7 July 2020
First you were like, “whoa!” Then we were like, “WHOA!” And then you were like, “Fibropapillomatosis.”
This is part of a student blog series as part of the University of Pittsburgh’s Disease Ecology Class that our own Shane M Hanlon is currently teaching. Find out more about the series and read all the posts here!
By Colby Miller
There is currently a disease that is costing green sea turtles, Chelonia mydas, more than just a fin or some “noggin” – it is taking their lives. Fibropapillomatosis (FP) is a disease with a cause that is unknown. Here is what we know.
FP is a disease that is thought to cause tumors on the skin, eyes and mouth of mainly green and loggerhead sea turtles in every area they inhabit. It’s been said that anywhere from 20-30% of cases experience tumor growth within internal organs like the lungs, kidneys and heart. There is a correlation between the size and maturity of sea turtles and the infection rate; younger sea turtles are primarily at a greater risk of becoming infected by FP. This disease causes immunosuppression within sea turtles that can lead to secondary bacterial infections. Records show that infestation of worms living within blood vessels and cause inflammation of internal organs are a result from these secondary infections. Overtime, research has shown that a majority of deaths from FP come from cases where tumors form in the glottis (the opening of the trachea.) The tumor prevents the glottis from fully closing which allows always debris and sea water to enter the lungs and cause harm to the sea creatures. Out of the immature sea turtles that are affected by FP, only 30% recover from the disease. These alarming numbers are main reasons from the current push for understanding the disease. The first case was described back in the 1920’s off the coast of Florida, and cases in Honolulu, Hawaii can be traces back to the mid-1950’s. Since 1995, Honolulu Field station and the National Marine Fisheries Marine Turtle Biology and Assessment Program have been working together to collect data on FP and its causes. It wasn’t until 2010 that the first confirmed case of Fibropapillomatosis was collected and confirmed in tumors of sea turtles.
In a current study lead by Donna J. Shaver and their colleagues, less that 4% of turtles caught on Texas coasts had tumors that tested positive for FP. In following years, this number grew vastly. There were 21.6% infected in 2016, 27.3% in 2017, and 35.2% in 2018. The numbers in Texas have been constantly increasing. The University of Florida deduced that the cause of FP is due to a virus or protein. The specific virus was suspected to be a herpes virus because they are known to cause tumors in other animals. The disease was reproduced in captive turtles by injecting tumor homogenates.
The big question is “what now?” These is so much about Fibropapillomatosis that is still unknown. With cases of FP consistently growing off the coasts of Florida and Texas, mo re research has to be done in order to completely understand what this will mean for sea turtles long-term. A majority of the current research has been dedicated to tracking the disease, but research has barely scratched the surface of what causes FP and how cases can be reduced and treated. Sources: