P. Romare, An evaluation of horizontal echo sounding as a method for behavioural studies of 0+fish in field experiments, J FISH BIOL, 58(6), 2001, pp. 1512-1523
A 120 kHz echo sounder, with two split-beam transducers, was used horizonta
lly to monitor the behaviour of 0+ roach Rutilus rutilis, from June to Augu
st, in field enclosures. 0+ roach outside the vegetated area of the enclosu
res were registered both as schools and as single swimming fish. Combining
echo counting and tracking with direct observation of echograms, an estimat
e of relative abundance of 0+ roach in the open water volume was obtained a
lso. With this set up, intermediate sized field experiments studying 0+ fis
h, may be performed during the whole summer season. (C) 2001 The fisheries
Society of the British Isles.