A rāhui or restriction has been placed over the 145 pilot whales who died in Mason Bay on Stewart Island at the weekend.
Ngāi Tahu cooperates with the Department of Conservation after the massacre and intends to follow various cultural protocols, including the placement of a rāhui or restriction of the whales.
Awarua Rūnanga Dean Whaanga said it was a sad event, especially given the large number.
"We are aware that all affected whales are dead and we wish that sufficient respect is shown for this taonga.
"The reason for the rāhui was to stop people from moving around the whales while disintegrating, especially for their own safety."
A spokesperson for the conservation ministry said they did not know why the whales were stuck and it could be caused by a number of issues, including illness, navigation errors and weather conditions.
"By the time DOC staff were able to get to the remote location, about half of the whales were already dead and some were partially buried in the sand."
Two pods were stranded on the south side of Mason Bay, about 2 km apart.
A heart-rending decision was made to euthanize the remaining whales due to their poor condition and hard-to-reach location, said RenC Rakiura, operations manager Ren Leppens.
"Unfortunately, the chances of successfully using the remaining whales were extremely low." The remote location, lack of staff in the area and the deteriorating state of the whales meant that the most humane thing you could do was euthanize. "
Niwa whale biologist Dr. Krista Hupman said that New Zealand has one of the biggest strandings in the world, but also the highest success rate for rescue.
It was unknown whether the large number of strandings was due to the large number of mammals in New Zealand or the environment, she said.
"You actually have a piece of land that actually stands out and they think that whales might get stuck."
More beachings seemed to occur in the course of the summer and Farewell Spit seemed to be one of the country's most notorious regions for stranding, which may be due to the topography of the region. Whangarei Harbor, Mahia Peninsula and the Chatham Islands were also prone to strandings.
Hupman said that not much was known about why the whales stranded, but they usually came to the beach for a reason. Factors include illness, navigation errors, geographical features, a rapidly falling tide, haunted by a predator or extreme weather. More than one factor can contribute to a stranding.
"Whether they fall into the trap or that it is real because one of the pod's members is ill and then follow the other whales, we have no idea why."
At Massey University, research is currently being conducted into whether replacing pilot whales is best for them or if the pushing back of them into the water causes more damage.
In recent years, the biggest stranding of whales in Farewell Spit in 2017 was when 650 pilot whales were stranded.