Scientists say Southern right whales could appear more often off Napier coastline

Scientists have raised the exciting possibility that rare southern right whales are rediscovering ancient migratory pathways to mainland New Zealand. Photo /Supplied

Experts say sightings of Southern right whales off the Napier coast could increase in the future.

Scientists have raised the exciting possibility that such encounters could soon become more common if the ocean giants are rediscovering ancient migratory pathways.

Educator at the National Aquarium of New Zealand Karlie Lett said there was a possibility people may start to see southern right whales appearing in Hawke's Bay more often during the next few years.

The population is thought to be increasing at around 5 per cent per year, and their natural habitat (especially for mothers and calves) is sheltered bays, so Hawke's Bay would be an attractive area to them, Lett said.

"There are records of spottings in the Bay over the last few decades. Generally, most sightings this far north are in the winter time so that's when we would have the greatest chance of seeing them."

University of Auckland researcher Dr Emma Carroll said the recovery of right whales around New Zealand was a good example of understanding what this meant for conservation.

In an earlier major study, she and colleagues revealed how migratory behaviour among the whales was learned by calves from their mother in the first year of life.

Calves were born in their mother's preferred wintering ground, and then travelled with their mother to her preferred summer feeding ground.

While mainland New Zealand long offered the species a good wintering ground – it's estimated there were once some 30,000 Southern right whales in our waters – that changed when whaling throughout the 1800s almost drove them to extinction.

"When right whales that visited mainland New Zealand in winter to breed and calve were killed off by whaling, the cultural knowledge of this area as a good wintering ground also disappeared," Carroll said.

"This is why we see many right whales in the subantarctic Auckland and Campbell Islands, but few around mainland New Zealand - the whales just don't learn about it anymore."

Because of our protection of the subantarctics, its New Zealand population had recovered to an estimated 2000 whales, as at 2009.

"There have been a handful of female right whales that have returned across years to calve around mainland New Zealand," she said.