Vertically migrating phytoplankton fuel high oceanic primary production

Abstract Marine net primary production (NPP) is remarkably high given the typical vertical separation of 50–150 m between depth zones light and nutrient sufficiency, respectively. Here we present evidence that many autotrophs bridge this gap through downward upward migration, thereby facilitating biological pumping rates oceanic NPP. Our model suggests phytoplankton migration (PVM) fuels up to 40% (>28 tg yr ?1 N) new directly contributes 25% total NPP (herein estimated at 56 PgC ). Confidence in these estimates supported by good reproduction seasonal, geographic variations In contrast common predictions, a sensitivity study PVM indicates higher under global warming when enhanced stratification reduces physical transport into surface ocean. findings suggest key mechanism driving marine biogeochemistry therefore requires consideration carbon budgets.