A chemical trial to help fix Rotorua's sick lakes has produced disappointing results, says a scientist.
Professor David Hamilton, who heads research into Rotorua's lakes at Waikato University, has also criticised the Government for not doing more to combat the problem.
Professor Hamilton was concerned the Ministry for the Environmenthad turned down a funding request late last year.
The money was required for a trial on Lake Okaro to discover if a special chemical would absorb phosphorus and limit algal growth. The regional council, Environment Bay of Plenty, paid for the project itself after its application was declined.
"We thought it had an excellent chance for funding," Professor Hamilton said. "The worry is that we've had very little national interest in the Rotorua lakes and yet they are a New Zealand icon that is just as important as Lake Taupo.
"Some of them are decaying before our very eyes."
Last year the Government said it would contribute $36.7 million to help restore water quality in Lake Taupo. But no such commitment has been made regarding Rotorua.
The ministry's chief executive, Barry Carbon, said yesterday $350,000 was approved last year to help Rotorua's lakes, which was "pretty generous".
Years of negotiation had preceded Taupo's deal and Rotorua's case had not yet been sufficiently advanced, he said.
But Rotorua lakes protection and restoration co-ordinator, Paul Dell, said the ministry's decision was disappointing.
"I think there's a major problem in that the Government has been so focused on Taupo, it hasn't realised that there are other lakes which require work," Mr Dell said.
In the meantime, Professor Hamilton said the Lake Okaro trial had not been as successful as was first hoped. "Summer wasn't really quite the right time to do it because it tested the chemical to the extreme and the dose was very light because it was just a preliminary trial," he said.
Environment BOP plans to repeat the trial as the chemical has been successfully used overseas.
