Nesting habitat characteristics of flatback Natator depressus, green Chelonia mydas and loggerhead Caretta caretta turtles in eastern Queensland, Australia

Abstract

Coastal areas provide essential habitats for marine turtle nesting and hatching, but they are under increasing threat due to climate change and other anthropogenic impacts. Very little is known about the nesting habitat characteristics of flatback Natator depressus, green Chelonia mydas and loggerhead Caretta caretta turtles in eastern Queensland, which limits our ability to evaluate which nesting beaches are at risk due to anthropogenic and environmental disturbances and prioritise conservation and monitoring actions. Here, we used generalised linear models to investigate the relationship between the presence/absence of flatback, green and loggerhead turtle nests and environmental and topographic characteristics of 237 potential nesting sites along the central and southern coasts of Queensland. The presence of nesting flatback turtles was strongly correlated with the mainland and non-coral cay islands with decreasing latitude, as there is an interaction between site type and latitude. In contrast, green turtles preferred to nest on coral cays rather than mainland and island beaches. Loggerhead turtles were more likely to nest on coral cays, the mainland, then islands, with presence increasing with latitude. Among these site types and higher latitudes, presence was stronger on sheltered than on semi-exposed beaches. Identifying environmental and topographical features influencing the presence of nesting flatback, green and loggerhead turtles is an important first step to improve the conservation of these species by prioritising sites for monitoring and managing threats to important beaches.