Boron proxy constraints on the magnitude of surface ocean acidification during the Paleocene-Eocene Thermal Maximum

2014 ◽  
Vol 31 ◽  
pp. 173-174
Author(s):  
Donald E. Penman
Keyword(s):  
Ocean Acidification ◽  
Surface Ocean ◽  
Thermal Maximum

scholarly journals Rapid and sustained surface ocean acidification during the Paleocene-Eocene Thermal Maximum

2014 ◽  
Vol 29 (5) ◽  
pp. 357-369 ◽  
Author(s):  
Donald E. Penman ◽  
Bärbel Hönisch ◽  
Richard E. Zeebe ◽  
Ellen Thomas ◽  
James C. Zachos
Keyword(s):  
Ocean Acidification ◽  
Surface Ocean ◽  
Thermal Maximum

scholarly journals Capturing the global signature of surface ocean acidification during the Palaeocene–Eocene Thermal Maximum

2018 ◽  
Vol 376 (2130) ◽  
pp. 20170072 ◽  
Author(s):  
Tali L. Babila ◽  
Donald E. Penman ◽  
Bärbel Hönisch ◽  
D. Clay Kelly ◽  
Timothy J. Bralower ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Carbon Isotope ◽  
Atmospheric Carbon Dioxide ◽  
Environmental Changes ◽  
Planktonic Foraminifera ◽  
Tight Coupling ◽  
Carbonate Chemistry ◽  
Surface Ocean ◽  
Thermal Maximum ◽  
Carbon Release

Geologically abrupt carbon perturbations such as the Palaeocene–Eocene Thermal Maximum (PETM, approx. 56 Ma) are the closest geological points of comparison to current anthropogenic carbon emissions. Associated with the rapid carbon release during this event are profound environmental changes in the oceans including warming, deoxygenation and acidification. To evaluate the global extent of surface ocean acidification during the PETM, we present a compilation of new and published surface ocean carbonate chemistry and pH reconstructions from various palaeoceanographic settings. We use boron to calcium ratios (B/Ca) and boron isotopes (δ 11 B) in surface- and thermocline-dwelling planktonic foraminifera to reconstruct ocean carbonate chemistry and pH. Our records exhibit a B/Ca reduction of 30–40% and a δ 11 B decline of 1.0–1.2‰ coeval with the carbon isotope excursion. The tight coupling between boron proxies and carbon isotope records is consistent with the interpretation that oceanic absorption of the carbon released at the onset of the PETM resulted in widespread surface ocean acidification. The remarkable similarity among records from different ocean regions suggests that the degree of ocean carbonate change was globally near uniform. We attribute the global extent of surface ocean acidification to elevated atmospheric carbon dioxide levels during the main phase of the PETM. This article is part of a discussion meeting issue ‘Hyperthermals: rapid and extreme global warming in our geological past’.

scholarly journals Surface ocean carbon dioxide during the Atlantic Meridional Transect (1995–2013); evidence of ocean acidification

2017 ◽  
Vol 158 ◽  
pp. 65-75 ◽  
Author(s):  
Vassilis Kitidis ◽  
Ian Brown ◽  
Nicholas Hardman-Mountford ◽  
Nathalie Lefèvre
Keyword(s):  
Carbon Dioxide ◽  
Ocean Acidification ◽  
Surface Ocean ◽  
Ocean Carbon

Impact of surface ocean acidification on the CO2 absorption rate

2011 ◽  
Vol 3 (1/2) ◽  
pp. 163 ◽  
Author(s):  
A. Shanableh ◽  
T. Merabtene ◽  
M. Omar ◽  
M. Imteaz
Keyword(s):  
Ocean Acidification ◽  
Absorption Rate ◽  
Surface Ocean

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.

Enhanced terrestrial weathering/runoff and surface ocean carbonate production during the recovery stages of the Paleocene-Eocene thermal maximum

2005 ◽  
Vol 20 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. Clay Kelly ◽  
James C. Zachos ◽  
Timothy J. Bralower ◽  
Stephen A. Schellenberg
Keyword(s):  
Carbonate Production ◽  
Surface Ocean ◽  
Thermal Maximum

scholarly journals OceanSODA-ETHZ: a global gridded data set of the surface ocean carbonate system for seasonal to decadal studies of ocean acidification

2021 ◽  
Vol 13 (2) ◽  
pp. 777-808
Author(s):  
Luke Gregor ◽  
Nicolas Gruber
Keyword(s):  
Ocean Acidification ◽  
Total Alkalinity ◽  
Global Ocean ◽  
Carbonate System ◽  
Data Set ◽  
Saturation State ◽  
Total Uncertainty ◽  
Mean Squared Errors ◽  
Surface Ocean ◽  
Basin Scale

Abstract. Ocean acidification has profoundly altered the ocean's carbonate chemistry since preindustrial times, with potentially serious consequences for marine life. Yet, no long-term, global observation-based data set exists that allows us to study changes in ocean acidification for all carbonate system parameters over the last few decades. Here, we fill this gap and present a methodologically consistent global data set of all relevant surface ocean parameters, i.e., dissolved inorganic carbon (DIC), total alkalinity (TA), partial pressure of CO2 (pCO2), pH, and the saturation state with respect to mineral CaCO3 (Ω) at a monthly resolution over the period 1985 through 2018 at a spatial resolution of 1∘×1∘. This data set, named OceanSODA-ETHZ, was created by extrapolating in time and space the surface ocean observations of pCO2 (from the Surface Ocean CO2 Atlas, SOCAT) and total alkalinity (TA; from the Global Ocean Data Analysis Project, GLODAP) using the newly developed Geospatial Random Cluster Ensemble Regression (GRaCER) method (code available at https://doi.org/10.5281/zenodo.4455354, Gregor, 2021). This method is based on a two-step (cluster-regression) approach but extends it by considering an ensemble of such cluster regressions, leading to improved robustness. Surface ocean DIC, pH, and Ω were then computed from the globally mapped pCO2 and TA using the thermodynamic equations of the carbonate system. For the open ocean, the cluster-regression method estimates pCO2 and TA with global near-zero biases and root mean squared errors of 12 µatm and 13 µmol kg−1, respectively. Taking into account also the measurement and representation errors, the total uncertainty increases to 14 µatm and 21 µmol kg−1, respectively. We assess the fidelity of the computed parameters by comparing them to direct observations from GLODAP, finding surface ocean pH and DIC global biases of near zero, as well as root mean squared errors of 0.023 and 16 µmol kg−1, respectively. These uncertainties are very comparable to those expected by propagating the total uncertainty from pCO2 and TA through the thermodynamic computations, indicating a robust and conservative assessment of the uncertainties. We illustrate the potential of this new data set by analyzing the climatological mean seasonal cycles of the different parameters of the surface ocean carbonate system, highlighting their commonalities and differences. Further, this data set provides a novel constraint on the global- and basin-scale trends in ocean acidification for all parameters. Concretely, we find for the period 1990 through 2018 global mean trends of 8.6 ± 0.1 µmol kg−1 per decade for DIC, −0.016 ± 0.000 per decade for pH, 16.5 ± 0.1 µatm per decade for pCO2, and −0.07 ± 0.00 per decade for Ω. The OceanSODA-ETHZ data can be downloaded from https://doi.org/10.25921/m5wx-ja34 (Gregor and Gruber, 2020).

scholarly journals Ocean acidification alters morphology of all otolith types in Clark’s anemonefish (Amphiprion clarkii)

2018 ◽  
Author(s):  
Robert Holmberg ◽  
Eric Wilcox-Freeburg ◽  
Andrew L Rhyne ◽  
Michael F Tlusty ◽  
Alan Stebbins ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ocean Acidification ◽  
Treatment Effects ◽  
Marine Biota ◽  
Critical Elements ◽  
Surface Ocean ◽  
Seawater Ph ◽  
Otolith Morphology ◽  
Near Future ◽  
Amphiprion Clarkii

Ocean acidification, the ongoing decline of surface ocean pH and [CO32-] due to absorption of surplus atmospheric CO2, has far-reaching consequences for marine biota, especially calcifiers. Among these are teleost fishes, which internally calcify otoliths, critical elements of the inner ear and vestibular system. There is evidence in the literature that ocean acidification increases otolith size and alters shape, perhaps impacting otic mechanics and thus sensory perception. However, existing analyses of otolith morphological responses to ocean acidification are limited to 2-dimensional morphometrics and shape analysis. Here, we reared larval Clark’s anemonefish, Amphiprion clarkii (Bennett, 1830), in various seawater pH treatments analogous to future ocean scenarios in a 3x-replicated experimental design. Upon settlement, we removed all otoliths from each individual fish and analyzed them for treatment effects on morphometrics including area, perimeter, and circularity; further, we used scanning electron microscopy to screen otoliths visually for evidence of treatment effects on lateral development, surface roughness, and vaterite replacement. Our results corroborate those of other experiments with other taxa that observed otolith growth with elevated pCO2, and provide evidence that lateral development and surface roughness increased as well; we observed at least one of these effects in all otolith types. Finally, we review previous work investigating ocean acidification impacts on otolith morphology and hypotheses concerning function, placing our observations in context. These impacts may have consequences teleost fitness in the near-future ocean.

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