Māori and Pacific leaders have signed a declaration seeking to grant tohorā, or whales, legal personhood.
He Whakaputanga Moana, signed by Kiingi Tuheitia and Tou Travel Ariki, head of House Ariki in the Cook Islands, aims to give tohorā more robust protections that are recognised internationally.
The declaration also seeks to protect the rights of tohorā to migrate freely, conserve and grow dwindling populations, establish marine protected areas, and use mātauranga Māori alongside science for better protections and set-up a dedicated fund for whale conservation.
Speaking at the signing event in Rarotonga, Kiingi Tuheita set out his hopes for the future of whale conservation.
"The sound of our ancestor's song has grown weaker, and her habitat is under threat, which is why we must act now.
"He Whakaputanga Moana is a Hinemoana Halo - a cloak of protection for our taonga, our ancestor - the whales," he said.
The Kaumaiti Nui of the Cook Islands, Tou Travel Ariki, echoed Kiingi Tuhetia's korero.
"We can no longer turn a blind eye. Whales play a vital role in the health of our entire ocean ecosystem. Their decline disrupts the delicate balance that sustains all life in Te Moana nui a Kiwa. We must act with urgency to protect these magnificent creatures before it's too late," he said.
Both leaders extended invitations to other Polynesian countries to get behind the proposal.
"Ultimately, He Whakaputanga Moana is a declaration for future generations. Our mokopuna deserve to inherit an ocean teeming with life, where the songs of whales continue to resonate across the vast expanse," Kiingi Tuheitia said.
"Let this declaration be a turning point. Let us ensure the whales, our kin, our pouwhenua, continue their migrations for generations to come."
Speaking to RNZ's Midday Report, Earth Council Alliance chairperson Lelei LeLaulu said it was a major move for whale conservation around the world.
"The issue of personhood for nature has not got the coverage that activists would like. This is a huge move and I think it will spur action in other parts of the world."
It is not the first time, however, action to give endangered species personhood has been undertaken, he said.
"It's the first for large mammals but other countries, like Ecuador, have legal protection for [places] where dolphins and other creatures live. Also, in Ecuador there is a huge legal case about the actual personhood of a monkey and next door in Columbia there is a huge court case about the rights of a bear. Lots of little things are happening."
LeLaulu said Aotearoa was a leader in such methods of conservation.
"You've got the Whanganui River, which also has rights recognised, the Urewera Ranges and also the Hauraki Gulf Marine Park where recognition of an ecosystem as something which has rights has sunken into the legal landscapes of New Zealand and other countries watching. It's huge.
"Eastern Polynesians were guided to their current home islands by the whales. There's a very strong spiritual and meta-physical tie to the whale," he said.