Niwa warns about anti-fouling paint

Ports in Nelson and the Milford Sound in Fiordland - a world heritage area - are predicted to be at the highest risk from anti-fouling paint, according to new research.

A study released last week by the National Institute of Water and Atmospheric Research (NIWA) claimed that small marine animals in New Zealand's harbours and marinas are being affected by high levels of copper from anti-fouling paint on boat hulls.

New modelling conducted by NIWA showed many New Zealand marinas could have copper concentrations above the guidelines for protection of marine aquatic life.

Anti-fouling paint slowly releases chemicals to prevent weed buildup that causes water friction and hull damage, and stopped foreign species piggy-backing into New Zealand waters.

NIWA principal scientist Chris Hickey said on Friday that the copper in the paint was used because it was designed to kill things.

However, chronic long-term exposure to copper could kill sensitive marine species such as crayfish, shrimp, juvenile shell fish and sea anemones.

"Any of the delicate encrusting sorts of things. It won't kill everything off, but you might just get a restricted type of environment."

He said the chemical formulation of the paint regulated the speed it found its way into the environment which would lessen the affect on marine biodiversity.

"All paints are not created equal, it is a technological issue. You want the copper on the surface of the paint but not leaching into the environment."

We were using the old tried and true sledgehammer approach, he said.

"If you buy cheap and nasty, this is the end point you will get to."

Having the new data was positive because it would help scientists provide recommendations on what types of paint to use, Dr Hickey said.

"Copper is our mainstay, but the thing is to look at other biocides like complex organics and incorporating natural things. They are there but they cost more, don't necessarily last as long, and don't suit casual use."

He said NIWA had constructed a computer simulation of copper buildup in New Zealand marinas and harbours and found that the model closely matched their real world observations.

"We set up a [simulation] marina and input the number of boats, the size of the harbour entrance, the size of the hulls of the boats, the leaching rate of the copper . . . we were very pleased to see that the results of the model were very comparable with the physical data."

The Environmental Protection Agency is calling for public submissions on the use of the paint after new information from international regulatory bodies in the European Union, Britain, Australia and the United States found certain anti-fouling paints could also cause cancer and affect people's organs and nervous systems.

The public have until Thursday, March 7, to make submissions.

The Marlborough Express