Photo by Stephen Jaquiery
Scientists are to check whether New Zealand muttonbirds
that spend the winter off the coast of Japan have been exposed
to radiation from the damaged Fukushima nuclear power plant.
In a new pilot study, University of Auckland scientists will
investigate whether radioactive cesium has entered the New
Zealand ecosystem or food chain via the birds.
The wrecked plant and its trapped contents have loomed over
Japan since floodwaters from the March 2011 tsunami knocked
out the plant's back-up generators that were supposed to keep
cooling its nuclear fuel.
The over-heating sparked meltdowns in three reactors and
forced 150,000 to flee, and tens of thousands have been
unable to return home to areas contaminated by radiation.
In the study, researchers will test the birds' feathers for
gamma rays that indicate the presence of the radioactive
Feathers will be collected from prime muttonbird sites in the
South Island, particularly Stewart Island.
New Zealand sooty shearwaters or titi migrate annually,
spending the summer mating and raising their chicks in New
Zealand before over-wintering off the coast of Japan.
Dr David Krofcheck, of the university's department of
physics, said the research was "very much about taking a
precautionary approach"as there was no evidence to indicate
that the birds had been vectors of radioactivity.
"But detection of gamma rays would tell us whether the birds
spend sufficient time near Fukushima to accumulate cesium-134
from nuclear fission," he said.
"Obviously the issue would then become whether that
radioactivity is being absorbed into local ecosystems or the
Pacific Bluefin tuna caught off the west coast of the United
States showed only a minute trace of cesium-134 from
Fukushima, 100 times less than normal radioactive elements
found in fish.
The sooty shearwater was of cultural and economic value to
Maori, who sustainably harvested the nearly fledged chicks
during the annual muttonbird season.
The season runs from April to May and was restricted to Maori
and their whanau who use the birds for food, oil and feather
Dr Krofcheck said consultation with Maori, the Rakiura Titi
Islands Administering Body, about the research would begin as
soon as possible.
"We will need to go through a number of approval processes
and engage in consultation with local people before anything
can happen as there are sensitive issues to consider before
work can begin."
The research is being done in collaboration with the
Department of Zoology, University of Otago.
Previous tests on muttonbird exposure to radiation from
Fukushima found no evidence of cesium being passed from
parents to chicks.
"Our study is complementary to that earlier work but tests
feathers instead of the birds themselves," Dr Krofcheck said.
"Obviously what we are hoping to find in this latest research
is that cesium levels in muttonbirds do not exceed exposure
levels you would expect from natural sources."
- By Jamie Morton of the NZ Herald