EVALUATION OF FISH UPSTREAM MIGRATION IN THE TWO FISHWAYS AT THE CHIYODA DIVERSION WEIR

Abstract

Two types of fishways (pool-and-weir fishway and natural-like bypass fishway) were installed in the Chiyoda Diversion Weir located in the middle reach of the Tokachi River in 2007. We surveyed fish upstream migration and flow characteristics in the two fishways, and evaluated the function of two fishways. It was clarified that target fish migrated upstream in two types of fishways depending on the swimming ability and fish standard length.