Guide wild over didymo spread

A Taupo trout fishing guide has lashed out at the Government over the discovery of dead didymo cells in central North Island rivers, saying the spread of the invasive algae could have been prevented.

Dead didymo cells were discovered in four North Island rivers this week the Tongariro, Whakapapa, Mangatepopo and Whanganui and the region's $250 million trout fishing industry faces a nervous wait for test results to confirm if live didymo cells are in the waterways. Results of those tests were not available this morning.

Taupo Trout Guides' Brendon Mathews said didymo could well have entered North Island rivers on the boots and equipment of visiting fishermen, many of whom fly from South Island spots to North Island rivers in the same day.

"They have not policed it at all," said Mr Mathews. "It's out of control.

"It gets me wild," added Mr Mathews, who said local guides were picking up customers from Taupo's airport where the anglers had walked past signs warning them about a potential for the transportation of didymo cells on their wet gear.

Mr Mathews described didymo as "a political hot potato" and said "back-slapping" government departments had not done the obvious thing to prevent its spread "ring-fence" North Island rivers and ban fishing in South Island rivers where didymo is found.

"They needed to restrict anglers to stop the spread of it," he said.

Mr Mathews author of Volcanic Trout, a guide to trout fishing in the area had expected didymo to reach the North Island and said the algae could "explode" in the central North Island waterways.

Another Taupo-based fishing guide, Dragonfly River Guides' Shane French, said the discovery of the dead cells was the talk of the trout fishing industry and "a massive concern" for operators.

"If it's found in the headwaters of a river, it can ruin the whole river."

He guided anglers who were fishing two or three different rivers in a day, and expected he would have to buy separate gear for each river to ensure he wasn't spreading didymo cells when switching from one to another.

Mr French said if didymo which leaves a weed mat on top of the water is confirmed in North Island rivers "it's going to make fishing really, really difficult".

He hoped to keep trading despite the didymo scare. "If people knew it was really bad, they might cancel trips."

Meanwhile, Environment Waikato is stressing the importance of checking, cleaning and drying any equipment being moved between waterways, following the discovery of the dead didymo cells.

Any equipment used in a waterway should be cleaned with a detergent solution or nappy cleaner for at least a minute before drying and left for 48 hours before use in another waterway.