HIGGINS' EYE CLAM

HIGGINS' EYE CLAM. Possibly the tri-state's most infamous mollusk. The Higgins' Eye clam, a federally endangered specie since 1976, first gained community attention when its discovery temporarily threatened construction of the DUBUQUE-WISCONSIN BRIDGE. Found only in the waters of the Upper [[MISSISSIPPI RIVER] and usually in sand or mud near the shoreline, the clam's thick olive green shells range from four to five inches long. This made the Higgins' Eye an important source of material for the BUTTON INDUSTRY. Hunted for its commercial value, the number of clams declined further when construction of LOCKS and dams changed the river habitat.

Pockets of Higgins' Eye clams have been discovered near the Wisconsin side of the Dubuque Wisconsin bridge and off Chaplain Schmitt Island. Young Higgins' Eye are usually carried as parasites of sauger pike until the clams mature to the stage when they fall to the river bottom to continue growing.

Higgins' Eye clams, once abundant from Minnesota to Louisiana, are not found below cities or industrial areas where water quality is poor. Researchers believe the population of the clam has been cut in half within the last one hundred years from such causes as heavy silting, over-harvesting, turbulence from boat propellers and various types of pollution.