The international CCAMLR Survey 2000 was conducted to support an updated estimate of the large scale krill biomass in the South Atlantic Sector of the Antarctic. Four vessels from Japan, Russia, the UK and the USA participated in the study during which 22 parallel hydroacoustic transects as well as four small scale shelf grids were investigated. Standard net tows were carried out during midnight and midday stations. Additional samples were take by opening-closing nets for the identification of acoustic targets. Analyses on the combined data sets from the net sampling program indicate that krill distribution showed three distinct geographical clusters of size frequency distributions. Small to medium sized juvenile and subadult krill mainly occurred east of the South Orkney Islands. Adult krill predominately smaller than 50 mm mean length dominated in a band to the north of the first cluster, while the adult krill larger than 50 mm mean size was found to the north of cluster 2 , but at the same time was mostly restricted to the area west of the South Orkney Islands. Implications are discussed arising from the stock composition and distribution patterns.
Abstract:
In 1998 the 2nd Ukrainian Marine Complex Antarctic Expedition (UMCAE) on board scientific research vessel "Ernst Krenkel" took place in the western part of the Atlantic sector of the Antarctic. It was arranged by the Ukrainian Antarctic Center of the Ministry for Affairs of Science and Technologies of Ukraine. The preliminary analysis of the data compiled allows revealing some specific features of the environmental conditions, state of the krill population, other functionally important components in the pelagic ecosystems of the areas under review. In Subarea 48.2 there were fixed water low temperatures and great amount of icebergs (together all these factors characterize the navigational season of 1998 as abnormally cold), recruitment of the stock (for the first time for recent years), low abundance of krill larvae, plenty of salps (their abundance and biomass occurred to be higher 1.6 times than the same indices for 1997). In Subarea 48.1 there were revealed the differences in size composition of krill and in its biomass on the fishing sites near the Elephant Island and the King George Island. In the former of them the basis of catches comprises krill of the third size group (evidently, generation of 1995); in the latter - krill of the second and third group with the evident share of the recruitment group.
