Comorbidities of Fibropapillomatosis in stranded green sea turtles (Chelonia mydas) along the West coast of Florida

Marisa R. Campbell, Eckerd College, Marine Science and Animal Studies Discipline

Ray L. Ball, Eckerd College, Animal Studies Discipline

Gretchen N. Lovewell, Mote Marine Laboratory, Stranding Investigations Program

Jessica L. Blackburn, Mote Marine Laboratory, Stranding Investigations Program

Fibropapillomatosis (FP) is a disease associated with herpesvirus ChHV5, primarily impacting green  turtles (Chelonia mydas) in tropical environments. Symptoms of the disease include gross tumors, debilitation, and lethargy. Juvenile to sub-adult green turtles populating inshore areas show highest disease prevalence. 

For this study, sea turtle stranding data from 2000-2020 from West Florida were reviewed. The objective was to identify any potential associations to causes and impacts of disease expression and comorbidities associated with FP. Descriptive observations were categorized into a semi-quantitative score for each data category and a Gastrointestinal Contents Score (GCS), which encapsulates  the quantity of gastrointestinal contents and duration since their last meal. 

The results show a higher likelihood of emaciation and entanglement in FP-diseased turtles, lower likelihood of vessel-strike-related injuries, and higher chance of turtles with FP stranding in winter months. Applying odds ratios revealed that FP Turtles are 3.97 times more likely to have hard feces, 1.85 times more likely to have depleted livers, 2.2 times more likely to overproduce bile, 3.85 times more likely to have fluid in their respiratory system, and 1.98 times more likely to host parasites. Marine leeches, a potential disease vector, were only found on turtles with gross tumors. FP-diseased turtles had a lower average GCS than the control group and more frequently had distended gallbladders, whereas the control group more frequently had empty gallbladders. Obstructed vision due to gross tumors was also found to increase an individual's likelihood of pathologies related to nutritional health.