Fish Farmer, May 21, 2007

ORNAMENTAL IMPORTS THREATEN BIODIVERSITY AND AQUACULTURE INDUSTRY

[Rachel's introduction: In Australia, fish farmers are worried that imported "ornamental" fish carry novel disease organisms that could infect commercial species.]

It has been suggested by University of Sydney Professor, Richard Whittington, a specialist in the health of aquatic animals, that the 8 to 10 million ornamental fish imported into Australia carry a "plethora of exotic pathogens and parasites recorded and not yet recorded".

"There is no doubt that aquarium fish that are being imported into Australia every week carry pathogens that have the potential to cause severe ecological impacts," he was reported as saying. Professor Whittington and Dr Roger Chong, of Queensland's Department of Primary Industries and Fisheries, report on the serious threat posed by imported ornamental fish, in an article published online prior to its publication in a peer reviewed journal.

As has been claimed by the Australian aquaculture industry, Whittington says that whilst this country has some of the most stringent customs and quarantine standards for importing ornamental fish, they are not good enough.

According to Growfish, one of the reasons he claims stems from international trade rules that only allow blocking the imports of ornamental fish where there is recognised scientific data to back up the ban.

The issue, Whittington claims, is the situation where collecting such detailed information on fish diseases is both "laborious and expensive" and that the majority of imported ornamental fish are from developing countries where disease surveillance is comparatively limited.

"Those [trade] rules need to be revised to enable us to protect ourselves," he was reported as having said.

He says Australia needs to be able to block imports of fish whose diseases (and parasites) have not been studied.

Biosecurity Australia (BA) advise that the rules require that imported fish must spend up to 21 days in quarantine. There is an initial inspection when the fish first arrive and any diseased fish must be re-exported, destroyed or treated by the importer, a BA spokesperson stated.

Whittington pointed out that this regime was ineffective in 2003 when there was a highly damaging outbreak of a serious viral disease, which stemmed from imported gourami fish.

A Murray cod farm in Victoria lost 90% of its stock to gourami iridovirus. Had the farm used the common practice of discharging its waste into local water ways the already threatened species could have been devastated, fortunately this was not the case on this farm. Whittington also noted that inspection of imported fish on arrival clearly cannot pick up non-systematic pathogens that aren't evident at the time, including those that don't impact on the imported ornamentals but are potentially dangerous to natives.

Further, he claims that inspections are ineffective and inspections won't be much use for new diseases that little is known about, he says.

A spokesperson for BA claimed there is a review of quarantine policy for ornamental fish with regard to iridoviruses currently underway and that BA organisation is closely examining Whittington and Chong's paper.

However, Whittington, is of the view that Australian regulators are constantly "one step behind" the latest threats, because a problem must occur prior to them getting the scientific data upon which to base a meaningful risk analysis.

"It's after the event every time," he was quoted as saying. Given the likelihood of problem diseases in imported ornamental fish, Wittington claimed BA should actively lobby internationally for Australia's right to use the precautionary principle where data is unavailable or suspect.

BA's spokesperson pointed out that the organisation is already involved in determining international standards for a "robust science- based approach to quarantine".

"We would review quarantine policies in light of any new science that may become available," the BA spokesman was reported to have said. But he claimed, however, that it is beyond BA's remit to make an official comment on Whittington's call for a more rigorous precautionary approach.

Wittington called attention to the fact that the Australian government has long held concerns over the disease potential of ornamental fish going back to the 1980s, following the entry into Australia of the bacterial pathogen Aeromonas salmonicida with imported goldfish from Japan.

As some of the goldfish were used for bait and unwanted animals were disposed of by members of the public into local waterways, he claimed that wild fish and fish on farms were infected with grave concerns held for the Atlantic salmon farms in Tasmania.

Wittington and Chong's paper also details the problems caused by fighting fish imported from Singapore in the 1980s and their threat to wild eels and farmed rainbow trout.

"There are examples of 22 species of imported aquarium fish that have set up breeding populations in rivers in Australia," says Whittington in local media.

"These infectious diseases could be the straw that leads to the extinction of endangered species, like the Murray cod."

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