People in the north Auckland suburb of Whangaparaoa have been told not to collect or eat shellfish due to increased levels of potentially fatal toxins.
A health warning from the Ministry for Primary Industries (MPI) has already been in place for the coastline beyond Kawau Island, near holiday hotspot Omaha -- and has now been extended just south of the Whangaparaoa Peninsula.
Brian Roughan, MPI's specialist advisor for seafood, says people should avoid eating shellfish from the affected areas at all costs -- and insists cooking or freezing the shellfish will not remove the paralytic shellfish poisoning (PSP) toxins.
"The symptoms can range from numbness, tingling or feelings around the face and mouth to dizziness, headaches, nausea, diarrhoea," he said.
"If you have a lot of the toxins, the symptoms can be even more severe; feelings of paralysis, and in very rare cases, it can cause death."
A sign erected near one of the affected areas (Newshub.)
Routine tests in the Mahurangi Harbour found levels of PSP were up to 1mg/kg -- above the safe limit of 0.8mg/kg set by MPI.
New Zealand Oyster Industry Association (NZOIA) president Jim Dollimore made the final decision to temporarily close commercial oyster farms within the area.
"The levels so far are still low, still below the level at which we're required to stop harvesting, but they've been increasing -- we're stopping harvesting now until the levels start to decline," he explained.
"We don't want it go above the level we stop harvesting because we'd then have to recall product, which is difficult when we're supplying fresh markets."
Mr Roughan says there is no indication of how long the oyster farm closures will be in place.
"[Algae] blooms can last for a long time, or change in weather pattern and they can go. We just have to monitor the shellfish to make sure they have purged the toxin out of their system."
Mr Dollimore was more optimistic, saying the NZOIA will be monitoring the situation every day, and when the levels start to decline they will reopen the harbour and resume harvesting.
"We're hoping it's short-lived -- we expect it to be just a few weeks at the most," he said.
"It's a difficulty and an annoyance, but it's a thing that happens all over the world all the time, and it's managed."
Newshub.
