Don't order shrimp unless you know where it comes from . . .

. . . because foreign shrimp might just be hazardous to your health! An article in the Daily Mail reports on the prawns imported from the Far East to Britain, but it applies also to shrimp imported from there to the USA (shrimp and prawn are very similar, and produced by the same suppliers).

Prawn farming is an ancient activity in tropical countries. Coastal peoples in Indonesia and Vietnam have trapped young marine prawns in brackish ponds for at least 500 years, feeding them up with fish scraps and household waste to eat or sell. The prawns, properly farmed, are sweet and juicy: it's a lucrative business.




But the trade has changed drastically since black tiger prawns became a popular luxury in wealthy parts of the world during the Nineties. The cottage industry was swiftly industrialised. From Ecuador to Indonesia, coastal farmers punched holes in sea defences to let salt water into their paddy fields.

As with salmon, coffee and a host of other once rare and expensive foods, the demand from rich countries brought more and more producers into the market.

Tiger or 'king' prawns and their siblings have become a staple of Britain's supermarkets. The result? Ever-falling prices, but increasing use of chemicals and dropping quality.

The chemicals used in these production systems - which pack 20 prawns into one square metre of foul, endlessly recycled water - have been shown again and again to harm the workers involved, the environment and very possibly the consumers.

. . .

The Huongs - again, like all their neighbours - opened the dykes and turned to prawn farming because of the fantastic profits available.

A field that would have provided enough rice for the family to eat, plus a little extra to sell for essentials, has become a life-changing asset. If this crop is successful, the Huongs will sell the prawns for £8,000 - if prices hold up - after only four months.

This is an enormous amount in a country where many rural people still survive on less than £1 a day. As a result, rice farmers have now become chemists, experts in the complex biology of intensively farmed prawns.

Across the dykes, we see men and women in conical hats dipping testtubes in the water, checking acidity levels and examining prawns in test nets for the dreaded signals of disease: reddening shells, mis-shapen bodies, white spots on their legs.

The prawns, packed into the ponds, are terribly prone to illness. Mr Huong's last batch of prawn larvae all died after a month - he doesn't know why. Indeed, white-spot virus almost killed off the entire industry in Vietnam two years ago.

Having gambled everything on prawns, people will do anything to protect their investment. That includes using any chemicals that may seem to help.

'Often we get consignments of antibiotics for human use that are past the date they can be used by,' a villager told me.

On the main road out of town, near Mr Huong's farm, there is a government sign. Under a vivid picture of jars, bottles and dead prawns, it lists all the chemicals that prawn farmers must not use - 51 of them.

They include many human antibiotics, penicillins, and some names I recognise from the bad days of the European fish-farming industry - nitrofuran, chloramphenicol and organophosphate pesticides.

This poster shows the efforts the Vietnamese government has been taking to educate farmers. But when everything hinges on a successful crop, it is inevitable that some are willing to take risks.

Back in Britain, I ran the long list of chemicals we had found in use at Mr Huong's prawn farm past Peter Bridson, who is in charge of aquaculture at the Soil Association. Nothing we had found surprised him.

'You see this repeatedly in industrial aquaculture. There's a get-rich-quick attitude. Everyone follows the boom, but one false step and it crashes. And disease is usually the problem.'

Most of the chemicals we photographed in Mr Huong's shed are pesticides, feed enhancers and growth stimulants.

'These types of products are commonly used in Asia,' says Bridson. 'The farmers experiment. Someone chucks something in his tanks and gets good results. He tells his mates and the product becomes mainstream in the area - whether it actually does anything or not.'

Mr 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, over-exertion or exhaustion' and as a tonic in cases of weakness or anaemia in animals. (Note that Bayer does not supply the chemical in Vietnam nor market it as a 'nutritional enhancer'.)

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 which is banned in France and Australia. It 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' - a 'medicine for digestion and liver function', made by a Vietnamese company called Cong Ty TNHH.

It contained 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 'under watch' by the U.S. Federal 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 U.S., and subject to EU controls on 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 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 in the feed for Mr Huong's prawns.

. . .

So how worried should we prawn lovers be? Well, Food & Water Watch, an American lobby group that has studied prawn farming for ten years, issued a warning in its latest report.

It said: 'The negative effects of eating industrially-produced tiger prawns 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'.

What is certain is that banned or controlled chemicals are coming into Europe with farmed prawns, despite the promises of governments and retailers to stop this happening.

Last year, the EU rejected shipments of farmed prawn from six major exporters in India because they contained chloramphenicol and nitrofurans - two once-common antibiotics which are now known to be carcinogenic. One causes leukaemia.

The EU claims this shows its regulations work, but the fact remains that the EU is thought to test only 1 per cent of such shipments. The real scale of the problem could be far wider. In Louisiana, a prawn-producing region which conducts its own tests on imports, chloramphenicol was found in 9 per cent of all foreign prawn shipments in 2007.

. . .

But boycotting farmed prawns won't hurt the real villains in all this. As in any tale of shipping foods of the poor world to the rich in bulk, it is big corporations, processors and retailers which make the bulk of profits, and they should therefore take responsibility. Unlike small-scale producers like Mr Huong, they would survive a collapse of the prawn market.

No, to make a difference across the tropics, we customers must demand better prawns, raised in a way that's good for them and the people who farm them. And that means we have to be prepared to pay more for them.




On my desk I have two 212g boxes from my local Tesco of uncooked peeled king prawns from Vietnam, which I found on sale at two for £5. That means the 60 or so prawns cost me just over 8p each.

Once the costs of shelling, freezing, packing and shipping have been factored in - not to mention the supermarket's own profit margin - the producer would have been obliged to sell his prawns for a few pennies each. That is simply not enough to ensure decent standards of welfare and production.

Bad prawn farming is caused by the same things as bad chicken farming - the relentless pressure on prices forced on producers by supermarkets.

The result is a prawn cocktail that only a chemist could love.

Food for thought indeed! I note that as long ago as 2002 the Food & Drug Administration announced increased testing of imported shrimp for some antibiotics. Looks like the problem's only gotten worse since then.

For myself, after reading this, I plan on buying only US-produced shrimp, and insisting that the supplier verify its origin and guarantee the information to be accurate. I'll feel safer that way.

Peter