Move over Whale-ington - Auckland has its own exciting news in the big ocean mammal department.

Marine biologists and whale-watchers alike are abuzz at a rare sighting of multiple blue whales - including a calf - in the Hauraki Gulf over recent days.

The hefty visitors have been spotted by Auckland Whale and Dolphin Safari tours, in what's been a record year of blue whale sightings.

In the past 12 months, the company's observers have recorded 15 sightings in the gulf - including six in just the past week - which was almost four times the usual number of encounters for such a period.

Advertisement

Around 60 people were on board one of the company's safaris yesterday, when a mother and her calf were seen among four blue whales visible in calm, flat conditions.

The sightseers were treated to close swims past the boat, and also got to see the mother lift her flukes out of the water as she dived - an even bigger rarity given the shallow depth of the area.

It was likely those seen were of the pygmy blue whale variety – slightly smaller than their true Antarctic cousins, and potentially part of a 700-strong population only just identified as being endemic to New Zealand waters.

While the South Taranaki Bight was a better-known hotspot for the species, the increase in sightings around the gulf suggested they might become more frequent around Auckland in the future.

The company was working closely with blue whale researchers by contributing data, some of which had helped identify the endemic population.

The sight-seers were treated to close swims past the boat, and got to see the mother lift her flukes out of the water as she dived. Photo / Auckland Whale and Dolphin Safari
The sight-seers were treated to close swims past the boat, and got to see the mother lift her flukes out of the water as she dived. Photo / Auckland Whale and Dolphin Safari

Its marine research and conservation officer Catherine Lea said food was likely the big draw bringing the rare species into the gulf - and she speculated that the summer's marine heatwave might have played a part in changing prey distribution.

"It seems to have knocked a few things out of whack."

Around 60 people were onboard one of the company's safaris yesterday, when a mother and her calf were seen among four blue whales visible in calm conditions. Photo / Auckland Whale and Dolphin Safari
Around 60 people were onboard one of the company's safaris yesterday, when a mother and her calf were seen among four blue whales visible in calm conditions. Photo / Auckland Whale and Dolphin Safari

Massey University marine scientist Dr Karen Stockin agreed that could have been a factor, but a lack of good data made it hard to know for sure.

Advertisement

"Regardless, it's exciting for us."

Stockin said sightings had risen from next to none when she began her studies 17 years ago, which could be a sign the species had been gradually recovering from the toll of historic whaling.

"It's fair to say that over recent years, there's been a steady amount of observations of blue whales using the gulf."

In the past 12 months, Auckland Whale and Dolphin Safari observers have recorded 15 sightings in the gulf - including six in just the past week. Photo / Auckland Whale and Dolphin Safari
In the past 12 months, Auckland Whale and Dolphin Safari observers have recorded 15 sightings in the gulf - including six in just the past week. Photo / Auckland Whale and Dolphin Safari

But people shouldn't draw a link between this week's spectacle and a rare southern right whale that brought traffic in the capital to a stand-still when it stopped by Wellington Harbour this month.

A whale-watcher gets an up-close look at one of the rare visitors. Photo / Auckland Whale and Dolphin Safari
A whale-watcher gets an up-close look at one of the rare visitors. Photo / Auckland Whale and Dolphin Safari

"Different species, different area, different feeding ecology," Stockin said.

"The only similarity I'd see is hopefully we'll also see this species more frequently as its own population recovers."