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WhÄnau taking eDNA samples at Whare Creek during the hÄ«koi at Jericho Valley. From left: Jane Kitson, Sharon Weir and Jess McCallum.
Environmental DNA testing has revealed threatened and elusive native species in a block of land being restored for traditional Māori food and resource gathering.
The 445-hectare block of land in the Jericho Valley, Te Kōawa Tūroa o Takitimu, is a Kāi Tahu tribal property vested in the Te Waiau Mahika Kai Trust to develop for mahika kai.
It was purchased by Te Runanga o Ngāi Tahu in 2001 and vested in the trust, which is undertaking the restoration project.
Part of the work has involved environment DNA (eDNA) testing – a technique that identifies the presence of flora and fauna in water samples by detecting the tiny traces of genetic material.
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Tane Hemi and Jack Lloyd from Te Anau School recording the details on an eDNA sample for Redcliff Creek in the Jericho Valley.
Te Anau School students started the work in May 2022 and a baseline of seasonal data within the Waiau catchment was recently completed.
Trust programme manager Vanessa Horwell said the results were surprising.
She was very excited to detect lamprey/kanakana and kōaro (which are part of the whitebait run) in the lower Redcliff Creek.
“They are a taonga species and a source of mahika kai for Māori,” she said.
Some of the species were jawless, migratory fish and from an ancient lineage that have existed for more than 360 million years. They only breed at the end of their life and die after spawning.
Three fish species classed as national vulnerable, meaning they face a high risk of extinction in the medium term, were identified.
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Gollum galaxias in a stream in the Catlins area.
They were the kanakana, Gollum galaxias, and the Southern flathead galaxias.
The Gollum galaxias was first discovered in 1990 and was found only in Southland, Catlins and Rakiura/Stewart Island. Gollums were detected at all the sites tested.
The testing also detected the furtive wetland-dwelling spotless crake/pūweto in the Jericho valley.
“We didn’t know [they were] in this area. They’re very elusive and relatively infrequently seen.”
Spotless crake/pūweto numbers have declined dramatically since people began draining wetlands and they are now classed as at risk.
The presence of vulnerable and at-risk species demonstrated the growing biodiversity within Te Kōawa Tūroa o Takitimu and the impact of allowing the land to regenerate, Horwell said.
“It’s incredible what Papatūānuku can achieve, with a bit of time and some human help.”
The Trust’s restoration efforts include intensive pest and weed control, as well as extensive native plantings of mahika kai (food) and rokoā (rongoā/medicinal) species.
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Brett Weir and Jane Kitson taking eDNA samples during the KÄi Tahu whÄnau hÄ«koi, at Jericho Valley.
Freshwater ecologist and environmental scientist and trustee Dr Jane Kitson said using the technology had enabled the community to reconnect with their environment in a hands-on way.
A recent example of this was a hīkoi with Kāi Tahu whānau where eDNA testing was undertaken, alongside cultural monitoring methods at several locations along the Waiau.
Wai kōura (freshwater crayfish) and wai kākahi (freshwater mussels) were detected at a lower river site during the hikoi.
