About The Project

This important pest eradication project covers Onetahua Farewell Spit and the land south to Whanganui Inlet, including The Kaihoka Lakes Scenic Reserve, Pākawau Forest in Kahurangi National Park and some private land bordering this area.

Onetahua Restoration Project birds graphic

Why Onetahua?

Pest Free Onetahua is an ecological project of international significance. The dynamic and diverse landscape is like no other, with thousands of migratory birds and endangered flora and fauna calling it home. It is also of great cultural and spiritual significance to Manawhenua ki Mohua as o te wairua o ngā tangata o te Waipounamu – the place where the spirits depart.

Leading the way in large-scale pest eradication on a mainland setting, this project lays a foundation for a thriving wildlife habitat rich in Māori traditions and ancestral stories. We will return nature to Onetahua and create a haven for the translocation of endangered bird species.

Onetahua is a wetland of international significance. A critical stopover for migrating wader birds, it gained international status as a Ramsar site in 1976. Pests threaten many of these birds and other native species - we want them gone and we’re not alone. We're part of a growing nationwide movement to eradicate predators and return habitats to their rightful owners - our native tāonga.

Predator Free 2050 is co-funding this project.

White Fronted Terns on Farewell Spit - Photo Credit Bradley Shields

Photo by Bradley Shields

Shifting Sands and Changing Landscapes

A Place Shaped by Wind and Water

Onetahua continues to grow in both length and width thanks to quartz sand deposits originating in the Southern Alps. These are carried by rivers to the Tasman Sea and onto Farewell Spit by the longshore sea currents. Its elegant curve, reminiscent of the Kiwi’s beak, reaches into Tasman Bay as a result of this process, which began millions of years ago - most likely in the Pleistocene epoch.

Archaeological findings, including middens and pits, show the early Māori occupation of Onetahua. With the arrival of European settlers, Onetahua - or Tuhuroa as it was then known to local Māori - would undergo a dramatic transformation. A diary entry from HP Wasbourn in 1933 describes the spit as once being covered with vegetation, but thanks to slash and burn techniques and stock grazing, the area was stripped of its greenery.

A Precious Tāonga of International Significance

Established as a Ramsar site in 1976, Onetahua's significance is internationally recognised. The site is the highest ranked ecosystem in the Tasman District (Leathwick & Singer 2019). With 20,000 migrating wading birds calling this area home each summer, some flying from as far afield as Siberia, its importance as one of the largest bird habitats in the country is undeniable. Some 90 species of bird have been recorded here in this hugely dynamic and diverse environment.

Flying =Birds on Farewell Spit - Photo Credit Bradley Shields

Photo by Bradley Shields

Australasian Gannets - Photo Credit Bradley Shields

Photo by Bradley Shields

So What’s Wrong With This Picture?

Species such as the Banded Rail, Pipit, Marsh Crake and the beloved Little Blue Penguin, are all in decline. More seriously, the fate of the Australasian Bittern is considered critical. Others fluctuate between vulnerable and endangered. What makes the spit so attractive to birds, a cornucopia of molluscs, echinoderms, crabs and worms that reveals itself at low tide also provides a lure for predators. These food-rich tidal flats on the inner side of the Spit attract possums, pigs, mustelids and rats into the fragile nesting areas of defenseless birds. The effect of this predation has been devastating and conservation workers report regular sightings of plundered nests and rooted up vegetation.

It's Not Just About the Birds

Onetahua is also home to other native species. Powelliphanta and other carnivorous snails, geckos, skinks, carabid beetles and weta are also at risk of predation. Vegetation on the Spit is susceptible to grazing by possums who have been causing damage to the Rata in Pakawau Forest. Hares are intense grazers of young seedlings, and greatly impede the regeneration of plant life.

What do we stand to gain?

Removing the pests that threaten our precious taonga will result in direct benefits. Restoring Onetahua to the thriving, raucous world of birds it once was will strengthen our communities, our ecosystems, our economy and our culture. We can lift our most vulnerable species from an endangered to recovering status - and engage our community and create valuable jobs for locals. Our understanding of the link between pest eradication and climate change is growing. Forest and Bird have preoduced a report showing the negative impact of animal browsing on the ability of native ecosystems to be carbon sinks. Stopping pests from stripping away vegetation will help reverse this trend. Many landowners are already engaging in their own trapping practices. HealthPost Nature Trust has been carrying out a smaller scale eradication programme of its own and Paddy Gillooly and his team at Farewell Spit Eco tours have been actively trapping on the Spit for many years. We can throw our weight behind these efforts, build on the good mahi that’s already been done and share our learnings with other eradication projects in New Zealand.

Who We Are

Our Partnership

Pest Free Onetahua is a partnership between Tasman Environmental Trust and Manawhenua Ki Mohua, working with local landowners, businesses and the residents of Golden Bay.