Kūtai mussels: How to clean up the Hauraki Gulf

By Stefan Dimitrof

Ngāti Manuhiri has celebrated Matariki by restoring the mauri of Te Moananui a Toi Hauraki Gulf through re-establishing mussel beds in the Mahurangi Harbour.

The kūtai drop on Friday was the largest shellfish bed restoration in the country, and is part of an ambitious environmental restoration project, led by mana whenua, to help revive the ancient mussel reefs, which used to populate the Gulf.

Hauraki Gulf Forum co-chair Nicola MacDonald and Ngāti Manuhiri settlement trust chief executive said it was amazing to be celebrating the first Māori public holiday.

“For the first time in 182 years we have our first Māori public holiday, Matariki, and what a wonderful way for ourselves as mana whenua for New Zealanders to celebrate this indigenous custom.”

MacDonald said they celebrated Matariki by the deployment of a shellfish bed restoration in the Mahurangi harbour, which is reportedly the largest in the world.

“What a wonderful way to lead the world in the ways that we can protect our beautiful taonga.”

'Effective natural water filters'

MacDonald said the current state of the beds was “really bad”. As part of the Hauraki Gulf Forum's work, it put out a state of the environment report that really showed the state of the Hauraki Gulf.

“Right now kūtai [green-lipped mussels] are functionally extinct in our lifetime.”

“I’m getting really tired as the co-chair of saying all of these beautiful taonga are becoming functionally extinct but they are because of our own human practices.”

Kūtai is a really effective natural water filter, with one mussel being able to clean up a bathtub equivalent of water.

“We know that if we are dealing with a lot of mud, sewerage and sedimentation, having these shellfish beds on the ocean floor can help filtrate the water and clean the paru up and that’s exactly what we are about to do."