Toxin alert likely to stay until August

By BRIDGET CARTER

Shellfish warnings in place around the country are unlikely to be lifted until August, as shellfish-poisoning algal blooms spread.

Shellfish is off limits in Hawkes Bay, the West Coast of the South Island, and the Bay of Islands, where there are now two different blooms contaminating seafood.

Northland Health shellfish co-ordinator Neil Silver said the algal bloom levels in the Bay of Islands were twice as high as he initially thought.

Test results he expects back today should indicate what those levels are doing to the shellfish.

"Mussels are certainly off the menu for the foreseeable future," he said. "I am concerned and am monitoring the situation very carefully."

Hawkes Bay health protection officer Noel Watson said toxin levels found in the bay's shellfish were the worst since November 2000.

Tests show 993 micrograms of toxin per 100 grams of flesh - 12 times over safety levels.

For the past two years, blooms have poisoned shellfish in the Hawkes Bay from May to August.

West Coast health protection officer Chris Bergin said the toxin in his area was likely to hang around for a further two months.

So far there have been no reports of people falling ill from eating shellfish in the warning areas.

Mr Silver said people could potentially die if they ate contaminated shellfish and did not seek medical help.

The two blooms in Northland are Alexandrium catenella, which has returned after poisoning shellfish on Northland's east coast from April 17 until last month, and Alexandrium tamarense.

Tamarense sparked a fresh shellfish warning for the region over a week ago, when Paralytic shellfish toxin levels of 135 micrograms per 100 grams of flesh were found in mussels - 55 micrograms over the safety level.

On the South Island's West Coast there are warnings for shellfish from the Buller River mouth to the Karamea River mouth because the bloom Protoceratium reticulatum is causing Diarrhetic shellfish poisoning toxin.

For the Hawkes Bay, the bloom called Gymnodinium catenatum is behind the high levels of the poisonous Paralytic shellfish toxin between Whareongaonga and Cape Turnagain.

In Northland, Mr Silver said, dangerous toxin levels had not yet been found in commercial oysters, but he was asking farmers in the area to be vigilant about testing.

Alex Clifford owns Kororareka Oysters at Orongo Bay, in the Bay of Islands, and sells about 50,000 dozen oysters a year.

He said he had temporarily stopped selling his oysters as a precaution until he received the results from further tests to confirm that they were in the clear.

"It is too big a risk. We could have sent a whole lot of product away that has to be rejected."

Mr Clifford said that although he was worried about the toxin in the bay, it was like the weather - something you could do nothing about.

"It is farming. That's what it is."

Map of toxic shellfish areas