C:H:N:O:P stoichiometry and oxygen demand of marine organic matter are driven by phytoplankton ecophysiology.

Subtropical marine phytoplankton are predicted to have lower oxygen demand due to more C–O bonds and carbohydrate-rich biomass, with global O2 inventory decreasing by ~11% under protein-rich allocation.

• Why it matters: Assuming phytoplankton hydrogen and oxygen content is constant can bias estimates of oceanic respiration rates and O2 consumption, affecting habitat for anaerobic metabolism and biogeochemical budgets.
• What they did: The study simulates phytoplankton allocation in a general circulation model to predict latitudinal C:H:N:O:P composition and corresponding O2 demand, then tests sensitivity of O2 inventory and regenerated C (C soft ) to allocation bounds.
• The result: When cells shift from carbohydrate-rich to protein-rich biomass, global O2 inventory and C soft decrease by ~11% and 14%, respectively, supporting that physiological adaptation and biochemical remodeling shape large-scale O2 and C patterns.

AI summary of the abstract · may contain errors · not medical advice · read the paper.