Farmed Shrimp, How Safe?

[jayt90]

Our supermarkets and specialty shops all have farmed shrimp for sale in frozen bags, or thawed on ice. The origin is usually Viet Nam, Thailand, or China. Last year a CBC-1 radio program on food described the production techniques: Rice paddies are converted to shrimp ponds because the selling price is higher. The baby shrimp are fed high protein pellets (similar to farmed salmon) and harvested when the right size is attained. After a few years the pond is drained and abandoned because it will no longer sustain growth. At this time the paddy cannot even be changed to rice prosuction, because there is too much pollution in the soil.

The shrimp expert went on to recommend small shrimp from Newfoundland, or larger sgrimp from Vancouver Island, although the latter goes almost entirely to Japan.

I suspect we should be wary of frozen Asian shrimp for the usual reasons, such as PCB's from the trash fish used in the pellets, but also from the shrimp waste that bukids up in the paddies over a period of time.

Those nice tiger shrimps sold on ice at the fishmonger's are generally out of the same bag!

[jango]

I suspect we should be wary of frozen Asian shrimp for the usual reasons, such as PCB's from the trash fish used in the pellets, but also from the shrimp waste that bukids up in the paddies over a period of time.

Shudder

Your suspicions are dead right.

[CalorieLab]

However the shrimp is produced, the only important thing is whether the end product contains poisons or toxins in a dangerous level. You'd think they could test for this and are in fact testing for this, here on this end. I wouldn't worry about it based simply on anti-globalization activists' scare stories. Remember, science = (1) hypothesis + (2) experimental verification of hypothesis. You can't stop after step 1. Do the PCBs actually exist in shrimp as delivered to the U.S? Has the level of PCBs been scientifically shown to cause disease to a non-trivial portion of the population that consume them?

The media seems to be full of alarmist anti-seafood stories these days: PCBs, mercury, etc. To the extent I've investigated the various stories, they turn out to be somewhat crackpot. If you're not going to eat seafood, you end up with beef (BSE, hormones), vegetables (hepatitis), whatever. In Japan, where I live, everyone eats seafood everyday, and the average lifespan is just fine. I think the key, for food safety as well as nutrition, is to eat a variety of foods, including a variety of seafood.

Mark

[Pan]

Nice to see you here again, Mark.

In Japan, is much farmed fish and seafood consumed?

[Fat Guy]

I suspect we should be wary of frozen Asian shrimp

I'm wary of sweeping generalizations!

[Adam Balic]

I'm wary of loss of mangroves, and therefore fish nurseries, due to Prawn/Shrimp farming in SE-Asian.

[Fat Guy]

Mangrove destruction occurs for a variety of reasons and poorly implemented shrimp farming is one of them. Though it is well publicized, it's not as significant as the timber industry, and it's only part of the picture formed by agricultural expansion, industrial growth, mining, etc. More importantly, not all shrimp farming is destructive to mangroves. Organizations like SEAFDEC are behind many environmentally friendly shrimp farms in Southeast Asia. It's not particularly productive or accurate to say Asian shrimp are bad, or Southeast Asian shrimp are bad, because to do so leads to the inevitable result of non-destructive farms getting caught in the same net as the destructive ones. And then what incentive is there to farm in an environmentally friendly manner? Those who take steps to do right should be recognized for it, not lumped in with the wrongdoers.

[Adam Balic]

Well I don't think I think I was "lumping" anything, however, now that you mention it I have yet to see any SE-Asian farmed prawns/shrimp labelled as "Environmentally Friendly" etc. So I would rather avoid them all, until that occurs. What percentage of the total are these SEAFDEC environmentally friendly shrimp that you speak of? 1%? 10% 90? How do I identify these products?

Saying "...not as significant as the timber industry" is also meaningless. So something that is a big negative, negates the need to be wary of a something that is not quite as negative, but still pretty negative?

Also at the end of the day the most commonly farmed species (Black Tiger Prawn), while having a good texture, they are quite flavourless.

Actually, since this is one of the fastest growing and dynamic food websites on the net, it would be of great value to the food community if eGullet could provide a range of accurate information on the topic, so that they can make the informed decisions, rather then generalisations as you mentioned.

As a starting point, the information that I have on Thailand shrimp farming is that according to the "National Economic and Social Development Board, 640,000 acres of the country's 960,000 acres of mangrove forests have been destroyed by waste water from shrimp farms and about 24% of shrimp farms are abandoned after a period of two to four yearsbecause the soil has lost its fertility and cannot be used forother purposes.". This is one of the most widely circulated items on the subject, is it accurate what do your sources say?

Edited January 14, 2004 by Adam Balic (log)

[Fat Guy]

As a starting point, the information that I have on Thailand shrimp farming is that according to the  "National Economic and Social Development Board, 640,000 acres of the country's 960,000 acres of mangrove forests have been destroyed by waste water from shrimp farms and about 24% of shrimp farms are abandoned after a period of two to four yearsbecause the soil has lost its fertility and cannot be used forother purposes.". This is one of the most widely circulated items on the subject, is it accurate what do your sources say?

This is the abstract I found on the Web awhile back; I've never followed up by acquiring the actual report:

Mangrove area decreased in Thailand by 54.5% between 1961 and 1996 due in part to mangrove conversions for shrimp ponds. By 1993, shrimp ponds were located on 32% of these converted mangrove lands, although some portion of these ponds was not primary conversions. Instead, mangroves were first converted for agriculture, salt production, or some other use and then later converted for shrimp culture when shrimp farming became more profitable. Thai shrimp culture practices before 1980 were mostly extensive with large ponds and low yields of perhaps 150 kg/ha/yr. Many of these extensive ponds were in inter-tidal, mangrove areas.  Starting during the mid-1980s, intensive shrimp culture with >5,000 kg/ha/yr. became the preferred practice in Thailand. Intensive shrimp ponds were mostly located above the inter-tidal zone, either above mangrove or in non-mangrove areas. Intensive culture produces much greater amounts of shrimp on much less land, while at the same time sparing mangroves. Between 1996 and 2000, a reverse trend occurred. Mangrove area increased in Thailand by 46% while shrimp production increased by 23,000 MT/yr and shrimp pond area increased 7%. Thailand's mangrove area during 2000 was about equal to its mangrove area in 1980, well before Thailand's shrimp culture expansion. We attribute these mangrove increases in part to abandonment of mangrove conversions and restoration of mangroves. Some restorations were due to natural propagation and some were assisted by government agencies and NGOs. Public and political awareness and support of mangrove restoration are an important element in their recovery.

http://www.emecs2003.com/abstract.htm

The source for this, a research report prepared for EMECS (Environmental Management of Enclosed Coastal Seas) is I believe one of the Japanese government's conservation-oriented programs. I believe SEAFDEC is also Japan-driven in large part.

I'm not sure what the source is for the figure cited by various environmental advocacy groups. I wasn't able to find a primary quote from the organization cited, only hand-me-down explanations like this one from Greenpeace:

An AP article from May 8, 1995 quotes Santi Bang-oa, assistant secretary-general of Thailand's National Economic and Social Development Board, saying that about 634,000 acres of his country's 950,000 acres of mangrove forests had been destroyed by years of shrimp farm construction, and that about 1/4th of the shrimp farms built are abandoned after a period and that the soil left behind is useless for other purposes."

http://archive.greenpeace.org/comms/97/summit/shrimp.html

[Fat Guy]

Also, from Scientific American:

It cannot be denied that a great deal of environmental damage has arisen from poor planning and management by shrimp farmers and lax government agencies in countries where this form of aquaculture is widespread. But shrimp farming is not always harmful to the environment. Unfortunately, some environmentalists have unfairly made sweeping condemnations of the entire industry. One charge leveled against shrimp farming is that rich investors make quick profits and then abandon farms. Here the critics are just plain wrong. Although some shrimp farms have proved unsustainable and been abandoned, these farms usually were small, often consisting of only one or two cheaply constructed ponds, which were situated on unsuitable sites and operated without sufficient capital and expertise. Properly sited and well-constructed shrimp farms cost from $10,000 to $50,000 per hectare of pond and are expensive to operate. Such large investments cannot be recovered quickly, so owners want to make sure that their farms are productive for many years. Shrimp farming is an interesting example of a situation in which a disproportionate amount of the environmental damage has resulted from smaller operators rather than from bigger

ones.

More: http://www.ioe.ucla.edu/academic/Fall2003/...Clay_101703.pdf

[Adam Balic]

Steve - the example is an abstract example for a conferance, and may not actually be based on any really data. But assuming that it is, a critical point would be how they define "Mangrove", are the new mangroves anything like the original (plant and animal compositition, amount of biomass, presence of key species etc etc). It is a fairly common practice for certain industries to use specific scientific jargon to hide the reality of the situation (not that this is nessarily the case in this instance). A paper increase in mangrove area is meaningless without clarification of there definitions.

As a consumer of shrimp/prawns, I really would like to know this information, as at the moment I avoid these farmed shrimp, but if I had the correct type of information I would pay a premium for shrimp farmed using non-destructive practices (if there is such a thing).

[helenjp]

I also avoid buying shrimp/prawn. I haven't checked in recent years, but I've more than once eaten shrimp that tasted strongly of bleach (not in Japan though), and in Japan I have frequently read that farmed shrimp are raised in water which is permanently laced with antibiotics.

Of course, Japan has it's own reasons for passing on information about imported food safety, but cheap shrimp is cheap for a reason...

[MarkinHouston]

The benefits of living within an hour of where the shrimp boats dock can not be underestimated! Farm-raised shrimp from Texas is also available in groceries here---should the same concerns raised in Asia apply here as well?

[CalorieLab]

Nice to see you here again, Mark.

In Japan, is much farmed fish and seafood consumed?

Country of origin (or prefecture of origin) is shown for most seafood, meat, and poultry. This may be legally required, but I'm not sure. Australian beef is popular these days, by the way.

Fish comes from all over. There is a fishmonger in my neighborhood whose specialty is ultra-cheap tuna from India. And today in the market I saw some fish steaks from Russia and some from Mexico. There was a sale on frozen salmon steaks for 88 yen apiece, very cheap. I assume this was imported and probably farmed (based on the Pantone-spec'ed, dayglo orange color of the flesh). Much of the unagi (eel) these days comes from China since it is so much cheaper. I remember buying some raw, head-on tiger shrimp from the Philippines the other month.

A seafood store proprietor I know tells me that outside of Tokyo there is more variety of fish consumed from local catches; in Tokyo the stores tend to sell the same dozen or so standard types of fish, often imported.

Mark

[Pan]

Thanks for your response, Mark.