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At the beginning of the industry, many methods of catching mussels were used including using ordinary rakes. In 1897 the "crowfoot" dredge was developed. This was a six foot pole or rod with many four-pronged hooks attached to it with ropes. Mussels resting on the mud or sand of the river bottom opened their shells to catch food.
When a hook was pulled over the shell, the mussel quickly snapped shut and was caught. By the start of the 19th century, the average clammer used two crowfoot dredges suspended from a boat. Drifting downstream, one dredge was being emptied of clams while the second was in the water catching more. On the best of days, this operation could result in the collection of as much as a thousand pounds of shell.
The original clam fishing area existed between Muscatine, Iowa and Red Wing, Minnesota. (1) Overfishing led to the near extinction of clam beds south of McGregor. In 1901 a surprising number of fresh water pearls were discovered north of McGregor. The size ranged from pinhead to a nickel and were round, oval, flat or half-round. In two days, a buyer paid $2,500 for pearls. Prices ranged from $25.00 to several hundred dollars. (2) The rush of new fisherman to the area led to the formation of the Clammers Union of Harper's Ferry to prevent encroachment. The plan of the Union was to lease all the land along the shore and the islands in the Mississippi on which clammers would need to land to prepare their shells. (3)
Many mussel hunters today, using an air compressor and long lengths of hose, dive into the river. With fifty-pound weight belts to hold them on the river bottom, divers collect clams in nets pulled up with motorized hoists.
Clamshells are shipped to Tennessee or Japan. Bits of shell, surgically implanted into oysters, are used to stimulate the formation of cultured pearls. Occasionally a lucky hunter may find a freshwater clam containing pearls-some valued at over one thousand dollars.
Heavy clam harvesting (first warned about by John BOEPPLE),chemical poisoning of the river, and silting of the river bottom have all caused the populations of clams in the river to decline.
1. "A New Eldorado," Dubuque Daily Telegraph, August 5, 1901, p. 5