The report summarises fishing catch and effort in the Ross Sea region (Subarea 88.1 and Small-Scale Research Units 88.2A–B) with the biological characteristics of the catch of Antarctic toothfish (Dissostichus mawsoni) through the 2023/24 fishing season. The implementation of the Ross Sea region Marine Protected Area (RSrMPA) from 1st December 2017 has concentrated subsequent fishing on the continental slope south of 70° S, with recent fishing effort extending into SSRUs 88.2A–B.
Scaled length distributions showed no decrease in the size of fish caught through time in any of the management areas. However, there was strong interannual variability in the area south of 70° S that was likely driven by changes in the fine-scale spatial distribution of fishing effort or the influence of strong and weak year classes entering the fishery. There was a small change in the sex ratio of Antarctic toothfish, with a gradual trend of more males caught in all areas until 2015; ratios in all areas are currently near the long-term average. The number of Antarctic toothfish recaptured over the last five years of the mark-recapture program was higher than the average annual number of recaptures over the past decade, which is expected due to the increased numbers of tagged fish released since 2018 in the S70 area, an increase in recovery effort in that area following the implementation of the RSrMPA, increased survivorship of tagged fish, and increased tag retention and detection.