Inter-nesting distribution of flatback turtles Natator depressus and industrial development in Western Australia

Offshore interactions of inter-nesting flatback turtles Natator depressus with resource industry activities are potentially frequent, yet the associated impact is largely unquantified.Consequently, there is a need to understand the degree of interaction and to provide data that can assist with effective conservation and management.We used satellite tracking to highlight the potential interaction of inter-nesting flatback turtles (n = 56) from 4 rookeries in Western Australia with regional resource industry activities.Flatback turtles demonstrated varying inter-nesting movements, with displacement distances ranging from 3.4 to 62.1 km.Some turtles at all 4 rookeries remained <10 km from the nesting beach.Core home range areas for inter-nesting flatback turtles ranged from 1.4 to 601.1 km 2 .The proportion of core home range areas for Thevenard and Barrow Island turtles that overlapped offshore petroleum title areas was 85.7 and 88.6%, respectively.The proportion of median daily positions that overlapped petroleum title areas was also high, 80.8% (Thevenard) and 87.3% (Barrow).There was no overlap of home range areas and median daily positions with petroleum title areas for Mundabullangana and Port Hedland turtles, although some inter-nesting movements of Port Hedland turtles were in close proximity to a proposed port expansion.The wide-ranging inter-nesting movement patterns highlight a need for the Australian Government and industry to expand the scope of Environmental Impact Assessments, ensuring adequate protection is provided to inter-nesting flatback turtles.The similar nearshore inter-nesting movement pattern recorded by some flatback turtles at each rookery provides an opportunity to establish boundaries for small-scale spatial and temporal protection measures.