An enduring, 20-year, multidisciplinary seal-borne ocean sensor research collaboration in the Southern Ocean

Over the last 20 years (2004 to 2025), a French-Australian research and ocean observing collaboration has collected >400,000 temperature-salinity profiles providing broad coverage within the Indian Sector of the Southern Ocean. The collaboration is the cornerstone of the emerging global Animal-Borne Oceanographic Sensors (AniBOS) network, from which the data are freely available to the operational, ocean and climate research, and public communities. These data are a primary source of information for the study of ocean properties in this remote region, enabling major advances in knowledge of dense water formation, glacial ice shelf melting, frontal structure and recent trends driven by climate change in the Southern Ocean. The data have also provided key observations of biological processes, redefining our understanding of the ecology of seals in the Southern Ocean and providing a detailed picture of how they utilise their dynamic ocean-ice environment. The two-fold delivery of essential oceanographic and ecological observations makes this a flagship program, one which has enabled a step-change in our understanding of coupling between physics and biology. Sustaining the observations delivered by AniBOS is critical within the context of a rapidly changing Southern Ocean, for detecting change and anticipating consequences for these unique coupled systems.