Cormorant fishing is a traditional fishing method in which fishermen use trained cormorants to fish in rivers. Historically, cormorant fishing has taken place in Japan and China, as well as other places throughout the world.
To control the birds, the fishermen tie a snare near the base of the bird’s throat. This prevents the birds from swallowing larger fish, which are held in their throat, but the birds can swallow smaller fish. When a cormorant has caught a fish in its throat, the fisherman brings the bird back to the boat and has the bird spit the fish up.