Water quality meeting tackles big issues of weed, catfish and nutrient levels in lakes

Lake Tarawera was a key focus at this year's Rotorua Lakes Water Quality Society AGM.

Controlling catfish, eradicating invasive lake weeds and improving nutrient levels are three key issues being tackled by the Rotorua Lakes Water Quality Society.

The group held its annual general meeting yesterday which was attended by about 100 people, including Rotorua MP Todd McClay, mayor Steve Chadwick and Bay of Plenty Regional Council chairman Doug Leeder.

Society chairman Don Atkinson said the meeting was well attended and a good chance to discuss the priorities around lake water quality moving forward.

"Firstly there will be a continued emphasis on improving fauna and getting rid of lake weed, especially considering historically our main focus has been on lake nutrients.

"Invasive weeds are dominating in Lakes Rotoiti, Rotorua and Tarawera. Around 90 per cent of the lake weeds are aggressive, invasive weeds, leaving only 10 per cent our native weeds."

Mr Atkinson said the return to native fauna was a "difficult task" but one the society was committed to improving.

He said the other two key areas of focus were improving nutrients in Lake Tarawera and the greater catchment and working to control the catfish population in Lake Rotoiti.

"We are aware eradication of catfish in large bodies of water has not been achieved but we are looking at ways to control the issue in Lake Rotoiti.

"These are big issues we are trying to tackle and it will be a challenge moving forward but there will be a public focus with our symposium at the end of July.

"I think we have made progress in the last year but we recognise we are only half way there - our job is only half done."

Mr Atkinson said the highlight of the meeting was the presentation delivered by Professor David Hamilton, who had driven science programmes on the lake for the past 15 years.

"David is taking up a position in Australia on the Australian Rivers Institute. We've considered him to be the oracle of science and he will be a huge loss for us."

Mrs Chadwick echoed those sentiments, saying it would be a struggle to replace Professor Hamilton.

"During his presentation David commented that it was so unusual to have such diverse interest groups discussing the future of our lakes. I think it was a lovely comment and reflects commitment to work together to maintain and improve our lakes."

She said the meeting was positive and a chance to make sure all interested parties were on the same page.

"It was great to have an open and frank update and hear the evidence and science backing the quality of our lakes."

Mr Leeder said the catfish problem was disappointing to the wider community but the regional council was making progress.

"We've caught between 400 and 500 catfish to date but that also indicates there is a hell of a lot more in there.

"At this stage we don't know how they got there or how long they've been there so we are working to get a handle on the population in Lake Rotoiti and the best way to deal with them."

Catfish are an unwanted pest because they feed on small native fish, trout and their eggs.