Research plan for the exploratory longline fishery for Dissostichus spp. in 2016/17 in Division 58.4.3a by France and Japan

In Division 58.4.3a, since 2012, research fishing has been conducted in the research block by two vessels using longlines: Shinsei Maru No. 3 (Japan) and the Saint André (France). The catch limit for Dissostichus spp. is 32 tonnes and the total reported catch up in 2014/2015 was 15 tonnes. A technical problem for the French vessel had shortened the fishing campaign. In this proposal, France and Japan commonly notifies their intention to continue their exploratory fisheries in Division 58.4.3a over the coming years in order to contribute to the tagging program and 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 2016/2017 developed under Conservation Measure 41-06. The biomass in division 58.4.3a was estimated during WG-FSA 2015 using the Petersen estimator at 398 tonnes. Despite further developments of CASAL integrated stock assessment models for this division in 2015, geometric mean of Chapman biomass estimators is used for the calculation of stock size in this division in 2015. The developing CASAL model has to assess stock biomass with reliable estimates of IUU removals and to define a maturity key and parameters for the von Bertalanffy growth curve from age readings. The catch limit should remain unchanged at 32 tonnes for 2016/17 to maximize the expectation of tag-recapture.