Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Marine habitat mapping of green turtle (Chelonia mydas) foraging grounds in the Northern Territory, Australia

Natalie Robson , Carol Palmer, Sam Banks , Michele Thums, Alana Grech, Joanna Day, Kakadu Rangers, Robert Risk , Dylan Cooper, Garnet Hooper

Abstract

Context: Green turtles (Chelonia mydas) are listed as vulnerable in Australia and are culturally significant to Indigenous Traditional Owners. However, their foraging habitats remain poorly understood, particularly in northern-Australia. Aims: To map green turtle foraging habitats in the Northern Territory, through collaboration with Indigenous Traditional Owners and ranger groups to support Sea Country management. Methods: Visual classifications of towed video transect data were used in a Support Vector Machine Learning Model to predict habitat across 379 km2 of remotely sensed satellite imagery, encompassing two green turtle foraging grounds within jointly managed parks: Trepang Bay (Garig Gunak Barlu Marine Park) and Field Island (Kakadu National Park). Key results: Foraging turtle habitat; algae and seagrass made up 30% of the Trepang Bay and 18.05% of the Field Island foraging areas. The classification accuracy of the model showed a high level of agreement at both sites (0.63 and 0.75 respectively). Conclusion: These habitats provide good foraging grounds for green turtles and support different age classes for various behaviours, including resting and predator avoidance. Implications: The simple and repeatable field methods used in this study allow for ongoing monitoring by ranger groups. The findings will support conservation planning and management in the Northern Territory.

MF25031  Accepted 18 April 2025

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