Author(s): Yohei Iiguni; Kouki Onitsuka; Juichiro Akiyama; Takuya Watanabe
Linked Author(s):
Keywords: Pool-and-weir fishway; Wall color; Hue; Value; Chroma; Migration
Abstract: Most of fishways installed in Japanese rivers belong to the pool-and-weir fishway. These fishways are usually made by concrete, so that pool-wall color is gray. On the other hand, it is pointed out that the fish behavior is affected by the wall color. Munsell found that color consists of hue, value and chroma. Unfortunately, the effect of wall color in the fishway on the fish behavior has not been investigated. In this study, the color of the channel bed and side-wall are changed systematically on the basis of Munsell color system, and observation of fish behavior was conducted with a digital video camera. As a result, it was found that the fish behavior is not influenced by hue and chroma, but influenced by value. Further, pool wall color was changed systematically and observation of fish behavior was conducted. The migration rate increases with an increase of value of color so that the migration rate takes maximum when the wall color is black.
Year: 2007