Chumming (American English from Powhatan) is the practice of luring various animals, usually fish such as sharks, by throwing "chum" into the water. Chum is bait consisting of fish parts, bone and blood, which attract fish, particularly sharks owing to their keen sense of smell.
Also known as rubby dubby (West Country and Yorkshire, UK), shirvey or chirvey (Guernsey, Channel Islands), burley, berley or berleying (Australasia), and bait balls.
Chumming is illegal in some parts of the world (such as in the state of Alabama in the U.S.,) because of the danger it can pose by conditioning sharks to associate feeding with the presence of humans.
Chumming is a common practice seen as effective by fishermen all over the world, typically in ocean waters.