Canterbury’s sea pest is becoming someone’s export margin

New Zealand spends a lot of money fighting marine pests and earns almost nothing from them. Ōnuku Rūnanga wants to flip that. This week it began harvesting invasive wakame from Akaroa Harbour, working with processor Premium Seas and food brand Ceres Organics, with eight local jobs already created and export ambitions aimed at Australia and Asia.

This is the kind of environmental story business should pay attention to. It is not a levy, a compliance regime or a consultant’s report. It is a pest being turned into inventory.

A legal pest with a product line

Undaria pinnatifida is native to Japan, Korea and China, arrived here in the 1980s and is classified as an unwanted organism because it outcompetes native kelp. Environment Canterbury describes it forming dense underwater forests that alter ecosystems and threaten mahinga kai, recreation and aquaculture. The Press reports an estimated 280 tonnes of it currently sits in Akaroa Harbour.

The problem is national. In 2024, MPI’s pest guide recorded more than 360 introduced marine species found in New Zealand waters since 2005, roughly half of them established. Most will never be worth anything. Wakame is the exception, because the rest of the world already eats it.

The model is straightforward. Premium Seas has built food-grade drying and handling equipment near Ōnuku Marae, and Ceres Organics is developing an organically certified range, with the first product expected on New Zealand shelves from February 2027. Premium Seas chief executive Lucas Evans says the whole operation, including a plant on a former alpaca paddock, came together in “just a year”. That speed is worth noting in a country where consenting a shed can take longer.

The permit is the moat

The most commercially interesting line came from Ōnuku chair Riki Tainui: “Fortunately for us Ngai Tahu has the only control permit in the country.” That is a significant barrier to entry. Anyone hoping to copy the Akaroa model elsewhere will need either a partnership with Ngāi Tahu or a similar permit of their own, and the regional pest framework, governed by the Biosecurity Act 1993, requires consultation and cost-benefit analysis before pest settings shift.

That matters because the partners explicitly see this as a template. The Press describes the ambition as turning marine pest control “from a cost into an industry” that could be replicated elsewhere. If the permissions bottleneck is tight, scale will depend on regulators as much as on demand. Back in 2022, the Sustainable Seas seaweed framework called for regulatory tolerance of scientific uncertainty to let the sector grow. Akaroa is a decent test of whether that tolerance exists.

The numbers that need watching

Two figures do not yet sit comfortably together. 1News cites a potential harvest of up to 300,000 tonnes a year. The Press puts the harbour’s current stock at 280 tonnes. Whatever the bigger figure measures, it is an aspiration, not a local supply forecast. Investors and buyers will want to know what sustainable annual volume a purpose-built plant can rely on.

That plant is the other variable. Compare the Ōhiwa Harbour starfish project, which in 2021 deliberately used accessible kit, “buckets and industrial kitchen gear”, to keep costs low. Premium Seas has gone the other way, with food-grade infrastructure that needs throughput and margin to justify itself. The pilot runs through 2026 and 2027, which is a short window to prove the economics.

There is also a subtler tension. Researchers working on kina barrens have warned against selling pest harvesting as a complete ecological fix. A business that profits from an unwanted organism needs it to keep turning up. Ōnuku’s framing helps here: the venture sits inside Te Kori ā te Kō, a 200-year harbour regeneration plan, so commerce is the funding mechanism rather than the goal.

A sector, not a one-off

Akaroa is not starting from scratch. In 2021, Nelson’s Waikaitu was preparing to export undaria-based crop products after $325,600 of MPI funding and eight years of R&D. In 2023, Ngāi Tahu-linked Whiore Enterprises, then led by Alan Groves, was pitching food and nutraceutical extracts in Norway. And in Ōhiwa, Cawthron’s Dr Matt Miller said in 2023 the aim was a “circular economy opportunity” where removal was funded by the product.

That cascade, food first and higher-value extracts later, is where the real margin sits. The 2022 framework argued New Zealand’s edge lies in high-value niche products carried by brands with strong social licence. A Māori-led, organically certified, pest-removing pantry product is close to a textbook case.

What happens next

February 2027 is the date to watch, when Ceres Organics’ first product hits shelves and export conversations get real. If the volumes hold and the plant pays its way, Akaroa will have shown that biosecurity can be a revenue line rather than a ratepayer cost. That is a better outcome than another control programme, and regulators should be making it easier, not harder, to copy.

Sources

• 1News: Canterbury rūnanga turning marine pest into business opportunity (2026-10-21)
• The Press: Akaroa’s unwanted seaweed goes from harbour pest to pantry product (2026-10-04)
• Environment Canterbury: Marine pests (2026-03-19)
• Environment Canterbury: Canterbury Regional Pest Management Plan (2025-11-06)
• MPI: New Zealand Marine Pest ID Guide (2024-02)
• NZ Geographic: Kina-nomics
• NZ Herald: Pest seaweed products set to hit export market (2021-06-09)
• Te Ao Māori News: Seaweed firm aims to turn invasive species into food, nutraceuticals (2023-05-18)
• RNZ: Skin cream farmed from starfish could save Ōhiwa Harbour mussels (2023-03-16)