A fish ladder, also known as a fishway, fish pass or fish steps, is a structure on or around artificial barriers (such as dams and locks) to facilitate diadromous fishes' natural migration. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps (hence the term ladder) into the waters on the other side. The velocity of water falling over the steps has to be great enough to attract the fish to the ladder, but it cannot be so great that it washes fish back downstream or exhausts them to the point of inability to continue their journey upriver.
Famous quotes containing the words fish and/or ladder:
“Slow, slow, as a fish she came,
Slow as a fish coming forward,
Swaying in a long wave;
Her skirts not touching a leaf,
Her white arms reaching towards me.”
—Theodore Roethke (1908–1963)
“You will see ... that it is easier to go down the social ladder than to climb it.”
—Albert Camus (1913–1960)