Sunbathing . . . A leopard seal rests in Oamaru's Friendly Bay. PHOTO: SUPPLIED/PHILIPPA AGNEW

It is that time of year again when Waitaki beaches become host to a very special visitor.

And as any good host should know, it is important to make visitors as comfortable as possible.

Between July and December each year, one to three leopard seals usually waddle out of the sea for a rest at Oamaru Harbour.

They also appear at other beaches in the North Otago region from time to time.

Two sightings had already been reported since August, Department of Conservation Oamaru Ranger Tom Waterhouse said.

Some stayed longer than usual – one season, a female leopard seal was reported 10 times.

Not known to breed in New Zealand, the seals typically came ashore to rest or complete a “catastrophic moult”, losing whole patches of fur and changing their entire coat in a process that could take a month, Mr Waterhouse said.

Their time ashore was important, which was why people needed to do their best not to disturb them, otherwise they might not return.

If disturbed, they could return to sea at time they needed to rest, affecting their “energy budget” and putting them at greater risk, he said.

This could cause the animal issues, from increased stress to reduced fitness or in extreme cases, illness or mortality if the seal was unwell or resting from an injury.

Mr Waterhouse advised people to remain at least 20m away from the seals and to make sure their children and dogs did the same.

“People should not disturb the seal, including making loud noises or throwing things, and should not try to feed or touch them.”

The seals are protected under the Marine Mammal Protection Act. It is an offence to disturb, harass, injure or kill them and dog owners could be prosecuted in the event of an attack.

But there were other consequences people should be wary of.

“[Leopard seals] are not outwardly aggressive but will defend themselves if they feel threatened.”

They could move quickly and had incredibly strong jaws. Their bite could cause serious injuries or pass on infectious diseases, Mr Waterhouse said.

Last week, a 2.1m long, slightly underweight leopard seal was spotted resting on a beach in Kakanui. It was found dead that afternoon and Te Runanga o Moeraki was notified.

Though the cause of its death was unknown, the sea creature would likely be necropsied.

As one of the ocean’s top three predators, leopard seals were remarkable animals and incredibly well adapted to living in a harsh environment.

“It’s an amazing experience to be able to see them on the New Zealand mainland, and if you get to see them moulting their dull dingy coat and donning their new silver and black spots, it’s quite a treat.

“Enjoy the amazing experience but respect them and their space.”