The southeast United States’ rivers and streams support the most diverse unionid (freshwater mussel) fauna on earth. These species are a focus of the GCP LCC because their sensitivity to habitat degradation, fish community changes, and changes in water quality and quantity make them akin to the proverbial ‘canary in the coal mine.’ They are essential components of riverine ecosystems, influencing nutrient cycling and macro-invertebrate diversity. Their decline during the past century stems from overharvest, water pollution, habitat fragmentation, and introduction of nonindigenous predators and exotic mollusks; however, habitat degradation has been the most influential.
