Reactions of cyprinids to infrasound in a lake and at the cooling water inlet of a nuclear power plant

Abstract

Behavioural effects of infrasound on cyprinids were tested. In Lake Borrevann, Norway, acute avoidance responses, at a distance up to 10 m from a 16 Hz infrasound projector were revealed by echosounding. At 10 m distance, a coarse estimate of the stimulus level (measured as the acceleration component of the particle motions) was c. 10 À3 m s À2 . Habituation was not evident during these tests. Two synchronized infrasound units were also installed 6 m apart in front of a cooling water intake of a nuclear power plant on the River Meuse, Belgium. Echosounding was used to compare the number of fishes entering the intake canal during on-off infrasound sequences. Relative to off-periods, the reduction of the number of fishes entering during on-periods was >80% at a distance of 0-12 m from the units. A significant reduction of 48% was observed considering the whole width (54 m) that was monitored. Fish impingement on the mechanical screens during the study revealed that >90% of the fishes entering the intake were cyprinids.

Discriminating the diel vertical migration of fish andChaoborus flavicanslarvae in a lake using a dual-frequency echo sounder

“…1). This is in agreement with previous horizontal echo sounding results from the same lake, which detected large numbers of fish near surface at night, but not during the day (Knudsen and Saegrov 2002;Sonny et al 2006). The gillnet CPUE was higher at night probably due to higher activity of fish.…”

Linking individual behaviour and migration success inSalmo salarsmolts approaching a water withdrawal site: implications for management

“…Recent studies have demonstrated behavioural avoidance in smolts related to hydraulic conditions (Haro et al 1998;Enders et al 2009), in-stream structures (Kemp and Williams 2008), overhead cover and absence of visual clues (Kemp et al 2005;Kemp and Williams 2009). Moreover, fish guidance may be accomplished using strobe lights (Johnson et al 2005), bubble curtains and sounds (Welton et al 2002;Sonny et al 2006) and deep, mid-channel furrows (Svendsen et al 2007). These findings indicate that smolts can be guided rapidly past the water withdrawal zone and over the weir crest to ensure passage.…”

Behavior of captive herring exposed to naval sonar transmissions (1.0–1.6 kHz) throughout a yearly cycle

“…At low frequencies, particularly below 20 Hz and in the near field of the sound source, particle motion is the dominant stimuli (Sand and Hawkins, 1973). Strong avoidance reactions to such sounds in the 0 to 20 Hz range have been observed for a wide range of juvenile and adult species such as salmon (Salmo salar) (Enger et al, 1993;Sand et al, 2001), gadoids (Handegard and Tjøstheim, 2005), and cyprinids (Sonny et al, 2006). Sand et al (2008) suggested that near field particle acceleration associated with the moving hull of a ship is the major stimulus causing herring to exhibit avoidance response.…”