Oyster crisis threatens $20 million industry

The virus that has shut some Bay of Islands oyster farms is threatening New Zealand's oyster exports worth $20 million, an industry leader says.

Late last year, Northland Health placed an indefinite ban on gathering oysters from 18 farms in the Waikare Inlet after traces of the Norwalk virus were found in the oysters. The virus comes from human faeces and causes gastroenteritis.

Many of the farms were collapsing as the oysters became too heavy for the wooden frames they grew on, a situation the farmers fear could cause an environmental disaster in the inlet.

Oyster Industry Association president Callum McCallum said the crisis surrounding the Waikare Inlet farms could threaten the entire country's export oyster industry, worth up to $20 million a year.

Any association between pollution and the oyster industry was potentially disastrous.

"People overseas don't know or care whether an oyster comes from Waikare or Waiheke. They see New Zealand oysters and associate them with New Zealand regardless of where they are from in New Zealand," Mr McCallum said.

"Our main advantage over oysters from other countries is our clean, green image. The Waikare situation is not good for that image."

The crisis not only affected commercial oyster farmers, but also ordinary people who wanted to collect the shellfish for themselves.

The situation would also lead to other countries imposing tougher testing standards on all New Zealand oysters. There was already anecdotal evidence that this was happening.

A risk management plan by the Waikare Inlet oyster farmers identified four major pollutants of the farms: the Kawakawa sewerage system, the Okiato Pt septic tank systems and commercial and recreational boats.

Northland Regional Council, which is responsible for monitoring water quality, needed to work with other local authorities to sort the problem out before it had devastating effects on the oyster industry nationwide, he said.

Regional council environmental monitoring manager Tony Phipps said no local authority in the world monitored water for viruses and there was no way of knowing this crisis was going to happen.

The regional council had done everything it could to monitor the water quality at Waikare.

Far North District Council was already upgrading the Kawakawa sewerage system, which would hopefully reduce the risk of pollution into the Waikare Inlet.

- NORTHERN ADVOCATE