Hawaiian green sea turtles are covered in tumors.
It’s difficult to see such a beautiful creature with hideous growths on its body.
The disease that causes the tumors is called fibropapilloma, and it affects green sea turtles worldwide.
Experts said the tumors are essentially a form of cancer. It was first found in Hawaii in the 1950s.
Scientists continue to study the virus, but they still have more questions than answers.
Wildlife disease specialist Thierry Work has studied turtles with fibropapilloma for 20 years.
He said it causes both external and internal tumors, mostly in green sea turtles, and animals with the disease are in a great deal of pain.
“If you get enough of these tumors, you start not functioning,” Work said. “It impedes swimming. It impedes breathing, eating and it kind of causes them to waste away and die.”
As for what causes it, Work said, “There’s really good evidence at the molecular, microscopic, level that there’s a herpes virus that’s associated with these tumors, but we’ve never been able to prove that.”
Work said finding that piece of the puzzle is key.
“There’s a lot of effort in the lab trying to grow the virus and we’re also trying to develop a blood test,” Work said. “If we can find a blood test, we can take a blood sample and say hey, this animal has been exposed. The virus is circulating. It gives you more time to intervene.”
KHON2 asked, “Are there any environmental issues that may be causing this?”
“There could be. Clearly with any disease, there’s always an environmental component to it, but what that environmental component is, we’re not really sure,” Work replied.
Cases of the disease increased during the 1980s and 1990s, according to Work, but he said there are now fewer cases of the disease.
“We think one possible reason is that with any infectious disease you develop what’s called herd immunity. Enough animals survive the disease and develop an immunity to it that they’re able to survive it. Then their off-spring have immunity to it and it declines over time. But it never completely disappears.”
There is a high concentration of turtles with the disease in Kaneohe Bay, though Work said they are not sure why.
“Maybe it’s because the bay is polluted, or maybe its because of the calm waters and the bay is protected,” Work explained. When a wild animal is sick, it,s going to try and find refuge in a safe area.”
And there are other areas where turtles don’t seem to be impacted.
“It’s found through all the main Hawaiian islands, but its very rare on the Kona coast and nobody really knows why. We have green turtles on the Kona coast on the Big Island but they rarely have the disease.”
The disease is transmissible. An infected turtle can give the virus to a healthy turtle, but Work said humans cannot get the disease.
“The wildlife is telling us something. There’s something about the environment or something about these animals that are making them predisposed to tumors and we should pay attention to that and try to get to the bottom of it,” Work said.
More information on fibropapilloma can be found on the USGS website.