Author(s): M. Holzner; F.G. Michalec; D. Sidler

Linked Author(s):

Keywords: Hydropeaking; Thermopeaking; Copepod swimming behavior; Laboratory flume; Drift entry

Abstract: Intermittent release of water from hydropower plants causes sudden variations in discharge that increase bed shear stress, dislodge benthic organisms and cause sharp variations in water temperature. We investigated separately the effects of a sudden variation in discharge or in water temperature on the small-scale swimming behavior of a widespread species of cyclopoid copepod in a laboratory flume that allows the tracking of organisms both in the water column and in a transparent sediment bed. Copepods increased substantially their counter-current swimming effort in response to increasing flow velocity, while decreasing temperature resulted in a substantially lower counter-current swimming effort. Our study highlights the importance of understanding the behavioural traits that mediate the response of stream invertebrates to disturbances in the hydraulic and thermal regimes of their environment.

DOI: https://doi.org/10.3850/978-981-11-2731-1_299-cd

Year: 2018