A characterisation of the toothfish fishery in Subareas 88.1
and 88.2 from 1997/98 to 2003/04

An exploratory fishery for Antarctic toothfish (D. mawsoni) has been in operation for seven seasons in Subarea 88.1 and for three seasons in Subarea 88.2. A large amount of data on toothfish and the associated bycatch from the fishing operations has been collected. This report is somewhat different to earlier reviews of the exploratory fishery. In the first instance, it reports catches by the new SSRUs used to manage Subarea 88.1; secondly, the report includes catch data from all countries fishing in the area, whereas previous reports included data from only New Zealand vessels; and thirdly, the reported catch is confined to C2 data.
The catch of D. mawsoni was 2414 t, and contributed 87% of the total catch in 2004. D. mawsoni was the dominant species caught in all 12 SSRUs fished. In 2004, about 12 t of Patagonian toothfish (D. eleginoides) was taken, almost entirely from SSRU 881B. The main bycatch species was Macrourus whitsoni, which contributed about 11% of the 2004 catch. Bycatch of skates (mainly Amblyraja georgiana) was only 19 t (less than 1% of the total catch1). Other bycatch species (including morid cods, icefish and moray cods) each contributed less than 1% of the catch overall.
Because of changes in the ice conditions and fleet composition, no two seasons have been the same. In 2001, 2003, and 2004, ice conditions restricted fishing and resulted in new areas being explored. The change in fishing patterns between seasons is reflected in the mean length and age composition of the catch. In the past few seasons, there has been a trend towards fishing in deeper water and this is reflected in an increase in the length and age of the toothfish catch and in the bycatch, particularly the increase in catch of morid cods and icefish.
An approach to allocating the rattail catch to the SSRUs in Subarea 88.1 was examined. The indicative catch limits appear to be little better than the catch limits set for the 2004 season. Further examination of the problem is warranted.