NSW oyster farmers are hoping a mysterious disease that wiped out stock at a creek north of Sydney has been contained.Testing by the Department of Primary Industries has confirmed a patch of shellfish that died in the Hawkesbury River were infected with Pacific Oyster Mortality Syndrome, which is not dangerous to humans.
Local farmers sent oysters for testing when they first began dying and immediately imposed restrictions on oyster movements within the Hawkesbury.
DPI aquaculture manager Ian Lyall said POMS posed no risk to human health, nor to Sydney rock oysters or native flat oysters.
"Pacific Oyster Mortality Syndrome only affects Pacific oysters," Mr Lyall said.
"The DPI is working closely with local oyster growers to manage a closure that restricts the movements of any oysters and equipment to other estuaries."
But he said little was known about how the syndrome spread and further outbreaks could have a devastating economic impact on farmers.
Local grower and Broken Bay Oysters Association president John Stubbs said the mortality rate at Mullet Creek on the Hawkesbury River was 100 per cent.
It was too early to say whether this latest outbreak had been successfully contained, he told AAP, but 14 BBOA businesses had been affected by the Mullet Creek outbreak.
"We do have other harvest areas and, touch wood, those harvest areas have remained unaffected," Mr Stubbs said.
"Because Georges River and Sydney Harbour were positive for (POMS) in 2010, we've had various meetings with the government and tried to nut out plans of attack."