Industry. The ‘Pacific Oyster Mortality Syndrome’ may be affecting oysters in some Tasmanian waters but so far not in Circular Head.
POMS, as it is commonly called, is a disease caused by a virus that only affects Pacific oysters (Crassostrea gigas). Mortality rates are highest among juvenile stock.
It is a threat to oysters but not to humans, say authorities.
The disease was first seen in Australia in New South Wales in 2010.
On January 28 this year, an oyster farm at Pittwater in the state’s south east, reported unusually high mortality rates within their oyster stocks. Laboratory testing confirmed the presence of POMS on February 1.
This has since affected the movement of oysters for stocking onto farms. A freeze is in place for the whole of Tasmania, restricting the movement of oysters and materials used in the production of oysters. The restriction does not affect oysters for consumption.
Bolduans Bay Oysters general manager Jon Poke said Biosecurity Tasmania has stopped the movement of all oysters between the state’s growing regions in order to ascertain the current spread of the virus.
As of Monday 10 of the state’s growing regions have been tested; seven have returned positive results.
Surveillance has confirmed the presence of POMS in seven growing areas: Pittwater, Island Inlet, Pipe Clay Lagoon, Blackman Bay, Dunalley Bay and Little Swanport and Great Bay on Bruny Island.
“We’ve had six tests done from this region so far and they’ve all been negative,” he said of Circular Head, which includes Duck Bay, Big Bay and Montagu. (Montagu is yet to be tested, testing will take place once the incubation period has passed.)
Mr Poke said it was “too early to tell” what the full impact on the industry will be.
“Supply will be affected; the volume of the oysters that are available to supply the market will certainly be affected.
“We’ve just got to stress that what oysters are on the market, are safe to eat.”
By way of example he said his son Josh and the Minister for Primary Industries and Water, Jeremy Rockliff, were eating oysters from the Pittwater site on Saturday.
That day, Mr Rockliff announced the state government would provide immediate assistance to oyster growers.
“The fee relief includes waiving this year’s licence fees, due in April, the next lease rental fees and the Tasmanian Shellfish Quality Assurance Program levy too,” he said.
The fee relief will assist every grower across Tasmania (104 lease holders) with an average assistance of approximately $7500, though this will vary depending on lease size.
Mr Poke said the Tasmanian industry, which supplies 90 per cent of Australia’s juvenile spat, has for the past six years been working to breed an oyster that is resistant to the disease.
Growers contribute funds to this ongoing research.
“We’ve got family lines that we’ve been selecting that are now undergoing a full challenge of the virus within growing farms in the south of the state,” Mr Poke said.
“We saw what had happened in France and New Zealand and that’s why we have been taking these measures.”