Revised research plan for the exploratory longline fishery for Dissostichus spp. in 2014/15 in Division 58.4.3a

In 2011/2012, the Saint André conducted its first exploratory fishery for Dissostichus spp. in division 58.4.3a. France notified its wish to continue this exploratory fishery over the coming years in order to achieve a robust stock assessment that would provide advice on a catch limit according to CCAMLR decision rules. This paper aims to present a research plan for 2014/2015 that takes into account the remarks made during the WG-SAM 2014. The objective is to progress on modelling tools and to improve the estimation of current biomass. The stock size in division 58.4.3a was estimated during WG-FSA 2013 using the Petersen estimator, CASAL model and the CPUE x seabed analogy method. The estimates of biomass are highly biased, because catch data used in the calculation derived from a small location at which catch rates were high, but these are extrapolated over the entire area, including to areas in which catch rates are known to be much lower. Given these results and the concentration of fishing effort, it is suggested to define a new survey design and to maintain the total catch limit of 32 tons agreed in 2012 in order to result in sufficient tag recaptures and to substantially refine the stock assessment next year. It is suggested also to define a catch limit with an appropriate local exploitation rate (4%) equivalent to 4 tons inside a research block where catches were high.