This paper presents an updated stock assessment for the Patagonian toothfish (Dissostichus eleginoides) fishery of the Crozet Islands, CCAMLR sub-area 58-6, with data up to the end of the season 2018/2019 (End of August 2019). This updated assessment model is based on the best available data and includes longline tag-release and tag-recapture data from 2007 to 2019 and priors and estimates on life traits model parameters (e.g. growth, maturity and natural mortality). It also uses commercial data that account for fish removals (fishing mortality and depredation) and support the estimation of their associated selectivity functions.
Compared to the previous assessment presented at WG-FSA 17 (Sinègre et al., 2017b), this assessment accounts for (1) updated data (2017/2018 & 2018/2019) (2) updated growth curve and (3) legal catches taken on the adjacent waters of Del Cano rise, outside the CCAMLR area. All model runs were conducted with the CASAL 2.30 2012-03-21 rev. 4648, that was agreed on by WG-SAM-14.
The updated model leads to smaller estimate of the virgin spawning stock biomass B0 than the one obtained in 2017, with an estimate of 54 610 tons (48 560-60 880). The estimate of the current SSB status of the stock is 63% (58.2%-66.6%) and the current catch limit satisfies the CCAMLR decision rules.
KEYWORDS: Dissostichus eleginoides, Crozet Islands, Stock assessment, Patagonian toothfish, State-space model, Population dynamic model