A characterisation of the toothfish fishery in Subareas 88.1 and 88.2 from 1997/98 to 2004/05

The exploratory fishery for Antarctic toothfish (D. mawsoni) has been operating for eight years in Subarea 88.1 and for four years in Subarea 88.2 with a large amount of data collected on toothfish and the associated bycatch.
The 2005 D. mawsoni catch was the highest on record with a total of 3477 t against a catch limit of 3625 t. The catch limit was almost reached in Subarea 88.1 and exceeded in Subarea 88.2. D. mawsoni was the dominant catch in all 11 SSRUs fished. The main bycatch species were rattails, which contributed 12% of the catch, and skates which contributed to about 2% of the total catch1.
Comparison of the location of fishing effort with ice distribution over the past six years has clearly demonstrated the strong influence of ice on this fishery. In 2001, 2003, and 2004, ice conditions were particularly bad and fishing was restricted to suboptimal areas. However, in 2005, ice conditions were very good, allowing vessels access to most of the main fishing grounds in both Subareas. This resulted in the closure of all SSRUs due to catch limits for toothfish, or bycatch limits for rattails, being reached by 18 March 2005.
The change in fishing patterns between seasons is reflected in the mean length and age composition of the catch. During the development of the fishery there has been a steady increase in depth fished, which peaked in 2003, but decreased slightly in 2004 and 2005. This is reflected in the mean length and age composition of the catch, which also declined slightly in 2004 and 2005.
1 Note that this does not include skate released at the surface.