Detection of leader net by whitefish Coregonus lavaretus during varying environmental conditions

• The behaviour of ultrasonically tagged whitefish Coregonus lavaretus, was studied in a 15 000 m(2) net enclosure. Avoidance manoeuvres of fish were recorded during short-time introductions of different obstructions at randomly chosen places in the enclosure. In all 28 individual fish were tested in 92 trials with different leader structures. There was a clear net avoidance both day and night. Typically the frequency distribution of reaction distances was bi-modal, with one peak frequency of turns from the net at 15-20 m distance and one at 3-5 m. The reaction at short distances can be explained at least partly by visual detection, but the concentration of turns at the larger range was clearly,independent of turbidity and daylight conditions and indicates a non-visual detection mechanism. (C) 2002 Elsevier Science B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Nyckelord

whitefish

behaviour

gear avoidance

leader net

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)