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[The New Zealand
Herald ]- April 30, 2003
A potentially deadly toxin has led to a warning to
stop gathering shellfish in the Bay of Islands,
putting at risk a multi-million-dollar export oyster
industry.
Shellfish in the Bay of Islands have shown the
presence of Paralytic Shellfish Poisoning (PSP) toxin
at more than three times the safe health limit, health
officials say.
'A safe level is 80mcg per 100g of flesh. The sample
showed 263mcg per 100g of flesh,' Northland Health
shellfish co-ordinator Neil Silver said.
The shellfish gathering warning extends from Cape
Brett to Howe Pt. Other areas on the east coast, north
and south of the Bay of Islands show the presence
below regulatory level. However, it is possible that
the area covered by the warning could be extended.
The symptoms of PSP include numbness and tingling
around the mouth, face or extremities; difficulty
swallowing and breathing, dizziness, double vision and
paralysis.
PSP toxin can cause death although no fatalities from
PSP have been reported in New Zealand to date. There
is no antidote to the toxin.
There have been no reports of people displaying PSP
symptoms in the Bay of Islands.
'If they show any of the symptoms they should go and
see their doctor as a matter of urgency,' Mr Silver
said.
It can take up to 12 hours for symptoms to develop.
An influx of visitors to the Bay of Islands over
Easter increased the risk of people collecting
shellfish in the area, he said.
Health officials believe the toxin is being passed
onto shellfish from an algae bloom called Alexandrium
catenella.
The toxin has been detected in the Bay of Islands
before and was present on the West Coast last year.
There have been several outbreaks of disease related
to Bay of Islands shellfish in the past few years.
These include a hepatitis A outbreak which affected 14
people involved in collecting contaminated mussels
from Moturoa Island in 1999.
Traces of the Norwalk gastroenteritis virus were
recorded in 1994, 1999 and again in 2001 in several
Auckland restaurants, and were linked to contaminated
oysters from the Waikare Inlet.
Bay of Islands oyster farmers' spokesman Charlie
Davenport said there was little the farmers could do
about the latest scare.
'It's a natural phenomenon and it might take a big
storm to churn it up and get rid of it,' Mr Davenport
said. 'But the farms will have to close and everybody
will be peeved off about it.'
It was not worth putting the export market at risk for
the sake of waiting a few days for it to clear, he
said.
The Bay's oyster industry was conservatively worth $30
million a year.
'It's a bit of a nuisance. But the oysters are not
that fat at the moment anyway and they will still be
there next week,' he said.
There are 19 oyster farms in Orongo Bay, 21 in the
Waikare Inlet (although 18 Waikare Inlet farms have
already been closed due to the Norwalk virus), 10 in
Kerikeri Inlet, four in Te Puna Inlet and one in Paroa
Bay.
Aquaculture Federation chairman Bevan Wilkie said
halting shellfish gathering in the Bay of Islands
would effect a multi-million-dollar industry.
He said 86 per cent of Northland's export oysters were
farmed in the Bay.
Only Seafood restaurant owner Calvin Shepherd, of
Paihia, did not envisage the ban having a major effect
on his business.
'The only real effect is that we will have to bring
oysters in from outside the area,' Mr Shepherd said
yesterday. |
