Twenty-seven pilot whales have died after they became stranded on a remote stretch of Northland coastline on Monday.

They were discovered on Twilight Beach (Paenga Rehia), about 11km south of Cape Rēinga, that is part of the popular Te Paki Coastal Track and the first leg of Te Araroa.

Ngāti Kuri Trust Board executive trustee Sheridan Waitai said walkers had come across the mass stranding.

The alarm was raised with Ngāti Kuri, who live and work in the area, and the Department of Conservation (DoC).

“We are always ready to go because this is the season and this is what happens,” Waitai said.

Ngāti Kuri assessed the site on Monday and confirmed there were 27 pilot whales stranded.

The location, the condition of the animals and tidal factors contributed to the decision not to launch a rescue operation.

Waitai said there had been times when others had tried to save and move stranded whales but it is hard on the marine mammals.

“Just touching them is awful for them. So, sometimes rescuing’s not really the best choice.”

The decision not to attempt to rescue the pilot whales on Monday had carried a lot of weight, especially as whales are considered family and tūpuna (elders) in Māori culture.

“It’s more the responsibility and the obligation to do it right and do the tikanga right,” Waitai said.

“You wouldn’t hang your father out in front of everybody and leave them out on the beach and whales are like whānau, so you don’t you treat them like that.”

Waitai said decisions are made so their whakapapa can be maintained through kōrero.

“So you can always uphold and remember who they are.”

All of the pilot whales have since died. In response, Ngāti Kuri developed a cultural and bio-hazard clean-up plan.

The iwi informed DoC who, on Ngāti Kuri’s invitation, deployed two of their staff to help.

“There have since been two tides that have flushed the beach clean and it is now safe to walk on,” Waitai said.

Ngāti Kuri asked that walkers keep off the dunes from Te Rerenga Wairua/Cape Rēinga to Kahokawa on Te Oneroa a Tohe/Ninety Mile Beach.

Waitai said the request was to prevent further bio-diversity damage to the dunes and to also protect cultural sites.

A rāhui was put in place but has since lifted.

Waitai praised the walkers for their help and for respecting the process, which included them being asked to leave the beach.

“We just said, ‘You’re welcome to stay up in the micro camp and rest up there, but not on the beach’. And there was no opposition. They were just they’re just really helpful.”

Pilot whales - which are in fact one of the largest members of the dolphin family - are considered prolific stranders.

A mass stranding of around 30 pilot whales near Farewell Spit on January 18 this year. Photo / Project Jonah

Information by DoC stated that while there were recordings of individual strandings nationwide, mass stranding hotspots were Golden Bay, Stewart Island, and the Chatham Islands.

The biggest recorded pilot whale stranding was an estimated 1000 whales at the Chatham Islands in 1918.

Northland’s largest pilot whale stranding is considered to be in August 2010 at Spirits Bay, about 30km away from Twilight Beach, when 80 to 100 pilot whales stranded. Of them, 58 died and the remainder were refloated or moved to nearby Rarawa Beach for release.

The rescue effort was recognised as one of the largest and most complex in the region. DoC, Project Jonah and Ngāti Kuri were all involved, their numbers bolstered by volunteers.

Another mass stranding took place in November last year when more than 30 pilot whales became stuck at Ruakākā Beach.

Four died and the remainder were successfully refloated.

Rescuers and Project Jonah volunteers try to refloat a pod of pilot whales that stranded on Ruakākā Beach. Photo / Sarah Curtis

Pilot whales beached near Ruakākā Beach. Photo / Joseph Hack

DoC has said most scientists believe individual whales strand because they are diseased and are coming to the end of their natural lifespan.

However, the department acknowledged mass strandings were more contentious and surrounded by numerous theories.

“The most likely hypothesis is that pilot whales’ echolocation is not well-suited to shallow, gently sloping waters, because they generally prefer high relief (steep) areas such as the edge of the continental shelf.”

DoC said this would also explain why most mass strandings happen in summer, when the whales follow popular food sources inshore.

“Another theory points to pilot whales’ highly sociable behaviour – when one whale loses its way and strands, its pod mates may swim to its aid."

Information by the department stated the theory that parasites affect the nervous systems of pilot whales and may be responsible for mass strandings was not well supported.