Green groups seek urgent river cleanup

Tough regulation and urgent action is needed on polluted rivers, conservation groups say.

The calls come after the Manawatu River rated as the most polluted of about 300 rivers and streams tested across the Western World.

The research, by the Cawthron Institute, measured oxygen changes in water and results indicated an unhealthy river ecosystem.

The river is polluted by agricultural runoff, treated sewage discharge and industrial effluent. Nitrogen from agriculture and phosphorus from sewage and wastewater led to nutrient imbalances in the river, algae blooms and slimy growths.

Fish and Game regional manager Phil Teal said there needed to be widespread and rapid action. Having the river pollution put in an international context was an "eye opener".

"It confirms what we know. But it is a surprise, we knew it was bad, but not that bad," he said.

"Something has to be done, no-one wants to swim or fish in highly polluted waters."

Forest & Bird spokeswoman Joan Leckie said the research was shocking. The findings would back up presentations at Horizons Regional Council's One Plan hearings beginning next week, aimed at cutting nitrogen pollution from farms.

The council, which commissioned the research, wants stiffer discharge regulations and set limits for farmers' nitrogen in soil.

UnitedFuture leader Peter Dunne said that for too long fertiliser runoff and effluent discharges had gone unpunished and urgent action was needed. He supported imposing tough limits on fertiliser use and waste discharge as industry self-regulation was not strong enough for many polluters.

Green Party co-leader Russel Norman said it could take 20 years before the Manawatu River was even at half the accepted swimming quality and the pollution posed a serious public health risk.

But the research had not deterred everyone.

Receptionist Mel Grant, 36, of Ashhurst has spent hours kayaking and swimming at her favourite spot near the Manawatu Gorge.

"We have all heard how bad it is supposed to be but nothing has happened to us yet. You only have to come here on a summer's day and the place is crawling with water users."

Palmerston North pensioner John Mitchell, 67, said he chose spots along the river carefully before letting his dogs swim.

"I've been bringing dogs here for 14 years and they've never suffered as they swim and drink the water."

During the summer of 2008-09 about 10 health-risk signs were erected at swimming spots on the river warning that toxic algae may be in the area.