More Didymo found

Didymo has infested a trophy brown trout fishery on the South Island's West Coast, also putting the Inangahua River at risk.

The Department of Conservation has confirmed that didymo, also known as rock snot, had been detected in the Waitahu River, the major tributary of the Inangahua.

The infestation was picked up during routine testing. The Waitahu is only a few kilometres from Reefton.

The Inangahua so far has tested clear but DOC didymo ranger Gordon Roberts said more testing would be done over the next fortnight.

The Waitahu is very accessible and its headwaters are popular with fishermen and hunters.

West Coast Fish and Game field officer Dean Kelly, of Hokitika, said the Waitahu was a trophy fishery with a big population of good sized fish. It is also quite a fragile fishery.

The river is used predominantly by anglers, who probably unwittingly carried the didymo from the nearby Buller River.

However, four-wheel drive enthusiasts and hunters also frequent the area.

Mr Kelly said it was now a matter of waiting to see how well established it became. Didymo had been in the Haast River for the past year but was still not visible; it was believed the high rainfall and sediment helped scour it out. The only place it was blooming was in lake outlets.

However, Mr Kelly said the test result showed the clean, check and dry message was not getting across.

NZPA