This dataset presents results from surface-tethered drifting sediment traps, zooplankton net tows, dissolved inorganic nutrient concentration analyses made on water column samples, and flow cytometry samples collected in the euphotic zone, from the open ocean Gulf of Mexico during cruises of the NOAA Ship Nancy Foster, May 10-30, 2017 (NF17), and May 5-19, 2018 (NF18). Sediment trap results include particulate organic carbon flux, particulate nitrogen flux, carbon isotope ratio of sinking organic matter (13C/12C), nitrogen isotopes of sinking material (15N/14N), chlorophyll a flux, and phaeopigment flux. Mesozooplankton results include separate files for: 1) wet weight, dry weight, carbon and nitrogen biomass estimates for total zooplankton and five size fractions; 2) carbon and nitrogen percent dry weight, stable carbon (13C/12C) and nitrogen (15N/14N) isotope ratios of five size fractions; and 3) size-fractionated chlorophyll and phaeopigment gut pigment contents, pigment-based estimates of mesozooplankton grazing on phytoplankton in the euphotic zone (grazing m-2 h-1) and biomass-specific rates of grazing relative to zooplankton dry weight and carbon. Dissolved inorganic nutrient concentration measurements include nitrate+nitrite (NO3-+NO2-), ammonium (NH4+), and soluble reactive phosphorus (PO43-). Flow cytometry results include abundances of phytoplankton taxa (Prochlorococcus, Synechococcus, Photosynthetic Eukaryotes) and non-pigmented bacteria (HBACT).