Effects of hydropeaking on the behaviour, fine-scale movements and habitat selection of an Iberian cyprinid fish

Abstract

Hydropeaking is widely known for changing the quantity and quality of the available habitat downstream of hydroelectric facilities, thus affecting all stages of fish life cycles. Hydropeaking impacts on salmonids are widely studied, but knowledge of its effects on cyprinids, which are dominant in Mediterranean areas, is scarce. In this study, 11 Iberian barbel (Luciobarbus bocagei, Steindachner 1864) were tagged with radio transmitters equipped with ElectroMyoGram (EMG) sensors, aiming: to (a) assess the behaviour, fine-scale movements and habitat selection of the target species in response to periods of artificial and abrupt flow variations (i.e., hydropeaking); and (b) identify, which environmental variables and, in particular, flow components can influence the species behaviour. Results from the six barbel that provided analysable data indicate that fish were more active during the day and in periods of ecological flow. Moreover, during hydropeaking, especially during the increase in flow magnitude, fish activity decreased with the tagged fish showing a refuge-seeking behaviour. This information can be used to minimize the changes caused in the aquatic habitat and fish communities occurring downstream of hydroelectric dams.