Predicting core areas of flatback turtle hatchlings and potential exposure to threats

We used particle tracking forced by an ocean circulation model (ozROMS) to predict the passive dispersal of flatback turtle hatchlings (Natator depressus) from 12 nesting sites off the coast of Western Australia. We used the modelled outputs to calculate the distribution of these ‘virtual hatchlings’ and infer core areas of hatchlings use over three dispersal phases (1–4, 10–15 and 25–30 days). The core areas of use were located on the continental shelf during all dispersal phases, which provides support for their proposed neritic development. We then calculated the overlap between core areas and two anthropogenic threats to marine turtles which are in-water artificial infrastructure and light pollution. We found that hatchlings were mostly exposed to these threats during their early dispersal. As such, mitigations might be necessary for the conservation of this species and life-stage. The important areas that we define in this study should be validated by field surveys and can be used to guide future management and conservation of this age class and species in the absence of empirical data. Output files from particle tracking software (Ichthyop) for each nesting site each year and ESRI shapefiles of the calculated important areas for Day 1 to 4, Day 10 to 15, Day 25 to 30, which consists of the 25%, 50%, 75% and 95% cumulative frequency distribution. Also included are the particle release locations for each site.