The river runs through the Hikurangi catchment, which plays host to Northpower’s hydro station.
This causes a hazard for young eels as they try to navigate their way past the power station to move upstream.
For six years local hapū, Ngā Kaitiaki O Ngā Wai Māori, have been working with Northpower, NIWA, Ministry for Primary Industries, DOC and other agencies to move juvenile eels or elver upstream past the hydro station.
Living Water is now supporting a research project in which Ngā Kaitiaki O Ngā Wai Māori and NIWA are looking at how the juvenile eels that have been moved past the station are surviving.
Eels are like canaries of the waterways indicating a healthy waterway.
Living Water North Island Programme Manager Tim Brandenburg says this collaborative project will help pinpoint things that are being done to improve the habitat for the eels, and therefore the waterway, and where there is still work to be done.
“This project is a great example of the collaborative freshwater restoration work Fonterra and DOC are supporting in all five Living Water partnerships. Throughout all these catchments we’re working in partnership to restore healthy freshwater ecosystems,” says Tim.
NIWA scientist Dr Erica Williams, who’s leading the research project says there’s very little research being done in New Zealand to learn what makes stream habitats suitable for elvers.
“The Wairua River area is like a living laboratory for elver research, so this project is going to be really useful. The more we know about elvers the more effective we can be in helping eels or tuna to thrive, not just in this river, but all around New Zealand.”
“Ngā Kaitiaki O Ngā Wai Māori have long been concerned about the falling tuna population in our rohe or region,” says Ngā Kaitiaki O Ngā Wai Māori member Allan Halliday. “This is the result of changes to the landscape like the hydro power station on the Wairua River.”
“We’re pleased this issue is being recognised and that we’re working with agencies like NIWA, DOC and Fonterra, through their Living Water partnership, to support our tuna.”
The two-week project involves catching elvers in streams connected to the Wairua River to asess their health and numbers. The elver will be caught in a way that causes them no harm then promptly returned to the stream.
Hikurangi is one of five catchments in significant dairying regions where Living Water - a partnership between Fonterra and the Department of Conservation (DOC) - is working with dairy farmers, iwi, conservation groups, councils, schools and other agencies to demonstrate sustainable dairying in healthy freshwater ecosystems.