scholarly journals Continuous fluorescence-based monitoring of seawater pH in a temperate estuary

2017 ◽  
Author(s):  
John W. Runcie ◽  
Christian Krause ◽  
Sergio A. Torres Gabarda ◽  
Maria Byrne
Keyword(s):  
Surface Waters ◽  
Ph Monitoring ◽  
Good Resolution ◽  
Carbonate Chemistry ◽  
Temperature Drift ◽  
Seawater Ph ◽  
Calcite Saturation ◽  
Seawater Carbonate Chemistry ◽  
Diel Variability ◽  
Diel Fluctuations

Abstract. Abstract. Electrical conductivity (salinity), temperature and fluorescence-based measurements of pH were employed to examine diel fluctuations in seawater carbonate chemistry of surface waters in Sydney Harbour over two multiple-day periods. The fluorescence-based technique provided a useful time-series for pH. Alkalinity with pH and temperature were used to calculate the degree of aragonite and calcite saturation (ΩCa and ΩAr respectively). Alkalinity was determined from an alkalinity-salinity relationship. Variation in pH over minute- to hour-long periods was distinguishable from background variability. Diel variability in pH, Ωara and Ωcal showed a clear pattern that appeared to correlate with both salinity and temperature. Drift due to photodegradation of the fluorophore was minimised by reducing exposure to ambient light. ΩCa and ΩAr fluctuated approximately on a daily cycle. The net result of changes in pH, salinity and temperature combined to influence seawater carbonate chemistry. The fluorescence-based pH monitoring technique is simple, provides good resolution and is unaffected by moving parts or leaching of solutions over time. The use of optics is pressure insensitive, making this approach to ocean acidification monitoring well suited to deepwater applications.

scholarly journals Technical note: Continuous fluorescence-based monitoring of seawater pH in situ

2018 ◽  
Vol 15 (13) ◽  
pp. 4291-4299 ◽  
Author(s):  
John W. Runcie ◽  
Christian Krause ◽  
Sergio A. Torres Gabarda ◽  
Maria Byrne
Keyword(s):  
Ph Monitoring ◽  
Technical Note ◽  
Good Resolution ◽  
Carbonate Chemistry ◽  
Temperature Drift ◽  
Seawater Ph ◽  
Repeatability Standard Deviation ◽  
Seawater Carbonate Chemistry ◽  
Diel Variability ◽  
Diel Fluctuations

Abstract. Electrical conductivity (salinity), temperature and fluorescence-based measurements of pH were employed to examine diel fluctuations in seawater carbonate chemistry of surface waters in Sydney Harbour over two multiple-day periods. A proof-of-concept device employing the fluorescence-based technique provided a useful time series for pH. Alkalinity with pH and temperature were used to calculate the degree of calcite and aragonite saturation (ΩCa and ΩAr, respectively). Alkalinity was determined from a published alkalinity–salinity relationship. The fluctuations observed in pH over intervals of minutes to hours could be distinguished from background noise. While the stated phase angle resolution of the lifetime fluorometer translated into pH units was ±0.0028 pH units, the repeatability standard deviation of calculated pH was 0.007 to 0.009. Diel variability in pH, ΩAr and ΩCa showed a clear pattern that appeared to correlate with both salinity and temperature. Drift due to photodegradation of the fluorophore was minimized by reducing exposure to ambient light. The ΩCa and ΩAr fluctuated on a daily cycle. The net result of changes in pH, salinity and temperature combined to influence seawater carbonate chemistry. The fluorescence-based pH monitoring technique is simple, provides good resolution and is unaffected by moving parts or leaching of solutions over time. The use of optics is pressure insensitive, making this approach to ocean acidification monitoring well suited to deepwater applications.

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 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 Acid–base physiology over tidal periods in the mussel Mytilus edulis : size and temperature are more influential than seawater pH

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182863 ◽  
Author(s):  
Stephanie Mangan ◽  
Rod W. Wilson ◽  
Helen S. Findlay ◽  
Ceri Lewis
Keyword(s):  
Mytilus Edulis ◽  
Environmental Changes ◽  
Interactive Effect ◽  
Marine Biota ◽  
Acid Base ◽  
Tidal Cycles ◽  
Seawater Ph ◽  
Seawater Carbonate Chemistry ◽  
Two Populations

Ocean acidification (OA) studies to date have typically used stable open-ocean pH and CO 2 values to predict the physiological responses of intertidal species to future climate scenarios, with few studies accounting for natural fluctuations of abiotic conditions or the alternating periods of emersion and immersion routinely experienced during tidal cycles. Here, we determine seawater carbonate chemistry and the corresponding in situ haemolymph acid–base responses over real time for two populations of mussel ( Mytilus edulis ) during tidal cycles, demonstrating that intertidal mussels experience daily acidosis during emersion. Using these field data to parameterize experimental work we demonstrate that air temperature and mussel size strongly influence this acidosis, with larger mussels at higher temperatures experiencing greater acidosis. There was a small interactive effect of prior immersion in OA conditions (pH NBS 7.7/pCO 2 930 µatm) such that the haemolymph pH measured at the start of emersion was lower in large mussels exposed to OA. Critically, the acidosis induced in mussels during emersion in situ was greater (ΔpH approximately 0.8 units) than that induced by experimental OA (ΔpH approximately 0.1 units). Understanding how environmental fluctuations influence physiology under current scenarios is critical to our ability to predict the responses of key marine biota to future environmental changes.

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.

Carbonate Chemistry Dynamics of Surface Waters in the Northern Gulf of Mexico

2010 ◽  
Vol 16 (3) ◽  
pp. 337-351 ◽  
Author(s):  
Nina Keul ◽  
John W. Morse ◽  
Rik Wanninkhof ◽  
Dwight K. Gledhill ◽  
Thomas S. Bianchi
Keyword(s):  
Gulf Of Mexico ◽  
Surface Waters ◽  
Carbonate Chemistry ◽  
Northern Gulf Of Mexico ◽  
Chemistry Dynamics

scholarly journals CO2 sensitivity experiments are not sufficient to show an effect of ocean acidification

2016 ◽  
Vol 74 (4) ◽  
pp. 926-928 ◽  
Author(s):  
Paul McElhany
Keyword(s):  
Ocean Acidification ◽  
Population Level ◽  
Population Abundance ◽  
Laboratory Studies ◽  
Species Sensitivity ◽  
Carbonate Chemistry ◽  
Marine Carbonate ◽  
Seawater Carbonate Chemistry ◽  
Experimental Treatments ◽  
Level Effect

The ocean acidification (OA) literature is replete with laboratory studies that report species sensitivity to seawater carbonate chemistry in experimental treatments as an “effect of OA”. I argue that this is unintentionally misleading, since these studies do not actually demonstrate an effect of OA but rather show sensitivity to CO2. Documenting an effect of OA involves showing a change in a species (e.g. population abundance or distribution) as a consequence of anthropogenic changes in marine carbonate chemistry. To date, there have been no unambiguous demonstrations of a population level effect of anthropogenic OA, as that term is defined by the IPCC.

Sign in / Sign up

Export Citation Format

Share Document