Japan proposes the revision of the Conservation Measure 41-04(2007): Limits on the explratory fishery for Dissostichus spp. in statistical subarea 48.6 in the 2008/09 season.
Abstract:
A proposal to undertake scientific research in CCAMLR Subarea 58.4.4 over the 2008-2009 seasons is introduced. The first survey has been undertaken by a commercial fishing vessel, Shinsei Maru No.3, in 07/08 season covering the whole SSRUs (Small Scale Research Units). In the course of this first year survey, important information, including information on distribution of toothfish, size composition of toothfish, and by-catch species, has been obtained. However, the information obtained by just the single year survey is not be sufficient in order to quantitatively assess the stock abundance and consider possibility of re-opening the area for new and/or exploratory fishery. Therefore, it is essential to continue the scientific research to accumulate scientific information on toothfish in this area. Furthermore, the presence of legal operators in this area could contribute to monitor and deter the activity of IUU vessels. In addition, tagging and sampling activities during the survey will particularly contribute to the future study on the distribution and population structure of Dissostichus spp.
Abstract:
This paper describes a new vessel modification to allow setting of longlines via a stern-setting tunnel, and the proposed experimentation to evaluate this method's effect on the sink rate of demersal integrated weight longline (IWL). The stern setting tunnel consists of an elongated steel tube, built in to the longliner during a dry-dock refit. The tube angles downwards from where the line exits the baiting machine, which is positioned in the aft section of the stern setting deck, to the exit point at the water line on the vessel's transom. The exit point of the tube is understood to be slightly off-centre towards the downward-swing side of the propeller. The sink rate of IWL longlines, conforming to the CCAMLR standard specified in conservation measure 24-02, is planned to be tested in a series of sets using time-depth recorders during current sea-trials and approximately three weeks of fishing in the New Zealand ling fishery. To evaluate the effects of the stern-tunnel method, the sink rates will be compared to similar vessels using IWL and the same setting machinery but setting conventionally over the stern. The sink rate tests are not expected to be completed until just before the WG-IMAF meeting and it is intended that the results will be tabled separately at the meeting commencement.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
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Abstract:
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
Abstract:
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.