A leopard seal named Owha has prompted a marine scientist to suggest the species is more common in New Zealand waters than previously thought.
NIWA cetacean biologist Dr Krista Hupman says evidence shows that Owha has been here for at least five years.
Dr Hupman, who has also been collating sightings over the past 150 years, says the seals have always been described as an Antarctic species, meaning New Zealand is outside their normal range.
"But this research shows that this is not the case for all leopard seals, and that these animals may have been here a lot longer and are a lot more common than we know," she said.
Before joining NIWA in Wellington in April, Dr Hupman was a Department of Conservation marine ranger in Auckland, where she learned of a leopard seal that had been seen near Warkworth.
The animal, Owha, made its way through the Waitemata Harbour to Westhaven Marina.
"We kept on monitoring her and monitoring her and she didn't leave," Dr Hupman said.
"The week I left Auckland, she decided to move up to Tutukaka and then to Whangarei, and she is still there."
At NIWA, Dr Hupman, together with Dr Ingrid Visser from the Orca Research Trust, began collating sightings of leopard seals back to the 1860s and they have come up with 500.
She has also been monitoring a seal in Marlborough, while Dr Visser has been monitoring a recent arrival in Whangarei.
"So what are they doing here?" Dr Hupman asked.
"There's a theory they just get lost in the ice floes and end up going north instead of south. I don't know if we can justify that anymore with what we're seeing now."