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:
“When the weather is bad as it was yesterday, everybody, almost everybody, feels cross and gloomy. Our thin linen tents—about like a fish seine, the deep mud, the irregular mails, the never to-be-seen paymasters, and “the rest of mankind,” are growled about in “old-soldier” style. But a fine day like today has turned out brightens and cheers us all. We people in camp are merely big children, wayward and changeable.”
—Rutherford Birchard Hayes (1822–1893)
“This monument, so imposing and tasteful, fittingly typifies the grand and symmetrical character of him in whose honor it has been builded. His was “the arduous greatness of things done.” No friendly hands constructed and placed for his ambition a ladder upon which he might climb. His own brave hands framed and nailed the cleats upon which he climbed to the heights of public usefulness and fame.”
—Benjamin Harrison (1833–1901)