Medical Mystery

By: Mike Dadich

Sick Turtles Leave Mote with a Medical Mystery

After spending 10 years treating common animals with common ailments using common remedies, veterinarian Charles Manire wanted a challenge.


Manire, who came to Mote Marine Laboratory in 1992, found his challenge as the lab’s chief veterinarian working with marine mammals and sea turtles and all of their unusual illnesses.


His most recent challenge: Finding out why some loggerhead sea turtles have risen to the surface of the Gulf of Mexico with air in their coelemic cavities. The air makes them unable to submerge to search for food, leaving them to simply wash ashore and waste away.



Eight sick turtles were discovered in April, May and June from Anna Maria Island south to Fort Myers. They all had aplastic anemia, a potentially fatal condition that prevented them from producing new blood cells, Manire said.


The turtles have no visible lesions or wounds; all Manire knows is that some turtles are getting sick, and he doesn’t know why or how widespread the
problem is.


On the Case

The animals Manire treats include dolphins, whales and sea turtles. Often, he has to rely on his experience at Mote to treat them with remedies he thinks will work best.


After all, there’s not much known about the veterinary care of marine mammals and reptiles, so there’s no quick reference book for the sick ones. “It’s not a simple process,” he said. “It’s a lot like being a detective looking for clues.”


The clues in the case of the sick loggerhead sea turtles include aplastic anemia and excessive gas in the coelomic cavities.


The coelomic cavity is present in reptiles and all other animals except mammals, and is similar to the mammalian abdominal cavity. It contains all of the turtles’ vital organs and intestines.


More pressing is the anemia, which has left the loggerheads unable to produce blood cells. That makes it impossible for them to fight off infection or replace blood cells that have died naturally.


The organs of the anemic turtles start to fail because they aren’t getting the oxygen they need, said Petra Cunningham-Smith, Mote’s behavioral husbandry and rehabilitation coordinator. “The blood gets watered down and kind of looks like cherry Kool-Aid,” she said.


The Theories

Manire hypothesized that the turtles got sick from a viral infection or by eating prey or other items high in heavy metals.


The death of one of the eight sea turtles rescued gave Manire and his team the opportunity to test his theories.


A necropsy showed no indication that the turtle had ingested any lead or other heavy metal substances. “The animal was passing primarily crab parts and plant material,” Manire said.


The plant parts, however, were unidentifiable. Manire wasn’t even sure it was seagrass, since it’s unusual for loggerhead sea turtles to eat grasses.


Still, that’s hardly sufficient evidence to suggest that plants caused the mysterious illness, Manire said.


Manire’s next step was to send blood and tissue samples to the University of Florida’s pathology lab for testing. Those tests revealed no evidence of any viral infection.


The Break?

Although Manire’s first two tests revealed little to explain why the turtles were sick, he did discover large amounts of copper in the dead turtle’s tissues. “The problem is that we don’t know what normal levels of copper in this animal are,” he said. “It’s a clue, not an answer.”


Another issue could be blood flukes, or worms, that Manire has been seeing in all the sick loggerheads brought in for rehabilitation in the past year or so. “Blood flukes are fairly common,” he said. “What’s uncommon is that they’re causing granulomas in almost every organ of the turtles’ bodies.”


A granuloma is an inflammation caused by a body’s reaction to a foreign substance.  “We’ve even seen it in the brain tissue of turtles we had here last year. This could all be tied to the same thing. But we just don’t know.”


So the search for the answer that will solve the mystery of the sick sea turtles continues.

“I’m concerned about the pollution of the oceans and how the creatures out there are affected,” he said. “The ocean is not a dumping ground.”


Manire sent a notice to the Florida Fish and Wildlife Conservation Commission to warn the agency about the possibility of an epidemic.

 


For now, all Manire can do is treat the sick turtles and hope they make full recoveries. The solution to what is causing the sickness could be a long way off.. “With cases like these, you can’t be afraid to say, ‘I don’t know,’” Manire said. “I wish I had the answers. I just have clues.”


Learn more about: Sea Turtle Rehabilitation at Mote

Don't hide inside your shell. Turtle populations have declined in recent years and not only because of mysterious illnesses. We can't ignore that. Nor can we ignore the fact that we desperately need your financial support to fund the research that can bring them back.





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Mote Marine Laboratory has been a leader in marine research since it was founded in 1955. Today, we incorporate public outreach as a key part of our mission. Mote is an independent nonprofit organization and has seven centers for marine research, the public Mote Aquarium and an Education Division specializing in public programs for all ages.

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