CCAMLR

Data of satellite monitoring (GOES-E) of the sea surface temperature (SST) and realtime data from vessels allow us to understand the hydrologic situation off South Georgia (Subarea 48.3) in December, 1999 - January, 2000. Using the database of the SST maps for 1990-1991 and the current standard weekly SST maps, we have developed mean monthly SST maps, maps of the SST anomalies, and maps of difference between the current SST maps (the season of 1999-2000) and those for the season of 1990-1991. Analysis of the SST distribution in Subarea 48.3 developed by January, 2000 has revealed an unfavorable hydrologic situation for formation and maintenance of mass concentrations of krill (Euphausia superba) in shelf waters off South Georgia. This is primarily explained by an intensive advection of the Weddell Sea waters. The SST maps for December, 1999 and January, 2000 illustrate the event. The transformed Weddell Sea waters spread far north-westward up to 50-51° S and the associated krill transport passes the South Georgia shelf on the east because there are no favorable conditions to form mass concentrations in these waters.

The analysis of fishing data obtained from the ship’s log of the Polish commercial vessel M/T Pollux facilitated the characterization of catches and concentrations of krill between February and June from 1997 to 1999 in statistical area 48. Records from each haul were used for analysis and since the vessel carried out catches along with other Polish vessels, the results describe Polish catches in this period and area. Each fishing season was different. In 1997 the catches were carried out in sub-area 48.1 and 48.3, in 1998 they were exclusively carried out in sub-area 48.1 and in 1999 in sub-areas 48.1 and 48.2. On average, the vessel made from 7 to 9.5 hauls daily which lasted an average of 60-70 minutes. Differences in catch rates in various areas and years were observed. The highest catch rates (4-5 t/h) occurred near Elephant Island and King George Island, as well as near the South Orkneys and King George Island in 1998 and 1999, respectively. During the day, commercial krill concentrations occurred deeper, at depths of 10-140 m, while at night the concentrations were closer to the surface, at depths of 10-100 m. The day catch rates were several times higher than at night (4.35-9.33 during the day and 0.8-3.33 at night). In general, the night concentrations were shallower than the day-time ones in the area of King George, however, in 1997 and 1998 the situation was the opposite.

The Japanese stern trawler Chiyo maru No. 5 conducted krill fishing operations in CCAMLR Subarea 48.1 during February, 2000. Under an agreement by the Japanese and United States governments, a CCAMLR International Scientific Observer was present on the vessel. This paper presents much of the information collected in graphical form, and serves as a compliment to the Final Report of Scientific Observations submitted by the scientific observer (Rain, 2000). Fishing operations were conducted off the South Shetlands Islands north of Elephant Island and the lower South Shetlands Islands. Information on length frequency, maturity, and feeding intensity were summarized based on 5 regions off the South Shetland Islands where hauls were clustered. The biological information collected during this commercial fishing operation agrees well with the findings of the CCAMLR 2000 synoptic survey within Subarea 48.1.