The Southern Ocean is a large part of the global carbon cycle and phytoplankton play a key role by converting CO2 to organic carbon, which can be transported to the deep ocean. Previous works examined phytoplankton presence and CO2 flux but didn’t take community species composition into account. The purpose of this research, funded by a PCC Research Acceleration award to P.I.’s Alison Gray and Hannah Joy-Warren, was to determine the relationship between phytoplankton community composition