scholarly journals Strain-specific responses of <i>Emiliania huxleyi</i> to changing seawater carbonate chemistry

2009 ◽  
Vol 6 (2) ◽  
pp. 4361-4383 ◽  
Author(s):  
G. Langer ◽  
G. Nehrke ◽  
I. Probert ◽  
J. Ly ◽  
P. Ziveri
Keyword(s):  
Carbon Content ◽  
Genetic Basis ◽  
Inorganic Carbon ◽  
Emiliania Huxleyi ◽  
Organic Carbon Content ◽  
Carbonate Chemistry ◽  
Carbon Production ◽  
Seawater Carbonate Chemistry ◽  
Different Strains ◽  
Particulate Inorganic Carbon

Abstract. Four strains of the coccolithophore Emiliania huxleyi (RCC1212, RCC1216, RCC1238, RCC1256) were grown in dilute batch culture at four CO2 levels ranging from ~200 μatm to ~1200 μatm. Growth rate, particulate organic carbon content, and particulate inorganic carbon content were measured, and organic and inorganic carbon production calculated. The four strains did not show a uniform response to carbonate chemistry changes in any of the analysed parameters and none of the four strains displayed a response pattern previously described for this species. We conclude that the sensitivity of different strains of E. huxleyi to acidification differs substantially and that this likely has a genetic basis. We propose that this can explain apparently contradictory results reported in the literature.

scholarly journals Strain-specific responses of <i>Emiliania huxleyi</i> to changing seawater carbonate chemistry

2009 ◽  
Vol 6 (11) ◽  
pp. 2637-2646 ◽  
Author(s):  
G. Langer ◽  
G. Nehrke ◽  
I. Probert ◽  
J. Ly ◽  
P. Ziveri
Keyword(s):  
Carbon Content ◽  
Genetic Basis ◽  
Inorganic Carbon ◽  
Response Pattern ◽  
Organic Carbon Content ◽  
Carbonate Chemistry ◽  
Carbon Production ◽  
Seawater Carbonate Chemistry ◽  
Different Strains ◽  
Particulate Inorganic Carbon

Abstract. Four strains of the coccolithophore E. huxleyi (RCC1212, RCC1216, RCC1238, RCC1256) were grown in dilute batch culture at four CO2 levels ranging from ~200 μatm to ~1200 μatm. Growth rate, particulate organic carbon content, and particulate inorganic carbon content were measured, and organic and inorganic carbon production calculated. The four strains did not show a uniform response to carbonate chemistry changes in any of the analysed parameters and none of the four strains displayed a response pattern previously described for this species. We conclude that the sensitivity of different strains of E. huxleyi to acidification differs substantially and that this likely has a genetic basis. We propose that this can explain apparently contradictory results reported in the literature.

scholarly journals Influence of CO<sub>2</sub> and nitrogen limitation on the coccolith volume of <i>Emiliania huxleyi</i> (Haptophyta)

2012 ◽  
Vol 9 (4) ◽  
pp. 4979-5010 ◽  
Author(s):  
M. N. Müller ◽  
L. Beaufort ◽  
O. Bernard ◽  
M. L. Pedrotti ◽  
A. Talec ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Photosynthetic Activity ◽  
Co2 Concentration ◽  
Emiliania Huxleyi ◽  
Cell Diameter ◽  
Geometrical Parameters ◽  
Carbon Production ◽  
Seawater Carbonate Chemistry ◽  
Particulate Inorganic Carbon ◽  
Phytoplankton Group

Abstract. Coccolithophores, a key phytoplankton group, are one of the best studied organisms with regard to the response to ocean acidification/carbonation. The biogenic production of calcareous coccoliths has made coccolithophores a promising group for paleoceanographic research aiming to reconstruct past environmental conditions. Recently, geochemical and morphological analyses of fossil coccoliths have gained increased interest in regard to changes in seawater carbonate chemistry. The cosmopolitan coccolithophore Emiliania huxleyi (Lohm.) Hay and Mohler was cultured over a range of pCO2 levels in controlled laboratory experiments under nutrient replete and nitrogen limited conditions. Measurements of photosynthetic activity and calcification revealed, as previously published, an increase in organic carbon production and a moderate decrease in calcification from ambient to elevated pCO2. The enhancement in particulate organic carbon production was accompanied by an increase in cell diameter. Coccolith volume was best correlated with the coccosphere/cell diameter and no significant correlation was found between coccolith volume and particulate inorganic carbon production rate. The conducted experiments revealed that the coccolith volume of E. huxleyi is variable with aquatic CO2 concentration within the tested range but appears to be a primary function of the coccosphere/cell diameter both under nitrogen limited and nutrient replete conditions. Comparing coccolith morphological and geometrical parameters like volume, mass and size to physiological parameters under controlled laboratory conditions is an important step to understand variations in fossil coccolith geometry.

scholarly journals Influence of CO<sub>2</sub> and nitrogen limitation on the coccolith volume of <I>Emiliania huxleyi</I> (Haptophyta)

2012 ◽  
Vol 9 (10) ◽  
pp. 4155-4167 ◽  
Author(s):  
M. N. Müller ◽  
L. Beaufort ◽  
O. Bernard ◽  
M. L. Pedrotti ◽  
A. Talec ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Nitrogen Limitation ◽  
Co2 Concentration ◽  
Emiliania Huxleyi ◽  
Cell Diameter ◽  
Geometrical Parameters ◽  
Carbon Production ◽  
Seawater Carbonate Chemistry ◽  
Particulate Inorganic Carbon

Abstract. Coccolithophores, a key phytoplankton group, are one of the most studied organisms regarding their physiological response to ocean acidification/carbonation. The biogenic production of calcareous coccoliths has made coccolithophores a promising group for paleoceanographic research aiming to reconstruct past environmental conditions. Recently, geochemical and morphological analyses of fossil coccoliths have gained increased interest in regard to changes in seawater carbonate chemistry. The cosmopolitan coccolithophore Emiliania huxleyi (Lohm.) Hay and Mohler was cultured over a range of pCO2 levels in controlled laboratory experiments under nutrient replete and nitrogen limited conditions. Measurements of photosynthesis and calcification revealed, as previously published, an increase in particulate organic carbon production and a moderate decrease in calcification from ambient to elevated pCO2. The enhancement in particulate organic carbon production was accompanied by an increase in cell diameter. Changes in coccolith volume were best correlated with the coccosphere/cell diameter and no significant correlation was found between the coccolith volume and the particulate inorganic carbon production. The conducted experiments revealed that the coccolith volume of E. huxleyi is variable with aquatic CO2 concentration but its sensitivity is rather small in comparison with its sensitivity to nitrogen limitation. Comparing coccolith morphological and geometrical parameters like volume, mass and size to physiological parameters under controlled laboratory conditions is an important step to understand variations in fossil coccolith geometry.

scholarly journals A three-dimensional niche comparison of <i>Emiliania huxleyi</i> and <i>Gephyrocapsa oceanica</i>: reconciling observations with projections

2018 ◽  
Vol 15 (11) ◽  
pp. 3541-3560 ◽  
Author(s):  
Natasha A. Gafar ◽  
Kai G. Schulz
Keyword(s):  
Inorganic Carbon ◽  
Austral Summer ◽  
Emiliania Huxleyi ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Change Scenario ◽  
Carbonate Chemistry ◽  
Co2 Levels ◽  
Particulate Inorganic Carbon ◽  
Gephyrocapsa Oceanica

Abstract. Coccolithophore responses to changes in carbonate chemistry speciation such as CO2 and H+ are highly modulated by light intensity and temperature. Here, we fit an analytical equation, accounting for simultaneous changes in carbonate chemistry speciation, light and temperature, to published and original data for Emiliania huxleyi, and compare the projections with those for Gephyrocapsa oceanica. Based on our analysis, the two most common bloom-forming species in present-day coccolithophore communities appear to be adapted for a similar fundamental light niche but slightly different ones for temperature and CO2, with E. huxleyi having a tolerance to lower temperatures and higher CO2 levels than G. oceanica. Based on growth rates, a dominance of E. huxleyi over G. oceanica is projected below temperatures of 22 ∘C at current atmospheric CO2 levels. This is similar to a global surface sediment compilation of E. huxleyi and G. oceanica coccolith abundances suggesting temperature-dependent dominance shifts. For a future Representative Concentration Pathway (RCP) 8.5 climate change scenario (1000 µatm fCO2), we project a CO2 driven niche contraction for G. oceanica to regions of even higher temperatures. However, the greater sensitivity of G. oceanica to increasing CO2 is partially mitigated by increasing temperatures. Finally, we compare satellite-derived particulate inorganic carbon estimates in the surface ocean with a recently proposed metric for potential coccolithophore success on the community level, i.e. the temperature-, light- and carbonate-chemistry-dependent CaCO3 production potential (CCPP). Based on E. huxleyi alone, as there was interestingly a better correlation than when in combination with G. oceanica, and excluding the Antarctic province from the analysis, we found a good correlation between CCPP and satellite-derived particulate inorganic carbon (PIC) with an R2 of 0.73, p < 0.01 and a slope of 1.03 for austral winter/boreal summer and an R2 of 0.85, p < 0.01 and a slope of 0.32 for austral summer/boreal winter.

scholarly journals The role of ocean acidification in <i>Emiliania huxleyi</i> coccolith thinning in the Mediterranean Sea

2014 ◽  
Vol 11 (10) ◽  
pp. 2857-2869 ◽  
Author(s):  
K. J. S. Meier ◽  
L. Beaufort ◽  
S. Heussner ◽  
P. Ziveri
Keyword(s):  
Ocean Acidification ◽  
Mediterranean Sea ◽  
Abundant Species ◽  
Emiliania Huxleyi ◽  
Carbonate Chemistry ◽  
Carbonate Production ◽  
Surface Ocean ◽  
Nw Mediterranean ◽  
Seawater Carbonate Chemistry

Abstract. Ocean acidification is a result of the uptake of anthropogenic CO2 from the atmosphere into the ocean and has been identified as a major environmental and economic threat. The release of several thousands of petagrams of carbon over a few hundred years will have an overwhelming effect on surface ocean carbon reservoirs. The recorded and anticipated changes in seawater carbonate chemistry will presumably affect global oceanic carbonate production. Coccolithophores as the primary calcifying phytoplankton group, and especially Emiliania huxleyi as the most abundant species have shown a reduction of calcification at increased CO2 concentrations for the majority of strains tested in culture experiments. A reduction of calcification is associated with a decrease in coccolith weight. However, the effect in monoclonal cultures is relatively small compared to the strong variability displayed in natural E. huxleyi communities, as these are a mix of genetically and sometimes morphologically distinct types. Average coccolith weight is likely influenced by the variability in seawater carbonate chemistry in different parts of the world's oceans and on glacial/interglacial time scales due to both physiological effects and morphotype selectivity. An effect of the ongoing ocean acidification on E. huxleyi calcification has so far not been documented in situ. Here, we analyze E. huxleyi coccolith weight from the NW Mediterranean Sea in a 12-year sediment trap series, and surface sediment and sediment core samples using an automated recognition and analyzing software. Our findings clearly show (1) a continuous decrease in the average coccolith weight of E. huxleyi from 1993 to 2005, reaching levels below pre-industrial (Holocene) and industrial (20th century) values recorded in the sedimentary record and (2) seasonal variability in coccolith weight that is linked to the coccolithophore productivity. The observed long-term decrease in coccolith weight is most likely a result of the changes in the surface ocean carbonate system. Our results provide the first indications of an in situ impact of ocean acidification on coccolithophore weight in a natural E. huxleyi population, even in the highly alkaline Mediterranean Sea.

scholarly journals Total carbon analysis may overestimate organic carbon content of fresh waters in the presence of high dissolved inorganic carbon

2010 ◽  
Vol 8 (5) ◽  
pp. 196-201 ◽  
Author(s):  
Stuart Findlay ◽  
William H. McDowell ◽  
David Fischer ◽  
Michael L. Pace ◽  
Nina Caraco ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Carbon ◽  
Organic Carbon Content ◽  
Fresh Waters ◽  
Carbon Analysis

scholarly journals Influence of changing carbonate chemistry on morphology and weight of coccoliths formed by <i>Emiliania huxleyi</i>

2012 ◽  
Vol 9 (8) ◽  
pp. 3449-3463 ◽  
Author(s):  
L. T. Bach ◽  
C. Bauke ◽  
K. J. S. Meier ◽  
U. Riebesell ◽  
K. G. Schulz
Keyword(s):  
Sediment Cores ◽  
Emiliania Huxleyi ◽  
Marine Phytoplankton ◽  
Carbonate Chemistry ◽  
Production Rates ◽  
Organic Part ◽  
Carbonate Ion ◽  
Seawater Carbonate Chemistry ◽  
Decreasing Ph ◽  
Carbon Dioxide Co2

Abstract. The coccolithophore Emiliania huxleyi is a marine phytoplankton species capable of forming small calcium carbonate scales (coccoliths) which cover the organic part of the cell. Calcification rates of E. huxleyi are known to be sensitive to changes in seawater carbonate chemistry. It has, however, not yet been clearly determined how these changes are reflected in size and weight of individual coccoliths and which specific parameter(s) of the carbonate system drive morphological modifications. Here, we compare data on coccolith size, weight, and malformation from a set of five experiments with a large diversity of carbonate chemistry conditions. This diversity allows distinguishing the influence of individual carbonate chemistry parameters such as carbon dioxide (CO2), bicarbonate (HCO3−), carbonate ion (CO32−), and protons (H+) on the measured parameters. Measurements of fine-scale morphological structures reveal an increase of coccolith malformation with decreasing pH suggesting that H+ is the major factor causing malformations. Coccolith distal shield area varies from about 5 to 11 μm2. Changes in size seem to be mainly induced by varying [HCO3−] and [H+] although influence of [CO32−] cannot be entirely ruled out. Changes in coccolith weight were proportional to changes in size. Increasing CaCO3 production rates are reflected in an increase in coccolith weight and an increase of the number of coccoliths formed per unit time. The combined investigation of morphological features and coccolith production rates presented in this study may help to interpret data derived from sediment cores, where coccolith morphology is used to reconstruct calcification rates in the water column.

scholarly journals Emiliania huxleyi increases calcification but not expression of calcification-related genes in long-term exposure to elevated temperature and p CO 2

2013 ◽  
Vol 368 (1627) ◽  
pp. 20130049 ◽  
Author(s):  
Ina Benner ◽  
Rachel E. Diner ◽  
Stephane C. Lefebvre ◽  
Dian Li ◽  
Tomoko Komada ◽  
...  
Keyword(s):  
Carbon Content ◽  
Emiliania Huxleyi ◽  
Differentially Expressed ◽  
Organic Carbon Content ◽  
Rna Seq ◽  
Ambient Conditions ◽  
Negative Effects ◽  
Genome Wide ◽  
Global Carbon

Increased atmospheric p CO 2 is expected to render future oceans warmer and more acidic than they are at present. Calcifying organisms such as coccolithophores that fix and export carbon into the deep sea provide feedbacks to increasing atmospheric p CO 2 . Acclimation experiments suggest negative effects of warming and acidification on coccolithophore calcification, but the ability of these organisms to adapt to future environmental conditions is not well understood. Here, we tested the combined effect of p CO 2 and temperature on the coccolithophore Emiliania huxleyi over more than 700 generations. Cells increased inorganic carbon content and calcification rate under warm and acidified conditions compared with ambient conditions, whereas organic carbon content and primary production did not show any change. In contrast to findings from short-term experiments, our results suggest that long-term acclimation or adaptation could change, or even reverse, negative calcification responses in E. huxleyi and its feedback to the global carbon cycle. Genome-wide profiles of gene expression using RNA-seq revealed that genes thought to be essential for calcification are not those that are most strongly differentially expressed under long-term exposure to future ocean conditions. Rather, differentially expressed genes observed here represent new targets to study responses to ocean acidification and warming.

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