We assess the metabolic demand of mesopelagic zooplankton for carbon, nitrogen, and phosphorus in the North Pacific Subtropical Gyre (NPSG). We compare zooplankton metabolic demand with the attenuation of sinking particle fluxes, and find the average metabolic demand for resident midwater zooplankton can account for 1.3× the loss of sinking particulate organic carbon and particulate nitrogen fluxes, and 2.6× the loss of particulate phosphorus fluxes. Zooplankton metabolic demand for carbon remains significant (0.4-1.9×) relative to the loss in sinking particulate fluxes, even when new depth-specific dry weight conversion factors and recent global-bathymetric models of zooplankton metabolism are applied. These new models reduce zooplankton carbon demands to reasonably match particle flux attenuation in the mesopelagic zone. Zooplankton metabolic demand for phosphorus is particularly large in comparison to particle flux attenuation (1.5-9×), and when temporal change in the molar carbon : phosphorus ratio of the attenuation in particulate fluxes are considered, mesopelagic zooplankton in the NPSG may episodically become phosphorus-limited. Midwater zooplankton have the potential to be important mediators of carbon flux to the deep ocean in the NPSG.