Ichthyoplankton samples were obtained during the Italian Antarctic Oceanographic Cruise carried out in the western Ross Sea in November-December 1994. The present study focused on improvement of the knowledge of the larval fish community in relation to its distribution and relative abundance. A midwater trawl (Hamburg Plankton Net) was used to collect samples at 26 stations. Larval and juvenile specimens of twentyone species belonging to six families (Artedidraconidae, Bathydraconidae, Channichthyidae, Macrouridae, Nototheniidae and Paralepididae) were collected from surface to 380 m depth. Mean relative abundance of larval fish in the whole area was about 2.7 specimens / 1000 m3 of sea water filtered. The upper 100 m of the water column showed the greatest species diversity and abundance. Postlarvae and juveniles of Pleuragramma antarcticum were the most abundant, followed by larval and postlarval specimens of Chionodraco sp. It was noteworthy the high number of Trematomus lepidorhinus (570 larvae) found in a single station off Terra Nova Bay. Our data give evidence of a great species diversity of the larval fish community in the western Ross Sea and show a greater abundance of fish larvae in inshore than in offshore waters.

This study was based on the data from the ichthyoplankton survey made in March-April 1989 by R/V "Vozrozhdenie" in the subtropical frontal zone over the South Atlantic ridge crest between 38°30’ - 45°S. and 15° - 20°W. Larvae were collected with BONGO and JUDAY nets in oblique arid vertical hauls at 500 - 0m. The method of delta-distribution of random values (Aitchison, Brown, 1957; Pennington, 1983) was used to count the larvae. The data obtained was taken to estimate the recruitment biomass (fish aged up to 1 year) in this species for the area of 87750 square miles studied. The abundance of larvae in this area was 4.3 x 10 ind., while the biomass of one year old fish obtained was 10750 tons. A whole chain of similar reproductive grounds is assumed to exist in the notal zone of the Atlantic and other sectors of the South Ocean to be able to sustain a large biomass of E. carlsbergi in waters of the south po1ar frontal zone.

Positions of commercial krill operation for 1980/81 season to 1998/99 season in the area to the north of South Shetland Islands were analyzed by using GLM (generalized linear model). Fishing season, the timing, and the longitude were significant factors to explain the variability of latitudes where operations were undertaken. Operations tended take place in the north in early 1980s, but from mid-1980 onwards, they tended to happen in the south, with exceptions of 1994/95 and 1995/96 seasons. Predicted latitudes of operation significantly correlated with Salp densities in the Elephant Island area (Spearman's rank correlation , p<0.05), but not with krill densities. This may be due to the intention of fishing vessels to reduce the salp in the products.

The paper covers the-results of an acoustic estimation of distribution for krill and non-krill zooplankton within the area of South Sandwich Islands that has been obtained with multy-frequencies algorithms according to the data on survey by Russian vessel ATLANTIDA under CCAMLR Survey-2000. Distribution of acoustic characteristics for krill and non-krill fractions of antarctic zooplankton has been compared. It has been showed that within the field locations occupied by waters of the Weddell Sea and Frontal Zone of Weddell Gyral the bulk of zooplankton had been made of krill, while non-krill fraction dominated in water masses of the Antarctic Circumpolar Current.