Preliminary assessment of Patagonian toothfish in Subarea 48.3

A preliminary assessment of toothfish (Dissostichus eleginoides.) in Subarea 48.3 is presented.

1. The assessment results from this year’s analyses are very similar to those of 2011. SSB in the terminal assessment year continues to be estimated at around 54% of virgin biomass, consistent with the CCAMLR harvest control rule.
2. The 3-fleet assessment model provides slightly improved fits to CPUE data and to catch at age observations and achieves this by assuming a different selection pattern for the intermediate (1998-2003) period and a slightly changed selection pattern for the most recent period
3. Model outputs from the 2-fleet and 3-fleet assessments are very similar with the exception of the recruitment.YCS estimates which differ markedly in 1990 but follow similar trends in all other years.
4. Recruitment remains uncertain although there is some evidence of the progression of strong year-classes through the catch at age data.
5. MCMC diagnostics and trace plot indicate poorer results than for previous assessments and require further investigation.
6. Yield calculations have yet to be completed.