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Global Aquaculture Issues - 3/2012

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Vietnam's struggle with antibiotic residues

Thursday,29 March,2012 08:09:50

In the latter part of last year and the early part of this year Japanese and Canadian government screening has unearthed many examples of higher than allowed enrofloxacin residues in farmed catfish  (basa and tra or pangasius) and shrimp. It is not clear if there are only a few companies that are doing this or if it is widespread. From my perspective, either would not be surprising. It is important though to appreciate that it is highly unlikely that even if a consumer were to consume fish or shrimp that had just been fed this antibiotic that it would pose any measurable threat to the consumer. The threshold levels that have been legislated for antibiotics are determined by technology limitations and not by risk assessment.  

This makes for ready fodder for NGOs that want to scare the public into believing that they are consuming something that could harm them or for competitive industries that believe that trying to undermine public confidence in an imported product is a constructive way to deal with competition.

Buying and using antibiotics in the U.S. for use in aquaculture can carry stiff penalties if unapproved antibiotics are used. This discourages their use, although realistically a farmer that is faced with a catastrophic loss of his crop could resort to doing whatever it takes to mitigate this. Generally farmers are well educated, understand the risks and focus on using those few antibiotics that are approved by the FDA. They understand withdrawal times and may have insurance in the event of a catastrophic loss.

In Vietnam the case is different. Farmers are not usually well educated and they are easily taken advantage of by salesmen that care more about their immediate profits then helping the customers to better understand what they are doing wrong and to correct it.

Despite the myths pangasius are just as susceptible to disease as other fish species and they are typically cultured at extremely high densities since they can breath air if dissolved oxygen levels are too low in the water. This is a stress and culturing fish at these extremely high densities allows for ready transmission of pathogens between fish.

Diagnosis of the underlying cause of mortality is rarely done and farmers have to resort to whatever tools that have available to stave off financial disaster. The same goes for shrimp. As rearing densities increase and farmers take short cuts they see more disease. Enrofloxacin is readily available. It is important to understand as well that in the U.S., there are only a few antibiotics that are available for treating specific bacterial diseases. Use of any other antibiotics (there are some exceptions) is problematic and there are many who believe that the U.S. should be telling countries that the only antibiotics that can be used on fish or shrimp imported into the U.S. are those that are approved for use in the U.S. This would cause serious hardship for a large number of farmers and encourage cheating. 

What can Vietnam do?  The government can step in and require that all product that is exported be screened by government labs or trusted third-party labs. Alternatively harvest permits can be issued to farms only after testing reveals that there are no residues. Banning the use of enrofloxacin will only drive its use underground (if it has not already been done so).  By properly following withdrawal and usage guidelines much of the trouble can be avoided. Educating farmers can be helpful although without some form of penalty that is actually enforceable for not following the guidelines there is little hope of the situation being remedied.

Typically when violations of this type are as common as are being reported, there can be very serious repercussions with complete import bans being enacted on the species of concern. This would be economically injurious and disastrous to Vietnam as well as many suppliers if a major importer, such as the U.S. or EU were to do this. What is curious in all of this is why the U.S. is apparently not reporting the same thing. There are some that argue that this might be a reflection of the U.S.’s inadequate screening testing.  

The bottom line is that the ultimate responsibility for this lies with the importer. They should be ensuring that their suppliers comply with the legal requirements. This is readily achievable by having routine unannounced audits of processing plants and requiring that all product be tested using ELISA to start on each lot and more sophisticated technologies for corroboration. Relying entirely on third party for profit certifications, while useful, does not relieve the importer of this responsibility. If bans or mandated government screening forcing many month delays while product is being tested are enacted then there will be dire economic consequences. 

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Yellow journalism is alive and well…unfortunately

Friday,9 March,2012 07:56:00

I recently was pointed in the direction of a short film produced by a major NGO about shrimp farming in Thailand. I am amazed at how an organization of this stature can be so far from seeing the reality and repeat the fallacies that others have. 

The film makes it look like shrimp farmers in Thailand have cut down large areas of mangroves to build their farms. While there is no doubt that some mangroves were cut, this was a long time ago and is no longer standard practice and has not been for many years. To suggest that shrimp farming is the major culprit in cutting mangroves is not only false but totally irresponsible. Most of the mangroves were cut to provide fuel for use as charcoal to cook food. This is well documented.   Soils that support mangroves make lousy shrimp farms. Most of Thailand’s shrimp farmers follow a code of conduct that does not allow mangroves to be cut with few exceptions and it is common to see companies planting mangroves to compensate for those that were cut often planting many times the few that might have been removed.

The film also suggests that drug use is wide spread and points to a bag that contains a mixture of microbes as a potential source of antibiotics. This is nonsense. The addition of microbes to ponds, while often of little use, is a benign practice that does not involve the use of antibiotics. The use of antibiotics in Thailand is tightly regulated and it is simply not true that it is a common practice. The Thailand Department of Fisheries along with their FDA equivalent are aware of international bans on the use of specific antibiotics and while there likely is some use, the vast majority of shrimp farmers do not use antibiotics at any time during the rearing cycle.

The use of Burmese workers is also brought up and it is suggested that slave labor is used and that they are housed under deplorable conditions. Again this is wrong. While it would be naïve for one to think that there are not cases where this does occur, it is far from the norm. There are many Burmese workers in processing plants. They are there because they will work for less money than Thai workers, although they must be paid the legal minimum wage. They may live on the plant grounds and by Western standards they may not be housed in luxurious accommodations but by local standards however they are comfortable and their presence is regulated by the government. They have to have government permission to work and they can quit any time that they want. In some cases they may be subcontracted and these subcontractors are also regulated.  

Why can’t these NGO’s print and film the truth? Why do they persist in making it look like the worst is the norm? There are a lot of honest, hard working people that depend on shrimp farming for their livelihoods. Reporting of this nature can hurt them economically and reinforces the negative stereotype that some NGO’s seem to want. It is confrontational in nature and ensures that an us versus them mentality persists. There is nothing wrong with finding that these are not perfect systems but we would all be better off if this was done in a truthful manner and not whitewashing an entire industry because of a few bad players.   

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