Abstract
Fibropapillomatosis is an easily recognisable condition that has been recorded in marine turtles resident in Australian waters for decades.1,5 Recently, a high prevalence of individuals with tumors has been noted in previously unaffected populations of green turtles (Chelonia mydas) along the Queensland coast. Spirorchid blood flukes are also a common occurrence,2,3 but their significance in terms of impact on the health of the individual turtle may be related to environmental conditions and species of fluke. Coccidial encephalitis was responsible for an epizootic in green turtles characterised by neurological symptoms and death in green turtles in Moreton Bay over a six week summer period in 1991.4 A series of extreme weather events culminating with cyclone Yasi in February 2011 were responsible for extensive destruction of seagrasses along the Queensland coast. This resulted in a dramatic loss of body condition for a high proportion of individuals in local green turtle populations and an increase in strandings of underweight animals. These animals presented with various conditions ranging from haemorrhagic enteritis, gut impactions, high Spirorchid fluke load and emaciation. Many of these conditions were likely secondary to the impacts from a lack of suitable food. When more than 80 large green turtles of healthy appearance, died in Upstart Bay between June and July 2012, with seizures observed in moribund animals, coccidiosis was considered amongst other infectious causes. Freshly dead animals were subjected to full postmortem investigation and several further analyses. To this point, the cause of the mortalities remains unknown, although a rapidly acting neurotoxic agent is suspected. The Upstart Bay incident epitomises our position on the iceberg with respect to our knowledge and understanding of marine turtle health and causative links to the local habitat. There is much we know about marine turtle health and much we appreciate that we should learn more about, but there are also the unknowns that we don't even know exist.
* Presenting author
Literature Cited
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