An endangered Green Turtle returned to the ocean today, nearly four months after losing a flipper to a life-threatening fishing line injury.

The juvenile turtle completed a remarkable recovery, splashing back into the water outside Sydney Headlands thanks to a joint operation by Taronga Wildlife Hospital and Sydney Water Police.

Nicknamed ‘Catherine’ by hospital staff, the turtle was released with a small satellite tracker attached to her shell that Taronga researchers hope will help unlock the secret migration habitats of marine turtles.

“It was amazing to see this beautiful creature spreading her flippers in the wild again and know that she will also contribute to our understanding and conservation of her endangered species,” said Taronga Wildlife Hospital Manager, Libby Hall.

“This period of a juvenile turtle’s life is known as ‘The Lost Years’, as we really don’t know where they migrate. It’s astonishing that these creatures have been on our planet for over 200 million years, but there’s still so much we don’t know about them. We need to learn where they are travelling so we can better protect this important habitat.”

Catherine was brought to Taronga for lifesaving care in July, after being found floating in the water near Catherine Hill Bay with fishing line wrapped around her left front flipper.

“It had almost completely severed the flipper and she also had fishing line coming out of her mouth,” said Libby.

The flipper couldn’t be saved, but Catherine bounced back after months of intensive care. She moved into a larger pool in late October as part of her rehabilitation, showing hospital staff that she could swim strongly and find food despite her missing limb.

“She’s got two big back flippers that she uses to do all her manoeuvring and she’s managing to manipulate food really well with her remaining front flipper. Hopefully she’ll grow up to become a healthy, adult turtle and continue to explore our oceans for many years to come,” said Libby.

Libby said Catherine’s story was a timely reminder for people to properly dispose of fishing line and rubbish and avoid single use plastics.

“Most of the turtles we see at the hospital have been injured by marine debris. Catherine was one of the lucky ones, but a great many marine creatures die after swallowing plastic or becoming entangled in fishing line,” she said.

Taronga Wildlife Hospital cares for and treats up to 1,000 injured or orphaned native animals every year, including wombats, wallabies, possums, echidnas, birds and sea turtles.