And these happen to be three countries that together produce nearly half of America's seafood. Bloomberg News discovered in 2012 that shrimp and tilapia farms feed their ponds pig feces in China and chicken manure in Thailand, which, if improperly handled, can contaminate the final product. A quarter of America's food-borne illnesses involve imported seafood.

The crowded, unsanitary conditions of Asian shrimp farms mean they're often splashed full of antibiotics. Most shrimp farms are dug in mangroves and typically need to be abandoned every three to nine years because nothing can live in the the buildup of toxic slime, antibiotics, and heavy metals beyond that.