A new breed of Pacific oyster is giving hope to the Australian seafood industry after outbreaks of a deadly disease decimated stocks across New South Wales and Tasmania.
Developed by Australian Seafood Industries, the new oyster is resistant to Pacific Oyster Mortality Syndrome (POMS). POMS is a virus that affects baby oysters (spats) when their environment reaches 19 degrees for 10 consecutive days or more.
In 2013, an outbreak of POMS wiped out the New South Wales oyster industry, spreading to Tasmania in 2016. It has also been detected in feral oysters in South Australia, although no outbreaks have been seen in commercial fisheries.
“It stops them dead,” said Dr Len Stephens, chair of Oysters Australia.
“The industry [was] shell shocked for a year or two.”
The development of a POMS-resistant oyster includes breeding trials with a group of growers on the Hawkesbury and Georges rivers in New South Wales.
“[Breeding resistant oysters has] proved to be a very wise decision for the industry,” said ASI managing director Matt Cunningham, who has been running the trials.
If successful, the resistant Pacific Oysters are likely to be highly sought after by fisheries across the globe. POMS struck oysters in France in 2008 and New Zealand in 2010, obliterating stocks.
Australia’s oyster sector recovered from POMS outbreaks much quicker, due to ASI’s breeding program. However, the outbreak still had a significant toll on oyster farmers.
“[POMS killed] virtually 100 per cent of Pacifics in a matter of days,” according to New South Wales oyster farmer Bruce Alford.
“Four farmers [out of thirteen] were left here in 2013. Everyone else sort of shut up shop and went and did other jobs.”
Results from the initial POMS trial should be released in the next few months.
“We’re pretty confident that we’re going to have at least a pretty good resistance level and it’s only going to get better as the next couple of years go on,” said Mr Alford, who is taking part in the trial.
Based on the Hawkesbury River, he also farms Sydney rock oysters which were decimated by QX disease in 2004. QX – named because it was first detected in Queensland, with an unknown cause – is a parasite that affects the digestive gland of the oyster, effectively starving them to death.
He sees breeding programs as the key to managing disease outbreaks.
“[The industry] won’t exist without [ASI’s] input through the POMS resistance program. If they ever have to stop, then we have to shut up shop. We’ve got no way forward without the breeding program.”
For Mr Alford, breeding a POMS-resistant oyster has provided a new level of hope to the industry.
“Everyone’s looking towards what they’re going to do next year, which is something we haven’t been able to do for the last seven or eight years.”
Disease outbreaks have had a significant impact on price stability for the oyster sector. At the Sydney Fish Market, Pacific oysters hover around $19-22 per dozen during the festive period, increasing to $20-27 per dozen after the 2016 POMS outbreak in Tasmania.