Mass relocation offers new hope for world's largest green turtle nesting site

A groundbreaking rescue mission has saved thousands of baby turtles from drowning, as rising tides threaten the world's largest green sea turtle rookery.

Large scale egg relocations on Raine Island to combat rising sea levels have proved successful with 70 percent of eggs hatching. Picture: DETSI.

Baby sea turtles at risk of drowning in their nests have been offered fresh hope after an Australian first trial proved highly successful.

Roughly 64,000 turtles lay their eggs each year on Raine Island, the world's largest green sea turtle rookery 620km northeast of Cairns, but rising water levels mean high tides more frequently cover the once bone dry cay, inundating nests and drowning turtles.

In a bid to safeguard the endangered species, more than 3,000 eggs were transported from Raine Island to Sir Charles Hardy Islands last year to test if large scale relocations could work – 70 per cent of eggs hatched.

After mating, more than 64,000 female green sea turtles make the pilgrimage to Raine Island each year to lay their eggs. Picture: DETSI.

Reef Authority Field Management Strategy Mark Read said the results proved survival was possible.

“Raine Island is the most important green turtle rookery in the world, and what happens here matters for the species across the entire Great Barrier Reef and beyond,” he said.

“Green turtles face enormous pressures from climate change, and projects like this are critical in giving them a fighting chance.”

Like many reptiles, sea turtle gender is determined by incubate temperature, with sand above 29 degrees producing egg clutches about 99 per cent female.

As global temperature rise this gender balance has been steadily skewed, leaving fewer and fewer males.

Rising global temperatures have led to rapid feminisation rates of current turtle populations. The Raine Island Recovery Project team are working on nest cooling and shade trials to revert this imbalance. Picture: DETSI.

The refugees hatchlings were also mostly females, but the Raine Island Recovery Project Manager Katharine Robertson said the results now paved the way for cooling trials.

“The relocation work, guided by Traditional Owner rangers and our field teams, shows what’s possible when science and culture come together,” she said.

While the hatchlings were still mostly female, the strong hatching success gives us confidence to trial new methods to cool nests this summer.

“This project is about innovation, persistence and giving these turtles the best possible chance.”

This year 50 clutches of eggs have already been relocated with shade and cooling trials set to begin. Picture: DETSI.

For the 2025/2026 season, 50 egg clutches have been relocated to Sir Charles Hardy Island with the inclusion of shade and cooling techniques to try and rebalance feminisation rates.

Wuthathi Elder Johnson Chippendale said the project showed how traditional knowledge and western science can work together,

“Raine Island (Thukuruu) is highly significant culturally to Wuthathi people, the reef systems, seas and all the species surrounding,” he said.

We are proud to be partners in the project, involved in on grounds works including the egg relocation works, aimed at increasing the number of female green turtles’ combating climate change with traditional and scientific knowledge combined.”

The $3.5 million multi year project was funded through the Australian Government’s Saving Native Species program and delivered through the Reef Authority, National parks and Department of environment, technology, science and innovation.

Originally published as Mass relocation offers new hope for world's largest green turtle nesting site