The export of organic carbon from sunlit surface waters to the deep ocean is a well-known and important process in the global carbon cycle. Without this so-called ‘biological carbon pump’ atmospheric CO2 levels would be ~ 200ppm higher than they are today. For decades the magnitude of particulate organic carbon (POC) flux has been measured using floating and moored sediment traps and more recently estimated from optical measurements by BGC-Argo profiling floats. Whether the magnitude of this flux will be affected by climate change is the focus of ongoing research, with models suggesting a reduction in export flux by 2100. Here we present comparisons of sediment trap data with estimates from floats and modelling studies, from the Australian and New Zealand sectors of the Southern Ocean. Decades-long time-series from moored sediment traps reveal seasonal and interannual variations in POC flux that can be related to the shorter-term fluxes derived from BGC-Argo floats. We will discuss the regional differences between different sectors and biogeochemical provinces of the Southern Ocean and signs of potential change, with comparisons of these field measurements to recent modelling efforts.