Sarah Biren
Sarah Biren
January 15, 2024 ·  6 min read

How Shrimp Farming and Other Seafoods are Threatening Your Health

This article was originally published on May 11, 2016, and has since been updated.

The American Heart Association recommends two servings of fish a week, which is a pretty modest request. However, the wild and farmed fish you eat could be filled with mercury, Bisphenol A, or other chemicals because retailers and fishers are eager to cut corners. Educating yourself about possible contamination is important so you aren’t handing your money to people who put the public in danger.

Farmed Fish Vs. Wild Fish

Unfortunately, both wild-caught fish and farmed fish have their unique risks. Even when you’re careful to buy fish that hasn’t been raised in cramped conditions, many naturally occurring and man-made contaminants find their way onto your plate.

Wildfish: Mercury and Symptoms

Chemicals and waste drain into bodies of water, contaminating our fish with:

  • Mercury
  • PCB’s
  • Chlordane
  • Dioxins
  • DDT

These chemicals build up in the food chain until we eat them, seeping into our brains and kidneys. Overexposure to things like Mercury can cause:

  • Shakes and Tremors
  • Difficulty Walking
  • Vision Problems
  • Memory Problems
  • Complications during pregnancy
  • Language Skills

Contamination in our fish is usually small, but doses increase with fish higher on the food chain, like tuna and sharks, and as we consume more of them.

Contamination of Farmed Fish

Farmed fish often have as much mercury as wild fish, in addition to other problems. We put antibiotics in farmed fish because their tanks are overcrowded, and disease spreads rapidly without them. These antibiotics collect inside the fish for months until they are passed onto us when we eat them.

Additionally, these tanks need a variety of chemicals to maintain liveable water, such as:

  • Algaecides
  • Disinfectants
  • Herbicides
  • Pesticides
  • Probiotics

These chemicals we use to ensure efficiency can also increase your odds of diseases like cancer when they are consumed by fish that we eat.

The three most popular fish in America are shrimp, salmon, and tuna. Without the right knowledge and because of mass consumption, these fish can cause unnecessary harm to all of us.


In 2014, the United States imported 5.2 billion dollars of shrimp from Indonesia, Vietnam, and India. Most of this shrimp comes from farms raised in overcrowded environments. Here, they are fed pellets containing antibiotics, while mismanaged ponds have fecal matter, chemicals, and excess food building up.

Part of the problem is that health requirements are much lower in these countries. For example, a grower in Vietnam used ice covered in bacteria to chill his shrimp.

Additionally, almost 1 out of 3 Shrimp from Malaysia have nitrofuran and chloramphenicol residue, which are elements of antibiotics, risking the development of superinfection in humans as we consume these and other antibiotics unnecessarily.


Tuna contains a lot of mercury because bigger and longer-living fish will eat more over time. We ingest this build-up when eating a can of tuna which can be harmful in large doses.

Also, the chemical Bisphenol-A (BPA) seeps into our food from our cans.

Adding to the problems of tuna is its sodium content. Some brands carry almost 350 milligrams of salt.


About 1 billion dollars of Chilean Salmon crossed the U.S border in 2014. Reuters reported that this salmon is using “record levels of antibiotics” to treat farmed fish with diseases that cause lesions and hemorrhaging. Additionally, this wasn’t a one-time issue. Diseases in farmed fish have been around for 30 years in Southeast Asia and South America, illustrating the constant reliance on antibiotics.

How to Avoid Dangerous Farmed Fish and Contamination

Don’t swear off fish for good! Fish provide significant nutritional benefits if you buy the right kind. Consider these factors when shopping for these fish.


3 ounces of shrimp can provide 20 grams of protein. Shrimp are also good sources of selenium, which is  good for fighting cancer, cardiovascular disease, and thyroid disease.

Some rules to get the most out of your Shrimp:

  • Look for shrimp certified by the Wild American Shrimp or the Marine Stewardship Council. They mark shrimp that are produced without antibiotics.
  • Buy wild North American shrimp which are often more sustainably caught.
  • Has a mild smell – not too fishy or sour.
  • It’s translucent but not cloudy.
  • It feels firm.


Tuna has 56% of your daily requirement of protein and is full of Omega-3s.

Some rules to get the most out of your Tuna:

  • Buy it in BPA-free pouches instead of the cans.
  • Light tuna has less mercury than white tuna
  • Skipjack tuna has less mercury than yellowfin and albacore tuna.
  • Don’t exceed more than 6 ounces of tuna a week to avoid mercury build up.
  • Avoid salted cans of tuna


Lastly, salmon is filled with Omega-3’s, polyunsaturated fats, reduces the risk of heart disease, and could help the development of fetuses. It is also a valuable source of vitamin b12, selenium, vitamin B6, astaxanthin, thiamine, and niacin.

Some rules to get the most out of your salmon:

  • Buy it wild or buy it farmed from Norway, as they use significantly fewer antibiotics.
  • Organic, doesn’t make it healthier, it just means it was farmed.
  • Avoid cans with BPA or cans in general
  • Atlantic Salmon is always farmed and often has more toxins than wild Alaskan salmon.
  • Frozen is okay

How to Cook it:

You can grill, sauté, or bake salmon


At the end of the day, fish is full of nutrients that we rarely get from chicken, beef, and pork. Using seafood for protein, instead, can provide a lot of benefits. However, it’s vital to make sure that your fish is caught or produced responsibly and it’s useful to speak to your retailers and restaurants to ensure that they are giving you the best that you deserve.

Keep Reading: 14 Fish You Could Consider Never Eating