Haematologic and plasma biochemical reference intervals for flatback turtles Natator depressus

Blood reference intervals (RIs) provide an indication of systemic health and are central to any baseline health survey. RIs are available for all sea turtle species, except for the flatback turtle Natator depressus . We developed the first nesting and foraging flatback turtle RIs from a healthy reference population of 211 individuals. We found flatback turtle RIs were generally similar to other published sea turtle RIs. For flatback turtles, we detected significant differences in blood reference values (RVs) by life stage (nesting vs. foraging), sex, and location, as well as by measurement technique (laboratory vs. field). Clinically significant differences justified the establishment of separate RIs for nesting and foraging flatback turtles and for laboratory and field techniques. Clinical application of these blood RIs for individuals in rehabilitation includes disease diagnosis, health monitoring, and the development of prognostic indicators. As sea turtles are regarded as sentinels of environmental health, flatback turtle baseline health data will also be useful for population health monitoring and as a reference for future studies where changes in RIs may indicate an environment in decline.