Short-term photoacclimation effects on photoinhibition of phytoplankton in the Drake Passage (Southern Ocean)

► Natural phytoplankton communities photoacclimate within upper mixed layer (UML). ► De novo xanthophyll cycle pigment synthesis occurs on timescales of vertical mixing within UML. ► Photoacclimation within the UML did not lessen photoinhibition during surface irradiance exposure. ► Photoinhibition may affect phytoplankton growth in regions with a deep UML and low mean irradiance.