scholarly journals Boron incorporation in the foraminifer <i>Amphistegina lessonii</i> under a decoupled carbonate chemistry

2014 ◽  
Vol 11 (12) ◽  
pp. 16743-16771 ◽  
Author(s):  
K. Kaczmarek ◽  
G. Langer ◽  
G. Nehrke ◽  
I. Horn ◽  
S. Misra ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Culture Media ◽  
Optical Emission ◽  
Boron Uptake ◽  
Carbonate Chemistry ◽  
Carbonate System ◽  
Field Samples ◽  
Species Specific ◽  
Boron Isotopic Composition

Abstract. A number of studies have shown that the boron isotopic composition (δ11B) and the B/Ca ratio of biogenic carbonates (mostly foraminifers) can serve as proxies for two parameters of the ocean's carbonate chemistry, rendering it possible to calculate the entire carbonate system. However, the B incorporation mechanism into marine carbonates is still not fully understood and analyses of field samples show species specific and hydrographic effects on the B proxies complicating their application. Identifying the carbonate system parameter influencing boron incorporation is difficult due to the co-variation of pH, CO32-, and B(OH)4-. To shed light on the question which parameter of the carbonate system is related to the boron incorporation, we performed culture experiments with the benthic symbiont-bearing foraminifer Amphistegina lessonii using a decoupled pH–CO32- chemistry. The determination of the boron isotopic composition and B/Ca ratios was performed simultaneously by means of a new in situ technique combining optical emission spectroscopy and laser ablation MC-ICP-MS. The boron isotopic composition in the tests gets heavier with increasing pH and B/Ca increases with increasing BOH4-/HCO3- of the culture media. The latter indicates that boron uptake of A. lessonii features a competition between B(OH)4- and HCO3-. Furthermore, the simultaneous determination of B/Ca and δ11B on single specimens allows for assessing the relative variability of these parameters. Among different treatments the B/Ca shows an increasing variability with increasing boron concentration in the test whereas the variability in the isotope distribution is constant.

scholarly journals Boron incorporation in the foraminifer <i>Amphistegina lessonii</i> under a decoupled carbonate chemistry

2015 ◽  
Vol 12 (6) ◽  
pp. 1753-1763 ◽  
Author(s):  
K. Kaczmarek ◽  
G. Langer ◽  
G. Nehrke ◽  
I. Horn ◽  
S. Misra ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Culture Media ◽  
Optical Emission ◽  
Boron Uptake ◽  
Carbonate Chemistry ◽  
Carbonate System ◽  
Field Samples ◽  
Species Specific ◽  
Boron Isotopic Composition

Abstract. A number of studies have shown that the boron isotopic composition (δ11B) and the B / Ca ratio of biogenic carbonates (mostly foraminifers) can serve as proxies for two parameters of the ocean's carbonate chemistry, rendering it possible to calculate the entire carbonate system. However, the B incorporation mechanism into marine carbonates is still not fully understood and analyses of field samples show species-specific and hydrographic effects on the B proxies complicating their application. Identifying the carbonate system parameter influencing boron incorporation is difficult due to the co-variation of pH, CO32- and B(OH)4-. To shed light on the question which parameter of the carbonate system is related to the boron incorporation, we performed culture experiments with the benthic symbiont-bearing foraminifer Amphistegina lessonii using a decoupled pH–CO32- chemistry. The determination of the δ11B and B / Ca ratios was performed simultaneously by means of a new in situ technique combining optical emission spectroscopy and laser ablation MC-ICP-MS. The boron isotopic composition in the tests gets heavier with increasing pH and B / Ca increases with increasing B(OH)4- / HCO3- of the culture media. The latter indicates that boron uptake of A. lessonii features a competition between B(OH)4- and HCO3-. Furthermore, the simultaneous determination of B / Ca and δ11B on single specimens allows for assessing the relative variability of these parameters. Among different treatments the B / Ca shows an increasing variability with increasing boron concentration in the test whereas the variability in the isotope distribution is constant.

scholarly journals Decoupled carbonate chemistry controls on the incorporation of boron into <i>Orbulina universa</i>

2017 ◽  
Vol 14 (2) ◽  
pp. 415-430 ◽  
Author(s):  
Ella L. Howes ◽  
Karina Kaczmarek ◽  
Markus Raitzsch ◽  
Antje Mewes ◽  
Nienke Bijma ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Inductively Coupled Plasma ◽  
Culture Media ◽  
Boron Uptake ◽  
Carbonate System ◽  
Ample Evidence ◽  
System Parameters ◽  
Effects Of Ph ◽  
Orbulina Universa ◽  
Primary Relationship

Abstract. In order to fully constrain paleo-carbonate systems, proxies for two out of seven parameters, plus temperature and salinity, are required. The boron isotopic composition (δ11B) of planktonic foraminifera shells is a powerful tool for reconstructing changes in past surface ocean pH. As B(OH)4− is substituted into the biogenic calcite lattice in place of CO32−, and both borate and carbonate ions are more abundant at higher pH, it was suggested early on that B ∕ Ca ratios in biogenic calcite may serve as a proxy for [CO32−]. Although several recent studies have shown that a direct connection of B ∕ Ca to carbonate system parameters may be masked by other environmental factors in the field, there is ample evidence for a mechanistic relationship between B ∕ Ca and carbonate system parameters. Here, we focus on investigating the primary relationship to develop a mechanistic understanding of boron uptake. Differentiating between the effects of pH and [CO32−] is problematic, as they co-vary closely in natural systems, so the major control on boron incorporation remains unclear. To deconvolve the effects of pH and [CO32−] and to investigate their impact on the B ∕ Ca ratio and δ11B, we conducted culture experiments with the planktonic foraminifer Orbulina universa in manipulated culture media: constant pH (8.05), but changing [CO32−] (238, 286 and 534 µmol kg−1 CO32−) and at constant [CO32−] (276 ± 19.5 µmol kg−1) and varying pH (7.7, 7.9 and 8.05). Measurements of the isotopic composition of boron and the B ∕ Ca ratio were performed simultaneously using a femtosecond laser ablation system coupled to a MC-ICP-MS (multiple-collector inductively coupled plasma mass spectrometer). Our results show that, as expected, δ11B is controlled by pH but it is also modulated by [CO32−]. On the other hand, the B ∕ Ca ratio is driven by [HCO3−], independently of pH. This suggests that B ∕ Ca ratios in foraminiferal calcite can possibly be used as a second, independent, proxy for complete paleo-carbonate system reconstructions. This is discussed in light of recent literature demonstrating that the primary relationship between B ∕ Ca and [HCO3−] can be obscured by other environmental parameters.

scholarly journals Light and temperature effect on δ<sup>11</sup>B and B/Ca ratios of the zooxanthellate coral <i>Acropora</i> sp.: results from culturing experiments

2012 ◽  
Vol 9 (5) ◽  
pp. 5969-6014 ◽  
Author(s):  
D. Dissard ◽  
E. Douville ◽  
S. Reynaud ◽  
A. Juillet-Leclerc ◽  
P. Montagna ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Temperature Effect ◽  
Environmental Parameters ◽  
Light Conditions ◽  
Ambient Seawater ◽  
Linear Temperature ◽  
Light Intensities ◽  
Species Specific ◽  
Increasing Temperature ◽  
Boron Isotopic Composition

Abstract. The boron isotopic composition (δ11B) of marine carbonates (e.g. corals) has been established as a reliable proxy for paleo-pH, with the strong correlation between δ11B of marine calcifiers and seawater pH being now well documented. However, further investigations are needed in order to better quantify other environmental parameters potentially impacting boron isotopic composition and boron concentration into coral aragonite. To achieve this goal the tropical scleractinian coral Acropora sp. was cultured under 3 different temperature (22, 25 and 28 °C) and two light conditions (200 and 400 μmol photon m−2 s−1). The δ11B indicates an internal increase in pH from ambient seawater under both light conditions. Changes in light intensities from 200 to 400 μmol photon m−2 s−1 could bias pH reconstructions by about 0.05 units. For both light conditions, a significant impact of temperature on δ11B can be observed between 22 and 25 °C corresponding to enhancements of about 0.02 pH-units, while no further δ11B increase can be observed between 25 and 28 °C. This non-linear temperature effect complicates the determination of a correcting factor. B/Ca ratios decrease with increasing light, confirming the decrease in pH at the site of calcification under enhanced light intensities. When all the other parameters are maintained constant, boron concentrations in Acropora sp. increase with increasing temperature and increasing carbonate ions concentrations. These observations contradict previous studies where B/Ca in corals was found to vary inversely with temperature suggesting that the controlling factors driving boron concentrations have not yet been adequately identified and might be influenced by other seawater variables and species specific responses.

Simultaneous Determination of Species-Specific Isotopic Composition of Hg by Gas Chromatography Coupled to Multicollector ICPMS

2008 ◽  
Vol 80 (10) ◽  
pp. 3530-3538 ◽  
Author(s):  
Vladimir N. Epov ◽  
Pablo Rodriguez-Gonzalez ◽  
Jeroen E. Sonke ◽  
Emmanuel Tessier ◽  
David Amouroux ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Isotopic Composition ◽  
Simultaneous Determination ◽  
Species Specific

scholarly journals Light and temperature effects on δ<sup>11</sup>B and B / Ca ratios of the zooxanthellate coral <i>Acropora</i> sp.: results from culturing experiments

2012 ◽  
Vol 9 (11) ◽  
pp. 4589-4605 ◽  
Author(s):  
D. Dissard ◽  
E. Douville ◽  
S. Reynaud ◽  
A. Juillet-Leclerc ◽  
P. Montagna ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Environmental Parameters ◽  
Natural Environments ◽  
Light Conditions ◽  
Linear Temperature ◽  
Annual Variations ◽  
Light Intensities ◽  
Apparent Decrease ◽  
Species Specific ◽  
Boron Isotopic Composition

Abstract. The boron isotopic composition (δ11B) of marine carbonates (e.g. corals) is increasingly utilised as a proxy for paleo-pH, with the strong correlation between δ11B of marine calcifiers and seawater pH now well documented. However, the potential roles of other environmental parameters that may also influence both the boron isotopic composition and boron concentration into coral aragonite are poorly known. To overcome this, the tropical scleractinian coral Acropora sp. was cultured under 3 different temperatures (22, 25 and 28 °C) and two light conditions (200 and 400 μmol photon m−2 s−1). The δ11B indicates an increase in internal pH that is dependent on the light conditions. Changes in light intensities from 200 to 400 μmol photon m−2 s−1 seem to indicate an apparent decrease in pH at the site of calcification, contrary to what is expected in most models of light-enhanced calcification. Thus, variations in light conditions chosen to mimic average annual variations of the natural environments where Acropora sp. colonies can be found could bias pH reconstructions by about 0.05 units. For both light conditions, a significant impact of temperature on δ11B can be observed between 22 and 25 °C, corresponding to an increase of about 0.02 pH-units, while no further δ11B increase can be observed from 25 to 28 °C. This non-linear temperature effect complicates the determination of a correction factor. B / Ca ratios decrease with increasing light, consistent with the decrease in pH at the site of calcification under enhanced light intensities. When all the other parameters are constant, boron concentrations in Acropora sp. increase with increasing temperatures and increasing carbonate ion concentrations. These observations contradict previous studies where B / Ca in corals was found to vary inversely with temperature, suggesting that the controlling factors driving boron concentrations have not yet been adequately identified and might be influenced by other environmental variables and/or species-specific responses.

Extraction and Determination of Boron Isotopic Composition in Tourmalines

2012 ◽  
Vol 40 (11) ◽  
pp. 1654-1660 ◽  
Author(s):  
Xiong YAN ◽  
Shao-Yong JIANG ◽  
Hai-Zhen WEI ◽  
Yan YAN ◽  
He-Pin WU ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Boron Isotopic Composition

scholarly journals Environmental controls on the boron and strontium isotopic composition of aragonite shell material of cultured <i>Arctica islandica</i>

2015 ◽  
Vol 12 (11) ◽  
pp. 3351-3368 ◽  
Author(s):  
Y.-W. Liu ◽  
S. M. Aciego ◽  
A. D. Wanamaker
Keyword(s):  
Isotopic Composition ◽  
Chemical Compositions ◽  
Shell Material ◽  
Boron Uptake ◽  
Concentration Data ◽  
Arctica Islandica ◽  
Fractionation Factor ◽  
Environmental Controls ◽  
Seawater Ph ◽  
Species Specific

Abstract. Ocean acidification, the decrease in ocean pH associated with increasing atmospheric CO2, is likely to impact marine organisms, particularly those that produce carbonate skeletons or shells. Therefore, it is important to investigate how environmental factors (seawater pH, temperature and salinity) influence the chemical compositions in biogenic carbonates. In this study we report the first high-resolution strontium (87Sr / 86Sr and δ88 / 86Sr) and boron (δ11B) isotopic values in the aragonite shell of cultured Arctica islandica (A. islandica). The 87Sr / 86Sr ratios from both tank water and shell samples show ratios nearly identical to the open ocean, which suggests that the shell material reflects ambient ocean chemistry without terrestrial influence. The 84Sr–87Sr double-spike-resolved shell δ88 / 86Sr and Sr concentration data show no resolvable change throughout the culture period and reflect no theoretical kinetic mass fractionation throughout the experiment despite a temperature change of more than 15 °C. The δ11B records from the experiment show at least a 5‰ increase through the 29-week culture season (January 2010–August 2010), with low values from the beginning to week 19 and higher values thereafter. The larger range in δ11B in this experiment compared to predictions based on other carbonate organisms (2–3‰) suggests that a species-specific fractionation factor may be required. A significant correlation between the ΔpH (pHshell − pHsw) and seawater pH (pHsw) was observed (R2 = 0.35), where the pHshell is the calcification pH of the shell calculated from boron isotopic composition. This negative correlation suggests that A. islandica partly regulates the pH of the extrapallial fluid. However, this proposed mechanism only explains approximately 35% of the variance in the δ11B data. Instead, a rapid rise in δ11B of the shell material after week 19, during the summer, suggests that the boron uptake changes when a thermal threshold of > 13 °C is reached.

scholarly journals On CO<sub>2</sub> pertubation experiments: over-determination of carbonate chemistry reveals inconsistencies

2010 ◽  
Vol 7 (2) ◽  
pp. 1707-1726 ◽  
Author(s):  
C. J. M. Hoppe ◽  
G. Langer ◽  
S. D. Rokitta ◽  
D. A. Wolf-Gladrow ◽  
B. Rost
Keyword(s):  
Perturbation Methods ◽  
Input Parameter ◽  
Ion Concentration ◽  
Carbonate Chemistry ◽  
Carbonate System ◽  
Saturation State ◽  
Carbonate Ion ◽  
Input Parameters ◽  
Seawater Carbonate Chemistry

Abstract. Seawater carbonate chemistry is typically calculated from two measured parameters. Depending on the choice of these input parameters, discrepancies in calculated pCO2 have been recognized by marine chemists, but the significance of this phenomenon for CO2 perturbation experiments has so far not been determined. To mimic different pCO2 scenarios, two common perturbation methods for seawater carbonate chemistry (changing either DIC or TA) were applied using state-of-the-art protocols and equipment. The carbonate system was over-constrained by measuring DIC, TA, pH, and pCO2. Calculated pCO2 matched measured pCO2 if pH and TA or pH and DIC were chosen as input parameters, whereas pCO2 calculated from TA and DIC was considerably lower than measured values. This has important implications for CO2 perturbation experiments. First, calculated pCO2 values may not be comparable if different input parameters were used. Second, responses of organisms to acidification may be overestimated when using TA and DIC for calculations. This is especially troublesome for experiments with calcifiers, as carbonate ion concentration and thus calcite or aragonite saturation state are overestimated. We suggest refraining from measuring TA and DIC only and rather include pH as input parameter for carbonate chemistry calculations.

Sign in / Sign up

Export Citation Format

Share Document