Groundbreaking study uses genetic sequencing to ID new viruses
For decades, efforts to reverse the decline in sea turtle populations have focused on man-made impacts to their environment. But new research from the University of Georgia has identified previously unknown viruses that may pose a risk to threatened and endangered turtles.
Although symptoms of viral infections have been noted in sea turtles in the past, diagnosing the exact cause of those symptoms was difficult. Using genetic sequencing, scientists in UGA’s College of Veterinary Medicine have identified 19 viruses in the turtles, including seven novel ones.
The study could prove particularly valuable in the event of a future disease outbreak.
Without a baseline understanding of the viral communities present in sea turtles, researchers responding to an outbreak would have to search from scratch for a potential viral cause, said Dr. Weerapong “Mac” Laovechprasit, lead author of the study and a resident in the college’s pathology department.
Establishing that foundation now could save scientists years of investigative work, a critical advantage when an emerging disease is affecting an already vulnerable population.
Dr. Weerapong “Mac” Laovechprasit, at right in photo above and in the lab below, tends to a stranded Hawksbill sea turtle in Rayong City, Thailand. Laovechprasit is a marine veterinarian serving a residency in UGA VetMed’s Pathology Department. (Provided photo)
Laovechprasit previously discovered a virus strongly associated with fatal neurological disease in aquatic turtles. “That led to the question of what other viruses exist in this understudied system,” said Dr. James Stanton, corresponding author of the study and interim department head of pathology at the UGA College of Veterinary Medicine.
“Viral discovery turns unknown unknowns into known unknowns that we can then target for study,” Stanton said. “Most of these viruses may never prove to cause disease, but discovering and cataloging them gives us the foundation to recognize the ones that do and determine whether they pose a meaningful threat to already imperiled sea turtle populations.
Previous studies have identified fewer than a dozen viruses known to cause illness in sea turtles. As a result, conservation efforts have focused on human-caused threats, including pollution, poaching and coastal development.
Five of the seven sea turtle species found in the world are threatened or endangered. A disease outbreak could lead to further loss of critical population numbers.
The researchers tapped a network of marine wildlife specialists on the Atlantic and Pacific coasts of the United States to gather fecal specimens from rehabilitated and free-rangingsea turtles that were captured and released to analyze viral threats.
Those samples revealed some viruses that were genetically related to pathogens known to infect aquatic invertebrates and fish. Seven of the viruses had not been identified before in any species, and one belongs to a previously unidentified scientific family of viruses.
Laovechprasit was a marine veterinarian in his native Thailand prior to winning a Fulbright Thai Graduate Scholarship to pursue a doctorate in comparative biomedical sciences and veterinary pathology at UGA.
Published by Infection, Genetics and Evolution, the study was conducted in collaboration with researchers at the Georgia Sea Turtle Center on Jekyll Island; the National Marine Fisheries Service Office of Protected Resources at the University of Florida in Gainesville; The Turtle Hospital in Marathon, Fla.; Mystic Aquarium in Mystic, Conn.; the New England Aquarium in Boston; and Upwell in Morro Bay, Calif.
In top photo, a sea turtle is prepped for treatment at the Georgia Sea Turtle Center on Jekyll Island. The center, which focuses on conservation and education, collaborated with UGA researchers on this study. (Georgia Sea Turtle Center photo)
