Hull paint may affect marine life

Milford Sound is at risk of environmental damage from anti-fouling paint, new research says.

A study released last week by Niwa claims 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.

But Environment Southland, the body charged with environmental regulation and managing water quality in Southland, says more testing may need to be done.

Environment Southland maritime manager Kevin O'Sullivan said the council would ask Niwa for the details of the study to determine if further action was needed.

Actions could include running tests to compare with the Niwa model, Mr O'Sullivan said.

Niwa used the Marine Antifoulant Model to Predict Environmental Concentrations to predict concentrations of anti-fouling compounds at 11 ports and 13 marinas around New Zealand.

It found high levels in Milford Sound and Nelson.

The model was tested against actual results in Auckland, which showed elevated levels of copper in high use areas, however it was difficult to see how those results reflected the situation in Milford Sound without seeing the full study, Mr O'Sullivan said.

The Niwa study 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 stops foreign species piggy-backing into New Zealand waters.

Niwa principal scientist Chris Hickey said the copper in the paint was used because it was designed to kill things.

However, chronic long-term exposures to copper could kill sensitive marine species such as crayfish, shrimp, juvenile shell fish and sea anemones. Chemical formulation of the paint regulated how quickly it found its way into the environment which would lessen the affect on marine biodiversity, he said.

"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."

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, Mr Hickey said.

"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 their nervous systems.

The public have until March 7 to make submissions.

The Southland Times