This case study shows how ecosystem-based management, te ao Māori, and a blue economy can work together.

16 million ‘teenage’ kuku have been discovered growing successfully in a traditional kuku bed in Ōhiwa Harbour following a mātauranga Māori-led research restoration project between Iwi, hapū, researchers, local councils and the Ōhiwa Harbour Implementation Forum. Collaboration with kaumatua was an integral part of the restoration.

Credit: Kura Paul Burke

Predatory pātangaroa (seastars) cause kuku population to plummet

In 2007, 116 million kuku (mussels) were in the Ōhiwa Harbour in the eastern Bay of Plenty, near Whakatane. By 2019, the number of kuku had plummeted to under 80,000.

The main reason for the kuku decline was an overabundance of predatory pātangaroa (seastars) who were eating the mussels out of existence.

Kuku are a taonga (treasured) species for the local iwi, and crucial to the health of the ecosystem. Professor in marine science and aquaculture Kura Paul-Burke (Ngāti Whakahemo, Ngāti Awa, Ngāti Pūkeko), along with local iwi and interested kai gatherers, have all watched the kuku population deplete – and the pātangaroa population explode – over the last 20 years.

“In 2007, there were 112 million baby kuku in a continuous 2km reef – by 2019 there were less than 80,000 in the entire harbour,” says Kura Paul-Burke. “Meanwhile, in 2019, we found 50,000 seastars per hectare – you’d expect to see around 15 per hectare in a healthy balanced ecosystem.”

Three of the four kuku beds in the harbour had disappeared in the last 12 years, affecting the harbour’s kaimoana (seafood), mahinga kai (cultivation) and mauri (vital essence), and reducing the ability of mana whenua to express manaakitanga (expression of respect and hospitality to visitors through provision of kaimoana).

Credit: Dave Allen

Mātauranga Māori and ecosystem-based management in harmony to help restore kuku

Kura Paul-Burke first began working with iwi and hapu in 2007 to take a mātauranga-led approach to restoring the kuku population in Ōhiwa Harbour. She began by working with local kaumātua and the mātauranga they shared around where the traditional mussel bed boundaries in the harbour were.

The Sustainable Seas National Science Challenge became involved in 2020 with a research project Awhi Mai Awhi Atu; enacting a kaitiakitanga-based approach to ecosystem-based management. The project was led by Kura Paul-Burke, and co-developed with the hapū/iwi of Ōhiwa harbour. The project has been supported by the Bay of Plenty Regional Council and the seven partners of the co-management Ōhiwa Harbour Implementation Forum.

This project has arisen from the issues, challenges, actions, and aspirations of Māori and is grounded in Whanaungatanga — the principle of working in meaningful, genuine collaboration to influence how mātauranga Māori and science principles and practices are translated operationally in ways that recognise cultural values, knowledge systems and opportunities.

As part of the project, restoration stations containing mussel spat were co-developed with iwi and located in the harbour using tikanga based on mātauranga Māori. As Kura Paul Burke progressed with the project, it became apparent the pollution from the plastic spat lines used to regenerate the kuku were not aligned with Māori cultural values and intergenerational legacy.

Tohunga weavers helped create natural fibre spat lines from locally growing ti kouka leaves that had the strength to support the kuku spat clusters to grow as a whānau, with the natural spat lines biodegrading over time. As the kuku grew into teenagers and the spat lines fell to the seafloor, the kuku would land as a whānau, and continue to grow and regenerate on the seafloor as a whānau.

Credit: Dave Allen

Credit: Dave Allen

A delightful discovery

In July 2023, on a chance maintenance dive of the kuku restoration stations, Kura Paul-Burke’s team made the incredible discovery that one of the traditional mussel beds has bounced back to 16 million ‘teenage’ kuku.

This exciting and hopeful discovery shows that a mātauranga-led restoration approach, used alongside marine science, has managed to restore kuku numbers and reverse the decline. Kura Paul Burke is already helping to empower others to take a mātauranga-led approach to restoring their shellfish populations across the motu.

Credit: Dave Allen

With protection, the future is bright for teenage kuku

Following several decades of continued collective efforts in a mātauranga-led approach to marine management in the Ōhiwa Harbour, the kuku population finally appears to be bouncing back.

The kuku restoration project in Ōhiwa Harbour will continue with support from the research project co-development partners — hapū/iwi of Ōhiwa harbour, the Bay of Plenty Regional Council, and the Ōhiwa Harbour Implementation Forum.

But the young teenage kuku need time to grow into adults and help stabilise the new 16 million strong bed. The kuku still need to be protected from the predator pātangaroa (starfish) and from people who might try to harvest them before they have a chance to grow.

A blue economy bonus to help sustain restoration

In an innovative approach, the overabundant pātangaroa (starfish) have been used to create a collagen cream with profits going back to restoring the mauri of the Ōhiwa Harbour.

The product was developed to find ways for removal of starfish from the harbour to be at least partially self-financing.

Kura Paul Burke:

"People were wanting us to just remove the starfish, but they're meant to be there, in balance. Would you just throw them away? They have their own mana and their own mauri. So, we thought maybe we could use them to make a product, and then all of the profits could come back to help us protect the harbour. That was our rationale — from the harbour, for the harbour."