CCAMLR

This paper provides a summary of longline and trawl fishing effort, seabird bycatch, and seabird bycatch mitigation measures in Australian fisheries outside the Convention Area. Mandatory seabird bycatch mitigation measures are in place in all longline fisheries within Australia's national jurisdiction. Seabird bycatch is generally low and typically below 0.05 birds per 1000 hooks. Seabird bycatch is thought to be low in Australian trawl fisheries but, as yet, there are insufficient observer data to fully assess each trawl fishery. As part of efforts to better assess seabird bycatch in Australian trawl fisheries, a pilot study has commenced to undertake an initial appraisal of seabird bycatch in the largest Australian trawl fishery. Depending on the findings; the need for further assessments and implementation of mitigation measures will be considered.

This paper proposes that, for fishers whose vessels comply with certain conditions, the requirement in Protocol C1 of Conservation Measure 24-02 to test the sink rate of integrated weight longlines (IWL) before entering the Convention Area is an impost on fishers that is no longer warranted. Testing could instead be conducted in the first week of fishing inside the Convention Area, potentially reducing compliance costs to fishers while appearing to pose little likelihood of increased seabird bycatch. The conditions to be satisfied include that the vessel used IWL gear in the immediate previous season that fully complied with the required sink rate and that there have been no changes since then to the IWL, other vessel gear and equipment, and operating procedures used for line setting. Other requirements of CM24-02, including for regular sink rate testing of IWL gear during fishing in the Convention Area and reporting of sink rate test results, would remain unchanged, as would the requirements applicable to fishers using other types of longlines.

The results of the microscopic analyses of the Antarctic toothfish (Dissostichus mawsoni) fecundity and eggs size, caught in December-March the Pacific and Indian Ocean area of the Antarctica are presented. We analyzed the main reproductive characteristics which determinate the individual fecundity of the Antarctic toothfish: individual absolute fecundity by the largest oocytes, share of largest trophoplasmic oocytes and their diameter. The frequency of Antarctic toothfish females with the ovaries on IV stages of maturity was 1.2 – 10% in the different regions. It was revealed that maximum level of fecundity characteristics had prespawning females from the Ross Sea, and minimum – toothfish females from the Indian Ocean area of Antarctica. The individual absolute fecundity is varied from 0.03 to 0.61 million eggs, and relative fecundity – from 11.48 to 42.53. The diameter of largest trophoplasmic oocytes is varied from 2.8 to 3.15 mm.

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.