Efforts to save Canterbury mudfish include using ‘electric fish-fence’

The Press –

In a rural Canterbury stream, mixing electricity and water will soon provide a safe haven for a hardy population of Canterbury mudfish.

Environment Canterbury (ECan) biodiversity officer Johannes Welsch headed the collaborative project between the Department of Conservation (DOC), ECan and landowners, and said the potential of the technology was exciting.

It would be installed on the spring-fed Bealey Stream, the only outlet to the Hororata River for the largest remaining mudfish enclave at Haldon Pastures. The protection it provided could lead to a tenfold expansion in habitat size for the critically endangered fish in the steam.

DOC has been monitoring mudfish numbers there for more than 10 years and found it was one of the few remaining enclaves of the fish in the area after the 2015-16 drought.

The technology, developed by American-based company Smith-Roots, works in the same manner as electric fishing.

Welsch said the 6 metre to 7m long canvas array emitted an electric field, which was stronger nearer the source. It would stun any fish that came too close, then the stream’s flow would push them out into the Hororata River.

While it would prevent predators such as eels or trout entering the area, it would still allow mudfish access to the Hororata River to potentially repopulate other areas.

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