Experimental study on fish attraction at a fishway inlet based on localized color configuration

With the widespread construction of fishway facilities, increasing attention has been paid to improving their efficiency. Insufficient attraction efficiency at fishway inlet remains a key factor limiting overall passage performance, and enhancing inlet attraction has therefore become a major focus of fishway research. This study deployed colored stickers with attractive and repulsive effects at the fishway inlet and conducted systematic live-fish experiments using Schizothorax prenanti to evaluate their effectiveness in improving inlet attraction efficiency. The experimental results demonstrate that: (1) The deployment of colored stickers significantly affects fish upstream migration behavior. Specifically, deploying attractive green stickers on the guide wall and partition wall clarified fish migration direction and substantially improved inlet attraction efficiency. In Case II, the attraction efficiency increased by 29.02%, while the upstream migration time was reduced by 24.55%. (2) Fish exhibited distinct behavioral differences in zones with different colors. Within the green sticker zones, fish exhibited deceleration behavior (indicated by a 5.97% decrease in velocity contribution); conversely, in the yellow areas, they displayed a rapid escape response, with a 10.90% increase in swimming velocity contribution compared to the blank group. These results indicate that the appropriate use of color-based visual stimuli can effectively enhance the attraction performance of fishway inlet. The proposed layout case provides a practical reference for the design and optimization of fishway inlet attraction measures.