| That
is one of the reasons why NIWA has just established a
new
National Centre for Aquatic
Biodiversity and Biosecurity – to help
understand the effects of these exotic invaders, and
assess the possible ways of controlling them.
The Centre will focus on
aquatic biodiversity research, threats to biodiversity
from non-indigenous species already in New Zealand, and
from possible new arrivals that could have undesirable
impacts on our freshwater and marine communities.
“A key role of the
National Centre is to communicate,” says Centre
Coordinator Dr Wendy Nelson, “so we can better target
and deliver high quality research, and improve
collaboration between government agencies, regional and
district councils, iwi, industry, and science
organisations”.
Dr Nelson says the
greatest threat to our biosecurity may actually be
ignorance. “For many areas we don’t know what species
are out there, and we don’t know what species are coming
in on vessels or being brought in by the aquarium
industry.” She says the limited number of surveys and
shortage of expertise have been major problems.
One of the most striking
recent introductions is the Asian paddle crab, which is
far more aggressive than New Zealand’s native paddle
crab. It was first noticed by two fishers who caught
them in flounder nets in the Rangitoto channel in
Waitemata Harbour. There are now about twice as many of
them in the harbour than the native paddle crab – and
they are more widely spread.
“It’s possible that this
invasive crab reached New Zealand in the ballast water
or ballast intake pipes of vessels, but we may never
know for sure, “ says Dr Nelson. “They could also have
arrived here as larvae or juveniles on the hulls of
vessels, or perhaps from established populations
up-current of New Zealand.”
Another recent discovery
was a small fish which has become established in
subtidal waters in Whangapoua Harbour in the Coromandel,
and Waitemata Harbour. This little fish, a goby, has
bright iridescent blue spots along its sides, and was
caught in shallow muddy areas near seagrass beds and
mangroves.
“It probably arrived in
ballast water from Australia or further afield.
Temperate fish species like the goby are more likely to
survive and reproduce in New Zealand than tropical
marine fish species because the conditions here are
similar to some of the temperate regions where they come
from, such as Japan and Korea.”
NIWA recently surveyed
over 300 sites in 25 harbours throughout the top half of
the North Island and discovered two other Australian
gobies established around the east and west coast of
northern New Zealand.
“We don’t yet know the
full impact of these invasive species on the New Zealand
environment, but first of all we plan to find out how
well established they are, and then what their role is
in the ecosystem and how they affect our biodiversity.”
Contact
For further
information contact:
Dr Wendy Nelson
Phone +64-4-386 0600
w.nelson@niwa.co.nz
Dr Don Robertson
Phone +64-4-386 0300
d.robertson@niwa.co.nz |
