Raine Island Restoration Yields Success in Boosting Endangered Green Turtle Numbers

Significant conservation interventions at Raine Island, recognized as the world's largest green turtle rookery, are demonstrating substantial positive results for the endangered species. Population assessments conducted in early 2026 confirm a continued surge in green turtle numbers, following the formal conclusion of the Raine Island Recovery Project in late 2025. This rookery is ecologically vital, supporting nearly 90 percent of the green turtle population in the northern Great Barrier Reef region.

The comprehensive recovery initiative, which commenced in 2014, involved extensive topographical reshaping and measures to mitigate nesting hazards. Data from the Great Barrier Reef Foundation indicates the project added an estimated 640,000 hatchlings over its duration. Key structural work included moving 40,000 cubic meters of sand to elevate nesting beaches above tidal inundation risks, effectively doubling the usable nesting habitat. Furthermore, 1,750 meters of custom fencing were installed to prevent adult turtles from falling onto their backs on rocky terrain and perishing from heat exhaustion; one rescue crew saved 696 nesting females during a single period.

The project integrated Traditional Owners, including the Wuthathi People and the Meriam Nation (Ugar, Mer, and Erub) People, who are actively involved in deploying satellite tags to monitor post-nesting migration routes. Scientific methodology also advanced, with researchers like Dr. Andrew Dunstan of the Department of Environment and Science pioneering the use of Unmanned Aerial Vehicles (UAVs) for population surveys. A drone count in December 2019 estimated 64,000 turtles waiting to nest, suggesting historical data based on non-toxic paint stripes may have underestimated the population by a factor of 1.73.

The conservation focus is now shifting toward the pervasive threat of climate change, specifically rising sand temperatures that skew hatchling sex ratios toward females. High sand temperatures at Raine Island since the mid-1990s have resulted in almost exclusively female hatchlings, jeopardizing long-term population viability. The pivotal temperature for green turtles in this region is approximately 29.3 °C; temperatures just 1 °C above this threshold yield 80% female hatchlings. Experimental efforts are underway to relocate egg clutches to cooler, shaded areas on Sir Charles Hardy (Wuthathi National Park) to test if lower incubation temperatures can produce a more balanced male-to-female ratio.

This critical work on Raine Island, a nesting site for over 1,000 years, represents a successful model of intervention, bringing together the Queensland Government, industry partners like BHP, scientific institutions, and Traditional Owners. The Great Barrier Reef Foundation projects that the sustainable benefits will yield millions more hatchlings over the next decade, reinforcing the importance of the island's strictly limited public access under its National Park (Scientific) status.