I showed the long list of chemicals we found to Peter Bridson, who is in charge of aquaculture at the Soil Association in the United Kingdom. He oversees the policing of the salmon farms in Scotland which, controversially, the Soil Association decided three years ago to certify as organic. Nothing we had found in Vietnam surprised him: "This is what you see again and again in industrial aquaculture. There's a get-rich-quick attitude, everyone follows the boom. But then, one false step, and it crashes. And disease is usually the problem.”
 

Most of the chemicals we photographed in Huong's shed are pesticides, feed enhancers and growth stimulants. “These types of products are commonly used in Asian hatcheries,” says Bridson, who has worked in tropical fish farming. “The farmers experiment. Someone chucks something in his tanks and gets good results. He tells his friends and the use of this product becomes mainstream in the area -- whether it actually does anything or not.”

Huong's Super Star contains a chemical commonly used as a “nutritional enhancer”. It is marketed by the company Bayer in Europe as “Butaphosphan”. On Bayer's website all I can find is a recommendation that it be used for injecting into sheep, dogs and cats suffering from “stress, overexertion or exhaustion” and as a tonic in cases of weakness or anaemia in animals. (Bayer does not supply the chemical in Vietnam nor market it as a “nutritional enhancer”.)

The problem is that some chemicals may do more harm than good -- and not just to the image of the tropical prawn. Super Star also contains methyl hydroxybenzoate, an anti-fungal preservative that is banned in France and Australia and has been linked to cancer in some beauty treatments.

The most dubious thing we found in the Huong's arsenal of chemicals was in a pot named “N300”. It is a “medicine for digestion and liver function”, made by a Vietnamese company called Cong Ty TNHH. It had beta glucan, a harmless component of many human nutrition supplements, but also norfloxacin, an antibiotic usually used to treat gonorrhea and urinary-tract infections in humans. It is currently “under watch” by the United States Food and Drug Administration because of increased reports of nasty side effects, including damage to tendons.

Norfloxacin and its siblings, the fluoroquinolones, are banned for use in animals for human consumption in the United States, and subject to European Union controls in imports. Misuse of the fluoroquinolones is increasingly blamed for the rise in resistance to anti-bacterial medicines, and five floxacins are listed on the poster of banned chemicals that we saw at the entrance to the village.

Since 2005, Vietnam's fishery ministry has banned the use of fluoroquinolones in fish destined for the North American market, but not, apparently, for European countries. From the pile of empty N300 jars we saw, there is a lot of fluoroquinolone going into the feed for Huong's prawns.
Numerous surveys have been done on the effects of the antibiotics that are used in prawn farming across the world (31 were identified in Vietnam in a 2006 study, among a total 155 drugs). The surveys conclude that, although the antibiotics may rise to detectable levels in the bodies of the prawns, the most likely damage is being done to the environment in which they're farmed.

It's young Thi Mai who may have problems when doctors try to treat her for skin complaints, diarrhoea, respiratory problems and infections, including malaria, which is common in this swampy landscape. They may find that she is resistant to the antibiotics. Scientists have speculated that some unusual outbreaks of salmonella poisoning in Europe and the United States may have been started by antibiotic-resistant salmonella in farmed fish from Asia.

And the leakage of antibiotics and pesticides into the delicate ecosystem in the coastal shallows of the shrimp-farming countries will have effects that no one fully understands yet. Peter Bridson worries that the chemicals will intensify, because the water system is closed, with water being reused from one farm to another, and for human consumption.

David Moriarty, a scientist at Australia’s University of Queensland, who has studied the wide-scale use of norfloxacin and other anti-bacterials in aquaculture, wrote nine years ago of disturbing effects in prawn farms in the Philippines: “Many of the pathogens appear to have mutated to more virulent forms than were present a decade ago ... I feel that the incidence of disease has been exacerbated by the actions of the [prawn] farmers.” Moriarty now works promoting probiotics to tropical prawn farmers, as an alternative to lacing the waters with chemicals.

Meanwhile, the Soil Association -- which is currently processing applications for organic certification from several tropical prawn farms -- has decided not to allow any use of antibiotics in prawn-growing farms that want to carry its label. The Vietnamese, meanwhile, are working hard to police the use of antibiotics and other chemicals better. VASEP, the prawn exporters' and producers' organisation, points out that 25 new licences were granted to Vietnamese processors by the European Union in January 2008, an endorsement of the fisheries ministry's "urgent efforts" to improve sanitary and safety standards in the prawn industry.

So is that it for tiger prawn kebabs? How worried should we prawn lovers be? Well, norfloxacin is used by countless other farmers in Asia, but it is not illegal in most of those countries (though I could not find it on Vietnam's lengthy list of approved chemicals). There are increasing environmental fears about its overuse, and worries over the effect on human health of all the quinolones. But unless you have a serious king-prawn habit, you are unlikely to ingest anything like a human dose of norfloxacin.

Food & Water Watch, an American NGO that has studied prawn farming for 10 years, states in its latest report: "The negative effects of eating industrially produced shrimp may include neurological damage from ingesting chemicals such as endosulfans, an allergic response to penicillin residues or infection by an antibiotic-resistant pathogen such as E coli." That is a judicious "may". A rational person in this age of food scares would have to conclude you're unlikely to suffer more ill effects from eating farmed prawns than from any other industrially produced food animal. But I wouldn't eat them every day.

It is certain, however, that banned or controlled chemicals are coming into the country with farmed prawns, despite the promises of governments and the retailers. Last year the European Union rejected shipments of farmed prawn from six major exporters in India because they contained chloramphenicol and nitrofurans -- two once-common antibiotics, one now known to cause leukaemia, the other a carcinogen.

The European Union claims that this shows its regulations work, but the fact remains that it is thought to test only around 1% of such shipments. The United States imports US$3.9 billion worth of farmed prawn (or shrimp, as its known there) a year, yet tests hardly more of the shipments than does the EU. All the same, it rejected 2,817 shipments of seafood in 2005, most of them farmed "shrimp". And in Louisiana, a shrimp-producing region which conducts its own tests on imports, chloramphenicol was found in 9% of all foreign shrimp shipments in 2007.

I'm grateful to Taras Grescoe for that last piece of information. His fascinating new book, Bottomfeeder, describes the mad and scary practices of the fishing industry in nauseating detail. Grescoe says he thinks farmed prawn is the most disgusting of all the industrial farmed products -- worse than salmon, worse than battery chicken. And he won't eat them.

It's not just the chemicals that turned him off. The land grab for prawn farms that has destroyed the mangrove forest has harmed wild animals and humans too. Seventy per cent of Ecuador's mangrove has gone. Rights to land are well-established in Vietnam, for women and men, but in other tropical countries there are disturbing reports of abuse of coastal peoples by big business cashing in on the boom. Food & Water Watch has visited one district of Andhra Pradesh state in India where 2,000 families have become "shrimp refugees", displaced by big corporations who wanted their land for prawn farms.

Unlike Grescoe, though, I'm not going to stop eating the prawns. That's too easy. Going on farmed-prawn strike won't hurt the villains in this story. They are, as in any tale of shipping the foods of the poor world to the rich in bulk, the big corporations, the processors and the retailers. They would survive a collapse of the industry; the people who won't are the poor coastal fishermen of Vietnam and 50 other countries for whom prawn farming is proving a way out of poverty. These people have risked much to satisfy our demand for exotic seafood. There's no way back when you flood your family's rice paddy with seawater for tiger prawns. The salt from the water will make it impossible to grow rice again for years.

There are other ways to help them. Oxfam, which has been working in Tra Vinh for 10 years, is helping some of the farmers set up co-operatives and loan schemes to make traditional fishing and farming more lucrative: we visited villages where the whole community has become partners in a cockle-fishing enterprise. Its sustainable, it creates jobs and it's doing well.

But to make a difference across the tropics, we customers must demand better prawns, raised organically and in a way that's good for them and the people who farm them. We have to be prepared to pay more for them. On my desk, I have a 212-gram box from my local supermarket of uncooked peeled king prawns from Vietnam, which I found on sale at a two-for-£5 (US$8) deal. That means the 60 or so prawns cost me about 12 pence (20 US cents) each -- after shelling, freezing, packing and shipping. That is just two pence more than Huong hoped to sell his prawns for. It's not enough. The price is the same for trawled wild prawns from the North Atlantic.

Bad prawn farming is caused by the same things as bad chicken farming -- the relentless downward pressure on prices forced on producers by supermarkets. So, there's a good reason to buy organic. And a good reason too, to ask your supermarket to ensure that more of the money you are spending on a tiger prawn goes back to Huong and his colleagues. Pay him a bit better, and he could farm a bit better. It's that simple.
 

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Copyright Guardian News and Media Ltd., 2008

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