Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (North Atlantic): Atlantic Salmon,

Species profiles are literature summaries on the taxonomy, morphology, range, life history and environmental requirements of coastal aquatic species. They are intended to assist in environmental impact assessment. Atlantic salmon are a highly prized sport fish and their flesh is gourmet table fare. Once abundant in New England's coastal rivers, they are only now being restored to portions of their original habitat. Populatons declined following development of industries along rivers and commercial fisheries in estuaries. Atlantic salmon are anadromous. Spawning, embryo development and growth of young fish occur in freshwater streams and rivers. Juvenile survival is highest in clear, cool (27 C), well oxygenated (dissolved oxygen 5 mg/l) streams. Flowing smoltification, a physiological change enabling entry into salt water, fish migrate downstream and then to oceanic feeding grounds near Greenland, where they grow rapidly. Sexually mature fish return to their natural rivers to spawn. Migration into estuaries and lower reaches of river begins 7 months before the October-November spawning period. Migrating adults require dissolved oxygen concentrations greater than 6 mg/l for successful upstream movement. Because juveniles migrate through the coastal zone in spring and adults in summer and fall the species is especially vulnerable to the consequences of coastal development.