Sustainable Fish? Try Tilapia.

For all the warnings about which fish are most at risk, most endangered, or on the “no eat” list, there are a few bright spots out there. Can you say tilapia?

Big, fast-growing, tasty, and relatively free of toxic mercury, tilapia are also a favorite of freshwater aqua-culturists. Unlike some other popular menu items—tuna, swordfish, and salmon, for example—most tilapia found in restaurants is just a year or so old (compared to the average salmon which is three years old, and much of the tuna used in sushi, which can be six to 20 years old). Dining on younger fish, which grow faster and thereby replenish their species, is much more preferable than taking older, slower-to-reproduce species.

Photo: Luis Galdamez/Reuters

Native to Africa—the most popular species is known as Nile tilapia—the warm water-loving tilapia are now grown in such tropical environments as Papua New Guinea, the Philippines, and Indonesia, in freshwater lakes. In the U.S. they are found in the wild almost exclusively in southern Florida. Since tilapia require little fishmeal and fish oil in their feed, the “growing” of them involves very little pollution—unlike many types of fish farming. They are also favored by farmers for their ability to “clean” ponds of plants and nutrients unused by other fish species, substantially reducing oxygen-depleting detritus, helping to make other fish in the area bigger and healthier.

When buying at the supermarket or ordering in a restaurant, ask where the tilapia comes from. U.S.-farmed tilapia are the best; those from Asia and Central and South America may be less controlled. Aggressive tilapia, if they escape farm pens into the wild, can be hard on other native fish.

For other “good to eat” species like Pacific halibut, pole-caught mahi-mahi and U.S.-farmed catfish, be sure to follow recommendations by the Blue Ocean Institute and the Monterey Bay Aquarium and their seafood guides.

As for how much you should expect from the chefs and servers in your favorite restaurants: If you ask your server where the fish you’ve ordered comes from and he isn’t quite sure, ask him to check with the chef. If the chef doesn’t know…walk down the street to the next fish house!