Zooplankton samples were collected during the RV Meteor cruise M174 (April–May 2021) using a Multi Plankton Sampler (Multinet Midi, 200 µm mesh size). Sampling included oblique tows at discrete depth intervals (0–25, 25–50, 50–100, and 100–200 m), integrated oblique tows (0–200 m), and horizontal tows at selected stations. The cruise surveyed coastal and oceanic waters under and beyond the influence of the Amazon River Plume. Zooplankton samples were separated into two size fractions (>1 mm and <1 mm), digitized using a ZooScan imaging system (2400 dpi resolution), and processed with ZooProcess software. Images were subjected to automated classification followed by manual taxonomic validation using the EcoTaxa web application. Data were subjected to quality control following the protocols of the Pelagic Size Structure Database (PSSdb; https://pssdb.net/). Morphometric measurements obtained from scanned images were used to estimate individual abundance, which was subsequently integrated for each taxonomic group and standardized by the sampled water volume. When multiple tows sampled the same depth interval, abundance values were combined using midpoint integration to obtain weighted mean estimates representative of the corresponding depth interval. This dataset provides taxon-specific mesozooplankton abundance (individuals/m⁻³) for samples collected along a gradient of Amazon River Plume influence in different depth strata during cruise M174.