Carbon fixation and oxygen evolution by phytoplankton in the Canadian high arctic

Summary In the Canadian high arctic, in summer, in situ profiles of oxygen evolution and carbon fixation by phytoplankton showed excellent qualitative and quantitative agreement with an apparent photosynthetic quotient in the range from 1.3 to 1.8. Water column photosynthesis was linear in the available light at the surface. Daily rates photosynthesis exceeded 1 mg C m^-2 d^-1, implying a minimal estimate for annual production in the range from 35 to 70 g C m^-2 y^-1.