From tiny whitebait to the giant kokopu they become; the largest member of the galaxiid family lived a secret existence in the wetlands of Waiheke until their discovery in 2014. Since then, their numbers have been declining.
“Giant kokopu have been quietly disappearing from Auckland streams and wetlands for many years,” says Matt Bloxham, senior regional advisor (freshwater) for Auckland Council.
“Sediment entering streams and wetlands from housing developments, erosion and gravel roads has had a significant impact.
“We’ve lost two populations because of sediment quite recently; one at West Hoe Heights in Orewa, and another at Whakanewha on Waiheke Island”. Matt adds, “we’re working to improve key habitat for giant kokopu on Waiheke, but all efforts will be in vain unless we can manage the threat posed by sediment”.
When sediment accumulates in the slow-moving pools giant kokopu inhabit, it impacts on the insects that giant kokopu feed on as well the fish’s ability to see them.
“In extreme cases, sediment can smother the gills of the fish and suffocate them,” says Matt.
To protect the giant kokopu, Auckland Council granted funding to Conservation Volunteers New Zealand via the Regional Environment Natural Heritage grant for their work in the Whakanewha area. A not-for-profit organisation, it manages approximately 1000 conservation projects across the country.
Auckland regional manager Clair Hobi says their project on the island has many aims, including increasing awareness and knowledge of the wetlands and its role in providing habitat for threatened species like giant kokopu.
“So far, we’ve facilitated a number of community planting days over the past two years and we’ve provided volunteer teams to take on plant maintenance,” Clair says.
“We really want to increase community and volunteer participation,” she adds “We definitely want to build up the populations of the giant kokopu.”
Auckland Council is working with Auckland Transport who’ve been very supportive of this work and are altering key sections of gravel road to benefit giant kokopu.
