Ocean ecosystem models predict that warming and increased surface ocean stratification will reduce the biological export of particulate carbon. This study presents a nearly three-decade time series from the Sargasso Sea showing that particulate carbon export is maintained despite warming and nutrient reductions. This is achieved through phytoplankton community shifts favoring cyanobacteria (high carbon-to-phosphorus ratios) and enhanced shallow phosphorus recycling, increasing nutrient use efficiency. The findings suggest surface ocean ecosystems might adapt to hydrographic changes faster than current models predict, positively impacting ocean carbon uptake.

Michael W. Lomas, Nicholas R. Bates, Rodney J. Johnson, Deborah K. Steinberg, Tatsuro Tanioka