Mudfish protection in Selwyn

by Kent Caddick

A Selwyn project, which seeks to use an electric barrier to protect the nationally-threatened Canterbury mudfish from predators, is the first of its kind in New Zealand.

Environment Canterbury, Department of Conservation and local landowners around Haldon Pasture Springs in the Selwyn district met with American hydrological engineer, Jason Kent, recently to begin mapping out and planning the logistics of the estimated $120,000 project.

Environment Canterbury biodiversity officer, Johannes Welsch, said the pilot project could be a significant step forward in native fish conservation at sites threatened by trout.

“This is a unique opportunity to showcase how biodiversity, species protection and agriculture can work together — delivering sustainable farming and conservation in the diverse agricultural landscape of Canterbury,” Mr Welsch said. The Canterbury mudfish protection project will utilise an approximate six to seven-metre-long canvas array covering the full stream bed, which will send out electric pulses discouraging trout and eel from swimming upstream into the tributaries but rather continue up the mainstem of the Hororata River away from important mudfish populations.

The Selwyn Waihora catchment has the largest remaining fragments of Canterbury mudfish of any other zone in the Canterbury region.

The Haldon Pasture Springs site is particularly significant as it is one of only a few, where mudfish in the Hororata catchment managed to survive during the 2015–16 drought.