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Diel activity of common bleak Alburnus alburnus in response to prey availability
Josefovičová, Anna ; Horká, Petra (advisor) ; Slavík, Ondřej (referee)
Fish behaviour and the structure of fish communities in rivers are known to be affected by various environmental factors. Turbidity imposes a considerable environmental constraint by influencing visibility and reducing the distance at which a predator detects prey. Previous studies have shown that fish become more active and extend their diurnal movements and home range size during the high turbidity period. However, this effect may also be associated with a lower food availability in turbid water and various other environmental factors like are day time, water temperature, discharge or oxygen concentration may also have an effect. This thesis present radio-telemetry study which examined factors influencing diurnal activity and home range size in common bleak Alburnus alburnus in riverine environment. The aim was to assess the response of bleak behaviour to various abiotic factors and prey availability, to establish the extent diurnal movements and home range size of bleak and to evaluate feeding strategy of fish. Four individuals of bleak were radio-tracked in the River Elbe during July - September 2007.The position of an individual fish was determined every three hours during one diurnal cycle, in total 10 diurnal cycles were recorded. During the same intervals, turbidity, water temperature,...
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