Upstream migration activity of cyprinids and percids in a channel, monitored by a horizontal split-beam echosounder

Fish activity as determined by gillnet catch: A comparison of two reservoirs of different turbidity

“…High fish activity at dusk and dawn and low activity at night corresponded well to active telemetric (Jacobsen et al, 2002(Jacobsen et al, , 2004Zamora and Moreno-Amich, 2002;Hautala, 2008) and hydroacoustic (Lilja et al, 2003) studies, as well as to passive trapping (Baade and Fredrich, 1998) and gillnetting (Olin and Malinen, 2003;Olin et al, 2004;Vašek et al, 2009) studies on common European fish.…”

Effects of the construction of a reservoir on the fish assemblage in an inflow river

“…In the natural environment, such as lakes, fish are known to make spawning and feeding migrations into inflowing streams (L' Abée-Lund and Vřllestad, 1985;Lilja et al, 2003). Similar behaviour has also been found for reservoir fish (Koščo and Košuth, 1995;Kubečka, 2003, 2004).…”

Overestimation of percid fishes (Percidae) in gillnet sampling

“…Helfman (1979) described this phase of faster activity as a flux, when swimming speed increased from 0.8 to 8.7 m min −1 in congeneric yellow perch Perca flavescens and the fish swam with fewer turns and stops. Similarly, the dusk and dawn activity also increases in roach and bream (Borcherding et al, 2002;Lilja et al, 2003;Jacobsen et al, 2004). Jacobsen et al (2004) described the movement of roach as higher during dusk and dawn (>50 and >75 m h −1 , in clear and turbid lakes, respectively, August measurement) than during the daytime and, especially, during the night.…”