Split-beam target tracking can be used to study the swimming behaviour of deep-living plankton in situ
Department of Biology, University of Oslo, P.O. Box 1064, Blindern 0316, Oslo, Norway
Corresponding author: email@example.com
Accepted: 24 January 2003
A scattering layer consisting mainly of krill (Meganyctiphanes norvegica) was studied with a submersible transducer, to assess the behaviour of individual organisms in situ by means of split-beam target tracking. Individuals were resolved and tracked, but a rapid increase in average swimming speeds with depth suggested that inaccuracies in the angular estimates affected the estimates. Attempts were made to smooth the tracks during post-processing. Smoothed speeds suggested that most (>78%) invertebrates swam at speeds below 12 cm s–1 (mode ~4 cm s–1), with components of speed larger in the horizontal plane than in the vertical.
Key words: Behaviour / Invertebrate / Swimming / Speed / Target tracking
© Elsevier, IRD, Inra, Ifremer, Cemagref, 2003