Nature

Drone footage shows 64,000 endangered sea turtles nesting near Australia’s Great Barrier Reef

Researchers in Australia captured thousands of green turtles on spectacular aerial footage, gathering at the Great Barrier Reef at the height of their nesting season. Thousands of female green turtles make their way to be to the largest green turtle rookery in the world at Raine Island every year. Rich in vegetation, the coral cay is about 385 miles (620km) northwest of Cairns in Queensland, Australia.

According to Australian Geographic, around 64,000 females migrate thousands of kilometres every year to lay their eggs at Raine Island. The latest drone footage captured by the Queensland Department of Environment and Science (DES) shows what could be one of the biggest turtle swarms ever observed in the area.

Despite their large numbers seen at the nesting site, they are considered endangered due to the destruction of marine habitats, loss of their nesting sites on beaches, the threat of hunting and overharvesting of eggs, as well as frequently being trapped by fishing boats and often drowning as a result.

 “We sort of became aware that although there’s these massive aggregations, the actual reproduction isn’t working so well,” Dr. Andrew Dunstan of the DES told CNN.

While trying to assist the green turtle population and tracking them, researchers found that drones were the most efficient and accurate at documenting the turtles.

“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,” Dunstan said in a statement.

Although the green turtle is distributed across the tropical and subtropical waters across the world, it is one of the largest, and the only herbivorous marine turtle and, according to conservationist group WWF-Australia, the Reef is a perfect nesting area because of its protected shores near the coast and islands.

The use of the drones showed that the 64,000 green turtles swarmed the island, much more than previous estimates.

“We were underestimating that a lot. We’re finding 1.73 times as many turtles with the drone and as we do when we directly compare with the observer counts,” Dunstan added.

While Raine Island in the northern Great Barrier Reef is the largest among the few remaining nesting sites, scientists are concerned that their expected reproduction rate is declining, predominantly because of difficult terrain, causing them to get trapped in the heat, fall off cliffs, and nests flooding.

The new information will be used to further improve methods of managing and tracking the turtle population and researchers hope to introduce artificial intelligence to automate counting the turtles captured on drone footage.

“Marine turtles have roamed the world’s oceans for more than 100 million years, and are an integral part of our tropical coastal ecosystems,” WWF-Australia wrote on its website“It’s taken humans just 200 years to tip the scales against their survival and these ancient mariners are now considered endangered or vulnerable.”