A run of shark sightings has prompted calls for swimmers to be aware about sharing the water safely.

Lifeguards recorded more than 40 first hand sightings of sharks across two regions in the past fortnight, Surf Life Saving reported on Tuesday.

And while lifeguards are used to sharing the water with sharks and most of those seen were not big enough to cause alarm, Surf Lifesaving eastern manager Chaz Gibbons-Campbell says he warns people to be cautious.

"In the last two weeks we've had 42 sightings across Coromandel and Bay of Plenty.

"That's from lifeguards seeing sharks swimming by, and most of them are on the small size range, so sort of under a metre and a half."

Sharks in Tauranga harbour

A Tauranga fisherman contacted SunLive on Monday asking "are people aware there are white pointer sharks down our end of the harbour?"

"On the 22nd of December I was fishing between Omokoroa and Matakana Island with a friend of mine. Fishing was slow but he suddenly shouted what the hell was that!" says the Tauranga fisherman.

"I looked in the direction he was pointing and a white pointer shark came clean out of the water, dropped back in and didn't show again. We shifted to another spot.

"I'm a retired commercial fisherman. I've fished the NZ coast for over 50 years. I know what sharks look like.This one looked about 2 to 3 metres long and heavy.

"I know some were tagged up the KatiKati end of the harbour last year. I've seen plenty of bronze whaler sharks in the harbour stealing fish from anglers lines just as you get them up to the boat but they don't seem to bother people.

"I've scuba dived for scollops up through the harbour right where we sighted this shark. I've water skied here, kayaked here, towed my kids and grandkids around on a ski bandit, but I wouldn't do it now."

Boating on Tauranga harbour. Photo: Rosalie Liddle Crawford.

He doesn't think the white sharks should be allowed in the Tauranga harbour.

"We wouldn't let lions or tigers wander round our streets or kid's playgrounds. White pointers are just as dangerious. These sharks are probably hanging around in the deeper channels but who knows."

Shark spotted at Whirinaki, north of Napier on Tuesday

Hastings man Timothy James Carrington got some close snapshots of a shark he estimated was about 2 metres long, and only about 2 metres from the beach at Whirinaki, north of Napier, on Tuesday.

He posted the photos to an online community group to warn people to be careful.

"It was in very close. I walked down the beach to tell a dog owner that was throwing sticks into sea [for his dog] ...that he was throwing the stick further out than shark was."

It was hard to tell what type of shark it was, he was, and many people had guessed it was a bronze whaler, but Timothy himself thought it could be a blue shark.

Timothy James Carrington spotted this shark he estimated to be about 2m long, off Whirinaki, just before noon on Tuesday. He says the shark was behind a "little break". Photo: Supplied/ Timothy James Carrington.

Chaz says even though the vast majority of sharks likely to be encountered at the beach were harmless, people should take safety precautions to keep safe.

"Don't swim where people are fishing ... and avoid swimming at dawn and dusk," when sharks are feeding, he says.

And, "around fishing... make sure that you are disposing of your fish carcasses appropriately, by not dumping them in the ocean."

Last week marine scientist Riley Elliott warned the El Nino climate shift could bring more cool and fish-rich waters to New Zealand's coastline, and draw out more sharks.

Department of Conservation marine scientist Clinton Duffy told RNZ the best way to stay safe if you spot a shark is to get out of the water as quickly and as quietly as possible.

A teenager was killed in a shark attack late in December off South Australia's coast. And several shark attacks had also already been reported in New Zealand waters this summer, including on the Wairarapa coast and in knee-deep water in a Southland estuary.

Additional reporting by RNZ