Devastated prawn farmers say the government should have acted years ago to stop the importation of raw prawns they suspect brought an exotic virus to Australia.
Agriculture Minister Barnaby Joyce on Friday announced the indefinite suspension of green, or raw, prawn imports after white spot disease was found at five farms near the Logan River in Queensland's southeast, and in wild prawns in the river itself.
Prawns worth tens of millions of dollars, which were being raised in ponds at the infected farms, have had to be destroyed since white spot was confirmed last month.
Mr Joyce says the virus could devastate Australia's $360 million industry if it takes hold.
Some farmers believe the issue could have been avoided if the government banned green prawn imports following a 2009 risk assessment which found that without proper safeguards, diseases carried by imported raw prawns could spread to Australian populations.
But instead of a ban, Biosecurity Australia beefed up quarantine rules to mitigate the risk.
Australian Prawn Farmers Association board member Nick Moore has welcomed the import suspension, but says it's akin to shutting the gate after the horse has bolted.
"Can you imagine deliberately importing a product with a virus that can actually infect non-infected stock? You wouldn't do that," he told ABC television on Friday.
"This has just taken time for a rather expensive penny to drop."
Mr Moore, who also manages an infected farm, said the owners of affected properties were each facing losses in the tens of millions of dollars, and there was no insurance available while prawns were still being raised.
The import suspension will remain indefinitely, but does not affect cooked prawns because the cooking process destroys white spot.
The virus poses no risk to human health but can rapidly kill prawns.