By Dr. Mercola
It’s a sad fact that we’ve more or less made an entire healthy food group toxic due to manmade pollution.
With just a few exceptions, most seafood is contaminated with environmental pollutants such as mercury and PCBs, and farmed seafood is typically fed antibiotics and other drugs.
In most respects, fish and shrimp farms are riddled with the same problems as land-based confined animal feeding operations (CAFOs), which include disease-promoting overcrowding, unnatural diets, and environmental pollution.
Even shrimp, which due to their small size, have been considered one of the safer kinds of seafood in terms of contamination, are not recommended unless you can verify that they're wild-caught from a clean source—and therein lies the problem.
What you see on the label isn’t always what you get, as many shrimp products are mislabeled and completely misrepresented.
Seafood Fraud Is Big Business
Last year, a report1,2 by the ocean conservation group Oceana revealed that over 30 percent of shrimp products sold in US grocery stores and restaurants are misrepresented. Fifteen percent were mislabeled in regard to production method (farm-raised or wild-caught) or species.
Farmed species were often labeled as “Gulf shrimp,” and different species were often mixed together in one bag, or otherwise mislabeled. One sample of frozen shrimp salad even contained a type of aquarium pet shrimp that is not intended for human consumption.
Ironically, if you’re looking for wild-caught shrimp, you may be best off purchasing products labeled simply as “shrimp,” as two-thirds of such packages contained wild-caught Gulf shrimp, while more than one-third of those labeled as “Gulf shrimp” were actually farm-raised!
Fish are also frequently misrepresented and mislabeled, and the ramifications can be more serious than simply overpaying for an inferior product. In an earlier test, published in 2013, Oceana3 discovered that 84 percent of white tuna sampled from US retail outlets were actually escolar—a fish that can cause severe digestive problems.
As noted by The Atlantic,4 seafood fraud is costing Americans an estimated $25 billion annually. But why misrepresent seafood?
For starters, less than one percent of imported seafood is inspected for mislabeling, and seafood businesses can avoid paying higher anti-dumping tariffs by misrepresenting the seafood being imported.
In one case, passing off Asian catfish as grouper saved the company more than $60 million in such tariffs.5 Grouper also sells for about four times the amount as catfish, so money is to be made on the resale end as well.
Lack of Inspection and Oversight of Imported Seafood Adds to the Problem
Today, the vast majority of shrimp (over 90 percent) come from industrial shrimp farms off the coasts of India, Indonesia, Thailand, Vietnam, and other countries where industry regulations may be less strict than the US.
For example, the US does not permit the use of antibiotics in shrimp farming, but many other nations use antibiotics in their operations.6 As noted in the featured video by Consumer Reports,7 it’s illegal to import shrimp raised on antibiotics into the US.
Antibiotics can hide lack of hygiene in the shrimp ponds, and overuse promotes antibiotic resistance. Yet in one recent test, Consumer Reports detected antibiotics in 11 of 342 samples of imported raw farmed shrimp, and lack of enforcement of the laws is part of the problem.
Bacteria were also detected on 60 percent of the shrimp tested, including bacteria that can cause staph infection and food poisoning, which is suggestive of poor hygiene among food processors.
Why Farmed Shrimp Is an Unsustainable and Risky Choice
Aquaculture promotes itself as a sustainable solution to overfishing. But in reality, seafood farms cause as many problems as they solve, and may even be making matters worse.
Carnivorous sea animals such as prawns need fish in their diet, and dwindling fish stocks in the wild has led to illegal fishing; some of it within national park waters off the coast of Thailand—an area that now supplies much of the fish meal to feed factory farmed animals, including farmed shrimp and prawns.
Trawling for “trash fish” along the coast of Southeast Asia to meet the demand for shrimp feed is having devastating effects on the ecosystem.
All sorts of tropical fish, and even rare shark species, sea sponges, starfish, and octopi end up as fish feed in this process, and catching small, immature fish reduces overall fish stocks, as bigger fish are left without a suitable food source. The end result is rapidly decreasing fish stocks for human consumption. In short, the entire balance in nature is being destroyed.
Shrimp farms are also having dramatically negative ramifications for already impoverished people. In Bangladesh, for example, many native farmers have lost their land to industrial shrimp farms, and once fertile crop land now lies buried under manmade prawn ponds, owned by non-locals.
Illegal toxic pesticides are also routinely used to farm shrimp in some of these areas, including endosulfan, a broad spectrum insecticide that is banned not only in Bangladesh, but also in more than 80 other countries due to its environmental and human toxicity.
If You Choose Wisely, the Benefits of Seafood Can Still Outweigh the Risks
While seafood can be contaminated with a number of different toxins, one of the major ones to beware of is mercury. Fish is a great source of important fats—both saturated and omega-3s—but the benefits of eating fish can easily be negated by selecting varieties that tend to be highly contaminated with mercury.
So, while the recommendation to eat more fish would be solid advice in a toxin free world, today you need to take mercury content into account, as mercury levels can vary more than100-fold from one species to another.
For example, research8 published in 2010, which quantified the contributions to total mercury in the US seafood supply by 51 different varieties of fish and shellfish, found that tuna was responsible for more than one-third of Americans’ total exposure to methylmercury.9
For a handy list that you can print out for reference, please see the Mercury Policy Project’s guide10 to mercury levels in different varieties of fish and shellfish. A recent article in Investigate West11 also addressed this issue, and includes a number of graphs showing not only mercury content in different fish, but also other contaminants such as PCBs. Tuna, snapper, and halibut top the list of fish containing the most mercury and PCBs (the results were from fish sampled in Washington State markets and the Puget Sound).
Among the safest in terms of contamination, and the highest in healthy omega-3 fat, are wild-caught Alaskan and sockeye salmon. Neither is allowed to be farmed, and are therefore always wild-caught. The risk of sockeye accumulating high amounts of mercury and other toxins is reduced because of its short life cycle, which is only about three years.
Additionally, bioaccumulation of toxins is also reduced by the fact that it doesn't feed on other, already contaminated, fish. The two designations you want to look for on the label are: “Alaskan salmon” (or wild Alaskan salmon) and “Sockeye salmon.” Canned salmon labeled "Alaskan salmon" is a less expensive alternative to salmon fillets.
A general guideline is that the closer to the bottom of the food chain the fish is, the less contamination it will have accumulated, so other safer choices include sardines, anchovies, and herring. Shrimp is also low in mercury, but as noted above, there are many other issues with shrimp, especially imported and farm-raised shrimp that makes it less than desirable from a health and environmental perspective.
Canned tuna, mackerel, swordfish, grouper, marlin, and orange roughly have some of the highest levels of mercury levels and are best avoided—especially if you’re pregnant or planning a pregnancy. For even more information about mercury in fish, I recommend reviewing the Mercury Policy Project’s website, Mercury and Fish: The Facts.
How to Avoid Getting Scammed When Purchasing Seafood
Under the US federal Country of Origin Labeling Law, also known as COOL, fresh seafood must disclose where the food was farmed or caught. However, this rule does not apply to processed foods, including seafood that is boiled, breaded, or added to packaged meals. Nearly half of all shrimp sold in the US are processed and therefore do not bear country of origin labels.
Restaurants are also exempt from this labeling requirement. This makes it virtually impossible to tell where it came from unless you’re buying unprocessed seafood—but even then it might be mislabeled... So how can you make sure you’re actually getting what you’re paying for?
If you’re buying wild shrimp, opt for shrimp that has been responsibly harvested. Consumer Reports recommends looking for products certified by the Marine Stewardship Council (MSC).12 This certification assures that every component of the manufacturing process – from how the raw materials are harvested to how the product is manufactured – has been scrutinized by MSC and has been independently audited to ensure it meets sustainable standards.
All of my krill products, for example, are MSC certified, allowing you to track where the krill oil came from in the Antarctic Ocean, as each batch of krill is carefully monitored all the way through, from catch to sale. Seafood Watch, which is part of the Monterey Bay Aquarium, can also guide13 you in the direction of more sustainable seafood choices. They even offer a Sustainable Seafood app14 for your smartphone. Other labels that signify more sustainable products include:
- Whole Foods Market Responsibly Farmed 3rd Party certification.
- Fishwise: The Fishwise label identifies how the fish was caught, where it came from, and whether the fish is sustainable (or environmentally threatened).
- Seafood Safe: The Seafood Safe label involves independent testing of fish for contaminants, including mercury and PCBs, and recommendations for consumption based upon the findings.
If you’re buying farmed shrimp (which I do not recommend), look for certifications by: NaturLand, Aquaculture Stewardship Council (ASC), or Whole Foods Market’s Responsibly Farmed label. These three groups certify that the shrimp has been raised according to aquaculture guidelines that protect the environment and prohibits the use of antibiotics. As for making sure you’re actually getting what the label tells you, The Atlantic15 suggests buying your seafood from a member of the Better Seafood Bureau.16
This trade organization reports fraud found along the seafood supply chain. You’re also less likely to get scammed if you seek out seafood that has not been imported, as domestic fisheries tend to follow the rules for seafood labeling. Many inland areas have seafood markets dedicated to fresh, high-quality seafood that is brought in daily.
Here you can talk to the owner directly, who should be able to give you details about where the seafood came from. Last but not least, when possible, purchase the whole fish as it’s far more difficult to misrepresent the fish species when it’s not cut up and filleted.