Females remain in coastal rivers and reservoirs.
Males locate close to tidal areas. Spawning begins when adults leave fresh water and brackish habitats and migrate to an area in the Atlantic Ocean east of the Bahamas and southwest of Bermuda in a region referred to as the Sargasso Sea. The larger females which live further upstream in rivers and reservoirs will begin migration out of fresh water once they are sexually mature, usually about five to seven years. As the females enter the coastal zones of the river, they are joined by the males, which as a rule do not venture far inland. Very little is known about the eels' behavior after they leave fresh water, but it is known that a single gathering of the reproducing adults does occur in the deep water of the Sargasso Sea.