Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates. North Atlantic American Eel

Species profiles are literature summaries of taxonomy, life history, and environmental requirements of coastal fishes and aquatic invertebrates. They are prepared to assist with impact assessments. The American eel is an ecologically and economically important catadromous species that occupies freshwater streams, rivers, brackish estuaries, and the open ocean during various phases of its life cycle. Adult eels apparently spawn in the Sargasso Sea, and ocean currents transport the developing larvae northward until the young metamorphose into juveniles capable of swimming shoreward and moving upstream into coastal areas, estuaries, and rivers. Developing eels commonly remain in freshwater or brackish areas for 10-12 years before migrating to spawn. American eels tend to be bottom-dwellers and feed on a variety of fauna that occupy the same habitats. Eels occupy areas having wide ranges of temperature, salinity, and other environmental factors, suggesting broad tolerance limits, but few studies of requirements have been reported. Salinity patterns and water currents created by river discharges into coastal areas apparently provide the gradient that cues shoreward of juvenile eels. Alteration of patterns of freshwater inflows to estuaries and bays could affect upstream migrations. Keywords: Estuaries, Fisheries, Life cycles, Growth(Physiology), Contaminants, Animal migrations, Anguilla rostrata, Environmental requirements, Reproduction(Physiology).