Proposal to continue the time series of research surveys to monitor abundance of Antarctic toothfish (Dissostichus mawsoni) in the southern Ross Sea, 2022/23–2024/25: Research Plan under CM 24-01

This paper proposes a continuation of the Ross Sea shelf survey (RSSS) for three years from 2023–2025. The primary objective (1) of the survey is to monitor Antarctic toothfish recruitment in the southern Ross Sea. This would be a continuation of the annual time series of research surveys carried out since 2012 using a random stratified design. Continuing the time series is essential as the data collected is used to estimate year class strength of Antarctic toothfish and provide essential input into the stock assessment used to inform management decisions. An additional objective (2) is to monitor trends in abundance of the larger (sub-adult and adult) toothfish in McMurdo Sound and Terra Nova Bay. These are areas where toothfish may form an important part of the diet of Type C killer whales and Weddell seals. The regions are sampled individually by rotation on alternate years. In addition, Objective 3 of this programme collects and analyses a wide range of data and samples from these areas including benthic invertebrates, fish stomach and tissue samples, and associated environmental and acoustic data. Objectives 2 and 3 are specified as high priority research topics in the research and monitoring plan for the Ross Sea region Marine Protected Area (RSrMPA). The proposed survey design is the same as previous years. The results of each survey and trends in the time series will be reported to WG-FSA for review each year and the results included in future Ross Sea toothfish stock assessments. A full review will be completed and presented to WG-SAM, WG-EMM, and WG-FSA in 2025