Spat with POMS affecting oyster supplies in disease-free South Australia

A reliance on POMS-affected Tasmania for oyster spat has led to shortages in South Australia, as the import of spat into the state has been banned for nearly two years. But because of the 18-month growing period from spat to commercial oyster, the full effects of the moratorium are only starting to be felt now.

Oysters are one of South Australia’s most valued premium seafood products, with the state typically producing about 5,400 tonnes annually — generating A$38m (US$29m) for the local economy in 2015-16.

It is Australia’s largest Pacific oyster growing state and includes premium regions such as Coffin Bay and Smoky Bay.

The South Australian Oyster Growers Association predicts production to be down by 50-70% in the coming months following the spat moratorium.

In response to the spat closure, two of Tasmania’s largest spat producers, Cameron of Tasmania and Shellfish Culture, have established hatcheries on South Australia’s Eyre Peninsula.

Cameron’s entered into a joint-venture with Australia’s largest abalone spat producer, SAM, in Port Lincoln, while Shellfish Culture opened its A$4m Eyre Shellfish hatchery in Cowell in October.

Cameron’s began sending spat to South Australian oyster leases earlier in the year, while the first juvenile oysters from Eyre Shellfish started making their way to local farms last month.

The South Australian Pacific Oyster industry began in the 1970s and has until 2016 relied on Tasmania for more than 80% of its spat.

Good position​

South Australian Oyster Growers Association executive officer Trudy McGowan said although the next year or so would be very difficult for oyster growers, there was a substantial long-term benefit.

“We’re treating it like farmers would a drought, but longer-term the industry will be in a really good position because we will have strong supply and no POMS disease​,” she said.

“The important thing going forward for us is that once we fill our backlog of spat — realistically that’s going to take at least until the middle of next year — we have the opportunity to sell spat to other parts of Australia and hopefully internationally as well​.

“South Australia should become the oyster capital of Australia because of the substantial infrastructure we now have with hatcheries and the fact we are POMS free so that’s a really good position for the state long term​,” she added

POMS, or Pacific Oyster Mortality Syndrome, was first detected in France in 2008 and has since been found in almost every major Pacific oyster producing region, including New Zealand, New South Wales and Tasmania.

South Australia’s pest-free reputation and clean, green image stretch well beyond the waters of Spencer Gulf. It is the only mainland Australian state to be free of phylloxera — a tiny insect with the ability to destroy vineyards — and fruit fly, which can severely impact fresh fruit industries.

McGowan said clean growing conditions, minimal boat traffic, strong bio-security practices and the lack of a wild Pacific oyster population to spread disease, were factors that helped keep South Australia POMS-free.

“That’s why we’re so protective of the environment: South Australia is very fortunate to have the cleanest waters to grow its oysters and other seafood​,” she said.

“The big advantage we have is that our oysters are grown in the ocean rather than in estuaries where there is a lot more run-off and more people​.”