Effect of iron and manganese supply on a natural phytoplankton community of the Weddell Sea and further consequence for carbon export


This study highlights the importance of manganese (Mn) next to iron (Fe) for the growth of specific Southern Ocean phytoplankton groups with important implications for carbon export in the Weddell Sea. A Fe-Mn bottle amendment experiment and an aggregation experiment were performed with a natural phytoplankton community during Polarstern expedition PS124 in 2021 in the Weddell Sea. At this location, seawater was pumped (using trace metals clean techniques) from 25 m depth to fill polycarbonate bottles. The Control treatment consist of the sampled seawater without any trace metals addition, while the other three treatments were enriched with either FeCl₃ alone (0.5 nM; +Fe treatment) or MnCl₂ alone (1 nM; +Mn treatment) or both trace metals together (+FeMn treatment). All treatments were done in triplicate 2.5 L PC bottles. After on average 7 days, samples for chlorophyll a content, particulate organic carbon and primary production were taken to detect FeMn co-limitation effect on species composition, primary production and carbon export. Results showed that when Fe and Mn were added together, primary production rates were highest due to an increased abundance of the prymnesiophyte Phaeocystis antarctica. This change within the phytoplankton community led to highly carbon-enriched aggregates and a four-fold increase in the carbon export potential compared to the doubling in the only Fe treatment. Our findings highlight that even small changes in plankton community composition can have significant effects on the carbon export potential of the Southern Ocean, a region of critical importance for anthropogenic carbon dioxide drawdown.

DOI https://doi.org/10.1594/PANGAEA.957278
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.957278
Creator Balaguer, Jenna ORCID logo; Koch, Florian ORCID logo; Flintrop, Clara ORCID logo; Völkner, Christian; Iversen, Morten Hvitfeldt ORCID logo; Trimborn, Scarlett ORCID logo
Publisher PANGAEA
Publication Year 2023
Funding Reference Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven https://doi.org/10.13039/501100003207 Crossref Funder ID AWI_INSPIRES https://www.awi.de/en/work-study/jobs/job-offer/inspires.html ; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven https://doi.org/10.13039/501100003207 Crossref Funder ID AWI_PS124_13 EcoPump; Deutsche Forschungsgemeinschaft, Bonn https://doi.org/10.13039/501100001659 Crossref Funder ID 404421353 https://gepris.dfg.de/gepris/projekt/404421353 Iron manganese co-limitation – a potential driver of Southern Ocean phytoplankton ecology; German Research Foundation https://doi.org/10.13039/501100001659 Crossref Funder ID 5472008 https://gepris.dfg.de/gepris/projekt/5472008 Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Resource Type Dataset
Format text/tab-separated-values
Size 99 data points
Discipline Earth System Research
Spatial Coverage (-30.383W, -76.100S, -30.303E, -76.095N); Weddell Sea
Temporal Coverage Begin 2021-02-28T17:55:04Z
Temporal Coverage End 2021-02-28T21:39:53Z