Thousands of Eels Dead as Pukepuke Lagoon Dries to Nothing in the Manawatu

Thousands of eels lie dead on what should be the floor of Pukepuke Lagoon, a wetland between Himatangi and Tangimoana in the Manawatu that has been part of the local landscape and the lives of tangata whenua for generations. The lagoon has dried out completely, and the scale of the wildlife loss is distressing those who know the place best.

The Department of Conservation has restricted access to the lakebed, allowing only investigators and personnel involved in salvaging remaining fish. Horizons Regional Council, DOC, and local iwi and hapū have jointly launched an investigation into what has happened and why.

For Rangitāne o Manawatu and Te Rūnanga o Ngā Wairiki Ngāti Apa, the lagoon and the species it supports carry deep significance. Debbie te Puni of the Rangitāne o Manawatu Settlement Trust put it plainly. “These are taonga species which have been part of our lives,” she told RNZ.

Pahia Turia, chairperson of Te Rūnanga o Ngā Wairiki Ngāti Apa, pushed back on any suggestion that the drying is simply nature running its course. “Many farmers will tell us this is a natural phenomenon. Nowhere in our history has this happened,” he said.

Pukepuke Lagoon has been shrinking for well over a century. Before European settlement the lagoon covered around 162 hectares. By the 1910s and 1930s that had already been reduced to roughly 49 hectares as surrounding land was drained and converted to farming. By 1940 the lagoon had contracted further to around 15 hectares, where it has roughly remained — until now. The complete drying of a wetland that had persisted, in greatly diminished form, for decades is not a gradual development. It is a threshold crossed.

Investigators are examining a range of contributing factors including groundwater extraction in the surrounding area, ongoing drainage issues, extreme weather conditions, and the cumulative effects of more than a century of land use change. Pukepuke is not the only body of water affected in the region — Dudding Lake and Lake Herbert have also been impacted, pointing to pressures that extend beyond any single site.

Horizons Regional Council chief executive Michael McCartney acknowledged the gravity of what has unfolded. “This situation was confronting and harm to taonga species is something none of us want to see,” he said.

Eels — tuna in te reo Māori — are one of New Zealand’s most significant freshwater species, both ecologically and culturally. Longfin eels in particular are endemic to New Zealand and classified as at risk of extinction. They are slow-growing and long-lived, with some individuals surviving well over a century. Populations take decades to recover from a significant loss. The sight of them dying on an exposed lakebed represents not just an immediate tragedy but a setback that could take a very long time to reverse — if the conditions that allowed them to thrive are ever fully restored.

Wetlands like Pukepuke perform a range of ecological functions beyond simply being home to eels and waterfowl. They filter water, store carbon, buffer against flooding, and support biodiversity across both aquatic and terrestrial species. New Zealand has lost approximately 90 percent of its original wetland area since European settlement, and the losses continue to accumulate through drainage, land conversion, and groundwater extraction. What happened at Pukepuke is an acute expression of a chronic, nationwide problem.

The investigation now underway faces a genuinely difficult task. Understanding the precise combination of factors that tipped a diminished but surviving wetland into complete failure requires pulling together hydrological data, land use records, climate information, and an understanding of how recent weather patterns have interacted with longer-term pressures on the system. The outcome of that investigation will matter not just for Pukepuke Lagoon but for how the region manages its remaining wetlands going forward and whether stronger protections can be put in place before other sites reach the same point of no return.

For the iwi who have spoken out this week, the language of environmental review and investigation, while welcome, does not quite capture what has been lost. These are not ecological units to be assessed in isolation. They are places that hold memory, identity, and obligation stretching back far longer than any of the land use decisions that have brought things to this point. What happened at Pukepuke Lagoon is a reminder that the consequences of decisions made about land and water over many decades do not always arrive gradually. When they do arrive, they can be sudden, visible, and deeply grieved.

The joint investigation is ongoing and no timeline for its findings has been announced.

Do you have knowledge of Pukepuke Lagoon or the wetlands of the Manawatu? Share your thoughts in the comments below.