ABSTRACT
This chapter describes a fence installed for a fish cultural operation which is usually considered to be a permanent installation, and is therefore of much more substantial design and construction than the adult counting fences. The original traps and barriers were made by lacing together thin branches from trees to form a screen of vertical slats supported on posts driven into the river bed. Wood and steel fences of the same design are being used for scientific purposes. They have enabled biologists to obtain exact counts of adult fish migrating upstream. Almost every fisheries biologist who has worked on salmon has come into contact at one time or another with a fence used for counting adult salmon on their upstream migration. The main body of the water passing over the crest of the dam passes down through the screen, leaving only enough on the screen at the downstream edge to carry fish into the trough and thence into the livebox.
