Methods for the Estimation of Krill Abundance in the Antarctic

摘要

In the energy budget of the Antarctic aquatic ecosystem, southern krill (Euphasia superba) occupy a central position. Because of their vast areal expansion and vertical distribution pattern, there can be no doubt that an assessment of krill must be based largely on hydroacoustic techniques. The present study should be seen as a contribution to the adaptation of hydroacoustic techniques to krill assessment. Field work was conducted from the South Georgia base of the British Antarctic Survey aboard its research vessel RR/V John Biscoe. Three specific objectives were identified: (a) to conduct acoustic experiments to assess the target strength of krill at different densities; (b) to determine diel changes in vertical distributions and the relationship between surface and deeper schools of krill; (c) if possible, to determine the size, configuration and density of krill swarms in and near Cumberland Bay.