Novel insights into the dynamics of green turtle fibropapillomatosis

Outbreaks of fibropapillomatosis (FP), a neoplastic infectious disease of marine turtles, have occurred worldwide since the 1980s. Its most likely aetiological agent is a virus, but disease expression depends on external factors, typically associated with altered environments. The scarcity of robust long-term data on disease prevalence has limited interpretations on the impacts of FP on turtle populations. Here we model the dynamics of FP at 2 green turtle foraging aggregations in Puerto Rico, through 18 yr of capture-mark-recapture data (1997-2014). We observed spatiotemporal variation in FP prevalence, potentially modulated via individual site-fidelity. FP ex pression was residency dependent, and FP-free individuals developed tumours after 1.8 ± 0.8 yr (mean ± SD) in the infected area. Recovery from the disease was likely, with complete tumour regression occurring in 2.7 ± 0.7 yr (mean ± SD). FP does not currently seem to be a major threat to marine turtle populations; however, disease prevalence is yet unknown in many areas. Systematic monitoring is highly advisable as human-induced stressors can lead to deviations in host- pathogen relationships and disease virulence. Finally, data collection should be standardized for a global assessment of FP dynamics and impacts.Acknowledgements. The long-term study at Culebra was achieved with the help of numerous field assistants and volunteers. Research support was provided by the Department of Natural and Environmental Resources of Puerto Rico (DNER), US National Marine Fisheries Service (NMFSNOAA, Section 6, grant no. NA 08 - NMF 4720436), US Fish and Wildlife Service, Chelonia, and WIDECAST. Ethical approval and licences were obtained from the NMFSNOAA (permit nos. 1253, 1518-01, 14949) and DNER (06- EPE-016). A.R.P. was supported by the Fundação para a Ciência e Tecnologia, through the grant (SFRH/ BD/ 85017/ 2012)