Effects of hydroelectric turbine noise on the behaviour of Leporinus taeniatus (Characiformes: Anostomidae) in captivity

Hydroelectric power plants (HPP) constitute one of the main forms of energy generation in the world, and its operation produces underwater noise through generators and turbines, which can potentially impact the aquatic fauna. Anthropogenic noise is a stressful factor and can affect behaviour, physiology and acoustic communication of many animal species. However, the noise impact produced by HPP on fishes has not been studied yet. In this research we investigated the noise impact of hydroelectric turbines on the behaviour of Leporinus taeniatus held captive in Brazil. We tested the hypothesis that noise could disturb fishes’ behaviour by affecting school organization, fish position in the tank and the speed of swimming. Two groups of 10 individuals were exposed to 30 sessions of noise played at an intensity of 100 dB re 1 µPa, during 40 s on days 0, 7 and 14. Behavioural data were obtained before, during, and after noise exposure. Results showed that the fish swam significantly faster, moving to the bottom and swimming in depolarised shoals during noise exposure in both groups. Temporal analysis showed that during noise exposure fish swam faster, were less stationary and used the bottom of the tanks more throughout sampling period. These data provide evidence that fish behaviour can be affected by the aversive stimulus of the noise of a hydroelectric turbine in operation. It also suggests that sound pollution issues should be taken into consideration when regulating the use of natural areas for HPP.