Opening the event held by Ōnuku Rūnanga at Akaroa marae, Rūnanga Chair Rik Tainui shared the 200-year vision guiding action to restore the mauri of Akaroa harbour and create pathways for ecological repair and local jobs – including through regenerative seaweed farming.
Home to generations of whānau and of immense significance to Ngāi Tahu, Ōnuku was the site where the Treaty of Waitangi was first signed within the Ngāi Tahu takiwā on May 30, 1840 — the first of three Treaty signings on Te Waipounamu, New Zealand’s South Island.
More than 150 years later, in 1998, it was also the place where the Crown formally delivered its apology to Ngāi Tahu for historical breaches of the Treaty. Today, the marae remains a living centre for kōrero around important tribal matters, while also welcoming the wider community for wānanga, celebrations, weddings, conferences and retreats.
Rik said the symposium was designed to inform, inspire and build shared purpose around the future of Akaroa Harbour: “which we know is no longer as healthy and abundant as it once was.”
“My ancestors arrived in Akaroa 800 years ago and I’m the 26th generation that this harbour has provided for, and we in turn have tried to protect it.”
Along with advocacy to remove wastewater from entering the harbour, the rūnanga has partnered with science, Government, local Government and iwi to restore ecosystems, remove pests, plant natives, and rewild the harbour through reseeding taonga species and seaweed systems.
But Rik said accessing funding for ecological restoration had been challenging. “Most funders are wanting to see a commercial return,” he shared. “Partnerships have been critical to our progress.”
Over the past eight years Ōnuku had worked with Government, local Government, science organisations and Rūnanga o Ngai Tahu. “Without these partnerships, much of what we’ve achieved wouldn’t have been possible.”
A focus of the symposium was climate adaptation. Rik said climate change was no longer a future problem and was already impacting the harbour and surrounding community.
The Rūnanga has a co-ordinated climate response plan, with integrated mātauranga Maori and environmental monitoring, nature-based solutions like saltmarsh and oyster reef restoration and catchment-level planning and partnerships.
“This is about building long term resilience not short term fixes.”
Seaweed farming was presented as part of the long-term strategy for Ōnuku which he described as “The future seaweed capital of Aotearoa.”
Ōnuku’s interest in seaweed farming started three years ago when Dutch-owned Kelp Blue leased water space in Akaroa. Ngai Tahu farming are currently using seaweed biostimulant on farm.
“Seaweed enables a regenerative harbour economy, and under Te Kori a te Kō, Ōnuku is designing an economy where restoration of mahinga kai (sustainable food systems) and biodiversity led by seaweed systems creates longterm ecological and economic benefit.
“We are starting a small seaweed pilot farm opposite our marae, that’s the beginning for us.”
He said the only downside of trying to get a resource consent is that the cost to Rūnanga is around $800,000 to secure one.
“This is simply outrageous to want to restore something and pay that before you start.”
Speakers at the Symposium included Ryan Marchington, Aquaculture and Operations Lead for New Zealand company Greenwave Aotearoa, which has a seed bank of native seaweed species and hatcheries in Tauranga and Kelly Tarlton’s in Auckland, and is growing native seaweed in Tory Channel, and the Coromandel.
“Greenwave Aotearoa’s work in sustainable aquaculture is helping regulators to understand that “seaweed is not fish!” and in pioneering seaweed farming infrastructure, points to the emergence of new regenerative industries that restore marine ecosystems while generating economic value,” said Rik.
“It opens up the possibility for communities like ours to participate in, and lead, nature-based economies at scale. We are already seeing that future begin here at Ōnuku.”
Another seaweed - Undaria, commonly known as wakame - is an invasive seaweed from Japan that’s also a food source. There was an estimated 50,000 tonnes around the South Island.
Rik said there was “an incredible opportunity” to improve the biodiversity of the harbour by removing the 250tonnes of undaria present there. The Ōnuku runanga recently signed a partnership with Ceres Organics and Premium Seas to turn some of the wakame into products like seaweed snack food, with locals to provide the harvesting.
Premium Seas founder Lucas Evans said the Joint Venture would build real opportunities for whānau over the long term. “The Ōnuku Nature Symposium was a powerful reminder of what this partnership can make possible.”
Questions from the floor focused on issues including marine farm consenting, carbon markets, land use change, sediment control and the impact of recreational and commercial pressures on harbour ecosystems.
The symposium featured a speech by former Reserve Bank Governor and Climate Change Commission Chair Rod Carr, who urged optimism around the opportunity for local communities and Aotearoa with its abundant nature, renewable energy, innovation and knowhow.
The symposium also heard a strong call for treated wastewater to be discharged to land rather than into the ocean, where it had caused long-standing cultural and environmental harm, particularly at Takapūneke, a site of deep significance to mana whenua.
“Last year there were nine direct discharges of raw sewage into Akaroa Harbour, the worst took the Council three days to fix the pipe. Today I ask our community and partners to stand with us and choose the option that protects our harbour for future generations.”
Ōnuku Rūnanga Board member Juliet Tainui-Hernandez said Rod Carr’s contribution reinforced the need for communities and decision-makers to respond to environmental challenges with coordinated, practical action.
“Rod shared that while dominant economic models have been linear, extractive, and have created winners and losers, we hold within our own systems of knowledge the foundations for something different - an economy grounded in connection, regeneration, and long-term balance.
“It’s a great reminder that the strength we hold is not only in what we know, but in how we know. In mātauranga Māori, in whakapapa, and in our deeply connected, holistic and relational approach to te taiao (environment).”
Dr Fiona Shanhun from Environment Canterbury spoke about seafloor mapping through the Iongairo project alongside DoC, which has built a baseline of seafloor habitats across Te Pātaka o Rākaihautū (known as Banks Peninsula).
The data informs decision-making, identifies opportunity, and measures impact over time. Already it has been used to ascertain the true impact of larger cruise ships in Akaroa harbour, which were moving enough volumes of sediment to have required a resource consent.
Following this talk, Mike Taitoko and Tasman Gilles of Takiwa Analytics spoke about “values-led” data systems, where 800 years of experience and matauranga can be drawn upon to inform better decision-making and help communities to ask the right questions.
Said Juliet Tainui-Hernandez: “There are few places where the conditions align as they do here in Akaroa - where whakapapa, leadership, science, innovation, and opportunity come together in service of something larger. Ōnuku and what we have here makes us uniquely positioned to lead.”