Abalone means rich pickings for some, but now a devastating virus is putting a dent in the state's $80 million share of the market. Paul Heinrichs reports that scientists are at a loss to explain how the virus appeared, where it came from, or what to do about it.

VICTORIA'S $80 million abalone industry, which turned $2 fishing licence holders into multi-millionaires, is experiencing its first big setback with the spread of a devastating new virus.

The industry contributes to Australia's supplying half the world's abalone but has become bitterly divided by suspicions that the disease might have spread from farms to the wild stocks.

Abalone, a rich-tasting and costly shellfish, is being wiped out in western Victorian waters by a herpes-like virus known as ganglioneuritis. The virus was unknown until it was first noticed 15 months ago on commercial abalone farms at Portland and near Port Fairy.

It is not known to have any ill effects on people, but infected abalone, which lose their grip on undersea rocks and eventually die, are not being harvested.

After the virus reappeared last May, the farms voluntarily quarantined themselves, sacrificed abalone stock worth millions of dollars and decontaminated equipment.

But the virus appeared in the sea off Port Fairy at the same time and has now spread east to Warrnambool 25 kilometres away and west to Portland, wiping an estimated $45 million from western region licence values.

Now the Victorian Abalone Divers Association, which represents the majority central region from Warrnambool to Lakes Entrance, is taking drastic steps to try to prevent the virus spreading to its lucrative waters.

It wants a voluntary ban on all fishing between Warrnambool and Port Campbell to make sure human activity does not inadvertently contribute to the spread.

Fisheries Victoria has also come under attack from state Opposition agriculture spokesman John Vogels, who accuses it of having been "very slack" in not quarantining the initial outbreaks, a charge it denies.

Executive director Peter Appleford says: "Once these diseases get into the wild, if they are spreading, there's nothing we can do to stop it."

Divers at Port Fairy such as Peter Riddle say the local wild abalone harvest will be severely reduced for years, damaging their incomes and reducing turnover through the local cannery.

Biosecurity measures are in place, but the virus appears to be spreading by sea, turning up in abalone in the Merri Marine Sanctuary off Warrnambool.

Dr Appleford says Fisheries Victoria's practice in the case has been reviewed and praised by international experts, who were called in to do epidemiological studies.

He says there is no certainty about how or where the virus came from.

The Australian Abalone Growers Association, which represents commercial farms, says a panel of experts feels it is most likely a naturally occurring virus has simultaneously affected the farm and wild sectors alike.

"We feel the reputation of our industry is being sullied with a wide range of accusations that do not have credible scientific support," spokesman Shane McLinden says.

• The Age