Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past?
<p>Morphological changes in coccoliths, tiny calcite platelets covering the outer surface of coccolithophores, can be induced by physiological responses to environmental changes. Coccoliths recovered from sedimentary successions may therefore provide information on paleo-environmental conditio...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-06-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/16/1007/2020/cp-16-1007-2020.pdf |
| _version_ | 1819020326978191360 |
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| author | G. Faucher U. Riebesell L. T. Bach |
| author_facet | G. Faucher U. Riebesell L. T. Bach |
| author_sort | G. Faucher |
| collection | DOAJ |
| description | <p>Morphological changes in coccoliths, tiny calcite
platelets covering the outer surface of coccolithophores, can be induced by
physiological responses to environmental changes. Coccoliths recovered from
sedimentary successions may therefore provide information on
paleo-environmental conditions prevailing at the time when the
coccolithophores were alive. To calibrate the biomineralization responses of
ancient coccolithophore to environmental changes, studies often compared the
biological responses of living coccolithophore species with paleo-data from
calcareous nannofossils. However, there is uncertainty whether the
morphological responses of living coccolithophores are representative of
those of the fossilized ancestors. To investigate this, we exposed four
living coccolithophore species (<i>Emiliania huxleyi, Gephyrocapsa oceanica</i>, <i>Coccolithus pelagicus</i> subsp. <i>braarudii</i>, and <i>Pleurochrysis carterae)</i> that have been evolutionarily
distinct for hundreds of thousands to millions of years, to a range of
environmental conditions (i.e., changing light intensity, <span class="inline-formula">Mg∕Ca</span> ratio,
nutrient availability, temperature, and carbonate chemistry) and evaluated
their responses in coccolith morphology (i.e., size, length, width,
malformation). The motivation for this study was to test if there is a
consistent morphological response of the four species to changes in any of
the tested abiotic environmental factors. If this was the case, then this
could suggest that coccolith morphology can serve as a paleo-proxy for that
specific factor because this response is conserved across species that have
been evolutionary distinct over geological timescales. However, we found
that the four species responded differently to changing light intensity,
<span class="inline-formula">Mg∕Ca</span> ratio, nutrient availability, and temperature in terms of coccolith
morphology. The lack of a common response reveals the difficulties in using
coccolith morphology as a paleo-proxy for these environmental drivers.
However, a common response was observed under changing seawater carbonate
chemistry (i.e., rising <span class="inline-formula">CO<sub>2</sub></span>), which consistently induced malformations.
This commonality provides some confidence that malformations found in the
sedimentary record could be indicative of adverse carbonate chemistry
conditions.</p> |
| first_indexed | 2024-12-21T03:49:26Z |
| format | Article |
| id | doaj.art-60bac58e659b4f54a3764b16c943178e |
| institution | Directory Open Access Journal |
| issn | 1814-9324 1814-9332 |
| language | English |
| last_indexed | 2024-12-21T03:49:26Z |
| publishDate | 2020-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Climate of the Past |
| spelling | doaj.art-60bac58e659b4f54a3764b16c943178e2022-12-21T19:17:01ZengCopernicus PublicationsClimate of the Past1814-93241814-93322020-06-01161007102510.5194/cp-16-1007-2020Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past?G. Faucher0U. Riebesell1L. T. Bach2Dipartimento di Scienze della Terra “Ardito Desio”, Università degli Studi di Milano, Milan 20133, ItalyBiological Oceanography, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel 24105, GermanyInstitute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia<p>Morphological changes in coccoliths, tiny calcite platelets covering the outer surface of coccolithophores, can be induced by physiological responses to environmental changes. Coccoliths recovered from sedimentary successions may therefore provide information on paleo-environmental conditions prevailing at the time when the coccolithophores were alive. To calibrate the biomineralization responses of ancient coccolithophore to environmental changes, studies often compared the biological responses of living coccolithophore species with paleo-data from calcareous nannofossils. However, there is uncertainty whether the morphological responses of living coccolithophores are representative of those of the fossilized ancestors. To investigate this, we exposed four living coccolithophore species (<i>Emiliania huxleyi, Gephyrocapsa oceanica</i>, <i>Coccolithus pelagicus</i> subsp. <i>braarudii</i>, and <i>Pleurochrysis carterae)</i> that have been evolutionarily distinct for hundreds of thousands to millions of years, to a range of environmental conditions (i.e., changing light intensity, <span class="inline-formula">Mg∕Ca</span> ratio, nutrient availability, temperature, and carbonate chemistry) and evaluated their responses in coccolith morphology (i.e., size, length, width, malformation). The motivation for this study was to test if there is a consistent morphological response of the four species to changes in any of the tested abiotic environmental factors. If this was the case, then this could suggest that coccolith morphology can serve as a paleo-proxy for that specific factor because this response is conserved across species that have been evolutionary distinct over geological timescales. However, we found that the four species responded differently to changing light intensity, <span class="inline-formula">Mg∕Ca</span> ratio, nutrient availability, and temperature in terms of coccolith morphology. The lack of a common response reveals the difficulties in using coccolith morphology as a paleo-proxy for these environmental drivers. However, a common response was observed under changing seawater carbonate chemistry (i.e., rising <span class="inline-formula">CO<sub>2</sub></span>), which consistently induced malformations. This commonality provides some confidence that malformations found in the sedimentary record could be indicative of adverse carbonate chemistry conditions.</p>https://www.clim-past.net/16/1007/2020/cp-16-1007-2020.pdf |
| spellingShingle | G. Faucher U. Riebesell L. T. Bach Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past? Climate of the Past |
| title | Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past? |
| title_full | Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past? |
| title_fullStr | Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past? |
| title_full_unstemmed | Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past? |
| title_short | Can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past? |
| title_sort | can morphological features of coccolithophores serve as a reliable proxy to reconstruct environmental conditions of the past |
| url | https://www.clim-past.net/16/1007/2020/cp-16-1007-2020.pdf |
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