Marine rescue groups are asking beachgoers to keep an eye out for an injured leopard seal, that is struggling to survive after being bitten by what experts believe was a juvenile great white shark.
The seal, which has a large chunk missing from its shoulder, was discovered on a beach on the New South Wales north coast on Sunday.
National Parks and Wildlife Service, ORRCA, and Dolphin Marine Magic monitored the seal for five days, before the Antarctic visitor disappeared from Minnie Water, east of Grafton, on Friday morning.
Veterinarian Dr Duan March said the condition of the seal had been deteriorating, but an improvement in its demeanour prompted them to wait another 24 hours before reassessing.
“With these animals you can’t rehabilitate and release because they’re an Antarctic species and that’s illegal,” he said.
“So if there is any intervention it’s euthanasia.
“At the time, the animal’s demeanour had improved a little bit, and the wound looked clean … so we made the decision to give it another 24 hours and reassess, and since then we haven’t been able to find it.”
Dr March said the wound appeared to be caused by a shark.
“I’d be speculating — but there were some tissue bridges between the teeth marks that weren’t associated with a crescent shaped wound,” he said.
“Whites are the most common species that will leave tissue bridges — gaps between the holes.
“So maybe a juvenile white transitioning from fish to mammals; maybe a 2.5 to 3-metre white.”
The seal, with a large bite on its shoulder, was discovered at Minnie Water, east of Grafton on Sunday, and reported to ORRCA and the National Parks and Wildlife Service. (Supplied: Aidan Ricketts)
ORRCA president, Jacqueline O’Neill, said anyone who came across a leopard seal, should keep their distance.
“They can be quite defensive,” she said.
“Definitely if anybody comes across this animal, you do need to keep at least a 40-metre distance between you and the animal.
“As cute as they may look, they actually can move quite quickly on land.”
Ms O’Neill said leopard seals were uncommon visitors to the NSW north coast, but not unheard of.
“The populations of seals and whales have been recovering since sealing and whaling ceased mid-way through last century,” she said.
“Each year we are seeing population increases for all sorts of marine mammals, leopard seals being one of them.
“So we can expect that as those populations start to recover we will see more of those animals moving a little further afield when they are short of food in the Antarctic regions.”
Anyone who sees the leopard seal should contact either the National Parks and Wildlife Service on 13000 72757, ORRCA on 02 9415 3333, or Dolphin Marine Magic Coffs Harbour on 1300 547 737.