scholarly journals Coral calcifying fluid aragonite saturation states derived from Raman spectroscopy

2017 ◽  
Vol 14 (22) ◽  
pp. 5253-5269 ◽  
Author(s):  
Thomas M. DeCarlo ◽  
Juan P. D'Olivo ◽  
Taryn Foster ◽  
Michael Holcomb ◽  
Thomas Becker ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Ocean Acidification ◽  
Environmental Changes ◽  
Isotope Geochemistry ◽  
Strong Dependence ◽  
Saturation State ◽  
Minimal Sample ◽  
Biomineralization Process ◽  
Elevated Co2 And Temperature

Abstract. Quantifying the saturation state of aragonite (ΩAr) within the calcifying fluid of corals is critical for understanding their biomineralization process and sensitivity to environmental changes including ocean acidification. Recent advances in microscopy, microprobes, and isotope geochemistry enable the determination of calcifying fluid pH and [CO32−], but direct quantification of ΩAr (where ΩAr =  [CO32−][Ca2+]∕Ksp) has proved elusive. Here we test a new technique for deriving ΩAr based on Raman spectroscopy. First, we analysed abiogenic aragonite crystals precipitated under a range of ΩAr from 10 to 34, and we found a strong dependence of Raman peak width on ΩAr with no significant effects of other factors including pH, Mg∕Ca partitioning, and temperature. Validation of our Raman technique for corals is difficult because there are presently no direct measurements of calcifying fluid ΩAr available for comparison. However, Raman analysis of the international coral standard JCp-1 produced ΩAr of 12.3 ± 0.3, which we demonstrate is consistent with published skeletal Mg∕Ca, Sr∕Ca, B∕Ca, δ11B, and δ44Ca data. Raman measurements are rapid ( ≤  1 s), high-resolution ( ≤  1 µm), precise (derived ΩAr ± 1 to 2 per spectrum depending on instrument configuration), accurate ( ±2 if ΩAr < 20), and require minimal sample preparation, making the technique well suited for testing the sensitivity of coral calcifying fluid ΩAr to ocean acidification and warming using samples from natural and laboratory settings. To demonstrate this, we also show a high-resolution time series of ΩAr over multiple years of growth in a Porites skeleton from the Great Barrier Reef, and we evaluate the response of ΩAr in juvenile Acropora cultured under elevated CO2 and temperature.

scholarly journals Coral calcifying fluid aragonite saturation states derived from Raman spectroscopy

2017 ◽  
Author(s):  
Thomas M. DeCarlo ◽  
Juan P. D'Olivo ◽  
Taryn Foster ◽  
Michael Holcomb ◽  
Thomas Becker ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Environmental Changes ◽  
Isotope Geochemistry ◽  
Strong Dependence ◽  
Saturation State ◽  
Raman Analysis ◽  
Direct Measurements ◽  
A New Technique ◽  
Direct Quantification

Abstract. Quantifying the saturation state of aragonite (ΩAr) within the calcifying fluid of corals is critical for understanding their biomineralisation process and sensitivity to environmental changes including ocean acidification. Recent advances in microscopy, microprobes, and isotope geochemistry allow determination of calcifying fluid pH and [CO32−], but direct quantification of ΩAr (where ΩAr =[CO32−][Ca2+]/Ksp) has proved elusive. Here we test a new technique for deriving ΩAr based on Raman spectroscopy. First, we analysed abiogenic aragonite crystals precipitated under a range of ΩAr from 10 to 34, and found a strong dependence of Raman peak width on ΩAr that was independent of other factors including pH, Mg/Ca partitioning, and temperature. Validation of our Raman technique for corals is difficult because there are presently no direct measurements of calcifying fluid ΩAr available for comparison. However, Raman analysis of the international coral standard JCp-1 produced ΩAr of 12.3 ± 0.3, which we demonstrate is consistent with published skeletal Sr/Ca, Mg/Ca, B/Ca, δ44Ca, and δ11B data. Raman measurements are rapid (≤ 1 s), high-resolution (

scholarly journals Calcification rates and the effect of ocean acidification on Mediterranean cold-water corals

2011 ◽  
Vol 279 (1734) ◽  
pp. 1716-1723 ◽  
Author(s):  
C. Maier ◽  
P. Watremez ◽  
M. Taviani ◽  
M. G. Weinbauer ◽  
J. P. Gattuso
Keyword(s):  
Ocean Acidification ◽  
Environmental Changes ◽  
Cold Water ◽  
Sea Water ◽  
Scleractinian Corals ◽  
Lophelia Pertusa ◽  
Ambient Conditions ◽  
Saturation State ◽  
Industrial Level ◽  
Global Environmental Changes

Global environmental changes, including ocean acidification, have been identified as a major threat to scleractinian corals. General predictions are that ocean acidification will be detrimental to reef growth and that 40 to more than 80 per cent of present-day reefs will decline during the next 50 years. Cold-water corals (CWCs) are thought to be strongly affected by changes in ocean acidification owing to their distribution in deep and/or cold waters, which naturally exhibit a CaCO 3 saturation state lower than in shallow/warm waters. Calcification was measured in three species of Mediterranean cold-water scleractinian corals ( Lophelia pertusa , Madrepora oculata and Desmophyllum dianthus ) on-board research vessels and soon after collection. Incubations were performed in ambient sea water. The species M. oculata was additionally incubated in sea water reduced or enriched in CO 2. At ambient conditions, calcification rates ranged between −0.01 and 0.23% d −1 . Calcification rates of M. oculata under variable partial pressure of CO 2 (pCO 2 ) were the same for ambient and elevated pCO 2 (404 and 867 µatm) with 0.06 ± 0.06% d −1 , while calcification was 0.12 ± 0.06% d −1 when pCO 2 was reduced to its pre-industrial level (285 µatm). This suggests that present-day CWC calcification in the Mediterranean Sea has already drastically declined (by 50%) as a consequence of anthropogenic-induced ocean acidification.

A POWERFUL TOOL TO STUDY COLLISIONAL PHENOMENA AND FOR COMBUSTION APPLICATIONS : THE HIGH RESOLUTION STIMULATED RAMAN SPECTROSCOPY

1987 ◽  
Vol 48 (C7) ◽  
pp. C7-761-C7-762
Author(s):  
B. LAVOREL ◽  
G. MILLOT ◽  
R. SAINT-LOUP ◽  
M. L. GONZE ◽  
J. SANTOS ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Stimulated Raman

scholarly journals Exploring Intramolecular Methyl–Methyl Coupling on a Metal Surface for Edge-Extended Graphene Nanoribbons

2021 ◽  
Vol 03 (02) ◽  
pp. 128-133
Author(s):  
Zijie Qiu ◽  
Qiang Sun ◽  
Shiyong Wang ◽  
Gabriela Borin Barin ◽  
Bastian Dumslaff ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
High Resolution ◽  
Graphene Nanoribbons ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Methyl Methyl ◽  
Atomic Force ◽  
Edge Extension

Intramolecular methyl–methyl coupling on Au (111) is explored as a new on-surface protocol for edge extension in graphene nanoribbons (GNRs). Characterized by high-resolution scanning tunneling microscopy, noncontact atomic force microscopy, and Raman spectroscopy, the methyl–methyl coupling is proven to indeed proceed at the armchair edges of the GNRs, forming six-membered rings with sp3- or sp2-hybridized carbons.

scholarly journals Thermal stress reduces pocilloporid coral resilience to ocean acidification by impairing control over calcifying fluid chemistry

2021 ◽  
Vol 7 (2) ◽  
pp. eaba9958
Author(s):  
Maxence Guillermic ◽  
Louise P. Cameron ◽  
Ilian De Corte ◽  
Sambuddha Misra ◽  
Jelle Bijma ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Ocean Acidification ◽  
Pocillopora Damicornis ◽  
Carbonate Chemistry ◽  
Negative Interaction ◽  
Saturation State ◽  
Stylophora Pistillata ◽  
Coral Calcification ◽  
Influence Of Temperature On ◽  
Different Time Scales

The combination of thermal stress and ocean acidification (OA) can more negatively affect coral calcification than an individual stressors, but the mechanism behind this interaction is unknown. We used two independent methods (microelectrode and boron geochemistry) to measure calcifying fluid pH (pHcf) and carbonate chemistry of the corals Pocillopora damicornis and Stylophora pistillata grown under various temperature and pCO2 conditions. Although these approaches demonstrate that they record pHcf over different time scales, they reveal that both species can cope with OA under optimal temperatures (28°C) by elevating pHcf and aragonite saturation state (Ωcf) in support of calcification. At 31°C, neither species elevated these parameters as they did at 28°C and, likewise, could not maintain substantially positive calcification rates under any pH treatment. These results reveal a previously uncharacterized influence of temperature on coral pHcf regulation—the apparent mechanism behind the negative interaction between thermal stress and OA on coral calcification.

High-resolution nonlinear raman spectroscopy of small molecules

1986 ◽  
Vol 141 ◽  
pp. 195-202 ◽  
Author(s):  
H.W. Schrötter ◽  
H. Berger ◽  
B. Lavorel
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Small Molecules

scholarly journals Metabolic cost of calcification in bivalve larvae under experimental ocean acidification

2016 ◽  
Vol 74 (4) ◽  
pp. 941-954 ◽  
Author(s):  
Christina A. Frieder ◽  
Scott L. Applebaum ◽  
T.-C. Francis Pan ◽  
Dennis Hedgecock ◽  
Donal T. Manahan
Keyword(s):  
Ocean Acidification ◽  
Climate Change Impacts ◽  
Metabolic Cost ◽  
Shell Formation ◽  
Metabolic Demand ◽  
Shell Size ◽  
Saturation State ◽  
Shell Mass ◽  
Energy Limitation ◽  
Endogenous Reserves

Abstract Physiological increases in energy expenditure frequently occur in response to environmental stress. Although energy limitation is often invoked as a basis for decreased calcification under ocean acidification, energy-relevant measurements related to this process are scant. In this study we focus on first-shell (prodissoconch I) formation in larvae of the Pacific oyster, Crassostrea gigas. The energy cost of calcification was empirically derived to be ≤ 1.1 µJ (ng CaCO3)−1. Regardless of the saturation state of aragonite (2.77 vs. 0.77), larvae utilize the same amount of total energy to complete first-shell formation. Even though there was a 56% reduction of shell mass and an increase in dissolution at aragonite undersaturation, first-shell formation is not energy limited because sufficient endogenous reserves are available to meet metabolic demand. Further studies were undertaken on larvae from genetic crosses of pedigreed lines to test for variance in response to aragonite undersaturation. Larval families show variation in response to ocean acidification, with loss of shell size ranging from no effect to 28%. These differences show that resilience to ocean acidification may exist among genotypes. Combined studies of bioenergetics and genetics are promising approaches for understanding climate change impacts on marine organisms that undergo calcification.

HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: I. EXPERIMENTAL METHODS

1954 ◽  
Vol 32 (5) ◽  
pp. 330-338 ◽  
Author(s):  
B. P. Stoicheff
Keyword(s):  
Raman Spectroscopy ◽  
High Resolution ◽  
Magnesium Oxide ◽  
Raman Spectra ◽  
Experimental Methods ◽  
Resolving Power ◽  
Polar Molecules ◽  
High Current ◽  
Rotational Constants ◽  
Moments Of Inertia

An apparatus for obtaining intense Raman spectra of gases excited by the Hg 4358 line is described. It consists of a mirror-type Raman tube irradiated by two high-current mercury lamps, completely enclosed in a reflector of magnesium oxide. The lamps are externally water-cooled along their entire length and emit sharp lines of high intensity.Rotational Raman spectra of gases at a pressure of 1 atm. have been photographed in the second order of a 21 ft. grating in exposure times of 6 to 24 hr. The Raman lines are sharp and a resolving power of about 100,000 has been achieved. It will be possible to resolve the rotational Raman spectra, and hence to evaluate the rotational constants of molecules having moments of inertia of up to 300 × 10−10 gm. cm.2 Such investigations will be especially useful for non-polar molecules.

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