Epidemiology of Marine Turtle Disease and Mortality in Southern Queensland, Australia
Causes of disease and mortality in marine turtles are poorly understood. Over a 4-yr period (2006–2009), the major anomalies in blood variables and causes of stranding in green turtles (Chelonia mydas) from southern Queensland, eastern Australia, were determined. After establishing baseline values for blood variables using healthy turtles (n=211), clinically unhealthy turtles (those in poor body condition, displaying clinical abnormalities and/or having a history or current presentation of fibropapillomatosis; n=25) had blood variables outside of the reference intervals: albumin, 48% of unhealthy animals; alkaline phosphatase, 35%; aspartate transaminase, 13%; creatinine, 30%; globulin, 3%; glucose, 34%; lactic dehydrogenase, 26%; phosphorus, 22%; sodium, 13%; thrombocytes, 57%; and monocytes, 5%. Blood variables suggested abnormal function of cardiovascular, renal, hepatic and/or gastrointestinal systems.1 Primary causes of mortality in stranded turtles (n=100) were diagnosed as spirorchiidiasis (41.8%), gastrointestinal impaction (11.8%), microbiologic infectious diseases (5.2%) and trauma (5.2%). Minor contributors to mortality (36%) included multiple diffuse pathologies, respiratory, other parasitic infections, neurologic, excretory, urogenital and skeletal pathology.2 Spirorchiidiasis had (i) more observed cases of infection in summer compared with other seasons (p=0.029) and (ii) immature turtles had more severe pathology than mature turtles (p=0.032). Number of observed cases and severity of spirorchiid lesions were highest in the brain compared with heart, gastrointestinal tract and spleen (all p>0.1).2 To link findings, further investigation is required, including the examination of the role of water quality and urbanization in potentiating these syndromes.
The authors thank the Australian Government Department of the Environment, Water, Heritage and the Arts Marine Species Recovery and Protection Grants Programme, the Great Barrier Reef Marine Park Authority, SEQ Healthy Waterways, and the University of Florida for financial support.
1. Flint, M., J.M. Morton, C.J. Limpus, J.C. Patterson-Kane, P.J. Murray, and P.C. Mills. 2009. Development and application of biochemical and haematological reference intervals to identify unhealthy green sea turtles (Chelonia mydas). The Veterinary Journal: DOI: 10.1016/j.tvjl.2009.1006.1011.
2. Flint, M., J.C. Patterson-Kane, C.J. Limpus, and P.C. Mills. 2010. Health surveillance of stranded green turtles in southern Queensland, Australia (2006–2009): an epidemiological analysis of causes of disease and mortality. EcoHealth. DOI: 10.1007/s10393-010-0300-7.