Group 2i Isochrysidales produce characteristic alkenones reflecting sea ice distribution
| Autor: | Nora Richter, Karen J. Wang, Timothy D Herbert, Patricia Cabedo-Sanz, Tyler R. Kartzinel, Simon T. Belt, Yongsong Huang, Sian Liao, Markus Majaneva, Joseph B Novak |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Water mass
Alkenone 010504 meteorology & atmospheric sciences Science General Physics and Astronomy 010502 geochemistry & geophysics Matematikk og Naturvitenskap: 400::Basale biofag: 470 [VDP] Palaeoclimate 01 natural sciences General Biochemistry Genetics and Molecular Biology Article Palaeoceanography Sea ice Gephyrocapsa oceanica 0105 earth and related environmental sciences Emiliania huxleyi Temperature record geography Multidisciplinary geography.geographical_feature_category biology General Chemistry Biogeochemistry biology.organism_classification Sea surface temperature Oceanography Environmental science Seawater |
| Zdroj: | Nature Communications Nature Communications, Vol 12, Iss 1, Pp 1-10 (2021) |
| Popis: | Alkenones are biomarkers produced solely by algae in the order Isochrysidales that have been used to reconstruct sea surface temperature (SST) since the 1980s. However, alkenone-based SST reconstructions in the northern high latitude oceans show significant bias towards warmer temperatures in core-tops, diverge from other SST proxies in down core records, and are often accompanied by anomalously high relative abundance of the C37 tetra-unsaturated methyl alkenone (%C37:4). Elevated %C37:4 is widely interpreted as an indicator of low sea surface salinity from polar water masses, but its biological source has thus far remained elusive. Here we identify a lineage of Isochrysidales that is responsible for elevated C37:4 methyl alkenone in the northern high latitude oceans through next-generation sequencing and lab-culture experiments. This Isochrysidales lineage co-occurs widely with sea ice in marine environments and is distinct from other known marine alkenone-producers, namely Emiliania huxleyi and Gephyrocapsa oceanica. More importantly, the %C37:4 in seawater filtered particulate organic matter and surface sediments is significantly correlated with annual mean sea ice concentrations. In sediment cores from the Svalbard region, the %C37:4 concentration aligns with the Greenland temperature record and other qualitative regional sea ice records spanning the past 14 kyrs, reflecting sea ice concentrations quantitatively. Our findings imply that %C37:4 is a powerful proxy for reconstructing sea ice conditions in the high latitude oceans on thousand- and, potentially, on million-year timescales. Some algae produce compounds called alkenones that can reconstruct sea surface temperature through geological time, but in high latitudes unknown species complicate use of this proxy. Here the authors find a lineage of sea ice algae that produces alkenones and can be used as a paleo-sensor for sea ice abundance. |
| Databáze: | OpenAIRE |
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