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Published: 2003-11-05 00:00:00

Environment Waikato councillors debated whether they should spend resources on researching how to control pests or more on control work.

Cr Evan Penny told last week’s Council meeting that the Council should do “more zapping” and practical work on the ground, rather than more studies into pest habits. He referred to frustration in not spending more on koi carp control.

“We know how to kill things and while it is not the long-term answer, it does work. We are going to research, collaborate and co-ordinate the thing to death and not one koi carp will go belly up as a result.”

Environment Waikato is working on a number of initiatives to combat koi carp in the Waikato’s waterways where it is recognised as a major pest.

It is working with DoC and Environment Bay Of Plenty to put up signs about how to avoid spreading the pest. An Environment Waikato staff member has been assisted to Australia to see how the fish is dealt with there. A university study is underway to investigate some basic koi carp biology in New Zealand conditions.

Chief Executive Harry Wilson said there was a market to use the fish as bait and a number of people were starting to see the potential for koi carp. However those harvesting the fish were having problems selling them.

“We need to get the harvesters and the retailers in the same room and talk about the benefits of removing koi in large quantities and making use of them.”

Biosecurity Committee Chairman Helen Lane said she understood Councillors’ impatience but if action was to be effective the research needed to be done. Any solution would cost, she said. Biosecurity Group Manager John Simmons said a bait system was being investigated which killed koi carp but did not affect non-target species. The fish lived in vast water expanses where it was difficult to target them.

The Council would concentrate on smaller water bodies that were manageable and clear them up first.

“Our understanding of their biology is poor but once we have a better grasp of their behaviour we may be able to manipulate their habitat by adjusting lake levels, for example. There are no quick fix solutions and this fundamental research is necessary.”

Cr David Peart said while research was important, the Council needed to look at specific water bodies and do something, especially where there were biodiversity reasons to do so. The Whangamarino area had rare and endangered species and the continued growth of koi carp was not good for the future.

“We have to pick a few places, keep the numbers down and achieve a positive environmental outcome while we wait for longer term solutions,” he said.