Green turtles thrive

Eye in the sky helps green turtles thrive

The largest and most important green turtle rookery in the world lies on the northern tip of the Great Barrier Reef, approximately 620 kilometres north-west of Cairns.

Raine Island has been a nesting place for the vulnerable green turtle for more than 1,000 years. The vegetated coral cay covers just 27 hectares and is host to as many as 60,000 nesting turtles during a season. But this marine paradise is under threat. Without action, Raine Island’s role as a turtle sanctuary is in danger of collapse.

Large numbers of females come to the island to nest, but few eggs survive. Monitoring by the Queensland Government found that tidal inundation was destroying thousands of eggs and severely reducing hatchling numbers in an already fragile green turtle population.

This is Raine Island, where the world's largest population of endangered green turtles comes to nest.

As many as 20,000 turtles nest here at a time, but Raine Island’s role as a turtle sanctuary is in danger of collapse. Every year scientists have watched nesting and hatching failure on a grand scale.

BHP Billiton, the Queensland Government, the Great Barrier Reef Marine Park Authority, Traditional owners and the Great Barrier Reef Foundation are collaborating on a 5-year project to protect and restore Raine Island’s critical habitat to ensure the future of key marine species including green turtles and sea birds.

The initial stages of the project involved reprofiling a trial area covering approximately 10 percent of the available nesting areas. Steep cliffs formed by erosion were also fenced off to stop female turtles falling, being trapped and dying on their backs.

This new fencing has reduced the adult mortality rate on the island by more than 50 percent.

Results so far are extremely encouraging. Hatching success rate has jumped from just over 36 percent over the previous 3 years to 56 percent. While the numbers of clutches destroyed in the nests was slashed from 43 percent down to 28 percent.

Weather station data logger monitoring cameras now provide live 24-hour access to conditions on the island.

This unique project shows how partners from business, government, reef management traditional owners and not-for-profit are all working together to protect and restore the Great Barrier Reef for future generations.

Adult turtles are at risk as well. As many as 2,000 adult female turtles can die in a large nesting season, being trapped beneath the island’s rocky cliffs, stuck beneath rock or stranded and heat exhausted on the beach.

The Raine Island Recovery Project Team is connecting the physical and digital worlds to save this precious marine habitat by using drone technology.

The Raine Island Recovery Project is a 5-year collaboration between BHP, the Queensland Government, the Great Barrier Reef Marine Park Authority, the Wuthathi Nation and the Kemerkemer Meriam Nation (Ugar, Mer, Erub) Traditional Owners and the Great Barrier Reef Foundation.

The project is protecting and restoring Raine Island’s critical habitat to ensure the future of key marine species including green turtles and seabirds. In particular, the project is addressing the low nesting and hatching success to increase hatchling numbers and to reduce the high adult turtle mortality that occurs on the island to help the recovery of the green turtle poulation.

Rain Island is such a special place, which is of critical importance to the northern Great Barrier Reef's endangered green turtle population, nesting seabirds and the many other species that depend on it.

Great Barrier Reef Foundation Managing Director Anna Marsden

The introduction of drones has been a game-changer for the team dedicated to protecting and restoring this island’s critical habitat.

The technology is helping scientists observe the turtles around Raine Island, in a way that hasn’t been possible before. Researchers can monitor turtle numbers and distribution in the water surrounding the island, and survey nesting beach conditions affecting the low levels of hatching and laying.

Drones are also proving to be an effective method of monitoring other key species that depend on Raine Island’s fragile ecosystem for their survival, including seabirds.

Raine Island is home to the most important seabird rookeries in the Great Barrier Reef World Heritage area. It is also a known breeding ground for some rare and endangered seabird species which can be counted and tracked through the drone monitoring program.

In the past, this was a challenging undertaking. But researchers are now using drone imagery to count seabirds with greater accuracy and monitor species like the Masked Booby. The technology removes the need to enter the islands centre to manually count and observe seabird activity, therby minimising human activity around breeding birds. 

This use of new technology allows for more efficient and accurate data collection than traditional methods. The connectivity that drones allow has rapidly advanced the team’s data collection and monitoring capability, while minimising impacts and helping preserve the island's sensitive ecology.

Drone footage is used to monitor habitat impacts by tracking changes to the sand profile of the island caused by erosion. Drones provide efficient and accurate topographic mapping, a key part of tracking these ongoing changes to the island’s nesting beach.

The trial has also confirmed that by using drones we will be better able to understand and preserve the sensitive ecology of this natural wonder.

Raine Island Recovery Project lead researcher, Dr Andy Dunstan

These ground-breaking methods of data collection and monitoring have already achieved encouraging results.

Raine Island Recovery Project lead researcher Dr Andy Dunstan said early results of the topographic mapping were showing that the reprofiled area of beach was maintaining itself and resulting in more green turtle hatchlings.

"Protecting the island's precious ecosystem is a priority and the Raine Island Recovery Project is a working example of what can be achieved when we bring together government, business, reef managers and Traditional Owners for the benefit of the reef."

Great Barrier Reef Foundation Managing Director, Anna Marsden

The Raine Island Recovery Project is an example of what can be achieved when the digital world meets the physical world. When connectivity is used, we can make a huge improvement to Queensland’s environment.