CCAMLR

This paper is presented for the Commission’s consideration and sets out the projected outcome of the budget for 2007, a draft of the 2008 budget and an indicative forecast for the 2009 budget. The presentation is in the format determined by the Commission at its 2002 Meeting.

Chaenocephalus aceratus (Family Channicthyidae) is one of the dominant species of demersal fish living on the South Georgia shelf where it is caught in low numbers as by-catch in the mackerel icefish and Antarctic krill commercial fisheries. Data collected during 14 demersal fish surveys, from 1986 to 2006, are analysed to investigate biomass, distribution, growth and diet. Biomass estimates from a swept area method ranged from 4462 tonnes to 28740 tonnes on the South Georgia and Shag Rock shelves although few fish were caught at Shag Rocks. Analysis of length frequency data indicated that growth was fast in the first five years with males and females attaining lengths at first spawning of 440 mm TL and 520 mm TL. The diet was comprised of fish and crustaceans, with an ontogenetic shift in diet from Euphausia superba and mysids to benthic fish and decapods observed to begin at 250 mm TL. In larger fish (> 500 mm TL) the diet was dominated by fish. C. aceratus diet is sufficiently different from the other species of channichthyids around South Georgia to suggest that these species have undergone resource partitioning.

The distribution and diet of juvenile (<750 mm) Patagonian toothfish are described from 4 annual trawl surveys (2003-06) around the island of South Georgia in the Atlantic sector of the Southern Ocean. Recruitment of toothfish varies inter-annually, and a single large cohort dominated during the four years surveyed. Most juveniles were caught on the Shag Rocks shelf to the NW of South Georgia, with fish subsequently dispersing to deeper water around both the South Georgia and Shag Rocks shelves. Mean size of juvenile toothfish increased with depth of capture. Stomach contents analysis was conducted on 795 fish that contained food remains and revealed that juvenile toothfish are essentially piscivorous, with the diet dominated by notothenid fish. The yellow-finned notothen, Patagonotothen guntheri, was the dominant prey at Shag Rocks whilst at South Georgia, where P. guntheri is absent, the dominant prey were Antarctic krill and notothenid fish. The diet changed with size, with an increase in myctophid fish and krill as toothfish grow and disperse. The size of prey also increased with fish size, with a greater range of prey sizes consumed by larger fish.

The distribution, length-frequency and diet of Patagonotothen guntheri are described from 14 bottom trawl surveys conducted on the Shag Rocks and South Georgia shelves in the austral summers from 1986 to 2006. P. guntheri (80-265 mm LT) were caught on the Shag Rocks shelf from depths of 111 to 470 m, but no specimens were caught on the South Georgia shelf. Multiple cohorts were present during each survey and length-frequency analysis of these cohorts suggests that growth is slow (K=0.133). Evidence from stomach contents and acoustic data (2005 & 2006) show that P. guntheri is primarily a pelagic feeder, migrating from the seafloor towards the surface to feed during daylight. The diet of smaller fish (

We describe the process used in the fisheries management system of the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) to minimise seabird bycatch, and the risk assessment methodology developed to assist this. We examine the progress of several Regional Fishery Management Organisations in taking steps to address seabird bycatch. CCAMLR has the most advanced system of management among the RFMOS covered in this review, and has made the most demonstrable progress in reducing seabird bycatch levels in its longline fisheries. A combination of proven mitigation measures, extensive monitoring by independent observers, annual expert review of seabird bycatch rates and evolving fishery and mitigation practices have been instrumental in reducing seabird bycatch in CCAMLR fisheries.

The most abundant icefish species observed in catches off the northern tip of the Antarctic Peninsula in the last 25 - 30 years has been the spiny icefish Chaenodraco wilsoni Regan 1914. C. wilsoni has been exploited on a commercial scale from the late 1970’s to the end of the 1980’s off Joinville – D’Urville Islands (CCAMLR Statistical Subarea 48.1) and in the Cosmonauts and Cooperation Seas and Prydz Bay in the Indian Ocean sector (CCAMLR Statistical Division 58.4.2). This paper presents new information on biological features and life history characteristics of C. wilsoni, based on research survey collections along the northern Antarctic Peninsula in 2006 and 2007 and samples taken in the commercial fishery in 1987. Length frequency compositions from the research surveys demonstrated that fish 21 – 34 cm long predominated in the catches. Sexual maturity is attained at 24 – 25 cm. Absolute fecundity and relative fecundity is low (1000 – 2500 eggs; 6 – 12 eggs). Oocyte diameter varied from 4.3 to 4.8 mm very close to spawning. Spawning at the tip of the Antarctic Peninsula is likely to occur in October-November. Remotely Operated Vehicle deployments in the northern Weddell Sea demonstrated that C. wilsoni exhibit parental nest guarding where males protect the eggs. The incubation period is likely to be 8 months long. Fish feed primarily on Antarctic krill (Euphausia superba) in the Antarctic Peninsula region and in the Cosmonauts and Cooperation Seas while fish take ice krill (E. crystallorophias), Pleuragramma antarcticum and myctophids to some extent in other areas. Age determination still awaits validation. Preliminary ageing attempts suggested a maximum age of about 8 – 10 years.