Real Food Encyclopedia | Tilapia

Tilapia, the common name for nearly a hundred species of cichlid fish, is seemingly everywhere. Over the past decade, this inexpensive mild white fish has popped up on grocery store shelves, restaurant menus, school lunch lines and hospital trays all over the country. Sales of the fish quadrupled from 2003 to 2007, making it the 4th most consumed seafood in the United States.

In nature, tilapia is mainly a freshwater fish that lives in shallow streams, ponds, rivers and lakes. Today, these fish are of increasing importance in aquaculture and aquaponics. Tilapia eat mostly plant-based diets which make them incredibly inexpensive to farm. Their vegetarian diet also takes the pressure off of wild caught prey species and eliminates the risk of the fish accumulating high levels of toxins like mercury that concentrate in fish higher up in the food chain. 

Because of these characteristics, tilapia have become the focus of large scale commercial fish farming operations in Papua New Guinea, China, Egypt, Indonesia, Vietnam and the Philippines.

In 2012, over three and half million metric tons of tilapia were produced worldwide (that’s almost eight billion pounds). Today, 78 percent of the tilapia imported to the US comes from large-scale farms in China. The US produces around 28 million pounds of tilapia per year, about a billion dollars worth.

Fun Facts about Tilapia:

  • Tilapias are native to Northern Africa and the Levant region and have been an incredibly important fish for small-scale fishermen there for millennia. Known as musht or St. Peter’s Fish in ancient Israel and the surrounding area, they were one of the three main types of fish caught by artisanal fishermen in Biblical times in the Sea of Galilee.
  • Commercial tilapia farmers use testosterone to reverse the sex of newly spawned females to eliminate their presence in the population and ensure that all their fish are male. Because tilapias are prolific breeders, having females in a tank leads to rapid increases in the number of small fish, rather than allowing farmers to maintain a stable population of more robust, harvest-size fish. 

What to Look for When Buying Tilapia

If possible, it’s best to purchase live tilapia from clean clear tanks, so you know they are fresh. Pick one that looks lively, not one that’s floating or motionless. If live fish aren’t available but the store is selling whole fish, check out the eyes to make sure they look clear; slimy, filmed-over eyes are a sign that the fish isn’t fresh anymore. Also, the gills should be clear of dirt and bright red in color, and the scales should be clean and shiny.

If live or whole fish aren’t for sale in your area, purchase tilapia fillets that have been recently harvested, look moist and ideally are packed in thin layers of ice. Make sure to smell the fish before buying it – if it has a fishy or musty smell, it’s probably not fresh. Tilapia should smell slightly sweet and appear uniformly white or have a slight pink tinge. Also, make sure the fillets aren’t sitting in excess water because the fish will absorb flavors from any liquid it’s sitting in. Seem like a lot to remember? Here’s a handy guide that summarizes all this info with nice illustrations.

Sustainability of Tilapia

Environmental Impact of Tilapia

Tilapia’s scrappy nature and preference for weeds, algae and insect larvae have made them the perfect biological weapon against other aquatic pests. In Kenya, tilapia were introduced as a biological control for malaria-infected populations of mosquitoes. The fish consume mosquito larvae, helping to reduce the number of adult insects carrying the deadly disease. In Israel, hundreds of thousands of tilapia have been introduced into local freshwater lakes where they are expected to act as bio-filters that boost diversity and balance out the lakes’ ecosystems by clearing out toxin-producing weeds. In Phoenix, Arizona and Thailand, tilapia have been introduced into ponds and canal systems as a means to control the growth of algae and purify the water without the use of harmful chemicals and herbicides.

However, according to WWF biologist Aaron McNevin, the widespread use of tilapia in poor countries to control weeds and mosquitoes “may not have been the best idea.” Tilapia’s aggressive feeding and breeding have made them a problematic invasive species. They’ve spread widely beyond their points of introduction in many fresh and brackish tropical and subtropical habitats around the world and often significantly disrupt native species. This has earned tilapia a spot on the International Union for Conservation of Nature’s 100 of the World’s Worst Alien Invasive Species list. In the US, invasive tilapia are found all over the south, especially in FloridaTexas and North Carolina where they survive in lakes, streams and the warm waters around power plant discharge zones.

In addition, there’s a lot of concern over the environmental impacts of poorly regulated large-scale tilapia farms in China and Central America. Tilapia in China are sometimes raised in water that is contaminated with raw sewage, industrial waste and pesticide-filled agricultural run-off. To make matters worse, these farms turn around and discharge polluted wastewater, further contaminating the local water supply. Farmers in China have been documented mixing illegal veterinary drugs and pesticides to deal with the toxic water, and these pharmaceuticals leave carcinogenic residues in the seafood, posing a serious health risk for consumers. Researchers studying a small tilapia farming operation in Nicaragua found that one pen full of the fish destroyed the entire ecosystem of a pristine lake, killing all of the important aquatic plants other fish species relied on.

When shopping, Monterey Bay Aquarium recommends selecting tilapia raised on farms in the United States and Canada or from closed tanks and in ponds in Ecuador as they tend to be the most sustainable production methods. If those aren’t available, tilapias farmed by Regional Springs in Mexico and Indonesia in net cages are good alternatives. The Monterey Bay Aquarium also says that typically, tilapia raised in ponds in China and Taiwan are also ok to purchase from a sustainability perspective, as long as you are aware of the concern over the use of chemicals and waste management at those facilities.

Tilapia Seasonality

Tilapia are warm water fish and can’t survive in outdoor ponds in places with cold winter months. In the southern United States, tilapia production in outdoor ponds begins in the spring and ends in the fall when the fish are harvested. Tilapia can be harvested at the end of the season or whenever the fish get to a desirable size. Indoor cultivation of tilapia in warm water recirculating tanks can extend the growing season of the fish throughout the year.

Eating Tilapia

Storing Fresh Tilapia

If you aren’t able to use your tilapia within a day or so of buying it, you can freeze it to extend the fish’s shelf life. Just make sure you remove all the air around the fish by either glazing it with water, wrapping it tightly in saran wrap or vacuum sealing it. For the best flavor, try to use the fish within 6 months of freezing.

Cooking with Tilapia

Tilapia is very versatile and works well in almost any recipe calling for a mild white fish. Try some of these:

Tilapia Nutrition

There’s been a lot of discussion about the nutritional value of tilapias over the last few years, with some even declaring that the fish is worse for your health than bacon. Like all fish, tilapias are low in saturated fat, calories and carbohydrates. However, unlike predatory fish like salmon and mackerel, farmed tilapia eat mostly corn and soy which lacks the fish oils and healthy omega-3 fatty acids that medical research has shown improves heart health and assists in brain development. 

According to Edgar R. Miller of John Hopkins University, these nutrients are the main reason that doctors and nutritionists are recommending people eat more fish in the first place. Farmers can add omega-3 supplements to their feed to increase levels of these compounds in the fish, but the additives tend to be expensive and can create more pollution.

On the bright side, tilapia do have higher levels of omega-3s than either mahi mahi or tuna and tends to have very low levels of mercury because they are fast growing, have short life spans and eat a vegetarian diet. The fish also offer 26 grams of protein per serving, about half your daily requirement. Tilapias also contain important nutrients like calcium, magnesium, phosphorous and potassium.