But like all sea life, you want to be careful when purchasing shrimp, whether at the grocery store or at a restaurant.
Freelance writer Barry Estabrook's outstanding Politics of the Plate blog had a great, informative article on the topic of shrimp recently. It turns out that "90 percent of the shrimp we eat come from Asia, and most are farmed in fetid pools ("sewage lagoons" in the words of one commercial shrimp farmer)."
Ew. This raises a lot of red flags. First, Barry goes on to note that "the practice is environmentally destructive." This is true of most fish farming, unfortunately. Fish farming was meant to be the ecological alternative, one which would take pressure off wild populations while still providing a solid alternative. Unfortunately the waste pouring out of fish farming operations fouls the water, and the animals themselves pass diseases to their wild cousins. (Estabrook details the horrifying conditions at Asian shrimp farms in his 2007 article for Gourmet magazine, "Dare I Eat A Shrimp?")
In addition to this, in order to raise the shrimp to maturity, Asian shrimp farmers will often freely pour antibiotics and "other illegal chemicals" into their pools in a desperate, unlicensed bid to earn a living. You can hardly fault them, but it's also probably not something you want to be eating.
Rated as a "Good Alternative" is American wild-caught shrimp. But wild-caught shrimp are usually fished out with nets that are dragged along the ocean bottom, scooping up every creature in their path. "Bycatch" is the clinical term for this, but it really amounts to "huge waste of life."
The holy grail of the environmentally-conscious shrimp eater is the Pacific Northwest wild-caught spot prawn. These are fished with traps similar to crab pots, which prevent the entry of (almost all) other animals. What little bycatch occurs is easy to toss overboard unharmed.