With two of the largest oyster farming areas on the East Coast under threat, it may not be on the Australian Christmas table this year.
It was previously reported that authorities were investigating a link between a "stomach-like disease" and one of the most important sources of Sydney oysters.
Oysters at Wallis Lake near Forster and Tuncurry on the central north coast of NSW are under investigation and authorities have stopped fishing and selling oysters from the lake since 17 October, The Telegraph reported.
Meanwhile, heavy rain and flooding have led to the closure of oyster rental areas on NSW's south coast, making it impossible to catch every estuary south of Sydney, with Christmas just weeks away, ABC reported.
Closed estuaries on the south coast account for nearly 60 per cent of NSW's total oyster production.
Because oysters filter the water in which they live, water quality can have a significant impact, so when bacterial or saltwater levels in waterways are affected, authorities can close leases and cannot be fished.
An oyster producer in Wallis Lake, speaking on condition of anonymity, said closing the oyster farm was "the worst possible time" due to the approaching Christmas.
A spokesperson for the NSW Department for Primary Industries said, "Farms will remain closed until it is confirmed that the oysters at Wallis Lake are safe." On NSW's south coast, Pambula oyster farmer Roy Glessing said he would not be able to harvest his oysters after 250mm of rain in recent days unless the saltwater level in the system increased.
It's hard to say if we'll be open at Christmas," he said, adding that much depends on the amount of rain in the coming weeks.
His oysters will eventually be sold in Canberra, Melbourne and Sydney. Mr Glaising said this could lead to a shortage of oysters over the Christmas period and a major economic blow to oyster farmers on NSW's south coast.
Many local farmers rely on cash flow around Christmas, and now is the peak time to sell oysters. ”