Entrapment of Fish Fingerlings in Pumping Installations as Related to Features of Their Behavior and Orientation in the Stream of Water
behavior, entrapment, fingerlings, illumination, intake, irrigation, night, protection, reservoirs, streams, structures, visual orientation
Journal or Book Title
Problems of Ichthyology
The principal cause of the entrapment of fingerlings of teleostean fishes in water-intake structures is the loss of visual orientation in the stream of water. In this connection, in open-water reservoirs with water transparency exceeding 30 cm (according to the Secchi disk) 70-90% of the fingerlings are entrained into these structures at twilight and night. To protect the fingerlings the intake of water for irrigation must be restricted at twilight and night. If this is not possible, then, along with other measures, illumination at twilight and night should be employed as an effective means for protection of the fingerlings.