Opponents of Michigan fish farms say there is no room for them in the lakes because of sport fishing and other recreational activities. sfgamchick/Flickr hide caption

itoggle caption sfgamchick/Flickr

Thierry Chopin from the University of New Brunswick examines a raft that holds strings of seaweed. The seaweed grows around pens of farmed salmon and soaks up some of the nutrients that would otherwise pollute the Bay of Fundy. Richard Harris/NPR hide caption

itoggle caption Richard Harris/NPR