Photo Credit: Karl Jansen
Pictured here is a fish ladder located at the Hiram M. Chittenden Locks (a.k.a. Ballard Locks) in Seattle, WA. A fish ladder is simply a structure that allows migratory fish to swim upstream or around a barrier placed in the water by humans. In this case, the structures were a dam and some locks. The need for fish ladders was recognized after the placement of barriers in aquatic ecosystems had negative effects on fish populations.
Photo Credit: Alex Mead
This is a fish ladder. It is used in conjunction with dams and weirs to allow migratory fish to pass around the main falls of the dam. It consists of small steps of waterfalls, one right after each other, so fish can make the jump from level to level getting up around the dam to continue their swim upstream. Without fish ladders many migratory fish couldn’t go up stream for spawning and the fish population would undoubtedly suffer.