Krill larvae in the Atlantic sector of the Southern Ocean during FIBEX 1981

Summary During the First International BIOMASS Experiment krill larvae were sampled by several research vessels. The present paper compiles data gathered by of Polish, German and Argentinian expeditions undertaken during 19 January–19 March 1981 in the Scotia Sea, Drake Passage and Bransfield Strait regions. In the 1980/81 season the most intense spawing occurred at the end of December and in the beginning of January. In the eastern part of the region development of krill larvae was much more advanced than further to the west. The highest numbers of larvae were observed in the central part of the survey area, in the open ocean and on the shelf slope zones. In the Bransfield Strait larvae were most abundant in the north and north-east. These larvae appeard to have drifted to the north and north-east and occurred outside the region of the main concentrations of adult krill. As such, larval distribution reflected a meandering current at a reference level of 500 db, which was flowing in a general south-west to north-easterly direction. The Weddell Scotia Confluence did not form a border either to the occurrence of krill larvae or of adults.