CCAMLR

Patagonian toothfish, Dissostichus eleginoides, collections (n-186) from three ocean basins were analysed for Hg concentration and comparisons were made by gender, total length (TL), wet weight (WW), and basin. There was no difference between TL-WW relationships by gender within any basin across the range examined. However, fish were significantly smaller within the Atlantic basin (mean=84.52 cm; 5.57 kg; n=142) than the Pacific (99.07 cm; 9.12 kg; n=15) and Indian (102.72 cm; 14.0 kg; n=29) basins, which were not different from each other. Similarly, Hg concentration did not differ by gender or size across the range examined and was less for Atlantic basin fish ) mean=0.23 ppm) than either Pacific (0.73 ppm) or Indian basin (0.80 ppm) fish, which did not differ.
The Pacific and Indian basin fish had Hg concentrations within the range found for other fish like shark, swordfish, tilefish, and king mackerel, that are considered high in Hg concentration by the U.S. Food and Drug Administration. In contrast, those from the Atlantic basin were found to have similar lower values in fish like haddock, halibut, cod, albacore tuna, and orange roughy.
Explanation of these geographical differences in Hg may be 1) the noted size differences among basins, or 2) the actual sample locations and associated hydrogeographical and oceanographical conditions. For example, sampling sites for the Pacific Ocean lie well outside the Antarctic Convergence whereas the Indian Ocean sites straddle the Convergence. The Atlantic sites lie well within the Antarctic Convergence, suggesting that the Polar Front may provide some type of hydrographic barrier, as suggested in other studies on Patagonian toothfish, to anthropogenic sources of contamination. With a steady global market demand for Dissostichus this could pose a human health risk that has yet to be adequately explored.

The new continuous krill fishing system uses both a small-meshed midwater trawl and a powerful pumping system for continuous pumping the catch out of the trawl bag. It was discussed the potential threats of new technology to Antarctic marine ecosystem. It was shown that application of this fishing technology may result in considerable by-catch of the juvenile fish and larvae in krill fishery.

The Spanish system is used in a range of demersal and semi-pelagic longline fisheries throughout the southern hemisphere and has been the source of a large number of seabird fatalities. An experiment was conducted on a chartered Spanish-rig vessel to improve the sink rate of longlines to reduce interactions with seabirds. The benchmark sink rate was that of integrated weight (IW) longlines, as used by autoline vessels, that are effective in reducing the mortality of white-chinned petrels, one of the world’s most difficult seabird species to deter from baited hooks. Results to shallow depth (0-2 m) were given priority because Spanish system gear, while fast to deeper depths (10-20 m), is slow to clear surface waters. The experiment determined the effect of setting speed (6 knots, 8 knots and 10 knots), distance between weights on longlines (30 m, 40 m and 50 m) and mass of the weights (4 kg, 6 kg and 8 kg) on sink time profiles of longlines. The variable was the sink time to six target depths from 1-20 m as determined by time-depth recorders attached to lines. Separately, a trial was conducted to determine differences in sink rates between traditional Spanish system line weights (netting bags of rocks) and elliptically-shaped steel weights. In the vessel charter experiment there was a statistically significant interaction between setting speed and distance between weights to ? 10 m depth. Overall, distance between weights and mass of the weights were the principal determinants of sink times to target depths. Longlines with weights 30 m apart and either 6 kg or 8 kg traditional weighs, or 40 m and 8 kg weights, most closely approximated the sink profile of IW-autoline in the shallow depth ranges irrespective of setting speed. In the weight-comparison trial 4 kg steel weights and 8 kg traditional weights sank at comparable rates and are considered to be interchangeable. Best practice seabird bycatch mitigation for line setting operations would involve a) setting longlines with weights 30 m apart (minimizes lofting in propeller turbulence), b) use of 5-6 kg elliptical steel weights instead of traditional weights, c) limiting setting speed to the 6-8 knots range, d) lining bait compartments of setting baskets and stern setting surfaces of vessels with marine grade stainless steel (to reduce incidences of hook-ups and line tension astern), e) releasing line weights before line tension occurs (eliminates a source line tension astern), f) use of dual, hydraulically-driven bird scaring streamer lines (to reduce crew work load and improve compliance) to CCAMLR standards and with 50-60 m aerial extent, g) attaching streamer lines to vessels ?5 m either side of the position the hook line leaves the vessel and use of a ‘lazy’ line to increase effectiveness in cross winds and to enable streamer lines to be positioned according to the weather conditions each time longlines are set. Strict compliance to the recommendations above has the potential to eliminate albatross mortality and reduce mortality of deep diving seabird species to very low levels.

F/T Saga Sea is a Norwegian registered factory trawler owned by the Aker Seafoods Antarctic AS, and is licensed to fish krill in Area 48.1-4. Aker has developed a patented new environmental friendly continuous trawling system, named Aker Eco Harvesting System. The system is described in the paper and is based on a conventional trawl with a connected rubber hose to the cod end of the trawl. The catch is brought onboard continuously through a suction driven system. The system is completely closed. The vessel has a processing plant onboard, which is approved for manufacturing food and feed grade products from Antarctic Krill. Approved product categories are krill meal, krill oil, round frozen krill, krill mince and krill protein concentrates. The vessel has so far carried out two fishing trips since 19 June 2006. The last trip started in September. The vessel carries an UK (MRAG) international scientific observer onboard. There is an agreement between the Aker Seafood Antarctic and The Institute of Marine Research in Norway to use Saga Sea as platform for collecting scientific data, and laboratory facilities are installed.

This paper presents an analysis of the distribution of albatrosses and petrels in the area under the jurisdiction of the Western and Central Pacific Fisheries Commission (WCPFC), using data from the BirdLife Global Procellariiform Tracking Database.
• The WCPFC area includes 41% of the global breeding distribution of albatrosses and petrels.
• Albatross distribution is concentrated north of 20ºN and south of 30ºS.
• WCPFC longline fisheries set approximately 100 million hooks each year north of 20ºN and below 30ºS, representing 16% of WCPFC’s total longline fishing effort.
• Some species spend a significant proportion (>40%) of their time in high seas areas. Key high seas areas include the Tasman Sea and areas north of the Hawaiian Islands. The distribution in high seas areas emphasises the importance of WCPFC in bringing about a collaborative approach to reducing seabird bycatch.
• Few tracking data are available for giant-petrels, petrels and shearwaters in the WCPFC area. Range maps indicate that several, including species known to be vulnerable to bycatch, have ranges that span the tropical Pacific

Report from the second meeting of the WCPFC Ecosystem and Bycatch Specialist Working Group 2006, with background on draft seabird recommendations

The works on study of the diet composition of Antarctic toothfish were conducted from December to March during the two fishery seasons (2004-2005 and 2005-2006) in different fishing areas of the Ross Sea located between 67°S to 76°S. 192 longline settings were made. In total, over two seasons 3000 stomachs (1913 stomachs in 2005 and 1087 ones in 2006) were analyzed. In 2005 fish was caught at depths of 523-2000 m. The total length (TL) of individuals ranged from 49 to 201 cm with weight from 0.8 to 123 kg. In 2006 Antarctic toothfish was caught at depths of 478-1702 m and its TL ranged from 49 to 192 cm with weight from 0.8 to 110 kg. The substantial part of Antarctic toothfish stomachs were empty (42% in 2005 and 41% in 2006). For feeding Antarctic toothfish fish was the main food object (78% in 2005 and 54% in 2006), with predominance of Antarctic grenadier (Macrourus whitsoni) and icefishes Channichthyidae. Squids were on the second place by the frequency of occurrence.

This document reports that how new bottom long line system instead of Spanish long line system was applied to exploratory long line fisheries for Dissostichus spp. in 2005/06 season, indicating distinctive points on fishing gear, line setting and line hauling process, and explaining the reason why there was no seabirds caught at line setting and line hauling either.

During February-March 2006, the United Station Antarctic Marine Living Resources (U.S. AMLR) Program in collaboration with the German Federal Research Centre for Fisheries conducted a bottom trawl survey of the northern Antarctic Peninsula (southern Bransfield Strait) and Joinville/D’Urville Islands. This area included the likely historical fishing grounds of a trawl fishery for the spiny icefish (Chaenodraco wilsoni) conducted from the late 1970’s to the mid-1980’s, as well as rarely sampled shelf areas to the south. Estimates of seabed area by strata between 50-500 m for the region surveyed are computed. Information on demersal finfish biomass, spatial distribution, size and maturity composition, and dietary patterns from the survey is presented. Most biomass of finfish in this region occurs around the likely historical fishing grounds, north of Joinville Island. In addition to the inventory of species encountered, estimates of total stock biomass were computed for the eight most abundant demersal species: Chaeonodraco wilsoni, Chionodraco rastrospinosus, Cryodraco antarcticus, Gobionotothen gibberifrons, Lepidonotothen larseni, Lepidonotothen squamifrons, Notothenia coriiceps, and Trematomous eulepidotus. The species with the highest biomass was G. gibberifrons. Observations on benthic bycatch, and differences in finfish species composition and abundance between this surveyed region and the adjacent South Shetland Islands region of Subarea 48.1 are given. High–Antarctic finfish fauna are considerably more prominent on the Antarctic Peninsula shelf region relative to the South Shetland Islands shelf region, and overall abundance of finfish is considerably lower. This is likely due to the influence of colder water from Weddell outflow, lower productivity, and lower prey availability along the Antarctic Peninsula region. Biomass for all species of demersal finfish in this region is currently not at a level for which commercial exploitation would be advisable.