Catfish hunter aims to cream a profit from pest

By JO-MARIE BROWN

A "ticking ecological bomb" lies in Lake Taupo but one woman is determined to fish it out and make money while she's at it.

Rawinia Konui has spent 15 years battling to rid the lake of catfish, and has now begun selling the pest to Asian communities as a delicacy.

The "ugly" catfish were illegally introduced to the lake in the early 1980s and their numbers have exploded.

Dr Brendan Hicks, a freshwater fish ecologist at Waikato University, said catfish were a "ticking ecological bomb" and could seriously damage the native fishery if their numbers continued to swell.

Though the exact population size was unknown, hundreds of thousands of catfish were believed to live in Lake Taupo, feeding on native fish such as koura (crayfish), he said.

It was the sudden disappearance of koura in the 1980s that led Ms Konui's family to ask her to do something about the catfish problem.

Her great-aunt would fish for koura to take to church functions but by 1990 her fishing basket was dominated by "the ugly fish".

Anglers also grew concerned that catfish might be eating trout or stealing their food.

Ms Konui aims to turn a profit and create jobs while eradicating the pest. She has contracts to supply live catfish to markets in Auckland, Hamilton and Wellington and has signed a deal with a catfood cannery.

"From something very negative will hopefully come something very positive," she said.

"We'll help to conserve our fishery, which will help increase the quality of the trout as well as providing work for our people."

Profit was still a long way off, she said, but the 3000 catfish caught in the venture's first week would sell in Auckland for about $5000.

Ms Konui would be thrilled to fish herself out of business as eradication, rather than money, is her main focus. "I love native fish and I want to ensure that they're there for our great-grandchildren to enjoy."

Department of Conservation fishery scientist Dr Michel Dedual said catfish did not appear to be damaging the trout fishery yet.

The pest was mainly found in the Waikato River system. How it got into Lake Taupo was a mystery.

Dr Dedual said DoC would keep a close eye on the catfish population because the species might create problems in the future.

Waikato University student Grant Barnes, sponsored by DoC, studied the lake's catfish plague for his master's thesis in 1996. One night he caught 1300 in a single net.

Mr Barnes agreed that catfish could harm the environment. "They're the possums of the lakes in that they eat things they shouldn't."

Catfish had few predators and a female might lay 6000 eggs a season.

Though New Zealanders shunned them, catfish were considered a delicacy in southern states of America (where they originated) and Asia.

"They taste really yummy and Lake Taupo's such a clean, beautiful, pristine lake that the quality of the fish grown there reflects that."

A Chinese businessman was keen to export the catfish.