Developing Essential Biodiversity Variables for the Southern Ocean: From data gaps to valuable insights

The Southern Ocean is central to global heat and carbon cycling, connecting all the major ocean basins and regulating Earth’s climate system, and hence providing ecosystem services of global significance. However, its ecosystems are increasingly vulnerable to climate change and localized human-induced pressures, such as (biological) resource extraction, pollution, ship traffic, and tourism. Effective conservation and management require systematic and reliable monitoring frameworks. The Essential Variables concept offers a robust approach to integrate fragmented data, to standardize data collection, and to generate policy-relevant data products enabling informed responses to rapid environmental change. This paper synthesizes the key outcomes of a workshop held in Hobart, Australia, alongside the Southern Ocean Observing System Symposium, in 2023. To advance the adoption, development, and operationalization of Essential Variables tailored to the Southern Ocean, researchers with diverse expertise came together to assess current data gaps in ocean observations and to establish monitoring priorities for marine ecosystems. The workshop provided a dedicated forum to identify key Southern Ocean-specific candidate variables, address methodological challenges, and design pathways for developing a systematic, open, and adaptable framework suited to the region’s unique ecological and environmental conditions. In this paper, we propose Essential Biodiversity Variables that are tailored to the Southern Ocean and are intended to monitor changes in sea ice, planktonic, benthic, and top predator systems. The adoption of Essential Biodiversity Variables specific to the Southern Ocean can enhance our capacity to track biodiversity trends, assess ecosystem health, and inform policy by transforming fragmented data into a cohesive, policy-relevant framework. However, the success of these efforts is only possible by securing sustained funding and enhancing interoperability and collaborations across research groups. This paper as well as the Hobart 2023 workshop are activities endorsed by the UN Decade of Ocean Science for Sustainable Development.