The annual random stratified trawl survey was undertaken in Division 58.5.2 in the vicinity of Heard Island and McDonald Islands during April 2020. Based on data from this survey, this paper provides an assessment of mackerel icefish (Champsocephalus gunnari) population structure, abundance and yield in Division 58.5.2 to the west of 79o 20’ E using standard CCAMLR methods (CMIX and Generalized Yield Model). Additionally, recent work has been undertaken as part of the krill management strategy re-implementing the Generalized Yield Model software in R, and the two implementations resulted in highly consistent assessment results.
The 2020 survey showed a large 2+ cohort in the population and a high biomass. Based on the Grym implementation, catches of 1276 t in the 2020/21 season and 1047 t in the 2021/22 season satisfy the CCAMLR decision rules.
Trinidad and Tobago
Party Status:
Observer
Abstract:
The General Capacity Building Fund (GCBF) was created as a result of decisions made at CCAMLR-38 (SCAF-2019 report, paragraph 22). The Secretariat is required to report to the Commission on the activities of the Fund during 2020.
There is no abstract available for this document.
There is no abstract available for this document.
Abstract:
The biomass of Antarctic toothfish (Dissostichus mawsoni) in CCAMLR Subarea 48.4 is estimated from tagging returns, giving an average of 1,456 tonnes since 2016. Applying the CCAMLR agreed precautionary assumption of average biomass, using the 5-year average biomass, and harvest rate of γ = 0.038, implies a 2020/21 yield of 55 tonnes.
Historically, a precautionary approach has been applied in treating 48.4 Antarctic toothfish as a separate stock. Based on the biological characteristics of the catches in Subarea 48.4, and the surrounding regions, the Antarctic toothfish around the southern South Sandwich Islands are now hypothesised as being part of a much larger stock that extends south into Subareas 48.2, 48.6 and possibly 48.5. The current method of assessment, based on tag returns, consequently, is considered to provide an estimate of the local biomass.
