Increased strandings and decreased health in green turtles following extreme flooding events*

Following a severe weather event in the summer of 2021/2022 that produced extensive flooding throughout southern Queensland, unusually high numbers of green turtles were reported stranded and/or in poor condition in Hervey Bay, Queensland. In response to this, the Commonwealth-state Disaster Recovery Funding Arrangements (DFRA) assembled a multidisciplinary team of sea turtle biologists, wildlife veterinarians and toxicologists to assess the demographics, health, diet and toxicology of the local foraging green turtle population. A total of 145 turtles were assessed through physical examinations, blood sampling for health and toxicology, and gastric lavage for dietary analysis. Stranding data showed a marked increase in large turtles compared with previous years. Health indicators—including Scaled Mass Index, Body Condition Scores, and veterinarian-assessed categories of “healthy” or “unhealthy” (based on blood biochemistry and haematology)—revealed a disproportionately high number of unhealthy subadult and adult turtles in Hervey Bay compared to other southeast Queensland populations. Blood biochemistry parameters associated with health included white blood cell counts, heterophil-to-lymphocyte ratios, glucose, potassium, blood urea nitrogen, aspartate aminotransferase and creatine kinase. These results indicated physiological stress, possible immune disruption, prolonged fasting, metabolic dysfunction, and potential muscle, gastrointestinal, or liver disease. The age-specific differences in turtle health, combined with evidence of fasting, likely reflect reduced quantity and quality of local seagrass following the floods affecting food availability. Juvenile turtles may have a more diverse diet, making them more resilient to the loss of a particular forage item. Future research should focus on evaluating food availability and nutritional quality, habitat use across age classes, and metabolic demands to better understand the causes of nutritional stress in this vulnerable population and to inform effective conservation management.

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44th Symposium on Sea Turtle Biology and Conservation

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3106-1397

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