Towards the development of a stock hypothesis for Antarctic toothfish (Dissostichus mawsoni) in Subarea 48.6 in the context of Area 48

Over the past decade, data on Antarctic toothfish (Dissostichus mawsoni) in Subarea 48.6 has been collected through the deployment of Scientific Observers under the Scheme of International Scientific Observation. Scientific data collected in the past provides some understanding of depth, distribution and abundance of Antarctic toothfish in this region. The key building blocks towards developing a regional stock hypothesis are understanding distribution, reproduction, behaviour and movement of Antarctic toothfish, which will allow to answer key questions relating to formative life history stages, such as where toothfish spawn, where eggs and larvae are distributed to, where juvenile, sub-adult and adult toothfish are, how toothfish move to and from spawning grounds, and how Antarctic toothfish throughout the Area 48 region are connected. Understanding these points will allow to develop a plausible life history for D. mawsoni in this region. This paper reviews and summarises available data for CCAMLR Subarea 48.6 and adjacent Subareas to identify gaps that need to be addressed in order to propose and validate a regional stock hypothesis for Antarctic toothfish.