Screening acoustic deterrents against Ctenopharyngodon idella

The construction of dams will hinder the migration of migratory fish, and the water diversion structure and pumping activities will cause damage and death of juvenile or adult fish. In order to solve this problem, measures such as deploying physical barriers can be taken to prevent fish from entering dangerous areas. However, such physical barriers are expensive and difficult to install and maintain. Therefore, as a non-structural measure that does not cause harm to fish, acoustic deterrents are widely used in water conservancy projects. The acoustic deterrent is an important means to prevent fish from entering dangerous areas and protect fish resources. In order to screen sounds as potential acoustic deterrents, this research used six single-frequency sounds (500-3 000 Hz) and a broadband sound (Alligator sinensis roar) as experimental sounds to screen deterrents against Ctenopharyngodon idella juveniles. The behavioral responses of C. idella juveniles to different sounds were compared by alternately broadcasting at both ends of the flume. The results showed that most of the experimental fish responded to the sound, and the roar of the A. sinensis had significantly different effects from other sound groups. In the single-frequency sound experimental group, the average number of responses was the largest when playing 500 Hz single-frequency sound, which was (1.7±0.6) times, while the average number of responses was as high as (5.0±0.9) times when playing the roar of A. sinensis, which was significantly higher than other experimental sounds. In the total average speed, the total average speed of C. idella in the broadband sound group was significantly higher than that in other groups, indicating that C. idella was sensitive to the roar of A. sinensis and escaped. Studies have shown that C. idella shows negative phonotaxis to the roar of the A. sinensis, and the roar of the A. sinensis is a sound that has a driving and deterrent effect on C. idella. This research can provide a reference for the auxiliary means of inducing fish in fish passing facilities and avoiding fish entrainment in water conservancy structures.