PANGAEA_993517 Seawater carbonate chemistry and effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific Guo, Jiaying A; Strzepek, Robert F; Yuan, Zhongwei; Swadling, Kerrie M; Townsend, Ashley T; Achterberg, Eric Pieter; Browning, Thomas J; Bach, Lennart Thomas Seawater carbonate chemistry and effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific 2026-04-10 PANGAEA Dataset https://doi.pangaea.de/10.1594/PANGAEA.993517 Investigator Jiaying A Guo Jiaying.guo@utas.edu.au Investigator Yan Yang yangyan@xmu.edu.cn Earth Science Type of study Experiment number Treatment Salinity Temperature, water Nitrogen oxide Phosphate Silicate pH, total scale pH, standard error Alkalinity, total Alkalinity, total, standard error Chlorophyll a Chlorophyll a, standard error Maximum quantum yield of photosystem II Maximum photochemical quantum yield, standard error Bacteria, heterotrophic Bacteria, heterotrophic, standard error Synechococcus Synechococcus, standard error Prochlorococcus Prochlorococcus, standard error Picoeukaryotes Picoeukaryotes, standard error Nanoeukaryotes Nanoeukaryotes, standard error Microeukaryotes Microeukaryotes, standard error Microeukaryotes Nanoeukaryotes Picoeukaryotes Prochlorococcus Synechococcus Carbonate system computation flag Carbon dioxide Fugacity of carbon dioxide (water) at sea surface temperature (wet air) Partial pressure of carbon dioxide (water) at sea surface temperature (wet air) Bicarbonate ion Carbonate ion Carbon, inorganic, dissolved Aragonite saturation state Calcite saturation state geoscientificInformation Bottles or small containers/Aquaria (<20 L) Coast and continental shelf Community composition and diversity Entire community Iron and steel slag Laboratory experiment North Pacific Ocean alkalinity enhancement Open ocean Pelagos Primary production/Photosynthesis Silicates (e.g., olivine, basalt, wollastonite) Sodium hydroxide South Pacific Tropical Calculated using seacarb after Nisumaa et al. (2010) Complete OA-ICC Ocean Acidification International Coordination Centre unrestricted CC-BY-4.0: Creative Commons Attribution 4.0 International English PANGAEA Data Publisher for Earth & Environmental Science https://www.pangaea.de/ Data Center Contact Michael Diepenbroek info@pangaea.de

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Bremen Bremen 28359 Germany online 3819 data points text/tab-separated-values Guo, Jiaying A; Strzepek, Robert F; Yuan, Zhongwei; Swadling, Kerrie M; Townsend, Ashley T; Achterberg, Eric Pieter; Browning, Thomas J; Bach, Lennart Thomas (2025): Effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific. Communications Earth & Environment, 6(1), 270, https://doi.org/10.1038/s43247-025-02248-7 Guo, Jiaying A; Bach, Lennart Thomas (2025): Supplementary Data for manuscript Effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific [dataset]. figshare, https://doi.org/10.6084/M9.FIGSHARE.28578467.V1 Nisumaa, Anne-Marin; Pesant, Stephane; Bellerby, Richard G J; Delille, Bruno; Middelburg, Jack J; Orr, James C; Riebesell, Ulf; Tyrrell, Toby; Wolf-Gladrow, Dieter A; Gattuso, Jean-Pierre (2010): EPOCA/EUR-OCEANS data compilation on the biological and biogeochemical responses to ocean acidification. Earth System Science Data, 2(2), 167-175, https://doi.org/10.5194/essd-2-167-2010 Yang, Yan; Brockmann, Patrick; Galdino, Carolina; Schindler, Uwe; Gazeau, Frédéric (2024): An update of data compilation on the biological response to ocean acidification and overview of the OA-ICC data portal. Earth System Science Data, 16(8), 3771-3780, https://doi.org/10.5194/essd-16-3771-2024 Yang, Yan; Hansson, L; Gattuso, Jean-Pierre (2016): Data compilation on the biological response to ocean acidification: an update. Earth System Science Data, 8(1), 79-87, https://doi.org/10.5194/essd-8-79-2016 Gattuso, Jean-Pierre; Epitalon, Jean-Marie; Lavigne, Héloïse; Orr, James; Gentili, Bernard; Hagens, Mathilde; Hofmann, Andreas; Mueller, Jens-Daniel; Proye, Aurélien; Rae, James; Soetaert, Karline (2024): seacarb: seawater carbonate chemistry with R. R package version 3.3.3. https://cran.r-project.org/web/packages/seacarb/index.html Guo, Jiaying A; Bach, Lennart Thomas (2024): SO298 Ocean Alkalinity Enhancement (OAE) Incubation [dataset]. Institute for Marine and Antarctic Studies, https://doi.org/10.25959/BMV8-1K07

Here we conducted 19 shipbased experiments in the Equatorial Pacific, examining three prevalent alkaline substances (sodium hydroxide, olivine, and steel slag) and their effects on natural phytoplankton populations under realistic and moderate alkalinity enhancements (16–29 μmol/kg). This dataset is included in the OA-ICC data compilation maintained in the framework of the IAEA Ocean Acidification International Coordination Centre (see https://oa-icc.ipsl.fr). Original data were downloaded from figshare (see Source) by the OA-ICC data curator. In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2024) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2026-04-09. ** For all details see the full metadata description at "https://doi.pangaea.de/10.1594/PANGAEA.993517"!

http://mel.xmu.edu.cn/en/ http://www.marinespecies.org/aphia.php?p=taxdetails&id=160572 Synechococcus https://cran.r-project.org/web/packages/seacarb/index.html seacarb: seawater carbonate chemistry with R. R package version 3.3.3 https://doi.org/10.1038/s43247-025-02248-7 Effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific https://doi.org/10.25959/BMV8-1K07 SO298 Ocean Alkalinity Enhancement (OAE) Incubation https://doi.org/10.5194/essd-16-3771-2024 An update of data compilation on the biological response to ocean acidification and overview of the OA-ICC data portal https://doi.org/10.5194/essd-2-167-2010 Calculated using seacarb after Nisumaa et al. (2010) https://doi.org/10.5194/essd-2-167-2010 EPOCA/EUR-OCEANS data compilation on the biological and biogeochemical responses to ocean acidification https://doi.org/10.5194/essd-8-79-2016 Data compilation on the biological response to ocean acidification: an update https://doi.org/10.6084/M9.FIGSHARE.28578467.V1 Supplementary Data for manuscript Effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific https://hdl.handle.net/10013/epic.32187.d001 Chlorophyll a https://www.iaea.org/services/oa-icc/science-and-collaboration/data-access-and-management OA-ICC DIF 9.4 2026-04-10 2026-09-21