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:
“If a fish is the movement of water embodied, given shape, then cat is a diagram and pattern of subtle air.”
—Doris Lessing (b. 1919)
“When Titian was mixing brown madder,
His model was posed up a ladder.
Said Titian, “That position
Calls for coition,”
So he lept up the ladder and had her.”
—Anonymous.