Mussel Resources of the Illinois River System: Value to Illinois' Economy andNatural Heritage. Long Term Resource Monitoring Program

摘要

The hisotrical importance of mussels to humans is well documented atarcheological sites throughout the Illinois River Valley. Native Americans used mussels for food and their shells for tools and ornaments. Early settlers harvested mussels for the infrequent but highly prized pearls they yielded. Beginning about 1891, mussels were used as the raw material for the pearl button industry, which became a multi-million dollar industry in the United States by 1899. With the advent of plastics, the pearl button industry died out by the late fifties, but in the sixties, the development of techniques for culturing pearls provided a new market for mussel shells. Today their shells are harvested from Midwestern rivers and exported to Japan, the current center of the cultured pearl industry. Reports submitted to the Illinois Department of Natural Resources indicate that in Illinois, annual sales of shells harvested from the Illinois and Mississippi Rivers averaged about 970 tons per year from 1963 through 1995, with the maximum reported harvest of 1963 tons n 1985. In 1996, shelters received an average of $1.70/pound for these shells. Today, freshwater mussels are one of the most endangered groups of organisms. Of 297 taxa described for North America, 213 (72%) are considered extinct, endangered, threatended, or of special concern. Management of our mussel resources is impeded by our incomplete knowledge about these complex organisms. They have a complicated life cycle which necessitates a fish host for completion of its largal stage. Field studies to better understand the life history and ecology of mussels often are confounded by impacts of navigation, habitat alterations, pollution, and harvest. Such investigations often require the use diving which is laboriuos, expensive, and can be dangerous. The preservation and enhancement of our mussel resources, the services they perform and their economic values are dependent upon the development and implementation of sound, science-based management strategies. Without increased efforts to understand and protect these organisms, their future is questionable.