Why are anadromous alewives important?
Anadromous alewives are an important part of the St. Croix River ecosystem. Anadromous alewives are important to the ecology of freshwater, estuarine, and marine environments. They are an indispensable nutrient source for freshwater ecosystems, providing nutrients in the form of eggs, excreted materials, and carcasses (Nedeau 2003). Ospreys, bald eagles, cormorants, loons, and great blue herons feed on migrating alewives each spring, at a time when many of these birds are nesting and rearing chicks. Alewives also provide an alternative food source for fish-eating birds at the same time juvenile Atlantic salmon are migrating downriver, and provide protective cover for upstream migrating adult salmon. Young-of-theyear alewives are a food source for game fish during the spring, summer and fall. Additionally, the alewife is the only known vertebrate host for the freshwater mussel Anodonta implicata (alewife floater), an important filter feeder that removes large amounts of algae, zooplankt
