Because they are long-lived and particularly sensitive to changes in water quality, mussels are important indicators of aquatic ecosystem health. The disappearance of mussels from a river or lake often signals that other aquatic species are at risk. North American freshwater mussels have an extraordinary life history and reproductive adaptations. An important feature of their life history is the unique and complex need of the larvae for a fish host to metamorphose from the larval parasitic stage to a free-living juvenile mussel. Freshwater mussels exhibit a variety of shapes from elongated or oval to subcircular, quadrate, or subtriangular.
Shells also vary by species in size, thickness, color, shape, and texture.
Although freshwater mussels are primarily sedentary, they use a highly muscular and flexible foot for movement, burrowing, or anchoring into the substrate or between rock crevices. Freshwater mussels are suspension feeders, filtering unicellular algae, bacteria, zooplankton, and suspended detrital particles from the water. Given the preservation goals of the National Park Service and the importance of mussels to aquatic ecosystems, the protection of mussels and their habitats should become integrated in program planning, management, and education by park managers. Protection of water quality and habitats for mussel populations will protect other water-dependent species in parks. Protection and restoration of significant mussel habitats.