Near-absence of surface zooplankton and pervasive anthropogenic particles along a zonal North Atlantic transect: a multi-vessel citizen-science image survey

Version 2 adds GOES_image_audit_package.zip, a complete reproducible re-analysis of the filter-image archive which supersedes the zooplankton class of GOES_ALL_DATA.xlsx This dataset contains the complete observational data underlying the study "Near-absence of surface zooplankton and pervasive anthropogenic particles along a zonal North Atlantic transect: a multi-vessel citizen-science image survey" (Dryden, Duncan & the GOES Foundation citizen-science consortium; submitted to Ocean Science, Copernicus; manuscript egusphere-2026-3979). Between 8 January and 3 February 2022, eight sailing vessels crossing the trade-wind North Atlantic (from the Canary Islands and Cape Verde to the Caribbean and Suriname) collected surface water samples on a fixed twice-daily schedule using a standardised 0.5-litre cartridge filter (20 µm). Each filter was photographed under a common microscope design at a 5 mm field of view, and an automated OpenCV image pipeline located the filter apertures, sized every particle larger than 20 µm, and classified it as zooplankton, phytoplankton, plastic particle, plastic fibre, black (combustion) carbon, or unidentified. In total the pipeline sized and classified 51,547 particles across 352 georeferenced surface stations. One vessel (Emma) additionally sampled a higher-latitude North Atlantic return leg in May 2023. Surface net-tow validation (120 µm mesh, day and night) was carried out independently in the mid-Atlantic. The workbook (GOES_ALL_DATA.xlsx) contains seven sheets: Summary — headline metrics for the survey (particle totals, station counts, class detection frequencies). By boat — per-vessel particle-class counts, number of stations, and the percentage of stations at which each class was detected. Image per-station (all boats) — the 352 sampled stations, with vessel, region, leg, sample identifier, latitude, longitude, per-class image counts, image total, and number of filter holes imaged. Copepod geotagged per-image — the 110 GPS-tagged images from the Copepod reference crossing, with image identifier, date-time, position, and per-class counts. Size classes by category — particle counts for each class binned into 20–200, 200–1000, and >1000 µm size ranges. Every particle size — the full particle-level inventory: one row per particle (51,547 rows), giving vessel, leg, latitude, longitude, class (category), maximum dimension in micrometres (size_um), and size class. Crew-logged counts — the volunteer crews' own hand-logged particle counts by station, provided for transparency. Notes on interpretation: identifications derive from citizen-science microscopy. The plastic-versus-phytoplankton partition is provisional pending FTIR/Raman confirmation, and "black carbon" is an optical description (dark, colourless particles) that may also include sediment, shadow, or dark plastic. The crew hand-logs (sheet 7) are qualitative context and are not used in the quantitative analysis, which rests on the automated image pipeline (sheets 2–6) and the independent net tow. Positions are from image GPS for the geotagged subset and from field logs otherwise.