CCAMLR

The paper is based on materials on D.mawsoni feeding collected by authors in the four near-continental seas of the Indian Ocean Antarctic area (Dupont D’Urville, Mawson, Davis, and Cosmonaut Seas) and on the Banzare Bank during 2004-2008. The food relationships are considered. The qualitative and quantitative composition of diet for young and adult Antarctic toothfish is studied. The predominant food objects are identified.

A large-scale acoustic survey of zooplankton stocks of the waters around South Georgia was carried out during November and December 1981. The data have been analysed as a survey using various definitions of strata. The total biomass in the area of 155 786 km2 was estimated to be 1.8225 x 106 t (Coefficient of Variation = 9.5%). This gives an estimate of mean density throughout the region of 11.7 t km-2. Although the estimate of the mean is not sensitive to the definition of strata, the variance of the estimate is. The analyses highlight the importance of careful planning of acoustic surveys

Estimation of krill target strength was made by ensonification of encaged live krill and using trawling-acoustic method . Ensonification of encaged live krill. For aggregations with mean lengths in the range (45,50) mm the mean single-krill target strengths are in the range (-68, -69) dB at 136 kHz. For aggregations with mean lengths in the range (43,47)mm the mean single-krill target strengths are in the range (-71, -77) dB at 20 kHz.
Trawling-acoustic method. For aggregations with mean lengths in the range (47,50) mm the mean target strengths in the range ( -71, -75) dB at 20 kHz were obtained. At the same frequency for aggregations with mean lengths in the range (41,47) mm the mean single-krill target strengths are in the range (-76, -81) dB.

At least six instances of long-line fishing gear (especially hooks) in association with breeding black-browed and wandering albatrosses were recorded at Bird Island, South Georgia in 1992J93. Although similar observations had been made in previous seasons, this is the highest incidence yet recorded in a single season.

Surveys of Antarctic fur seals entangled in man-made marine debris were carried out for the third consecutive winter and fifth consecutive summer at Bird Island, South Georgia. In the 1992 winter an unprecedented number of 97 entangled seals were seen, a ten-fold increase on the previous two years and with twice as many seals suffering serious injuries. Almost all animals involved were juvenile males, the main element of the population seen ashore at Bird Island at this time of year. In the summer, 84 entangled seals were seen. This was a 75% increase from 1992 and contained more adult females than usual. Otherwise, the nature of the entangling debris (50% packaging bands, 25% fishing net), the categories of seal affected (60% juvenile males, 30% adult females) and the severity of injuries (40% serious) was similar to previous years. The increased incidence of entanglement in both winter and summer is disturbing, particularly following two years of relatively low incidence. It cannot be accounted for by changes in the foraging ecology of fur seals at South Georgia nor by obvious changes in fishing practice, except possibly for the increase in vessels engaged in long-line fishing, which uses bait boxes tied with packaging bands. CCAMLR needs to renew its vigilance with respect to marine debris and should consider requiring the use of packaging bands on fishing vessels to be phased out.

An exploratory fishing survey was undertaken around the South Sandwich Islands ( FAO Subarea 48.4 ), to establish the presence and abundance of the Patagonian Tootfish Dissostichus eleginoides with a view to opening a new fishery under the auspices of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). The survey was undertaken by the Chilean long-liner B/F Friosur V, owned by the company Frioaysen S. A.. Fishing was by bottom longline, and data were collected following guidelines set out in the CCAMLR Scientific Observers Manual and in a memorandum of understanding between the Governments of Chile and the UK. A new fishery in Subarea 48.4 was found not be commercially viable due to an extremely low catch per unit of 5.37 g/hook. The low numbers of fish found may be been due to close proximity of the southern edge of the geographic range of D. eleginoides or to an unfavorable environment. Incidental catch consisted largely of Macrourus holotrachys and Raja (Amblyraja) georgiana. Interactions between fishing operations and seabirds were also examined, with no incidental mortality witnessed, but data were inconclusive due to the low number of long-line operations ( N=7 ) completed.