scholarly journals A Unique Diel Pattern in Carbonate Chemistry in the Seagrass Meadows of Dongsha Island: The Enhancement of Metabolic Carbonate Dissolution in a Semienclosed Lagoon

2021 ◽  
Vol 8 ◽  
Author(s):  
Wen-Chen Chou ◽  
Lan-Feng Fan ◽  
Chang-Chang Yang ◽  
Ying-Hsuan Chen ◽  
Chin-Chang Hung ◽  
...  
Keyword(s):  
Total Alkalinity ◽  
Carbonate Dissolution ◽  
Diel Pattern ◽  
Carbonate Chemistry ◽  
Seagrass Meadows ◽  
Diel Variations ◽  
Seawater Carbonate Chemistry ◽  
Aerobic And Anaerobic ◽  
Organic Matter Loading ◽  
Photosynthesis And Respiration

In contrast to other seagrass meadows where seawater carbonate chemistry generally shows strong diel variations with higher pH but lower partial pressure of CO2 (pCO2) during the daytime and lower pH but higher pCO2 during nighttime due to the alternation in photosynthesis and respiration, the seagrass meadows of the inner lagoon (IL) on Dongsha Island had a unique diel pattern with extremely high pH and low pCO2 across a diel cycle. We suggest that this distinct diel pattern in pH and pCO2 could be associated with the enhancement of total alkalinity (TA) production coupled to carbonate sediment dissolution in a semienclosed lagoon. The confinement of the IL may hamper water exchange and seagrass detritus export to the adjacent open ocean, which may result in higher organic matter loading to the sediments, and longer residence time of the water in the IL, accompanied by microbial respiration (both aerobic and anaerobic) that may reduce carbonate saturation level to drive carbonate dissolution and thus TA elevation, thereby forming such a unique diel pattern in carbonate chemistry. This finding further highlights the importance of considering TA production through metabolic carbonate dissolution when evaluating the potential of coastal blue carbon ecosystems to buffer ocean acidification and to absorb atmospheric CO2, in particular in a semienclosed setting.

scholarly journals Coral calcifying fluid pH is modulated by seawater carbonate chemistry not solely seawater pH

2017 ◽  
Vol 284 (1847) ◽  
pp. 20161669 ◽  
Author(s):  
S. Comeau ◽  
E. Tambutté ◽  
R. C. Carpenter ◽  
P. J. Edmunds ◽  
N. R. Evensen ◽  
...  
Keyword(s):  
Dissolved Inorganic Carbon ◽  
Reef Coral ◽  
Total Alkalinity ◽  
Published Data ◽  
Carbonate Chemistry ◽  
Stylophora Pistillata ◽  
Coral Calcification ◽  
Seawater Ph ◽  
Constant Ph ◽  
Seawater Carbonate Chemistry

Reef coral calcification depends on regulation of pH in the internal calcifying fluid (CF) in which the coral skeleton forms. However, little is known about calcifying fluid pH (pH CF ) regulation, despite its importance in determining the response of corals to ocean acidification. Here, we investigate pH CF in the coral Stylophora pistillata in seawater maintained at constant pH with manipulated carbonate chemistry to alter dissolved inorganic carbon (DIC) concentration, and therefore total alkalinity (A T ). We also investigate the intracellular pH of calcifying cells, photosynthesis, respiration and calcification rates under the same conditions. Our results show that despite constant pH in the surrounding seawater, pH CF is sensitive to shifts in carbonate chemistry associated with changes in [DIC] and [A T ], revealing that seawater pH is not the sole driver of pH CF . Notably, when we synthesize our results with published data, we identify linear relationships of pH CF with the seawater [DIC]/[H + ] ratio, [A T ]/ [H + ] ratio and [ ]. Our findings contribute new insights into the mechanisms determining the sensitivity of coral calcification to changes in seawater carbonate chemistry, which are needed for predicting effects of environmental change on coral reefs and for robust interpretations of isotopic palaeoenvironmental records in coral skeletons.

scholarly journals Calcification in Three Common Calcified Algae from Phuket, Thailand: Potential Relevance on Seawater Carbonate Chemistry and Link to Photosynthetic Process

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2537
Author(s):  
Pimchanok Buapet ◽  
Sutinee Sinutok
Keyword(s):  
Environmental Changes ◽  
Dissolved Inorganic Carbon ◽  
Critical Role ◽  
Photosynthetic Electron Transport ◽  
Marine Ecosystems ◽  
Total Alkalinity ◽  
Natural Setting ◽  
Carbonate Chemistry ◽  
Seawater Ph ◽  
Seawater Carbonate Chemistry

Calcifying macroalgae contribute significantly to the structure and function of tropical marine ecosystems. Their calcification and photosynthetic processes are not well understood despite their critical role in marine carbon cycles and high vulnerability to environmental changes. This study aims to provide a better understanding of the macroalgal calcification process, focusing on its relevance concerning seawater carbonate chemistry and its relationship to photosynthesis in three dominant calcified macroalgae in Thailand, Padina boryana, Halimeda macroloba and Halimeda opuntia. Morphological and microstructural attributes of the three macroalgae were analyzed and subsequently linked to their calcification rates and responses to inhibition of photosynthesis. In the first experiment, seawater pH, total alkalinity and total dissolved inorganic carbon were measured after incubation of the macroalgae in the light and after equilibration of the seawater with air. Estimations of carbon uptake into photosynthesis and calcification and carbon release into air were obtained thereafter. Our results provide evidence that calcification of the three calcified macroalgae is a potential source of CO2, where calcification by H. opuntia and H. macroloba leads to a greater release of CO2 per biomass weight than P. boryana. Nevertheless, this capacity is expected to vary on a diurnal basis, as the second experiment indicates that calcification is highly coupled to photosynthetic activity. Lower pH as a result of inhibited photosynthesis under darkness imposes more negative effects on H. opuntia and H. macroloba than on P. boryana, implying that they are more sensitive to acidification. These effects were worsened when photosynthesis was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, highlighting the significance of photosynthetic electron transport-dependent processes. Our findings suggest that estimations of the amount of carbon stored in the vegetated marine ecosystems should account for macroalgal calcification as a potential carbon source while considering diurnal variations in photosynthesis and seawater pH in a natural setting.

scholarly journals CO<sub>2</sub> perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations

2009 ◽  
Vol 6 (2) ◽  
pp. 4441-4462 ◽  
Author(s):  
K. G. Schulz ◽  
J. Barcelos e Ramos ◽  
R. E. Zeebe ◽  
U. Riebesell
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Carbonate Chemistry ◽  
Surface Ocean ◽  
Seawater Carbonate Chemistry ◽  
Similarities And Differences ◽  
Carbon Dioxide Co2

Abstract. Increasing atmospheric carbon dioxide (CO2) through human activities and invasion of anthropogenic CO2 into the surface ocean alters the seawater carbonate chemistry, increasing CO2 and bicarbonate (HCO3

A Unique Diel Pattern in Carbonate Chemistry in the Seagrass Meadows of Dongsha Island: implications for ocean acidification buffering

2020 ◽  
Author(s):  
Wen-Chen Chou ◽  
Lan-Feng Fan ◽  
Chang-Chang Yang ◽  
Ying-Hsuan Chen ◽  
Chin-Chang Hung ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Diel Pattern ◽  
Carbonate Chemistry ◽  
Seagrass Meadows

The role of tides on the carbonate chemistry of a coastal polynya in the south-eastern Weddell Sea

2021 ◽  
Author(s):  
Elise Droste ◽  
Melchor González Dávila ◽  
Juana Magdalena Santana Casiano ◽  
Mario Hoppema ◽  
Gerd Rohardt ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Weddell Sea ◽  
Water Masses ◽  
Total Alkalinity ◽  
The South ◽  
Carbonate Chemistry ◽  
Large Variability ◽  
South Eastern ◽  
Coastal Polynya ◽  
Eastern Weddell Sea

&lt;p&gt;Tides have a large impact on coastal polynyas around Antarctica. We investigate the effect of semi-diurnal tidal cycles on the seawater carbonate chemistry in a coastal polynya hugging the Ekstr&amp;#246;m Ice Shelf in the south-eastern Weddell Sea. This region experiences some of the strongest tides in the Southern Ocean. We assess the implications for the contribution of coastal polynyas to the carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) air-sea flux of the Weddell Sea.&lt;/p&gt;&lt;p&gt;Two site visits, in January 2015 and January 2019, are intercompared in terms of the dissolved inorganic carbon (DIC) concentration, total alkalinity, pH, and CO&lt;sub&gt;2&lt;/sub&gt; partial pressure (pCO&lt;sub&gt;2&lt;/sub&gt;). The tides induce large variability in the carbonate chemistry of the coastal polynya in the austral summer: DIC concentrations vary between 2174 and 2223 umol kg&lt;sup&gt;-1&lt;/sup&gt;.&lt;/p&gt;&lt;p&gt;The tidal fluctuation in the DIC concentration can swing the polynya from a sink to a source of atmospheric CO&lt;sub&gt;2 &lt;/sub&gt;on a semi-diurnal timescale. We attribute these changes to the mixing of different water masses. The amount of variability induced by tides depends on &amp;#8211; and is associated with &amp;#8211; large scale oceanographic and biogeochemical processes that affect the characteristics and presence of the water masses being mixed, such as the rate of sea ice melt.&lt;/p&gt;&lt;p&gt;Sampling strategies in Antarctic coastal polynyas should always take tidal influences into account. This would help to reduce biases in our understanding of how coastal polynyas contribute to the CO&lt;sub&gt;2&lt;/sub&gt; uptake by the Southern Ocean.&lt;/p&gt;

scholarly journals Evaluation of a semi-automatic system for long-term seawater carbonate chemistry manipulation

2013 ◽  
Vol 86 (4) ◽  
pp. 443-451 ◽  
Author(s):  
RODRIGO TORRES ◽  
PATRICIO H MANRIQUEZ ◽  
CRISTIAN DUARTE ◽  
JORGE M NAVARRO ◽  
NELSON A LAGOS ◽  
...  
Keyword(s):  
Automatic System ◽  
Carbonate Chemistry ◽  
Seawater Carbonate Chemistry

scholarly journals Carbonate System Parameters of an Algal-dominated Reef along West Maui

2018 ◽  
Author(s):  
Nancy G. Prouty ◽  
Kimberly K. Yates ◽  
Nathan Smiley ◽  
Chris Gallagher ◽  
Olivia Cheriton ◽  
...  
Keyword(s):  
Coral Reef ◽  
Reef Flat ◽  
Sampling Period ◽  
Total Alkalinity ◽  
Carbonate Chemistry ◽  
Diurnal Variability ◽  
Carbon Chemistry ◽  
Sources Of Pollution ◽  
Seawater Ph ◽  
Chemistry Dynamics

Abstract. Constraining coral reef metabolism and carbon chemistry dynamics are fundamental for understanding and predicting reef vulnerability to rising coastal CO2 concentrations and decreasing seawater pH. However, few studies exist along reefs occupying densely inhabited shorelines with known input from land-based sources of pollution. The shallow coral reefs off Kahekili, West Maui, are exposed to nutrient-enriched, low-pH submarine groundwater discharge (SGD) and are particularly vulnerable to the compounding stressors from land-based sources of pollution and lower seawater pH. To constrain the carbonate chemistry system, nutrients and carbonate chemistry were measured along the Kahekili reef flat every 4 h over a 6-d sampling period in March 2016. Abiotic process – primarily SGD fluxes – controlled the carbonate chemistry adjacent to the primary SGD vent site, with nutrient-laden freshwater decreasing pH levels and favoring undersaturated aragonite saturation (Ωarag) conditions. In contrast, diurnal variability in the carbonate chemistry at other sites along the reef flat was driven by reef community metabolism. Superimposed on the diurnal signal was a transition during the second sampling period to a surplus of total alkalinity (TA) and dissolved inorganic carbon (DIC) compared to ocean end-member TA and DIC measurements. A shift from net community production and calcification to net respiration and carbonate dissolution was identified. This transition occurred during a period of increased SGD-driven nutrient loading, lower wave height, and reduced current speeds. This detailed study of carbon chemistry dynamics highlights the need to incorporate local effects of nearshore oceanographic processes into predictions of coral reef vulnerability and resilience.

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.

Short-Term Spatial and Temporal Carbonate Chemistry Variability in Two Contrasting Seagrass Meadows: Implications for pH Buffering Capacities

2018 ◽  
Vol 41 (5) ◽  
pp. 1282-1296 ◽  
Author(s):  
Tyler Cyronak ◽  
Andreas J. Andersson ◽  
Sydney D’Angelo ◽  
Philip Bresnahan ◽  
Charles Davidson ◽  
...  
Keyword(s):  
Carbonate Chemistry ◽  
Short Term ◽  
Ph Buffering ◽  
Seagrass Meadows
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