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Understanding Diatoms’ Past and Future Biogeochemical Role in High‐Latitude Seas
Author(s) -
Krause Jeffrey W.,
Lomas Michael W.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl085602
Subject(s) - diatom , environmental science , biogeochemical cycle , oceanography , temperate climate , arctic , ecology , biology , geology
Because cold‐water diatoms’ baseline elemental density (BED) is substantially higher than temperate diatoms, previous polar studies may have underestimated diatoms’ contribution to elemental standing stocks, contribution to particulate organic carbon (POC) export and incorrectly modeled their susceptibility to future warming. We apply cold‐water diatom allometry to Arctic field samples and derive diatom growth rates ranging from 0.01–0.68 day −1 , versus unrealistically high rates estimated using temperate diatom allometry. Reanalysis of published Southern Ocean data (Antarctic Environment and Southern Ocean Process Study and European Iron Fertilization Experiment) shows that diatom POC was significantly underestimated and diatoms could have accounted for a majority of POC export. However, during some field programs (Kerguelen Plateau), temperate allometry properly accounted for diatom biomass. We also predict that warming sea surface temperature may alter high‐latitude diatom BED, suggesting that even if abundances do not change with warming, the reduced diatom BED will likely lower the trophic‐transfer efficiency and their total carbon flow to consumers.