CCAMLR

Basing on materials of research expeditions and fishing cruises to the Kerguelen Islands shelf in the period from 1970 to 1991, dynamics of size- age structure of marbled rockcod (Notothenia rossii rossii) population is shown. Data on age determination for 1970-1989 (Tankevich, 1990) and the data collected in the joint Soviet-French expedition on board RTMA Orlinoye in May-Jine 1991 were used to characterise the age composition. It was determined that in the initial years of exploitation of the stock, the major part of catches (more than 80%) was formed by repeated spawning fish. then as a result of fisheries, the share of the fish spawning for the first time increased considerably in catches and in some years (1981-1985) fisheries were based practically on recruitment. After the closure of the specialised fishery in 1985 and after the marbled rockcod by-catch at other fisheries was limited to 500 tons, a stable trend towards increase in the mean age and fish length was noted in catches. In May-June 1991 the mean length was 59.2 cm, mean age was 7.4 years; some 70% of catch consisted of repeated spawning fish. The author consideers the demographic populational structure in 1991 to be close to that observed in the initial years of exploitation and further closure of marbled rockcod specialised fishery can lead to increase in natural mortality of the population as the whole. Fish removal of older age groups is recommended to start in the nearest years. It will make it possible to control size- age structure changes in the spawning part of the population.

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.