Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite
Marine calcareous sediments provide a fundamental basis for palaeoceanographic studies aiming to reconstruct past oceanic conditions and understand key biogeochemical element cycles. Calcifying unicellular phytoplankton (coccolithophores) are a major contributor to both carbon and calcium cycling by...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2014-02-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/11/1065/2014/bg-11-1065-2014.pdf |
| _version_ | 1818950791080181760 |
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| author | M. N. Müller M. Lebrato U. Riebesell J. Barcelos e Ramos K. G. Schulz S. Blanco-Ameijeiras S. Sett A. Eisenhauer H. M. Stoll |
| author_facet | M. N. Müller M. Lebrato U. Riebesell J. Barcelos e Ramos K. G. Schulz S. Blanco-Ameijeiras S. Sett A. Eisenhauer H. M. Stoll |
| author_sort | M. N. Müller |
| collection | DOAJ |
| description | Marine calcareous sediments provide a fundamental basis for palaeoceanographic
studies aiming to reconstruct past oceanic conditions and understand key
biogeochemical element cycles. Calcifying unicellular phytoplankton
(coccolithophores) are a major contributor to both carbon and calcium cycling
by photosynthesis and the production of calcite (coccoliths) in the euphotic
zone, and the subsequent long-term deposition and burial into marine
sediments. Here we present data from controlled laboratory experiments on
four coccolithophore species and elucidate the relation between the divalent
cation (Sr, Mg and Ca) partitioning in coccoliths and cellular physiology
(growth, calcification and photosynthesis). Coccolithophores were cultured
under different seawater temperature and carbonate chemistry conditions. The
partition coefficient of strontium (<i>D</i><sub>Sr</sub>) was positively
correlated with both carbon dioxide (<i>p</i>CO<sub>2</sub>) and temperature but
displayed no coherent relation to particulate organic and inorganic carbon
production rates. Furthermore, <i>D</i><sub>Sr</sub> correlated positively with
cellular growth rates when driven by temperature but no correlation was
present when changes in growth rates were <i>p</i>CO<sub>2</sub>-induced. Our results
demonstrate the complex interaction between environmental forcing and
physiological control on the strontium partitioning in coccolithophore
calcite and challenge interpretations of the coccolith Sr / Ca ratio from
high-<i>p</i>CO<sub>2</sub> environments (e.g. Palaeocene–Eocene thermal maximum). The
partition coefficient of magnesium (<i>D</i><sub>Mg</sub>) displayed
species-specific differences and elevated values under nutrient limitation.
No conclusive correlation between coccolith <i>D</i><sub>Mg</sub> and temperature
was observed but <i>p</i>CO<sub>2</sub> induced a rising trend in coccolith
<i>D</i><sub>Mg</sub>. Interestingly, the best correlation was found between
coccolith <i>D</i><sub>Mg</sub> and chlorophyll <i>a</i> production, suggesting
that chlorophyll <i>a</i> and calcite associated Mg originate from the same
intracellular pool. These and previous findings indicate that Mg is
transported into the cell and to the site of calcification via different
pathways than Ca and Sr. Consequently, the coccolith Mg / Ca ratio should be
decoupled from the seawater Mg / Ca ratio. This study gives an extended
insight into the driving factors influencing the coccolith Mg / Ca ratio and
should be considered for future palaeoproxy calibrations. |
| first_indexed | 2024-12-20T09:24:12Z |
| format | Article |
| id | doaj.art-4cbd9ca38f7145cc8e706a8d43203198 |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-20T09:24:12Z |
| publishDate | 2014-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-4cbd9ca38f7145cc8e706a8d432031982022-12-21T19:45:13ZengCopernicus PublicationsBiogeosciences1726-41701726-41892014-02-011141065107510.5194/bg-11-1065-2014Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calciteM. N. Müller0M. Lebrato1U. Riebesell2J. Barcelos e Ramos3K. G. Schulz4S. Blanco-Ameijeiras5S. Sett6A. Eisenhauer7H. M. Stoll8Institute for Marine and Antarctic Studies (IMAS), Private Bag 129, Hobart, TAS 7001, AustraliaGEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1–3, 24148 Kiel, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1–3, 24148 Kiel, GermanyCentre of Climate, Meteorology and Global Change (CMMG), University of Azores, Rua do Capitão d'Avila, Pico da Urze 970-0042 Angra do Heroismo, Açores, PortugalGEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1–3, 24148 Kiel, GermanyNational Oceanography Centre, University of Southampton, European Way, SO14 3ZH Southampton, UKGEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1–3, 24148 Kiel, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1–3, 24148 Kiel, GermanyDepartment of Geology, University of Oviedo, Arias de Velasco, s/n 30005, Oviedo, Asturias, SpainMarine calcareous sediments provide a fundamental basis for palaeoceanographic studies aiming to reconstruct past oceanic conditions and understand key biogeochemical element cycles. Calcifying unicellular phytoplankton (coccolithophores) are a major contributor to both carbon and calcium cycling by photosynthesis and the production of calcite (coccoliths) in the euphotic zone, and the subsequent long-term deposition and burial into marine sediments. Here we present data from controlled laboratory experiments on four coccolithophore species and elucidate the relation between the divalent cation (Sr, Mg and Ca) partitioning in coccoliths and cellular physiology (growth, calcification and photosynthesis). Coccolithophores were cultured under different seawater temperature and carbonate chemistry conditions. The partition coefficient of strontium (<i>D</i><sub>Sr</sub>) was positively correlated with both carbon dioxide (<i>p</i>CO<sub>2</sub>) and temperature but displayed no coherent relation to particulate organic and inorganic carbon production rates. Furthermore, <i>D</i><sub>Sr</sub> correlated positively with cellular growth rates when driven by temperature but no correlation was present when changes in growth rates were <i>p</i>CO<sub>2</sub>-induced. Our results demonstrate the complex interaction between environmental forcing and physiological control on the strontium partitioning in coccolithophore calcite and challenge interpretations of the coccolith Sr / Ca ratio from high-<i>p</i>CO<sub>2</sub> environments (e.g. Palaeocene–Eocene thermal maximum). The partition coefficient of magnesium (<i>D</i><sub>Mg</sub>) displayed species-specific differences and elevated values under nutrient limitation. No conclusive correlation between coccolith <i>D</i><sub>Mg</sub> and temperature was observed but <i>p</i>CO<sub>2</sub> induced a rising trend in coccolith <i>D</i><sub>Mg</sub>. Interestingly, the best correlation was found between coccolith <i>D</i><sub>Mg</sub> and chlorophyll <i>a</i> production, suggesting that chlorophyll <i>a</i> and calcite associated Mg originate from the same intracellular pool. These and previous findings indicate that Mg is transported into the cell and to the site of calcification via different pathways than Ca and Sr. Consequently, the coccolith Mg / Ca ratio should be decoupled from the seawater Mg / Ca ratio. This study gives an extended insight into the driving factors influencing the coccolith Mg / Ca ratio and should be considered for future palaeoproxy calibrations.http://www.biogeosciences.net/11/1065/2014/bg-11-1065-2014.pdf |
| spellingShingle | M. N. Müller M. Lebrato U. Riebesell J. Barcelos e Ramos K. G. Schulz S. Blanco-Ameijeiras S. Sett A. Eisenhauer H. M. Stoll Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite Biogeosciences |
| title | Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite |
| title_full | Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite |
| title_fullStr | Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite |
| title_full_unstemmed | Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite |
| title_short | Influence of temperature and CO<sub>2</sub> on the strontium and magnesium composition of coccolithophore calcite |
| title_sort | influence of temperature and co sub 2 sub on the strontium and magnesium composition of coccolithophore calcite |
| url | http://www.biogeosciences.net/11/1065/2014/bg-11-1065-2014.pdf |
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