painted and unpainted turtles.

"The ratio of unpainted and painted turtles allowed us to estimate the total population for last December to be 64,000 green turtles waiting to nest on the island," Dr Dunstan said.

"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."

Raine Island is the world's largest green turtle nesting site, Great Barrier Reef Foundation managing director Anna Marsden.

"And that's why we're working with our Raine Island Recovery Project partners to protect and restore the island's critical habitat," she said.

The five-year, $7.95 million Raine Island Recovery Project is a partnership between BHP, the Queensland Government, the Great Barrier Reef Marine Park Authority, the Great Barrier Reef Foundation and the Wuthathi and Meriam Nation (Ugar, Mer, Erub) Traditional Owners.