This dataset consists of a quantitative imaging dataset of ZooScan-imaged mesoplankton (> 200 µm), collected with high-speed net aboard the schooner Tara during the Tara Pacific Expedition (2016-2018). Samples were collected at the surface, generally on a daily frequency, across the Atlantic and Pacific Oceans from open-ocean stations (151 samples; open-ocean label: [i00_oa###]) and from stations in coastal waters of 32 Pacific islands (54 samples; island label: [i##_oa###]). The full description and discussion of this dataset can be found in the associated data paper Mériguet et al. (in rev). This dataset consists of 256 352 plankton individuals, plankton parts, non-living particles and imaging artefacts, ranging from 300 µm to a few mm, individually imaged and measured with the ZooScan (Gorsky et al., 2010). The objects were classified into 159 taxonomic and morphological groups. All images and their taxonomic annotations are available in the open-access EcoTaxa (Picheral et al., 2017) project at this link: https://ecotaxa.obs-vlfr.fr/prj/11292. The 'EcoTaxa ZooScan Tara Pacific HSN 300 microns export' dataset contains the EcoTaxa tsv exports which associate each object with these metadata (station name, sampling coordinates, sampling date and time, etc., the main metadata are found in the Classic Metadata ZooScan Tara Pacific HSN 330 microns.csv table) and describe it by numerous morphological features extracted from each individual object by ZooProcess. The csv table named 'Export EcoTaxa ZooScan read me.csv' defines the 160 metadata and data found in the EcoTaxa tsv export. The 'Descriptors ZooScan Tara Pacific HSN 330 microns.csv' table combined the data from which we calculated quantitative descriptors of the planktonic communities: abundance (ind.m-3), biovolume (mm3.m-3; as a proxy of biomass) calculated from the area, riddled area and ellipsoidal measurement of each object (see Vandromme et al., 2012 for the 3 calculations of biovolume), and Shannon diversity index. This was done for all taxonomic annotations and for several levels of grouping; living or non-living, plankton groups and trophic association. The individual biovolumes of organisms were arranged in Normalised Biomass Size Spectra (NBSS) as described by Platt (1978), with size expressed as Equivalent Spherical Diameter (ESD, µm). NBSS calculations were made for all taxonomic annotations and for the different levels of grouping. There are available for each station in the NBSS ZooScan Tara Pacific HSN 330 microns csv tables.