Abstract Flatback turtles (Natator depressus) are endemic to northern Australia, but their movements at sea have remained understudied. Here, we compiled one of the world's largest single‐species satellite tracking datasets (n = 280 transmitters, deployed between 2005 and 2020) to investigate the movements and level of spatial protection afforded to five flatback genetic stocks across Western Australia during different behavioral phases (i.e., inter‐nesting, migration, and foraging). Flatbacks spent 99.5% of their time in Australian waters and are provided with a very high level of spatial protection (>98% overlap with Biologically Important Areas) during the inter‐nesting phase of their life cycle. Up to 85.6% and 59.1% overlap between marine reserves and the foraging and migratory ranges for flatback stocks, respectively, was found. However, our results identified additional foraging and migratory areas where protective measures would benefit multiple stocks at once. The detailed flatback distribution maps produced here will be key resources for managers and researchers and highlight the benefits of collaborative multi‐agency studies. Additionally, this work provides a useful analytical framework for future studies endeavoring to complete large‐scale, multi‐stock spatial distributions and overlap assessments for populations of conservation concern.
