The Southern Ocean plays an important role in the global cycling of carbon and other biogeochemical quantities, yet Earth system models often struggle to capture important features of Southern Ocean biogeochemistry. As the physical circulation of the Southern Ocean is closely linked to its biogeochemical properties, it makes sense to evaluate modeled biogeochemical properties using an internally consistent physical framework. Observations collected from biogeochemical Argo floats suggest that streamlines of the Antarctic Circumpolar Current are associated with similar biogeochemical properties (carbon, nutrients), and that along-stream deviations in these variables tend to occur in regions with complex bathymetry. Here, we build on these findings to develop a new evaluation framework for modeled Southern Ocean biogeochemistry. We quantify along-stream Southern Ocean biogeochemical properties from a collection of CMIP6 models. Our findings highlight model biases in along-stream biogeochemistry and help us to characterize the role of modeled bathymetry in along-stream biogeochemical anomalies