Most tilapia in the U.S. market are one of three species: blue, Mozambique and Nile.

In many of the developing countries where tilapia is raised, farming practices are less environmentally friendly than in the U.S. Since tilapia are not native to these areas, severe ecological damage can occur if tilapia escape to the wild. They can out-compete native species and greatly reduce aquatic vegetation.

In the U.S., tilapia are raised in closed tank systems, where the risk of escape is greatly minimized. Tilapia are fed mostly vegetable-based diets, and farming operations produce little water pollution. (More on fish farming, or aquaculture.)