Biodiversity patterns of epipelagic copepods in the South Pacific Ocean: Strengths and limitations of current data bases

implemented in QGIS 3.10 (QGIS, 2022) at 1 degree resolution, totaling 393 cells (Fig 1). How- ever, for all the spatial analyses, the basin was divided into two sections where more data were available. i.e., eastern and western side, excluding a longitudinal band containing cells between -110˚ and -170˚, that had low data coverage (only 16 cells available for that area) and could skew spatial patterns results. Therefore, 377 cells were considered for the analyses. Moreover, when representing alpha diversity patterns through kriging and an inverse distance weighted technique, all sampling cells containing less than 10 species were excluded, assuming they underestimated the species records and hence introduced biases in the patterns. Therefore, for those analyses, only 77 cells were considered. Data sources—Environmental database and processing The oceanographic variables used for analyses were obtained from Copernicus Marine Envi- ronment Monitoring Service (https://marine.copernicus.eu) to a resolution of 1 x 1 degree and 0.25 x 0.25 degrees. From this data source, we obtained sea surface temperature [47], salinity [47], total chlorophyll-a concentration [48], dissolved oxygen concentration [48], and mixed layer depth [49]. The resolution selected to analyze our data was 1 degree; hence, the environ- mental variables with a resolution of 0.25 degrees were resampled into a 1-degree resolution using QGIS 3.10 (QGIS, 2022). All data were averaged for the 0–200 m depth range, as well as

from years 1993 to 2019. For temperature data, two additional variables were generated: tem- perature stability and standard deviation of temperature, which were calculated based on tem- perature data in temporal lags of two years, with the package climateStability [50] implemented Fig 1. The South Pacific Ocean basin (red dashed area), its sampling coverage with georeferenced locations of the 393 cells (1˚ x 1˚) which were generated (blue squares) from data spanning between 1993–2019. The major near-surface currents shown for the whole basin were obtained from Harvard Dataverse (https://doi.org/10.7910/dvn/tkgo2z). CHC = Cape Horn Current; EAC = East Australian Current; HCS = Humboldt Current System; SEC = South Equatorial Current; SPSG = South Pacific Subtropical Gyre; WWD = West Wind Drift; ACC = Antarctic Circumpolar Current. Map projection is WGS 84/PDC Mercator (EPSG 3832). https://doi.org/10.1371/journal.pone.0306440.g001 PLOS ONE Biodiversity of copepods in the South Pacific PLOS ONE | https://doi.org/10.1371/journal.pone.0306440 July 11, 2024 4 / 28