CCAMLR

Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200-1500 m) of the sub-Antarctic Prince Edward Islands and surrounding sea rises have been investigated during the pilot survey conducted in April 2001 onboard fishing vessel MV Ibis. A total of 56 fish taxa were collected during the survey, of which 43 were identified to species level, 8 to the genus level and 5 to the family level. Among identified taxa, 36 constituted new records for the area investigated. Total CPUE (catch per unit effort) during the survey ranged from 1.1 to 268.1 ind.h-1. Both average fish diversity and total CPUE positively correlated with the trawling depth. Overall, mean sampling depth and near-bottom temperature explained 56% of both total fish CPUE and diversity variation. The hierarchal analysis identified three distinct fish assemblages with very pronounced dominant species, which occupied different vertical zones with likely specific environmental characteristics. Major shifts in communities have occurred at 500-600 m and 800-900 m depth strata, which were probably augmented by the physical and biological vertical zonation. Analyses of diets of selected fish species showed that they are feeding generalists consuming predominantly pelagic, including epipelagic, and meso-/benthopelagic prey. Diet data on 6 species and stable isotopes of 22 fish species revealed that with a few exceptions most species occupy the fourth trophic level and are tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect of alternative (possible importance of high Antarctic and chemoautotrophic versus photoautotrophic sub-Antarctic primary production) organic matter sources at the base of deep-sea food webs.

Based on the analysis of data on the searching fishery on Antarctic toothfish (D. mawsoni) by the Russian fishing vessels "Yantar" and "Volna" in the seasons of 2002/03-2003/04 it has been obtained that the long-line catchability and size composition of fish depended on the fishing depth, bottom orography and sharp change in the depth, etc. In this relation, to determine the areas and depth of Antarctic toothfish concentration the need for extension of searching fishery area boundaries was proven with the use of passive fishing gears in the meso- and bathypelagial.. The constructions and schemes to set the vertical and combined vertical-bottom longlines.

This report describes and quantifies occurrences of fishing gear, marine debris and oil associated with seabirds at Bird Island, South Georgia from 1 April 2003 to 31 March 2004. It is the eleventh such annual report. As in most previous years, more items of fishing gear (mostly longlining gear) were found in association with wandering albatrosses than with any other species, although the number has decreased substantially since last year. Grey-headed albatross collected the highest number of marine debris items, mostly small plastic fragments, of the study species. The quantity of fishing gear and entanglements associated with giant petrels (northern and southern) was well above the average, as was the number of debris items collected. An increase in the amount of debris and fishing items associated with brown skuas was recorded for the first time and was probably attributable to an increase in observer effort associated with greater field-work intensity. Hooks were typical of those used in the toothfish fishery around South Georgia and the Falklands and evidence of the discarding of longline hooks in offal and bycatch is of concern.

During the 2003/04 austral summer the fourteenth annual beach debris survey was carried out at Signy Island, South Orkney Islands. Debris was cleared each month between December and March from the three study beaches. The debris was counted, measured and classified by type, material, mass and size categories. A total of 21 items weighing 11.59kg were collected. The number of items found was lower than the total found during the previous season, as was the total mass of the waste recovered (a decrease of 61% and 57.56% since 2002/03 respectively). There was a decrease in the number of plastic packaging bands (5) from the total recorded the previous season (twenty three), this decrease reversing the rise in packaging bands experienced over the previous two seasons and marking a return to what has otherwise proved a declining trend since 1993/94. Despite this seasons decrease in these packaging bands, the fact that they continue to appear as beach debris indicates that the ban on their use aboard fishing vessels brought into force by CCAMLR in 1995/96 has yet to prove entirely effective and should continue. Plastic waste was predominant, as in previous seasons, making up 62% of all items recorded, followed by wood at 24%. The results of this seasons litter survey, clearly shows that the longevity of plastics and other materials with a high resistance to degradation in the marine environment remains a problem and highlights the need for continued monitoring to ensure that vessels are aware of, and comply with, regulations prohibiting the disposal of debris at sea.