Diurnal variations in mean volume backscattering strength of an Antarctic krill (Euphausia superba) patch

A series of acoustic transects and quantitative net hauls was made in a large patch of Antarctic krill (Euphausia superba) just north of South Georgia. The krill went through a diurnal pattern of dense swarming in daytime and dispersion after dark. This was accompanied by an 8 dB change in mean volume backscattering strength