In 1991, the 0 age-class of C. gunnari were sampled at Shag Rocks on 18 January, off Possession Bay, South Georgia during 19-20 January and off much of the north-east coast of South Georgia between to 19 January to 19 February.
The size- frequency of fish at Shag Rocks contained two modes of 31-46mm and 55-87mm SL. however, off Possession Bay only one mode of 25-57mm SL was apparent. Fish in combined samples off the coast of South Georgia were 24-63mm SL. The mean and median sizes of the fish at these locations were all significantly (p
The size difference between the larger size mode at Shag Rocks and those at South Georgia must be the result of different spawning seasons and/or egg development periods and/or growth rates. This suggests that there are two separate stocks of C. gunnari in a single CCAMLR statistical sub-area.
There is an apparent growth of around 0.76% SL d-1 (0.27mm SL d-1) for larvae on the South Georgia shelf which is comparable with previous reports of early growth in C. gunnari.
Abstract:
The diet composition and feeding intensity of mackerel icefish ( Champsocephalus gunnari) around Shag Rocks and the mainland of South Georgia was analyzed from 3,691 stomachs collected in January/February 1994. Main prey items were the amphipod hyperiid Themisto gaudichaudii, mysids (primarily Antarctomysis maxima), and krill (Euphausia superba) in the vicinity of South Georgia and T. gaudichaudii and Thysanoessa sp. around Shag Rocks.
Abstract:
Patagonian toothfish, Dissostichus eleginoides, spawn over the continental slope from July to September. Eggs have been observed primarily in the upper part of the water column over 2200-4400 m bottom depth. Embryos in stage III and IV of their embryonic development are described. Hatching is likely to occur in October/November. Scales do not start to form before the fish are 64-74 mm long.
Abstract:
Areas of seabed within 50m depth contours down to 100m and within 100m depth contours from 100 to 500m have been estimated from soundings obtained during plankton and bottom trawl surveys around Elephant Island (the northernmost island of the South Shetland Islands) from 1977/78 to 1992/93. The results are presented on a fine scale grid of 15’ lat x 30’ long.
Abstract:
Of 409 Notothenia coriiceps specimens tagged and released at Potter Cove, South Shetland Islands, in successive years from 1989 to 1992, 9 were recaptured at the same site after periods of 11-21 months. A comparison was carried out between the annuli found in scales removed before and after the period of liberty. In scales of those specimens recovered after 11-13 months, one extra annulus was laid down. The same analysis in one individual recovered after 21 months resulted in 2 extra closely spaced sclerites zones, which corresponded with an elapse of two winter seasons. The comparative analysis between scales taken at recapture and otolith cross sections of the same individual allowed a simultaneous counting of the annuli with good agreement. These results validate the principle of annual deposition of the annulus in scales and otoliths of N. coriiceps. A preliminary analysis of scales regenerated after release indicates that these observations are of value in validation studies.
Abstract:
An age-length key was prepared for Champsocephalus gunnari from the Subarea 48.3, based on the readings of otoliths randomly collected during the R/V Holmberg survey in Feb/Mar 1994. Small and medium sized fish (total length 12-33 cm) constituted the bulk of the samples (93%), while larger specimens (>33 cm) were scarce. At South Georgia, fish of age groups 1-4 were truly represented; at Shag Rocks, a large concentration of fish belonging to age groups 2 (90%) and 3 (10%) was found. The length weighted distribution of all the fish sampled in the Subarea 48.3 showed good correspondence between modes and, the mean lengths of age groups 1-2. Such correspondence was also obtained for age group 3 when the data from South Georgia were analyzed separately. Mean length at age presented here fall in the range of available results from previous surveys in the South Georgia region.
There is no abstract available for this document.
There is no abstract available for this document.
Abstract:
In the season of 1993-1994 Ukrainian fishing fleet conducted fisheries in two areas of Antarctic waters of the World Ocean: in the Atlantic (subareas 48.2 and 48.3) and the Indian (zone of the Kerguelen Islands, French EEZ, division 58.5.1) Oceans.
In 1994 Ukraine has resumed krill fishing stopped in 1993. It was conducted by two vessels: BAT GRIGORY KOVTUN and RKTS GENERAL PETROV. The first one worked in subarea 48.2 from 01.03.1994 to 10.04.1994 and from the middle of the second ten-day period of May to the middle of the first t en-day period of June. GENERAL PETROV worked from 21.04 to 17.05 in subarea 48.3 and from 28.05 to 11.08.94 in subarea 48.3. According to operative data, summary catch of krill in March-June 1994 was 8.708 t.
Three longliners of SRTM type worked at the specialized fishery of Patagonian toothfish in the period from October 1993 to February 1994. The total catch in the above period made 942 t,. from which 422 t were harvested in October late December and 520 t were fished in January - March.
In the reported period the priority trends in study of Antarctic bioresources were generalization and analysis of retrospective information on fishery, biology of the main fishery targets, the state of their stocks, as well as their interrelations with external environmental conditions.
To reveal biopruductive zones in the ocean and assess intensity of primary production of organic mater in them, a model of balance analysis of biogenous elements was constructed, including estimation of advective, diffusion, biochemical components and specific primary production.
The detailed processing of data on Soviet catch separately for divisions 58.4.1, 58.4.2, subarea 48.6 for the period fro m 1983 to 1990 has been completed, as well as that for division 58.4.4 for 1977-1991.