North America's tremendous richness of pearly freshwater mussels is unique. Biologists have identified nearly 300 species of mussels living in our streams and lakes. Freshwater mussels are bivalve mollusks with two hard outer shells and soft tissues inside. Prehistoric American Indians ate the soft tissues and used the lustrous shells for making tools and ornaments. Historically, the shells have been prized as raw material for manufacturing buttons and are currently used in the production of cultured pearls.

Many mussels are sensitive to changes in their environments. Populations of mussels have declined alarmingly in recent decades because of siltation, pollution, and competition from exotic mollusks like the zebra mussel. Of the eighty mussel species native to Illinois, more than half are currently threatened, endangered, extirpated, or extinct. We can protect mussels and other aquatic wildlife by cleaning up our streams and lakes to create healthy habitats where these animals can thrive.