Farmed mussels are a "Best Choice" because they are farmed in an environmentally responsible way.
Blue Mussels, Black Mussels, Green Mussels, Muurugai
Farmed mussels are available year-round, but fresh mussels may be limited in specific regions for food safety reasons. Mussels are served cooked in or out of the shell, but are also available smoked and canned, or frozen. Mussels are known as muurugai when prepared for sushi.
Mussels are cultured throughout most of the world and make up approximately 90 percent of the world consumption. The major producers are China, Spain, Italy, Thailand, France and New Zealand. The U.S. imports most of its mussels from developed nations with stringent environmental regulations.
As with related species - scallops, oysters and clams - farming methods for mussels are environmentally sound. Mussels do not rely on fishmeal or fish oil as part of their diet. Diseases are rare, so antibiotics and chemicals aren't necessary, and the farming operation often benefits the surrounding marine habitat.
Mussels are typically grown suspended in mid-water, not on the seafloor. This method is preferred over growing them "on-bottom" as dredging to collect the shellfish can temporarily damage seafloor habitat.