CCAMLR

The Secretariat communicated with a number of other international data managing organisations over the 1994 period. As part of the international data management network, it is essential that the Secretariat continues to attend relevant meetings, and keeps abreast of the rapid changes currently taking place in data exchange protocols, methodologies and technologies.

The ninth survey of the Japanese Whale Research Programme Under Special Permit in the Antarctic (JARPA) was carried out in the Antarctic Area IV (south of 60° S between 70°E and 130°E) and eastern part of Area In (south of 60° S between 35°E and 70°E). The survey was conducted for 118 days, from 26 November 1995 to 22 March 1996. The research fleet was composed of a research base vessel, engaged in the biological survey of minke whale sampled, three sighting /sampling vessels (SSVs) engaged in sighting and sampling and one sighting vessel (SV) dedicated exclusively to sighting activities. Survey in the eastern part of Area III was conducted before and after the survey in the entire Area IV. The survey in Area IV was conducted during the period in which the peak migration of minke whales was expected. Survey in the eastern part of Area III was conducted as a feasibility study on stock identity, and samples were taken during an early and late period of the feeding season in order to study intra-seasonal changes. During the sampling, one animal was taken randomly from schools sighted as primary sighting. This was made in order to improve the representation of the population. Dwarf form minke whales were not sampled. The SV was exclusively engaged in whale sighting survey in all the research areas, along an independent sighting track line. Sighting and sampling activities were independently conducted by the three SSVs, in parallel track lines to each other. Searching distance for these four vessels was of 21,455.5 n.miles. During the research period, 893 schools (2,021 animals) of the ordinary minke whale were sighted as primary sighting and 244 schools (564 animals) as secondary sightings. Out of 693 schools (1,439 animals) primarily sighted by the SSVs, 440 ordinary form minke whales (273 males and 167 females) were randomly sampled. The distribution pattern of minke whales in Area IV was not considerably different from that observed during the 1993/94 JARPA. In the previous research, high density was observed in the Prydz Bay. However, such high density was not found in the present research. Distribution of cetacean species during the research period suggest the segregations between minke and humpback whales, and between sperm and beaked whales including southern bottlenose whales. Those were related to the pattern of the ice edge in the research area. It is supposed that concentration of pregnant female in the Prydz bay lead to such difference, because no significant different is observed when the data of the Prydz bay is excluded from the western part of the Area IV. The eastern part of the Area III located closely to the Prydz bay and many large matured female were collected in eastern south of the Area III in the second survey. It seems that the most of female minke whale in the Prydz bay tend to migrate through in the eastern part of the Area Ill. During the survey, 3 schools (4 animals) of the blue, 25 schools (48 to 50 animals) of the humpback whale and 4 schools (4 animals) of the right whale were photographed for natural markings. Ten skin biopsy samples were taken from humpback whales and one sample was taken from the blue and right whales, respectively.

This paper summarizes Japanese krill catch data during austral summer in 1994/95 season. Main fishing grounds were persistently formed in the north of Livingston Island throughout the season (except April), and around Elephant Island during April to May. CPUEs in the fishing to the north of Livingston Island were relatively stable through out the season, however, it was highly variable around Elephant Island Krill with a modal length of 48-50mm were dominant in catches, extreamly larger than the previous season.

It has been suggested that modes of vibration of solid elastic spheres, such as those used in the calibration of echo sounder systems, can be affected by the manner of suspension. This hypothesis is investigated in the context of reported experimental calibration trials with the SIMRAD EK500/120-kHz echo sounder. In these, as many as four different spheres were used: 23- and 30.05- mm-diameter spheres composed of electrical grade copper and 33.2- and 38.1-mmdiameter spheres composed of tungsten carbide with 6% cobalt binder. Theoretical target strengths are computed for each sphere for the reported measurement conditions for a series of cases in which single vibration modes remain unexcited. The computed target strengths are compared with the corresponding experimental values. The working hypothesis is not supported by the data.

Krill distribution and density are reviewed for the Elephant Island area with regard to the representativeness of the study area (60° - 62°30'S and 53° - 57°30 'W) for the recruitment and density indices. Recruitment indices were re-calculated applying the delta distribution approach introduced by de la Mare (1994a). The high interannual variability of krill recruitment is confirmed by the present analysis. Results are compared for one (R1) and two year old (R2) age classes. Statistically significant fluctuations in krill density over the period 1977 to 1994 are also confirmed by this study using randomisation tests on an analysis of variance.

The diet of the Cape petrel Daption capense was investigated at Laurie Island, South Orkney Islands (60°46'S, 44°42'W), Antarctica, over the period January-February 1996. Stomach contents of adults and regurgitate of chicks were sampled during the post-hatching period. The analysis showed that during the whole sampling period Antarctic krill and fish represented the predominant preys in terms of frequency of occurrence. Fish prey formed near 64% by mass, with krill forming 35.8% during the whole sampling period. The species Electrona antarctica was the most frequent fish prey.
Amphipods were present in lower numbers and Cephalopods were only a very small portion of the diet of Cape petrel at Mossman Peninsula.
Diet composition in terms of frequency of occurrence, mass and number was compared with results of previous studies.

Mackerel icefish (Champsocephalus gunnari) are widespread on the South Georgia (54 degS, 36 deg W) shelf. Analysis of results on condition index indicated a strong inter-annual variation. High condition indices, indicative of good feeding conditions, were present when krill were abundant in the region. Years when krill were scarce and condition index was consequently low, were consistent with years when indices from land-based krill predators also indicated krill were scarce.

Acoustic surveys designed to assess krill abundance are costly in time and money, so the opportunity was taken in 1992 to produce a krill biomass estimate as a by-product of a fish stock-assessment surveyin CCAMLR Subarea 48.3. Acoustic transects were run between trawl stations using a sounder operating at 38 kHz and 120 kHz. The results have been analysed for all straight sections of track when the ship's speed exceeded 7 knots and when the ship was over the shelf around the main island of South Georgia. The appearances of echoes on echo charts were used to decide which echoes to include in krill estimates. The results were partitioned by depth to remove deep echoes that were thought to be mostly due to other scatterers. A threshold at one frequency was used to remove noise and any echoes too weak to be separated from the background. The remaining fraction was further subdivided using the ratio of backscattering strength at the two frequencies into a) echoes from krill-sized scatterers and smaller and b) echoes from larger scatterers. The data in the krill-size subset has been converted to density estimates, these are presented for day and for night sections of survey and at locations mapped around the island. An overall mean for daytime transects was 95 g m-2.