CCAMLR

Assessments of the abundance and potential yield of mackerel icefish (Champsocephalus gunnari) populations at Heard Island are developed from the results of four scientific surveys conducted in 1990, 1992, 1993 and 1997. The assessments include estimates of all the parameters required, based on the data collected during the surveys, including growth curves, natural mortality, ages and sizes of maturity and a weight length relationship. The results show that characteristics of icefish populations on the Heard plateau are sufficiently different from those on Shell Bank for them to be managed separately. Precautionary catch limits calculated using the Generalised Yield model are found to be 180 tonnes for the plateau and 18 tonnes for Shell Bank. An assessment based on the results of a survey conducted at the end of the 1997 fishing season would allow for a catch limit on the Heard plateau of 900 tonnes in the 1997/98 season and 600 tonnes in 1998/99.

The population and conservation status of the world's albatrosses are reviewed within the framework of recent taxonomic changes. The latest estimates of size of breeding populations (pairs) at all known localities of each of the 24 proposed species are presented; population trends are assessed where sufficient data are available. Despite increased efforts in population monitoring, the status (i.e.. population trends) of two-thirds of the world's ca. 150 albatross populations remain unknown. For those that are known, almost half are decreasing. The threats currently facing each species are briefly reviewed. The best available evidence indicates that longline fishing is the most serious threat facing albatrosses today. Twenty-one of the 24 species are known to be killed on longline hooks, including rare and endangered species. Widespread implementation of appropriate mitigation measures is urgently required.

Finfish stocks in the Antarctic Peninsula region (CCAMLR Statistical Subarea 48.1) have been exploited from 1978179 to 1988189 with most of the commercial harvesting taking place in the first two years of the fishery. Results of bottom trawl surveys conducted by Germany in the vicinity of Elephant Island in the 1980s showed that stocks of Champsocephalus gunnari, Notothenia rossii, Gobionotothen gibberifrons, Chaenocephalus aceratus have been considerably affected by fishing. Stocks of G. gibberifrons and C. aceratus had apparently recovered to a large extent by the second half of the 1980s. C. gunnari remained at a low level. The status of N. rossii is still unclear, although some recovery was apparent from length compositions obtained in the 1980s. The Antarctic Peninsula region was closed for finfishing from 1989190 onwards. Results of the first bottom trawl survey carried out after the closure of the area in November-December 1996 suggested that the fish standing stock biomass had further declined. Given the low abundance of C. gunnari and other species and the difficulties in managing fisheries which exploit mixed-species assemblages there appears to be little prospect at present in re-opening the fishery around Elephant Island.

The incidental mortality of birds in the fishery of Dissostichus eleginoides was analyzed for the Chilean fleet at Subarea 48.3 during 1996 to 1997. In 1996, 533 birds were killed and 478 in 1997. The most vulnerable species was Diomedea melanophrys representing 41,% of the total bird killed in both years, followed by Procellaria aequincotialis with 10% and 33% respectively. For 1995, 1996 and 1997 the BPUE (Birds killed per 1000 set hooks) was calculated, existing no significantly differences among fishing seasons.

Data on incidental mortality of seabirds and marine mammals associated with longline fishing around the Falkland Islands between August 1996 and May 1997 are briefly summarised. For seabirds, the overall average rate of incidental mortality was 0.34 birds per 1000 hooks; excluding a single set when 87 birds were caught, the average was 0.05 birds per 1000 hooks. Black-browed albatrosses comprised 90% of birds caught.