Tourist boats in the pristine Milford Sound are contributing
to a copper concentration so high it could kill 20 per cent
of marine life in the port area, new research by NIWA
The Fiordland port is one of 24 nationwide where National
Institute of Water and Atmospheric Research scientists warn
of a significant threat to marine life caused by the leaching
of copper from antifouling paints on vessel hulls.
Humans are also potentially at threat and an environmental
watchdog is now evaluating if some marine paints should be
Antifouling paints are applied to the surfaces of boats and
slowly release chemicals into the water to prevent the
build-up of aquatic pests such as plants and algae.
NIWA's modelling predicts "significant impacts" from the
copper concentrations as a result of those paints and the
levels are believed to be much higher than originally
expected, principal scientists Dr Chris Hickey said.
The level of copper concentration in the Milford Sound port
may be up to six times the guideline levels for protection of
aquatic life, he said.
NIWA released its research findings today[25/01] after tests
on Auckland marinas indicated its modelling was accurate.
The copper levels threaten to reduce the biodiversity inside
marinas and harbour areas, killing some sensitive species
such as shrimp, crayfish and juvenile shellfish, Dr Hickey
"The concentrations predicted and then subsequently validated
[by the Auckland tests] ... were a lot higher than we would
have expected," he said.
"There could be significant effects in those immediate
Dr Hickey said the copper concentration in some of the
Auckland tests was greater than the amounts from storm water
inputs into the harbour.
Some antifouling paints used on boat hulls may be restricted
from use in New Zealand, with an investigation currently
underway by the Environmental Protection Authority (EPA).
The EPA commissioned the NIWA research as part of its
investigation, which acting applications and assessment
manager Johanne Spring says has already identified risks
posed by some of antifouling paints.
Some of those risks may be managed by stricter controls being
placed on their use, she said.
"However, our research also shows that the risks to human and
environmental health from some antifouling paints may be so
significant that they should no longer be permitted for use
in New Zealand," Ms Spring said.
A report by the EPA on antifouling paints identifies
chemicals that are suspected of being potentially harmful to
The EPA has opened its investigation up to public submissions
and expects to report on the paints by May.
Fiordland's Marine Environment chief executive Malcolm Lawson
said the research would be considered by the Fiordland Marine
"There are ecologically-significant species within the
Milford Sound and I would be concerned if they were being
subject to any high levels of contaminants," he said.
Further tests should be conducted at the Milford Sound port
to confirm if the NIWA modelling was accurate, Mr Lawson
"At the moment this is a model but until such time as the
actual testing has been carried out and results evaluated,
it's very hard to decide on what the future action should
Real Journeys operations manager Paul Phelan said tourism
operators would support testing the Milford Sound port for
its level of copper concentration.
"If there's something untoward there I think people would be
open to [testing to confirm copper levels]," he said.
"I think people would support that. We try to protect our
resources and sustainability."
- Kieran Campbell