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:
“No one to hate except the slim fish of memory
that slides in and out of my brain.”
—Anne Sexton (1928–1974)
“Surely it is one of the requisites of a tasteful garb that the expression of effort to please shall be wanting in it; that the mysteries of the toilet shall not be suggested by it; that the steps to its completion shall be knocked away like the sculptor’s ladder from the statue, and the mental force expended upon it be swept away out of sight like the chips on the studio floor.”
—Elizabeth Stuart Phelps (1844–1911)