This paper presents an updated stock assessment for the Patagonian toothfish (Dissostichus eleginoides) fishery of the Kerguelen Islands EEZ, CCAMLR Division 58.5.1. It includes commercial fishery data up to the end of the season 2019/2020 (end of August 2020). The updated assessment model is based on the best available data and includes abundance estimates from random stratified trawl surveys (POKER, 2006, 2010, 2013 and 2017), longline tag-release and tag-recapture data from 2007 to 2020 and priors and estimates on model parameters such as life traits (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 year class strength (YCS) and selectivity functions.
Compared to the previous assessment that was presented to WG-FSA 19 (MassiotGranier et al., 2019), this assessment accounts for (1) updated catch and biological data (2019/2020), (2) updated age data from a new 4-year reading program, (3) updated priors on YCS and period of estimation (4) and updated depredation rate. All model runs were conducted using CASAL 2.30 2012-03-21 rev. 4648, that was agreed on by WG-SAM-14.
The updated model leads to a higher estimate of the virgin spawning stock biomass SSB0 than in 2019 with an estimate of 233 130 tons (95% CI: 207 030 – 265 460). The estimate of the current SSB status of the stock is 68,8% (95% CI: 64,5% - 73,1%) and the current catch limit meets the CCAMLR decision rules.