STUDY ON FISH HABITAT EVALUATION OF STREAM CHANNEL SYSTEMS OF SMALL RIVERS

Abstract

In order to make it clear that distribution of species number of fish in small rivers of the Ijira River in Gifu Prefecture, we aimed to investigate effect of the locations and overflow velocity of weirs and the environmental structures on the characteristics of the behavior of the fish. Measurement of environmental factor and survey of fish were carried out at 206 sampling sections in 2002, and river types were classified into four parts by cluster analysis on environmental factors, the rich-nature section, the medium-nature section, the poor-nature section, the no-nature section. The results show that distributions of some particular kinds of fish depended on the discontinuity points in the stream channel.