Food and beverage stories
Super oysters lift industry
Promising trials of a newly developed super Pacific oyster have instilled renewed confidence in Tasmania’s $26 million industry.
Local growers were harvesting more than 4 million Pacific oysters a year and Tasmanian hatcheries were supplying other States with 90 per cent of their spat requirements when they were stopped in their tracks in early 2016 by an unprecedented outbreak of Pacific oyster mortality syndrome (POMS).
The disease had decimated industries in France and Sydney and first appeared in Tasmania during a marine heatwave when water temperatures rose 4 degrees and remained elevated for weeks.
POMS wiped out millions of oysters in south-east Tasmania, cost farmers millions of dollars and caused temporary farm closures and the loss of many jobs.
A $7.6 million State-Federal response package included funding to speed up the development of a POMS-resistant oyster.
Scientist Matt Cunningham has been selectively breeding increasingly POMS-resistant oysters in a hatchery at the Institute of Marine and Antarctic Studies (IMAS) in Hobart.
In May, millions of his most resistant stock were introduced to Pitt Water, a growing area east of Hobart where the deadly virus was first identified.
“Funnily enough what we have to do in this game is to put them … in harm’s way, with the POMS virus,” Mr Cunningham told Fiona Breen of the ABC.
“We've got to trust that we’ve done a good job in breeding these oysters and that they are resistant.
“Unfortunately they are going to go out and be challenged and that’s the way we weed out the weak ones.”
The Pacific oyster industry nationwide had been funding the research since before the virus was first detected in Australia in 2011, in New South Wales waters.
Increased funds from the Tasmanian and Federal governments following the Tasmanian outbreak has enabled IMAS to ramp up its research.
“The seed that is going out into the water today is our Y16 seed … we had a great result in our hatchery,” Mr Cunningham said.
“Our 76 families give us a lot of genetic diversity and a lot of choices for the future.”
Those that survive the next wave of POMS, expected next summer, will be used to repopulate the Tasmanian industry.
Pitt Water oyster farmer Josh Poke is counting on the geneticists to pull the industry through.
Like most Tasmanian Pacific oyster farmers, he has gone through two major rounds of POMS and survived last summer’s second wave with mixed results.
“We probably lost 3.5 million of our seed oysters,” Mr Poke said.
On the Tasman Peninsula, third-generation oyster farmer Ben Cameron has adopted a window-farming approach, limiting operations to eight months of the year.
“It’s not a long-term solution. We need to be looking to extend our windows of operation, not to permanently contract them,” Mr Cameron told the ABC.
“I think the good thing about us having a hatchery is the access to … abundant surviving brood stock that we can breed from,” Mr Cameron said.
Before POMS arrived, the Camerons supplied millions of baby oysters to the South Australian Pacific oyster industry, which is still POMS-free.
The discovery of the virus in Tasmania led to a ban on the movement of anything oyster related between the two States and was a serious setback to the Camerons’ business and to the South Australian industry that relied on their spat.
Tasmania’s Pacific oysters have been improved through genetic selection over generations, ever since they were introduced to the State from Japan as war reparation in 1947.
Overseas producers gather their spat from the wild and this prevents them from matching the genetic improvements that have been made in Tasmania.
In a big move, the Camerons joined a South Australian seafood business to build a hatchery near Port Lincoln which has just started supplying farmers.
“The relief on some of these farmers faces, they are so happy, it’s a sign of hope and a sign they've got a future in farming,” Mr Cameron said.
The Tasmanian Budget in May confirmed funding for a $1.2 million biotoxin testing laboratory that will enable local growers to phase out time-consuming and costly interstate testing.
The new facility will be built in southern Tasmania.
While science and investment provides welcome good news in a troubled industry, oyster lovers can expect to continue to pay more in the near future.
A continuing national shortage of spat will constrain supply.
South Australian Oyster Growers Association spokesperson, Trudy McGowan, said: “Growers have received about a third of the spat they normally would receive and so this will lead to some level of shortage, but we are not sure how much.
“Prices may go up as you would expect with any shortage, but by how much is not known at this stage.”
If there is one message that is critical to the industry it is that Pacific oysters remain safe to eat.
“Oysters are a very safe product,” Mr Cunningham said.
“The POMS virus is very specific to oysters; it has no human impact whatsoever so keep eating oysters, we need you to keep eating oysters.”
Image courtesy of Martin Turmine
6 June 2017, Edition 184