Life in Lake Rotoiti dead by summer says environment chief

By JO-MARIE BROWN

The Ministry for the Environment's top official believes there is a "good chance" that algal blooms will kill all life in Lake Rotoiti this summer.

The comment, contained in a special report on the health of Rotorua's lakes, has prompted Environment Minister Marian Hobbs to announce today that she will help local authorities try to fix the problem.

The report from the ministry's chief executive, Barry Carbon, says if warm, calm weather allows blue-green algae to flourish again this summer all of Lake Rotoiti's remaining oxygen could be used up.

"If this happens, the fish and all life in the lake will die and it will become an unpleasant and smelly place," he said. Lake Rotoiti is one of a number of lakes around Rotorua suffering from poor water quality and algal blooms which at times make the water unsafe for swimming and uninhabitable for fish.

Human activity around the lakes is to blame. Vast quantities of nutrients have flowed into the water for decades from animal effluent, fertilisers, stormwater run-off, septic tanks and sewage, fuelling algal growth.

Ms Hobbs received the report this week and said the health of Rotorua's lakes was "clearly a cause for concern".

An expert in managing degraded lakes will be employed to help Environment Bay of Plenty halt the lakes' rapid decline.

"There are no quick, cheap and easy solutions to the problems with Rotorua lakes but they are nationally important for tourism and recreation," Ms Hobbs said.

The Government has already stepped in to help restore Lake Taupo's water quality on similar grounds - a move that was criticised by some who felt Rotorua's problems were being ignored.

Environment Bay of Plenty's Paul Dell, who is co-ordinating the work being done locally, has welcomed the Government's involvement.

Professor David Hamilton of Waikato University, who is leading research into Rotorua's lakes, agreed the minister's involvement was a positive step.

However, he questioned whether hiring an expert for a short time would help.

"We're pretty much up on the best technologies for chemical and physical treatment of lakes."