Several days later, tiny young lampreys called ammocoetes leave the nest and drift downstream to shallow areas that have little current and a mud bottom. There they burrow into the mud. These larvae are nonparasitic and feed on organic material filtered from the water. These new adults move down the streams and out to sea. Upon returning on their spawning run, they will be 2 to 3 feet long.
Sea lampreys are important in New York because of the damage they cause to other desirable fish.
Considerable effort has been made to reduce lamprey populations in the larger inland lakes. In these areas they cause extensive damage to sport fisheries. Distribution of sea lampreys in NY state. Dark dots represent where actual samples of sea lampreys were taken. White dots represent historic distributions.