At its 2011 meeting, the Scientific Committee agreed that a time series of relative abundance from a well-designed survey could be a useful input into the Ross Sea stock assessment model. The first survey was completed in February 2012 (), and the second survey was completed in February 2013 (Parker et al. 2013). In this paper we provide preliminary results of the third survey in the time series.
The objectives of this third survey were:
(i) To carry out a longline survey to monitor subadult toothfish in the southern Ross Sea (strata A–C) using standardised gear in a standardised manner; and
(ii) To sample additional experimental stations in an adjacent area to identify areas of high subadult abundance which could be included as strata in future annual surveys.
The survey was successful in completing all the planned stations. The catch composition was similar to the previous surveys, although raw catch rates were down in strata B and C. Standardised catch rates for the core strata were similar to 2013 and down on 2012, although not significantly. Experimental stratum I showed larger fish than in the other strata, in particular close to Ross Island in the south and in the north-eastern side of that stratum.
Further results will be provided at WG-FSA-14, including age data and comparison with commercial catches in 2014.