Once-crippled rock oyster industry forges ahead with disease-resistant technology


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November 04, 2018 06:12:20

Fifth-generation oyster farmer Rob Moxham doesn’t hesitate for a moment when asked what he’d like for his last ever meal.

“It’d be about 10-dozen nice fat Sydney rock [oysters],” he said.

“It wouldn’t be lobster, it wouldn’t be steak, it’d be 10-dozen nice fat Sydney rocks.”

It’s been a while since the farmer from Hawkesbury River north of Sydney has grown his own rock oysters, since the industry has been severely hit by bouts of disease.

In 2003, QX disease swept through what was then the third-largest oyster-growing estuary in New South Wales.

The deadly parasite virtually wiped out the Hawkesbury’s 23 growers, most of whom walked away from their farms.

A $3 million state government grant to help clean up derelict oyster leases helped Mr Moxham hang on until he and other growers could establish a Pacific-oyster industry in the Hawkesbury.

They removed about 8,000 tonnes of rubbish and by 2013 were again producing millions of dollars worth of oysters.

However, the recovery proved to be short-lived when a new disease outbreak struck.

That year, Pacific Oyster Mortality Syndrome devastated the river’s oyster populations virtually overnight.

At the time, Mr Moxham described the outbreak as like a bushfire, racing through 5 million oysters.

“You couldn’t see anything wrong with it, to being 100 per cent dead in 48 hours — it was incredible,” he said.

Since then, he has hung on grimly, hoping new disease-resistant genetics would revive the industry.

Towards a disease-resistant oyster

This year, Mr Moxham and fellow grower Bruce Balford have been working with scientists from the New South Wales Department of Primary Industries (DPI) on a new QX-resistance trial of 500,000 oysters.

After 18 years of research, the breeding program has reached an expected QX survival rate of 80 per cent.

Senior research scientist Dr Mike Dove said the program was slow in the early days because it relied on mass selection of oysters, which had problems with inbreeding and required the molluscs to grow for about three years before they could be selected for resistance.

Since 2014, the program has bred from family groups and so has been able to select better genetics from year to year.

“We can look at which families are particularly resistant and we can hone in on incorporating other traits which are important to commercial oyster farmers, namely growth and condition, and combine all that in a highly QX-resistant oyster,” Dr Dove said.

As the Hawkesbury industry shows tentative signs of life, elsewhere in New South Wales the Sydney rock oyster is enjoying a resurgence in popularity and price.

According to the DPI’s aquaculture manager Ian Lyall, the industry is worth more than $47 million and is expected to grow by 10 per cent this year.

“It’s a really solid recovery from a period when the industry was restructuring.”

“Now they’re adopting new technology, we’ve got new entrants to the game, many of the younger generation are coming in with new ideas and new investment,” he said.

“It’s built on the back of cooperation between industry and government and a really sound food safety program of world quality.”

Mr Lyall said the demand for the native species had increased off the back of disease problems for Pacific-oyster growers in Tasmania and South Australia, but the New South Wales industry had also improved its marketing.

“I think they lost that space for quite a few years, lost the agenda to other species of oysters and products in the entree market, but oysters are so good for consumers,” he said.

“They are such a natural product that [producers] are really taking advantage of, that demand for seafood, good quality seafood, and [consumers] are looking at the regions where their oysters are coming from, very much like the wine industry, and that’s really playing well for their marketing strategy.”

Mr Moxham said he was confident the Hawkesbury could once again host a $10 million oyster industry and that any of his four children could choose to follow the family tradition into oyster farming.

“I wouldn’t point them in that direction but I hope we can provide them with the opportunity to have a sixth-generation oyster farmer,” he said.

“The oyster industry in New South Wales is the oldest aquaculture industry and it’s the biggest aquaculture industry in New South Wales.”

“It’s been around for 130 years. If it takes a few years to get it back up and running I think it’s well worth it.”

He said the future health of the river depended on a healthy oyster industry because filter-feeding molluscs were so sensitive to pollution and provided the best early warning of any problems.

“It ticks all the boxes environmentally if you do it properly,” he said.

“If you haven’t got a decent oyster industry there then the river’s in trouble, it’s like the old cliche [of] the canary in the coalmine.

“It’s something worth fighting for, that’s for sure.”

Watch this story on Landline on Sunday at 12:30pm.

Topics:

fishing-aquaculture,

rural,

science-and-technology,

disease-control-methods,

control-methods,

pests-diseases-and-control-methods,

environmental-technology,

nsw,

sydney-2000,

australia



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