Asian Fish Farming

[ahjayem]

G'day All

Received this article in an aquaculture newsletter which I subscribe to.

ARGUMENTS OVER ASIAN FARMED FISH

BirdLife International, the world's leading bird conservation group, claims feeding chicken manure to fish as food is a wide-spread practice in Asia, and that the manure could carry diseases such as avian influenza and sources of gastrointestinal problems. The implication is that people who consume fish fed in this way risk contracting infections. The United nations Food and Agriculture Organisation has in the past strongly supported techniques using manure in aquaculture, but in a 2003 report noted the dangers of the practice, in a report entitled 'Integrated Livestock Fish Farming Systems'. The Australian peak body for seafood imports has condemned reports of Asian fish farms supplying Australia with fish fed using infected chicken manure. A spokesman pointed out that Asian fish was sent to European, American and Australian markets and was required to meet very high standards. Such imports are tested by the Australian Quarantine and Inspection Service, also by importers, with little chance of sources of gastro-intestinal infections not being detected.

Source: Gareth Parker in the West Australian (29/12/2005); Ben Spencer in the West Australian (30/12/2005).

Well, there you go.

RJM

[Leo_N.]

Adding manure is not a feed in itself, but rather a form of pond fertilisation. It aids algae growth, the algae later being consumed by herbivorous fish. This type of farming is common for carp and tilapia farms as these species actually will eat the algae.

There is not a lot of market for tilapia or carp in Australia, but I suspect that this is what the "imported freshwater fillets" from supermarkets are.

I would suspect that fish are an unlikely carrier of avian flu, but I am not particularly keen on risking it.

[DICER]

If they are filleted and the gut cavity remains unpunctured, then the risks of transmission would be lower.

Ruminants (eg. cows, sheep etc) have large amounts (titres) of viral particles in their stomachs, but this in no way effects our health. I'm not sure whether avian influenza or other animal-human viruses can be transmitted/carried through fish, but I'm sure someone out there has done some work in this area before. I don't believe that they could feasibly test for the presence of virus particles on fish fillets easily.

An interesting side point to this article is that a large number of viruses in the human stomach are in fact plant viruses. One recent study identified more than 20 plant viruses in the human gut. One of these infects capsicum/sweet pepper plants and was shown to do so. It's funny because they monitored the diet of individuals and found no traces of virus in capsicum they were eating. They suspect chili and salsa dips contain diseased varieties that make their way into sauces. In no way do plant viruses infect humans or actually live in our guts.

[Leo_N.]

We do test for viruses in fish with PCR. No virus that I know of is transmitted through the muscle - only viscera.

I think that the main concern is the risk of a mutation in the virus that will allow it to switch hosts. Because virions multiply so quickly the rate of mutation is high and therefore they can adapt quickly (this is why there sre so many strains of influenza and the vacines change all the time). I don't think that there have been any cases of non-avian carriers of the avian flu to date, but because it is so virulent the big concern is that it could mutate and become dangerous to humans and other animals.

[Jeremy]

in the courier mail yesterday....80,000 - 90, 0000 tonnes of imported vietamese catfish are consumed each year in Australia. These fish are farmed in ponds in the rice paddies. Sold as pacific dory as well as other things and substitution for other species is rife.

Jeremy

[szopen]

I just bought some of the "pacific dory" fillets from Vietnam.

I have no idea what fish it is but it is not a catfish for sure.

[Hagar]

Sorry - beg to differ . Fish sold in outlets and supermarkets as pacific dory is almost certainly asian freshwater catfish . A friend in the seafood game put me onto it and have since read similar confirmation . There is apparently a push to stop the mis-labeling of this fish and other 'generics'.

Did anyone else see the doco screened a couple of months ago that had a segment on these catfish being farmed in cages strapped under floating sampans in the Mekong delta . All the waste bits from the boat are swept thru a hole in the deck and into the cages to feed the catfish . Are you getting a mental picture ? . I no longer eat pacific dory or anything sold as that !

Chris

[MOZ]

The "90, 0000 tonnes of imported vietamese catfish " was also on Current Affair or Today Tonight in the last couple of nights!

Best answer catch your own! Then at least we know what we are eating!

MOZ

[Derek_Bullock]

I have researched this a number of times and have posted before but there is no such thing as a Pacific Dory. It is a clever marketing ply for catfish farmed in Asia more commonly called freshwater fillets or Basa. Below is an article in relation to it.

I certainly wouldnt ever eat it.


Derek


WHAT FISH IS THAT?

"Things that batter"

23/11/2005

By Anthony Hoy

Australia's appetite for fish and chips is being fed by Pacific dory, aka Mekong River catfish, which is set to dwarf our local fishing industry.
Anthony Hoy reports:

Fish and chips, a wedge of lemon, lashings of batter and salt - a splash of vinegar to dilute the grease, perhaps - and all washed down with a soft drink, a frosty ale or a glass of vino.

December, the start of the long, hot summer. Bring on the lazy weekends and coastal holidays. Forget slaving over a hot stove or a barbecue: dinner is served, at the beach, in cardboard cartons, or parceled up in newsprint lined with greaseproof paper.

But something is missing, and it's not the seagulls or the flies.

The good, fresh, local catch that Australians have for generations associated with their fish and chips - the flathead, snapper, silver and john dory, red fish, bream and whiting - are in increasingly short supply and, as a result, are becoming prohibitively expensive.

In their place in the fish-and-chips pack, like it or not, is "Pacific dory", the so-called "catch of the day" - an innocuous skinless, boneless and bland-flavored fillet.

Pacific dory is now Australia's biggest-selling fish, according to the Master Fish Merchants Association (MFMA).

With sales approaching a staggering 7000 tonnes this year, it is driving a fish shop revolution. Says MFMA chief executive, Michael Kitchener: "Because it is relatively cheap, retailing at around $10 per kilogram, the public love it."

The problem, according to the chairman of the Australian Fish Names Committee, Roy Palmer, is that Pacific dory has never seen the Pacific - or any other ocean, for that matter.

And it is nothing like a dory.

Here's food for thought: the fish you will probably sink your teeth into the next time you are beachside and hungry has been raised in cages suspended under houseboats and barges in the crowded and polluted waters of Vietnam's Mekong River.

The same snap-frozen and imported fish, says Palmer, is being sold as a popular line in Australian supermarkets under the deceptive marketing label, "freshwater fillet".

It is Pangasius bocourti, one of 21 species of freshwater catfish found in the Mekong basin, and - in a move designed to curb deceptive naming practices by fishmongers and supermarkets - last year christened "basa" under Seafood Services Australia's uniform fish names process.

"Basa's success in the marketplace has been a key factor in fish imports from Vietnam doubling in 2002-03 and then doubling again last year," says managing director of the Sydney Fish Market, Grahame Turk.

An estimated 300,000 to 400,000 Vietnamese are involved in the government-owned basa fishery.

It produces more basa than Australia's total seafood production of 550,000 tonnes a year, according to Turk, who is also deputy chairman of the Australian Seafood Industry Council. Vietnam's basa production, Turk says, is expected to reach 1 million tonnes a year within five years.

Vietnam's catfish exports have already decimated the local catfish industry in the US where producers are fighting back.

There is no basa-farming standard among Vietnamese processors, according to the American domestic fishing lobby, thus there is no distinction in the marketplace between professionally farmed product and caged fish from Mekong houseboats and barges.

Sewage systems along the Mekong struggle to keep pace with rapid development, and run-off from the river's hinterland is polluted by fertilisers and pesticides.

American industry sources claim large stocks of basa are fed through holes cut in the floors of houseboats, the human waste from which also goes straight into the river.

Food for the fish includes vegetable and crop waste, rice bran and animal waste.

The Mekong and associated aquaculture ponds have a high silt concentration, say the Americans, and it is common Vietnamese practice to soak the basa fillets in sodium tripolyphosphate (STPP), a chemical used as a preservative and seafood "texturiser".

This means that consumers who purchase basa by weight from Australian supermarkets need to be wary, because fish treated with STPP retain more water.

In August, the American states of Alabama, Mississippi and Louisiana suspended the sale of all Vietnamese aquatic products, following the discovery of the antibiotics ciprofloxacin and enrofloxacin in basa imports.

Ciprofoxacin and enrofloxacin - prohibited in western countries because of the risk of their transferring resistant micro-organisms to humans - were being used by some Mekong River basa producers to combat salmonella and other disease in fish.

The antibiotics can also lead to the development of the infectious disease campylobacter, which can cause diarrhoea, abdominal pain, fever, nausea and vomiting. Vietnam's Ministry of Fisheries has foreshadowed restrictions on the use of 11 antibiotics in its aquatic products sector.

The use of the name basa in place of Pacific dory is not yet mandatory in Australia, says Roy Palmer, "even though there are a lot of reasons why it should be".

An Australian standard for fish names is expected to be launched early in the new year, as a preliminary step towards legislative controls.

"One of the problems is that every state has different arrangements," Palmer says.

"Until there is uniformity, people can drive holes through these issues.

"And the Australian Quarantine Inspection Service [charged with responsibility for making sure imports meet Australian food standards] does not check fish names.

This remains a big problem."


Anthony Hoy