Distinct population-wide differences in contaminants and blood parameters in foraging green sea turtles

The rising diversity and concentration of contaminants have surpassed ecological thresholds, threatening marine ecosystems. The effects of pollutants on marine animals, particularly sea turtles, are receiving increased attention due to their role as indicators of human impacts. This study examined the health implications of contaminant exposure in three green turtle (Chelonia mydas) foraging sites in the southern Great Barrier Reef, Australia. Assessments were performed on 45 immature turtles from offshore (Heron, Lady Elliot Island) and inshore (Hervey Bay) foraging sites, hypothesising greater anthropogenic exposure inshore. A cytotoxicity assay tested blood toxicity, while trace element concentrations were compared with baseline reference intervals. Interestingly, this analysis revealed elevated cobalt and manganese levels in Hervey Bay turtles, and offshore turtles showed higher cytotoxicity despite appearing healthier, contrasting with low cytotoxicity and low body condition in Hervey Bay. These findings highlight the complexities of ecotoxicology and the need for comprehensive data on contaminant impacts.