How community action is helping īnanga thrive again
Nestled between the tidal estuary and the beech-covered slopes of the Abel Tasman foothills, Ōtūwhero Wetland is a landscape of quiet beauty and extraordinary ecological diversity. Here, saltmarsh gives way to wetland, stream, and forest, a complete sequence of vegetation rarely seen today.
For īnanga, this mosaic of habitats offers something truly special. The wetland’s natural terraces and benches sit at just the right height for spawning, creating perfect pockets where eggs can be safely laid and nurtured.
“Ōtūwhero is one of the few places left where the full wetland story still exists, from the tide to the forest.”
Last spring and summer brought conditions that couldn’t have been better for spawning. Intermittent rain arrived right on cue, feeding lush growth in sedges, rushes, and grasses. These dense stands provided ideal cover for īnanga eggs: moist, shaded, and well-protected.
But it wasn’t just the weather helping the īnanga this year. A community-led predator control programme made a crucial difference. Rat traps were strategically placed along the spawning zone and checked every two weeks throughout the season.
Monitoring data showed a clear pattern: spikes in rat and mouse numbers directly aligned with spawning activity, proof that timely trapping helped protect vulnerable eggs from being eaten.
“Our trapping data showed exactly when predators were targeting eggs. Acting fast made all the difference.”
Surprising Success Along the River
When the monitoring results came in, they were cause for celebration. Ōtūwhero’s īnanga spawning zone stretched over 150 metres of riverbank, far more extensive than most other sites in the region.
Usually, only one small bench supports spawning, but here several were active. Even more interesting, while many plant types grew across the area, almost all eggs were found nestled in native rushes (Juncus spp.), suggesting īnanga may prefer this species over others.
Restoration Rooted in Time
Restoration at Ōtūwhero has deep roots. Since 2011, the Ōtūwhero Trust has been planting, weeding, and trapping here, building on foundations laid even earlier by the Abel Tasman Educational Trust and DoC
The volunteers have endured plenty of challenges, from Cyclone Gita in 2018 to the floods of 2025, yet each time, they’ve come back to restore and replant what was lost.
Collaboration in Action
In recent years, new partnerships have helped take the project to the next level. Collaboration between the Ōtūwhero Trust, Tasman Bay Guardians, local iwi kaitiaki, and the Department of Conservation has brought fresh energy, shared knowledge, and stronger community engagement.
This partnership grew naturally, helped by Monique, a founding member of the Ōtūwhero Trust and now part of the Tasman Bay Guardians’ Wai Connection Project. Together, the groups have been combining practical restoration with scientific monitoring and outreach events.
TBG has hosted two community workshops at the site, one exploring īnanga habitats and life cycles, and another involving an eDNA testing session. The results confirmed that all migratory galaxiid species are present in the wetland, a powerful sign of ecosystem health.
Looking Ahead
The mahi continues. The plan is to keep restoring and replanting, introducing even more īnanga-friendly native species grown at the Department of Conservation nursery.
These future plantings will strengthen the spawning zones and create even better habitat, helping ensure that the next generation of īnanga, and the next generation of volunteers, both have a place to thrive.
“Every planting, every trap, every community day, it all adds up to a future where īnanga can flourish again.”
Lessons from Ōtūwhero
After years of work, three key lessons stand out from this project:
- Healthy habitat is everything – Dense, diverse vegetation gives īnanga the protection they need.
- Trapping matters – Controlling rats and mice before and during the spawning season directly boosts success.
- Access counts – Keeping livestock away from spawning banks ensures the vegetation will stay intact ready for spawning.
Together, these lessons show that with patience, community spirit, and good timing, even small local actions can create big ecological wins.
Want to Get Involved?
If you’d like to learn more or lend a hand at future community days, contact Tasman Bay Guardians or the Ōtūwhero Trust. Every helping hand makes a difference for our wetlands, our wildlife, and the generations to come.