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

RESEARCH ARTICLE Biodiversity patterns of epipelagic copepods in the South Pacific Ocean: Strengths and limitations of current data bases Manuela Pe´rez-Arago´ n1,2☯, Ruben EscribanoID2,3☯*, Reinaldo Rivera2☯, Pamela Hidalgo2,3☯ 1 Doctoral Program of Oceanography, Facultad de Ciencias Naturales y Oceanogra´ ficas, Universidad de Concepcio´n, Concepcio´ n, Chile, 2 Instituto Milenio de Oceanografı´a (IMO), Universidad de Concepcio´ n, Concepcio´n, Chile, 3 Department of Oceanography, Facultad de Ciencias Naturales y Oceanogra´ficas, Universidad de Concepcio´ n, Concepcio´n, Chile ☯ These authors contributed equally to this work. * rescribano@udec.cl Abstract Basin-scale patterns of biodiversity for zooplankton in the ocean may provide valuable insights for understanding the impact of climate change and global warming on the marine ecosystem. However, studies on this topic remain scarce or unavailable in vast regions of the world ocean, particularly in large regions where the amount and quality of available data are limited. In this study, we used a 27-year (1993–2019) database on species occurrence of planktonic copepods in the South Pacific, along with associated oceanographic variables, to examine their spatial patterns of biodiversity in the upper 200 m of the ocean. The aim of this study was to identify ecological regions and the environmental predictors explaining such patterns. It was found that hot and cold spots of diversity, and distinctive species assemblages were linked to major ocean currents and large regions over the basin, with

increasing species richness over the subtropical areas on the East and West sides of the South Pacific. While applying the spatial models, we showed that the best environmental predictors for diversity and species composition were temperature, salinity, chlorophyll-a concentration, oxygen concentration, and the residual autocorrelation. Nonetheless, the observed spatial patterns and derived environmental effects were found to be strongly influ- enced by sampling coverage over space and time, revealing a highly under-sampled basin. Our findings provide an assessment of copepods diversity patterns and their potential driv- ers for the South Pacific Ocean, but they also stress the need for strengthening the data bases of planktonic organisms, as they can act as suitable indicators of ecosystem response to climate change at basin scale. Introduction Spatial patterns of biodiversity in the marine environment have long been documented [1, 2]; however, factors and processes controlling such patterns remain unclear [3]. In the framework PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0306440 July 11, 2024 1 / 28 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Pe´rez-Arago´n M, Escribano R, Rivera R, Hidalgo P (2024) Biodiversity patterns of epipelagic copepods in the South Pacific Ocean: Strengths and limitations of current data bases. PLoS ONE 19(7): e0306440. https://doi.org/10.1371/journal. pone.0306440 Editor: Hans G. Dam, University of Connecticut, UNITED STATES OF AMERICA Received: April 20, 2023 Accepted: June 18, 2024

Published: July 11, 2024 Copyright: © 2024 Pe´rez-Arago´n et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All data used in this study on occurrences of Copepoda species and environmental variables are fully available in Zenodo repository https://doi.org/10.5281/zenodo. 8257222. Funding: This work was funded by the Instituto Milenio de Oceanografı´a (IMO) through the Agencia Nacional de Investigacio´n Cientı´fica y Tecnolo´gica de Chile (ANID) Grant IC_120019. The funders had no role in study design, data collection