A turtle has been found with seven fishing hooks in it, requiring a five-hour procedure to remove them from its intestines.
Vets at Taronga Wildlife Hospital said they had never seen this many hooks in one turtle before.
The 50kg green turtle was brought into the Sydney animal hospital from Lake Macquarie by a local who found the animal weak and floating in the water.
"I was very concerned that this turtle wouldn't survive because of the extent of the damage," senior vet Larry Vogelnest said.
"While she's not quite out of the woods yet, she is eating and doing well, so I feel quietly optimistic about the outcome."
X-rays revealed seven hooks inside the turtle, including four that were in a gang-hook formation.
Parts of the turtle's intestines had been damaged by the hooks and the fishing line.
It is not the first injury for the almost 40-year-old turtle. Locals noticed the turtle with damage to its shell two months ago, which was likely caused by a boat strike.
The turtle is the sixth one to have been brought into the wildlife hospital this year.
Fishing line a bigger problem
Dr Vogelnest said fishing line could do more damage to turtles than fishhooks.
That was because the line did not degrade in the intestines and tended to bunch up when the intestines contracted to push food through.
"That continuous movement makes the line cut through the wall of the intestine," Dr Vogelnest said.
"That was definitely happening in this animal, but thankfully had not cut all the way through."
Call for responsible hook disposal
The zoo is urging fishers to be careful of accidentally hooking turtles and seabirds after this recent discovery.
Dr Vogelnest would like anglers to seek assistance if they accidentally hooked a turtle while fishing.
"If you accidentally hook a turtle or a bird, such as a cormorant, please do not cut off the line and let it go," Dr Vogelnest said.
He said to reach out to a wildlife rescue organisation or bring the animal to Taronga Wildlife Hospital or a local vet for assistance.
"When cutting the line, it is important to leave a long length of line out of its mouth as that will help us get the hook out," Dr Vogelnest said.
"Prevention is always better than a cure, so I would encourage anglers to be responsible and to always safely discard of fishhooks and line."
Peter Gibson from the Recreational Fishing Alliance of NSW also recommended reaching out to a vet or wildlife rescue if fishers accidentally hooked a bird or turtle.
"Make sure that it's done as safely as possible, especially on high-value protected species that may suffer unreasonably," Mr Gibson said.
"If they can't easily dislodge the hook from a bird or an animal, they should probably try to get professional advice."
Changing equipment a part of the problem
Mr Gibson said part of the issue was that fishing gear no longer broke down as quickly as it used to.
Newer stainless steel hooks did not rust away as fast as older iron-based ones, while newer gel-spun fishing lines were more durable than old nylon lines.
"Most of the modern hooks are stainless steel and a lot of the newer fishing lines are much stronger and are less likely to break down under UV light," Mr Gibson said.
"They are more durable and anglers need to take more care to dispose of them safely."
Easter a busy time for fishing
Mr Gibson said there would be a surge of recreational fishing across the state over the Easter long weekend, especially if the weather was clear.
He said the activity had become popular during the pandemic.
"It was one of the outdoor activities that people were allowed to continue to pursue, as long as they followed reasonable social distancing," Mr Gibson said.
Dr Vogelnest said the wildlife hospital was expecting an increase in hooking incidents as more people went fishing.
"Fishing line and fishhook ingestion are the most common problems we see in animals that are admitted to our hospital," he said.