Warning: This story contains a graphic image.

It's feared Auckland's resident leopard seal, Owha, has made some enemies due to her pastime of biting into and sinking inflatable dinghies at the Westhaven Marina.

Photo: Supplied / Giverny Forbes

The 3m seal has a serious injury consistent with being shot or speared in the face, leading to concerns about her long-term prospects in one of the country's busiest stretches of water.

RNZ saw a family unloading chilly bins and fishing rods from their boat after spending the long weekend out on the Hauraki Gulf, when the nearly half tonne giant poked her head above the water then plonked herself onto their pontoon.

Encounters like this are not uncommon at the Westhaven Marina, where Owha has visited regularly for at least four years.

Marine biologist Brittany Mathias, from leopardseals.org, has been working with her since 2016.

"We've got a large apex predator living in the largest marina in Auckland and a lot of people don't believe she belongs here because she's regarded as an Antarctic species.

"Unfortunately it's a wildlife conflict and it's one of these things that we have to learn to deal with."

Ms Mathias said Owha had never attacked anyone, but one of her favourite things to do was to bite inflatable dinghies.

She was not quite sure how many have fallen victim, but it was more than 60.

"I think it's a bit of a play behaviour, a bit like a dog with a chew toy," she said.

"She's really curious and a little bit cheeky and she'll follow people in the boat to see what they're doing. She seeks out the attention of people and she just enjoys being in Auckland."

It's for this reason it's feared a disgruntled boatie may have tried to take the law into their own hands.

Photo: Supplied / Alex Grabham/Leopardseals.org

On Saturday Owha was seen with a wound above her nostril, bleeding heavily.

Wildlife veterinarian Jodi Salinsky took a boat out to see Owha on her favourite pontoon yesterday.

"The injury is just above her left nostril so over the last few days there's been been blood draining out of the nostril and out of the wound," she said.

"Obviously it may be a bullet but we couldn't swear 100 percent unless we had an x-ray, but that's the most likely scenario."

Dr Salinsky said Owha seemed to be doing as well as could be hoped.

"There's no visible signs of nerve damage, her face is really symmetrical and there's no swelling that we can see.

"But we still don't know if she is out of the woods or something else will transpire from her injury. So it's really important to make sure that she can feed and swim and haul out and do all of the things she would do normally."

Photo: Supplied / Giverny Forbes, Leopardseals.org

If Owha's condition does deteriorate, treating her wound would be a very complex task.

It's feared that if she's tranquillised she may retreat underwater, where she risks drowning.

Ngāti Paoa Trust Board's environment officer Karla Allies said people needed to understand that they are in Owha's territory - not the other way around.

"There were quite a few concerned berth owners because I think some dinghies being chomped and there were some people concerned about their little dogs being eaten maybe.

"However, she has never attacked anybody, she's never shown signs of aggression to anyone. She's just quite a scary-looking beast because she is massive and she's got some teeth on her. But she is beautiful."

The team will be back to check on Owha today.

Anyone who crosses her path is asked to call 0800 LEOPARD and to keep a distance of at least 20m.