Japan and South Africa propose to continue investigating the population structure and various demographic parameters of Antarctic toothfish (Dissostichus mawsoni) in the Subarea 48.6 in 2018/19 using standardized longline gear, established tagging techniques, and pop-up tags. The proposed research is pertinent to issues raised by the Scientific Committee (SC-CAMLR-XXXV, paragraph 3.3.252-3.265) and will supplement and expand previous efforts to characterize the local toothfish populations in the area to better understand stock structure, movement patterns and improve estimation of population characteristics and thereby contribute to the development of spatial population models and assessments in support of management advice.
Additional outcomes of the research include documenting relative abundance of Antarctic toothfish and Patagonian, tagging toothfish for biomass estimation and for stock linkage studies, and collecting information on distribution, and life history of bycatch species.
The plan represents a continuation of previous surveys by South Africa and Japan without significant change from the previous research activities. From 2018/19 fishing season, Norway had considered the joint survey participation, but due to various circumstances Japan and South Africa received an offer to withdraw their participation.