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Abstract

abstract

In the late austral summer of 1977/78, a cruise was made to the western South Atlantic in SAS Protea, with the objectives of studying krill with acoustics and remote sensing methods, making measurements of ocean colour with oceanographic and remote sensing methods, and making a small investigation of land and landwater margin features with aerial photography and spectroradiometry. Spectra of krill swarms and ocean colour were obtained. Acoustics data from krill swarms were collected from a 100 kHz side-scan sonar, a 120 kHz calibrated echo-sounder with a digital datalogger, and analogue integrator and analogue magnetic tape reader. It is concluded that remote sensing observations may be useful for some purposes, but are unlikely to be useful as a survey technique. Krill was found to be a good subject for acoustics study. Ocean colour measurements and spectra were obtained at 20 stations in the Southern Ocean, but chlorophyll values were uniformly low. Based on the results of this cruise, a number of recommendations are made to assist the development of acoustics survey methods for krill.