Wellington - New Zealand, which promotes itself as "100 per cent pure" in its publicity aimed at foreign tourists, has one of the most polluted rivers in the Western world, according to research published on Thursday. The North Island's 182-kilometre-long Manawatu River is fouled with treated sewage, industrial waste and fertiliser and animal effluent runoff from farms, ecologists with the independent Cawthron Institute reported.
Tests showed the river had the highest reading of depleted dissolved oxygen of 300 rivers and streams in North America, Europe, Australia and New Zealand.
On a scale in which anything over 8 is considered indicative of an unhealthy river system, the Manawatu posted a "ridiculous" count of 107 at one spot, Roger Young, a freshwater ecologist at the institute, told the Dominion Post newspaper.
He said international checks found the closest pollution reading to it was 59, at a site on a river near Berlin, downstream from a sewage outfall.
The Manawatu winds through the province of the same name, which has many dairy, sheep and horticultural farms and Young said run-off from the land, mainly nitrogen, leaching into the river was the main factor.
Greg Carlyon, of the Manawatu-Wanganui regional council, which commissioned the research, told Radio New Zealand the river had high levels of nitrogen and phosphorous, and tougher discharge regulations were being introduced.
But the river was nowhere near as polluted as many others, he said.
The council's website says water quality is its top priority, but Russel Norman, co-leader of the Green Party, said it could take 20 years before the river was brought up to "even half the accepted swimming quality."
