Researchers will map the migratory connectivity of green turtles in the Great Barrier Reef (GBR) to boost conservation efforts for the endangered species.
The study, led by The University of Queensland (UQ) PhD candidate Jaime Restrepo, will pinpoint critical feeding areas for green turtles and identify connectivity between key nesting beaches at Heron and Raine Islands and various feeding grounds throughout the GBR.
“Our study will utilise Stable Isotope Analysis (SIA), a cost-effective method to trace the biochemical signatures of common elements like carbon, nitrogen, and oxygen within turtle tissues,” Mr Restrepo said.
“Just as our bodies reflect what we eat, these elements in turtles’ diets act as natural markers of where they’ve fed.”
“SIA allows researchers to identify what a turtle has been feeding on based on its body composition, and accordingly linking them to specific geographical distributions, offering a cost-effective and accurate alternative to satellite telemetry, which often limits sample size due to high costs.”
In collaboration with the Queensland Department of Environment, Science, and Innovation (DESI), the team has been gathering tissue samples and deploying satellite tags on turtles from different feeding areas across the GBR since mid-2023.
Plans are underway to continue collecting samples until mid-2025, with a fieldwork expedition scheduled on Heron Island in January and February 2025.
“The project’s ultimate goal is to assess how different feeding areas contribute to the adult green turtle population across the GBR,” Mr Restrepo said.
“Understanding these migratory routes is essential for shaping conservation strategies to safeguard green turtle habitats and support population recovery.
“Green turtles play a crucial role in the nutrient cycle between marine and terrestrial ecosystems, but they are facing significant threats to their survival.
“By identifying key foraging areas, we can implement targeted measures to help these turtles thrive.”
Green turtles are listed as endangered globally and vulnerable within Australia, and despite decades of research on their home ranges and migratory behaviours, gaps remain in understanding the connectivity between their breeding and feeding habitats in the GBR.
Filling these gaps will enable conservationists to focus resources on critical habitats that sustain the green turtle population.
“With a comprehensive database of isotope values from various GBR habitats, we aim to develop an “isoscape” model, which will allow us to trace any green turtle to its primary feeding ground, shedding light on the essential feeding sites that need protection,” Mr Restrepo said.
“Our research holds promise for the preservation of green turtles and as a model for conservation efforts worldwide.”
