Study on the distribution, abundance and growth condition of Antarctic Krill (Euphausia superba) in the Prydz Bay region, Antarctica during the Austral summer of 1999/2000

Abstract

Antarctic Krill (Euphausia superba) were collected from the Prydz Bay region during the austral summer of 1999/2000. The sample - collection was made at 15 sites in 3 longitudinal transects. Although krill were encountered at 14 sites, the abundance was comparatively low in general. The main component of the krill population was of post-larval stages. The mean numerical and weight density of krill integrated for all sampling stations in the survey area were 16.17 ind. 1000 m(-3) and 12.02 g 1000m(-3), respectively. In the survey area, stations with larger krill density are mainly located in the slope zone, except that the largest sample was collected in the open sea zone. No krill occurred in the only station of the shelf zone during our investigation. Krill collected from the slope zone were under better growth condition than those from the open sea zone, but when the survey area is considered as a whole, the growth condition is normal. The results of the comprehensive analysis of the environmental factors show that the three large sample stations seem to be related with the cold water mass at 75 m depth and the confluence area between the high and low Chl a centers at the depth of 25 m