To the cheers of rescuers, Nundi the green sea turtle dives into the ocean after months of rehabilitation - carrying with her vital clues in understanding a dramatic increase in sick, injured and diseased marine turtles.
Fitted with a satellite tracker, she is now sending back valuable data to University of the Sunshine Coast researchers and others on her movements and foraging habits.
Before being released back in the waters off Queensland's Fraser Coast, researchers also analysed Nundi's blood health and gut microbiome, looking for new links between disease and gut health.
"Our goal is to do everything in our power to give turtles a second chance at life," says marine biologist Jacob Bowtell, a UniSC PhD candidate who oversees one of Australia's busiest sea rehabilitation facilities at Australia Zoo Wildlife Hospital.
Nundi awaiting release
"Turtles like Nundi are giving us vital information to better understand how we can increase the survival odds for rehabilitated turtles once they are returned to the ocean."
Solving a shell-wasting mystery
Mr Bowtell is a part of a team of UniSC researchers conducting a range of collaborative studies seeking answers to emerging diseases and other threats endangering the nation's marine turtles.
This includes satellite tracking of several rehabilitated turtles and research that is comparing the blood health and gut microbiomes of diseased turtles with healthy animals in the wild from Fraser Coast and Moreton Bay regions, and Lady Elliot Island.
It is a collaborative effort with key partners that include Wildlife Warriors, SeaWorld and the Queensland Department of Environment Tourism, Science and Innovation.
"Given that only one in a thousand marine turtles live to reach maturity and reproduce under normal circumstances, disease makes their survival odds even more daunting," Mr Bowtell said.
"When I first started as a sea turtle rehabilitation coordinator at Australia Zoo Wildlife Hospital over a decade ago, I saw very few sick or injured sea turtles at the wildlife hospital.
"In the past three years alone, we have seen about a 400 percent rise in admissions."
A growing number of admissions are turtles with diseases such as Fibropapilloma, Floater Syndrome and concerningly, a newly identified Soft-Shell Syndrome, which makes the turtle's carapace (shell) sponge-like, and in some instances, exposes bare bone.
Those cases are contributing to an unprecedented increase in turtle strandings and deaths.
In the Fraser Coast regional alone, Turtles in Trouble volunteers have rescued more than 1,400 turtles in the past three or so years. More than 300 needed to be transported to wildlife hospitals for specialist treatment.
For others it was too late, with rescuers finding more than 360 turtles already deceased.
Nundi's rescue and recovery
It is hoped that rehabilitated turtles like Nundi may provide much needed insights into the cause of this syndrome and ways to protect the marine animals from its devastating impacts.
Found weak, underweight and suffering from wasting of her shell when rescued by Turtles in Trouble volunteers on a Hervey Bay beach, the sub-adult green sea turtle was rushed to Australia Zoo Wildlife Hospital for treatment, led by Mr Bowtell.
"When we began treating Nundi, she was fighting a blood infection and becoming septic, which we suspected could be linked to Soft-Shell Syndrome," Mr Bowtell said.
Queensland's Fraser Coast region appears to be the epicentre of the wasting disease outbreak, with more than 150 cases reported since the start of 2022.
New global insights on gut-diseased turtles
For the first time, 20 years of stranding data collected by Australia Zoo Wildlife Hospital - including veterinary diagnoses and outcomes for over 2500 admitted sea turtles - will also be analysed to identify long-term trends and patterns in turtle health.
"This is the first study to take a comprehensive look at this data, and we expect it to reveal invaluable insights on the causes of turtle strandings and factors influencing survival rates," Mr Bowtell said.
A focus of UniSC research is on the gut biome of turtles presenting with disease, to determine if there is a connection to their diet and a lack of food caused by seagrass die-off following flooding and extreme weather.
Research in this area is scarce, despite species such as the green sea turtle relying heavily on their gut microbiomes to aid the digestion of seagrass, its main food source.
As a key element of the study, Mr Bowtell is conducting a feeding trial on 30 green sea turtles admitted to the wildlife Hospital.
"This is important to determine the connection between gut health and disease, and also to understand how our rehabilitation can impact their gut health too," he said.
"We are investigating ways diet may improve rehabilitation success and post-release outcomes, using the latest in testing techniques, including microbial sequencing. This will be a first for research on gut-diseased green sea turtles," Mr Bowtell said.
"Turtles in care are usually fed a high-protein diet of squid, fish and land-based greens, so we will compare their gut microbiome and long-term health with others given seagrass - their natural food in the ocean.
"Second to this study, ten sea turtles that have been rehabilitated have been fitted with satellite trackers, including Nundi.
"This will allow us to monitor post-release success and assess whether turtles resume normal foraging patterns on seagrass once recovered."
It is hoped the findings will lead to the development of a prognostic indicator for green sea turtles to predict and improve their chances of recovery.
New rehab and rescue centre to strengthen recovery efforts
UniSC Associate Professor Kathy Townsend , a global leader in sea turtle research, said rehabilitation centres played a pivotal role in the recovery of individual turtles.
"They are an initial sanctuary for compromised sea turtles and an invaluable platform for conducting research that is crucial to legislating and safeguarding these animals."
A high-priority project is the UniSC Milbi Centre - Marine Turtle Research and Rehabilitation on the foreshore of Hervey Bay, Queensland.
The centre will include a specialist turtle life support system and indoor and outdoor tanks to allow sick and injured turtles to be cared for and stabilised locally before being released back into the ocean or transported to wildlife hospitals for further treatment.
It is expected to take in its first turtles from early next year .
"We need to do all we can to give these animals the best possible chance to reach maturity and successfully reproduce," Dr Townsend said.
"Every recovered individual turtle returned to the ocean is essential to preserving the wild population."
