Predation by microzooplankton (MZ) is the single largest loss factor of marine primary production (PP) and alters the abundance and size spectrum of particles in the water column. MZ consume living cells and sinking aggregates and serve as prey to vertically migrating metazoans. Our hypotheses are 1) MZ predation of PP impacts rates of export production through all 5 pathways predictably and 2) high rates of predation yield low carbon export rates. We propose to quantify predation effects on PP, particle abundance and size distribution as a function of co-occurring environmental and biological conditions (i.e. Ecosystem/ Carbon Cycling States (ECC)) to gain a mechanistic and predictive understanding of the carbon flow in the euphotic zone and below. We will provide essential data described in the implementation plan and address elements of science questions 1& 2. We will identify linkages among predator mediated carbon flows, environmental drivers and export production, which are crucial for developing a) the diagnostic and prognostic relationships necessary to address SQ3 and b) the predictive modeling framework to achieve key goals of the EXPORTS mission.