Mass die-offs of our freshwater guardians expose a failing, fragmented management system. Iwi and hapū are calling for a unified, indigenous-led recovery plan.
Although it’s a delicacy for many around the country, you won’t find any smoked tuna on the menu at my marae. Where I come from in the far north, tuna – also known as eels – are kaitiaki, the guardians of our waterways. These taonga species not only sustain the waterways that nourish our communities but also embody centuries of cultural connection and responsibility. However, in recent years, that reciprocal relationship has been heavily unbalanced.
Over the past year, mass die-offs of tuna have been reported across Aotearoa. In Tāmaki Makaurau, over 200 dead tuna were discovered along the shoreline of the Ōrākei Basin in central Auckland, and at least 180 were found in a stream in Wattle Downs, South Auckland. Similar tragedies have happened across the country in recent times – with several thousand tuna found dead in Mataura, Southland, and equally alarming numbers in Northland. These repeated losses have raised urgent questions: Who is accountable for the declining health of our waterways? What are the underlying threats facing tuna, our apex freshwater predators, and what can be done to stop this crisis?
Jane Kitson (Kāi Tahu, Kāti Māmoe, Waitaha), a respected environmental consultant, explains: “These are such a precious taonga species and they’re threatened in so many different ways. Mass dieoffs can’t be acceptable anymore – we really need to work on stopping issues like relentless habitat loss, pollution, and climate change.” Her words capture the essence of a problem that is as much about environmental neglect as it is about the erosion of indigenous stewardship and mana motuhake.
A 2013 report by the Parliamentary Commissioner for the Environment, Longfin Eels: Status and Management in New Zealand, revealed a fragmented approach to managing our freshwater species. Responsibility was split among the Ministry for Primary Industries, the Department of Conservation (DOC), the Ministry for the Environment and councils. The report criticised inconsistent policies, weak enforcement and the failure to implement cohesive Freshwater Fisheries Management Plans – gaps that continue to leave tuna and their habitats vulnerable.
In response to the shortcomings, the National Policy Statement for Freshwater Management 2020 was introduced. Mandating councils to uphold Te Mana o te Wai, the policy requires a renewed focus on water health, stricter water quality standards, improved fish passage protections, and the inclusion of tangata whenua in long-term planning. However, despite these measures, coordinated action on the ground remains elusive.
Central to the conversation is Te Wai Māori, a statutory body established under the Māori Fisheries Act 2004. Originally tasked with scoping freshwater fisheries and Māori interests, Te Wai Māori has evolved into a hub for collaborative projects with iwi and hapū. Its initiatives span legal research on water ownership, contributing to eel aquaculture, and engaging in critical policy development. In 2017, growing concerns over declining tuna stocks led to the establishment of Te Mana o Ngā Tuna – a dedicated advisory group committed to advocating for, and protecting, this culturally significant species.
Erina Watene (Waikato, Ngaati Maahanga), co-chair of Te Mana o Ngā Tuna, explains the urgency: “The fragmented approach to tuna management isn’t working. There’s no national plan for tuna – people are all doing their bits within their own spaces. We need something that works across all agencies.” For Watene, the solution lies in harnessing the best of both worlds: indigenous knowledge and Western science.
Mātauranga Māori – our traditional ecological knowledge – offers more than historical insight; it provides a dynamic, evolving framework for understanding and restoring our ecosystems. “Mātauranga should lead alongside science – as complementary knowledge systems to support a unified, outcome-focused approach, including a national recovery plan for freshwater and tuna management to prevent further decline,” Watene says. By drawing on generations of practices and contemporary research, iwi and hapū are forging a path that places the welfare of the taonga above bureaucratic silos.
However, challenges continue. When the Ōrākei Basin incident unfolded, DOC simply referred media inquiries to Auckland Council – a move that, while procedural, illustrated the lack of clear accountability. “Every time I was talking about the health of the freshwater to the councillors, they didn’t seem too worried about it, but talking to my whānau, they were heartbroken and sad,” says Kitson, who has experience working with councils. This disconnect between official responses and community sentiment highlights a broader crisis – our waterways are in dire straits.’
Habitat degradation is one of the main causes of tuna dieoffs. Migrating from the ocean as glass eels and returning as mature fish, freshwater tuna face a rapidly deteriorating environment. Their migratory life cycle sees them hatch at sea, drift to Aotearoa as larvae, mature in freshwater, and migrate thousands of kilometres back to the Pacific to spawn.
Continuous cleaning and maintenance of waterways – often driven by farming practices that drain wetlands – strip tuna of the very structures they rely on to hide, breed, and thrive. When wetlands are removed, and culverts and drain clearances are installed without adequate environmental safeguards, vital connections between the sea and freshwater systems are severed.
Pollution also plays a significant role. Incidents of chemical spills – whether accidental or deliberate – have left tuna exposed to toxic contaminants. In the Mataura case, farm effluent discharge in a tributary was directly linked to the mass die-off of thousands of tuna. With contaminants moving downstream and degrading fish beyond recognition, it becomes nearly impossible to pinpoint the precise cause, further complicating efforts to hold polluters accountable.
Magnifying these environmental pressures is climate change. Rising water temperatures, reduced oxygen levels, and altered river flows add layers of stress on an already fragile ecosystem. “Tuna are quite hardy species, so if you have them dying, you’ve likely already lost countless other species in the system,” explains Kitson. In this sense, tuna serve as a warning bell – an indicator of the overall health of our freshwater networks.
In the face of these challenges, many iwi are not waiting for a top-down response. Instead, they are mobilising at the grassroots level to develop their own strategies for freshwater management. “We set aside our differences to put the taonga first – united as river iwi, we developed and implemented our own strategies to support tuna, because they transcend boundaries and have been here long before us,” Watene says. This approach – prioritising the interests of the species over individual or tribal interests – has produced promising results in local projects, where community-led initiatives are already making a difference.
These initiatives are not just about cleaning up after disasters; they are about proactive, preventative measures. Iwi-led monitoring programmes are crucial in identifying early signs of distress, ensuring that mass mortality events are reported and addressed before they spiral out of control. However, the current reporting system remains disjointed. With each regional council employing its own protocols, crucial data is lost in translation, hindering swift and coordinated responses. A national, unified system for reporting and responding to mass die-offs is urgently needed – a solution that many iwi believe should be led by, or at least include, tangata whenua representatives.
The need for a coordinated response extends beyond environmental management. It is also a matter of upholding mana motuhake – self-determination – among iwi and hapū. “We need to draw on our own management practices based on our mātauranga, not just rely on NIWA or DOC. Our knowledge has guided us for generations, and it must be at the forefront of any strategy to protect tuna,” says Watene. For tangata whenua working in this space, integrating traditional practices with modern environmental science is not only a matter of cultural pride but also of ecological necessity.
As government agencies debate policies and draft new plans, many iwi are focused on what can be done now. They are working tirelessly to restore waterways through habitat creation, enhanced monitoring, and community education. These efforts are aimed at not only preventing further mass mortality events but also at restoring the balance between people and the environment – a balance that is deeply embedded in Māori worldview.
Looking ahead, there is cautious optimism. Many in the community are investing in the next generation, nurturing rangatahi to become stewards of their ancestral lands and waters. Young champions, equipped with both traditional knowledge and modern scientific training, represent the hope that our freshwater ecosystems can be revitalised. “I’m particularly excited by the rangatahi coming through now. They are our future champions, and as they take up the mantle, there’s real hope that we can turn the tide,” says Watene.
However, the path forward remains fraught with challenges. The ongoing erosion of infrastructure for community-based research and monitoring – as seen in the dismantling of some National Science Challenge initiatives – threatens to undermine progress. Without sustained investment and a commitment to integrating Māori perspectives into national policy, the cycle of mass die-offs may well continue.
Ultimately, the crisis facing tuna is a microcosm of a much larger environmental emergency. Our waterways, which have long been the lifeblood of our communities, are suffering from neglect, mismanagement, and the impacts of a rapidly changing climate. To reverse this trend, it is vital that government, industry and community stakeholders come together under a unified vision – one that places the health of our taonga and the integrity of our freshwater ecosystems at its core.
For the likes of Kitson and Watene, the call to action is clear: a national recovery plan is needed, one that not only brings together various agencies and communities but also elevates mātauranga Māori as an equal partner with Western science. As iwi and hapū assert their rightful place in the governance of our natural resources, they remind us that the fate of tuna and all our freshwater species is linked to the wellbeing of our land, our culture, and our future.
In the end, caring for our waterways is about more than just environmental management – it is about honouring our heritage, protecting our taonga, and ensuring that the wisdom of our tūpuna guides us in an uncertain future. The hope is that, with unified action and a renewed commitment to traditional and scientific knowledge, the tragic die-offs of tuna will become a thing of the past, and our waterways will once again flourish for generations to come.
