Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

Predicting core areas of flatback turtle hatchlings and potential exposure to threats (#349)

Phillipa Wilson 1 2 , Charitha Pattiaratchi 3 , Scott Whiting 4 , Luciana C Ferreira 1 , Sabrina Fossette-Halot 4 , Kellie Pendoley 2 , Michele Thums 1
  1. Australian Institute of Marine Science, Crawley, WA, Australia
  2. Pendoley Environmental, Perth, WA, Australia
  3. Ocean Graduate School and the UWA Oceans Institute, University of Western Australia, Crawley, WA, Australia
  4. Marine Science Program, Department of Biodiversity, Conservation and Attractions, Kensington, WA, Australia

There is a lack of data on distribution of marine turtle hatchlings as they are too small for satellite telemetry. This is a critical knowledge gap, as hatchlings experience high mortality in coastal zones, and further risks to their survival may occur beyond these areas linked with threats associated with light pollution or in-water artificial infrastructure such as increased predation. To fill this gap, we used particle tracking forced by an ocean circulation model to predict the dispersal of flatback turtle hatchlings (Natator depressus) from 12 nesting sites off the coast of Western Australia. We used the model outputs to calculate the distribution of these “virtual hatchlings” and infer core areas of hatchling use over three dispersal phases (1–4 ,10–15 and 25–30 days). We then calculated the overlap between core areas and two anthropogenic threats (in-water artificial infrastructure and light pollution). 70-80% of the core areas during early dispersal (1–4 and 10–15 days) contained at least one threat and <50% of the area used between day 25 and 30 was exposed to threats. In the absence of empirical data on hatchling distribution, our results have predicted important areas of early life stage flatback turtles which can assist in conservation management.