Massey University freshwaterecologist Mike Joy speaks at
the New Zealand Freshwater Sciences Society's conference
inDunedin yesterday. Photo by Lind Robertson.
If New Zealand's ecosystem continues to decline at the
rate it has for the past 40 years, the country will have no
native fish by 2050, Massey University freshwater ecologist
Mike Joy says.
The only way to change that future was to reduce land-use
intensification, he said at the New Zealand
FreshwaterSciences Society's conference in Dunedin yesterday.
"We have a freshwater crisis in New Zealand and we are
slipping down the [international] rankings."
Reaction to his comments about the country's water crisis in
international media led to Dr Joy introducing himself as "Dr
Doom", "traitor", "egotist".
"I didn't sabotage New Zealand ... there is a huge amount of
support for standing up for reality."
He said 68% of the country's ecosystems were threatened and,
at that rate of decline, there would be no native fish by
Statistics like 90% of lowland rivers being unswimable, 43%
of lakes polluted, and 90% of wetlands gone, backed up the
argument, he said.
As did the fact dairy cow numbers had gone from 3.4 million
to 6.2 million and had grown "sevenfold" in the South Island,
irrigation had doubled, and nitrogen and fertiliser-use had
A study of environmental degradation in 179 countries showed
New Zealand ranked 130th, he said.
"If that is not a crisis, then what would it take."
New Zealand had failed to address the major issue behind the
crisis - land-use intensification which had led to a major
decline in freshwater ecosystems, Dr Joy said.
Recent promotion of irrigation schemes was only going to
increase it further.
"It's like leaky homes or Pike River. We've had 20 years of
hands-off; the cause of the worst impact has been left alone.
"The science is clear: we need to restrict intensity."
As a result of not dealing with the cause, the country now
faced an economic and environmental dilemma.
Environmental organisations needed to start monitoring the
right components and they should be reported nationally, he
"We've got great science but what we've got to do is use it."
It was crucial that environmental indicators were measured
properly so scientists could communicate to the community how
their actions were impacting on freshwater.
"I think it could be a lot worse than we think."
As scientists, they had a "duty" to raise the issue, he said.
Hong Kong-based freshwater ecologist Prof David Dudgeon
"Don't give up. Even if we are beyond the limits, it may not
be too late," the chair in ecology and biodiversity at the
University of Hong Kong said.
The theme of the conference was "Beyond the Limits" and in
answering that question, Dr Dudgeon said the world was
already beyond the limit. An indication of this was the
number of species on ICUN red-threat lists.
More data and monitoring was needed to track biodiversity
changes and ensure river bio-diversity was included in water
"The more information the better but it is more important we
apply what we already know."
Scientists could do better to advocate for freshwater if they
wanted to protect waterways or roll back some of the
degradation that had occurred, he said.
"We need to increase and raise public awareness of the
importance of freshwater bio-diversity to human livelihood,"
Dr Dudgeon said.
Humans and fresh water mammals were competing for the same
resource and some way needed to be found to reconcile humans
needs with preserving biodiversity.
"Humans have solved their water supply problem but not the
About 240 people involved in freshwater science and
management are attending the four-day conference at the
University of Otago.