Sea lampreys are native to the Atlantic Ocean. Between the months of March and October, they can be found along the coast of the United States as far north as Massachusetts and as far south as South Carolina. In October, North American lampreys migrate south along the Atlantic coast to warmer climates, some travelling as far south as Florida. Sea lampreys can also be found along the Atlantic coast of Europe as far north as Norway and ranging as far south as the Mediterranean. In October, they can travel as far south as Africa and to parts of the Indian coast. Sea lampreys have also been introduced to the Great Lakes region of the United States many times over within the past 200 years. Reports of this species in Lake Ontario date back to the early 1800s. Great Lake sea lampreys must first travel through the Gulf of St. Lawrence in order to gain access to the Atlantic coastal region.
Biogeographic Regions: nearctic (Introduced , Native ); palearctic (Native ); oriental (Native ); atlantic ocean (Introduced , Native ); mediterranean sea (Introduced , Native )