Passionate fighter for waterways

When he's not at Massey University lecturing about freshwater ecology and environmental science, Mike Joy is passionately trying to protect Manawatu's environment, and aims to get people to realise how bad the state of the river really is.

Laura Jackson caught up with Dr Joy to hear some home truths about the region.

A lot of opinions are being thrown around about the state of the Manawatu River, but for people to understand what's really going on, they need to think of the river as a living being, says Mike Joy.

Rivers are not simple – it's not just a whole lot of water going out to sea, he says.

The way he puts it, hundreds of years ago, the Manawatu River was a slim, athletic river. Now it is obese.

"We keep feeding it too much. It's like if people ate chips and cake and drank gallons of Coke – the system could not handle it."

The river is being fed too many nutrients from farm runoff, chemicals and sewage, he says.

This overloads the river and too much plant life grows, throwing the oxygen balance out and suffocating fish and vertebrate life.

But that's only one half of the problem. The other half is sediment.

"People came along, chopped down half the forest, ran stock on steep country, and land began falling into the river," Dr Joy says.

The river gets higher than the surrounding land, so the stopbanks have to be built higher, eventually turning the river into a massive drain.

The dumped sediment also kills the bugs the fish eat, and closes up crevices where fish would live.

"The life in the river needs food, it needs a house."

The answer is for people to stop dumping in the river, he says.

"Just because a river flows doesn't mean you should be able to dump in it."

The nutrients poured into the river should be used on land to grow plants, he says.

"It's a resource, it's not waste."

He wants councils to re-prioritise their spending to take care of the river.

When the fight for the environment gets too much, Dr Joy escapes on his boat to sail around Wellington's harbours or kicks back to the latest sounds in his CD player, Don McGlashan.

Before entering the world of science in 1993, he built boats, and still enjoys the hobby as a release.

He also likes to keep healthy with his favourite snack – his own home-made falafel.

- © Fairfax NZ News