Despite being one of the major threats to marine ecosystems, relatively little is known about micro- and nanoplastic pollution and its effect on the health of marine organisms. Marine turtles are exposed to various anthropogenic impacts making them ideal proxies for monitoring environmental health. In this study we use blood samples from green and hawksbill turtles to assess the overall health of three foraging populations with varying proximity to anthropogenic pressures and marine debris exposure. Foraging green and hawksbill turtles had blood samples taken and external health assessments carried out from Heron Island, Lady Elliot Island (Capricorn Bunker group, Great Barrier Reef) and Hervey Bay (Great Sandy Strait Marine Park). Although blood gas and biochemical health baselines have been established for marine turtles in other parts of the world, none have been carried out on these three populations. Measurable differences were seen in the health profiles and body condition indices of the island populations (Heron and Lady Elliot), and the mainland population (Hervey Bay) which was sampled post February 2022 flood events. By establishing health profiles and baseline data for each of these populations we can monitor the level exposure of marine debris and contaminants and quantify associated health impacts.