Turtle admissions rise as unknown disease emerges

AN unknown debilitating shell disease affecting already endangered green sea turtles is emerging off the Queensland coastline, with Australia Zoo Wildlife Hospital seeing an influx in turtle admissions suffering from the unknown disease.

Since December 2021, 49 green sea turtles rescued from a localised area of Hervey Bay suffering from a ‘shell-melting disease’ have been treated at the state-of-the-art wildlife hospital.

Australia Zoo Wildlife Hospital veterinarian and hospital supervisor Dr. Ludo Valenza explained that the turtles presenting tend to have “ulcerated open wounds on their shells and flippers” which she said often lead to the exposure of the underlying bone.

While they are still investigating the cause of the illness, Dr. Ludo shared that the believe it is linked to diminishing sea grass availability for the turtles, “which has been exacerbated, but not solely caused by” recent flooding events.

“We suspect that due to low food supply, the turtles are forced to eat a source of food that generally only contributes to a small part of their diet, and could be causing them to get sick. The shell disease is only what we see on the outside. Unfortunately, the turtles have been presenting with very severe gastrointestinal issues,” Dr. Ludo said.

“So far, 26 turtles are currently undergoing treatment, one turtle has been released back into the wild following a full recovery, and 22 turtles were humanely euthanised due to the severity of this disease,” she said.

While the majority being treated are from the Hervey Bay area, one juvenile green sea turtle, aptly names Lucky, presented with the unknown disease from a separate location on the Sunshine Coast. The concern is that “it means that turtles outside of the localised Hervey Bay region could also be suffering from a similar cause, ” said Dr. Ludo.

“The turtles are receiving around the clock care and undergoing extensive treatment at our specialised sea turtle facility. We are treating the affected turtles with antimicrobials to contain the infection and prevent it from spreading,” she said.

The Wildlife Hospital is working with Dr. Christabel Hannon of Obelia Consultancy and the University of Queensland to determining the cause of the illness.

Turtles presenting tend to have “ulcerated open wounds on their shells and flippers” which often lead to the exposure of the underlying bone.

“This disease is highly debilitating and can take months for the turtles to recover, and unfortunately sometimes they never do. The cascading effect of this disease on the population of green sea turtles could be catastrophic,” said Dr. Ludo.

“Female green sea turtles only breed every three or so years, and with only one in 1000 hatchlings turtles surviving to a mature age where they can breed. Every turtle is vital to the survival of this endangered species,” she said.

The Wildlife Hospital is working closely with the Department of Environment and Science to study further into this devastating illness.

“The Department of Environment and Science will continue to work with leading wildlife experts in veterinary science and turtle rehabilitation to investigate reports of this ulcerative skin disease in green turtles and try to determine the underlying causes so we can respond directly,” Marine Parks Principal Ranger Steve Hoseck said. 

“Although there have been no conclusive answers as to what is causing this disease at this stage, DES will continue to collaborate with organisations including Australia Zoo Wildlife Hospital to support the rehabilitation of affected turtles.”

The Australia Zoo Wildlife Hospital has treated more than 1500 sea turtles since opening its doors in 2004. With six out of seven species of sea turtles classed as endangered, it is critical to keep an eye out for sick or injured turtles, and contact your local rescue group or wildlife hospital for providing these animals with their greatest chances of survival.