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.