This document summarizes research on ocean acidification and its effects. It discusses how increased CO2 absorption by oceans leads to acidification, affecting calcium carbonate availability and organisms that use it in shells and skeletons. While most research focuses on single species responses, one study found increased calcification in coccolithophores during winter when pH is lowest, contradicting hypotheses. Experts agree ocean acidification due to CO2 emissions will continue for centuries and exceed past rates, but have less consensus on specific biogeochemical issues.
An investigation on role of salinity, pH and DO on heavy metals elimination t...GJESM Publication
One of the most paramount processes that play a considerable role in reducing the concentration of
heavy metals during estuarine mixing is flocculation. Not only does such a process cause a huge percentage of metals to come into the particulate phase, but also it provides ample nutrients for the aquatic life. In the present study, impact of such factors as salinity, pH and DO on flocculation of Cu, Zn, Pb, Ni, Cd and Mn throughout mixing of Chaluse River with Caspian Sea is investigated. The trend of flocculation of Pb (24.32%) < Zn (24.38%) < Cd (40.00%) < Cu (64.71%) < Ni (68.00%) < Mn (76.47%) reveals that among the studied elements Mn and lead experience minimum and maximum flocculation at diverse salinity regimes, respectively. Moreover, flocculation rate of studied metals fluctuates between 24.32 and 76.47 percent. It is interesting to note that much of metal flocculation occurs at the very lower (less than 2 ppt) salinity regimes.
Trace Metals Concentration in Shallow Well Water in Enugu Metropolispaperpublications3
Abstract: This work assesses the concentration of heavy metals in Enugu Municipal well-water considering the fact that some Enugu inhabitants depend on well-water as their major source of water supply. Water from twenty four (24) different hand dug wells from six locations were investigated for Zn, Cu, Pb, Mn, Cd, and Fe using Atomic Absorption Spectroscopy (AAS). The result of the study expressed as the means and standard deviations were compared to WHO and EU standards for drinking water, and it was found that well waters from Iva-Valley and Uwani areas suffer from Cd and Mn pollution. The remaining four locations (Emene, Asata, Abakpa Nike and Achara Layout) were all free from Cd and Mn pollution. Cu, Zn, Fe and Pb concentrations were either completely absent or below world threshold limits at all the locations.
An investigation on role of salinity, pH and DO on heavy metals elimination t...GJESM Publication
One of the most paramount processes that play a considerable role in reducing the concentration of
heavy metals during estuarine mixing is flocculation. Not only does such a process cause a huge percentage of metals to come into the particulate phase, but also it provides ample nutrients for the aquatic life. In the present study, impact of such factors as salinity, pH and DO on flocculation of Cu, Zn, Pb, Ni, Cd and Mn throughout mixing of Chaluse River with Caspian Sea is investigated. The trend of flocculation of Pb (24.32%) < Zn (24.38%) < Cd (40.00%) < Cu (64.71%) < Ni (68.00%) < Mn (76.47%) reveals that among the studied elements Mn and lead experience minimum and maximum flocculation at diverse salinity regimes, respectively. Moreover, flocculation rate of studied metals fluctuates between 24.32 and 76.47 percent. It is interesting to note that much of metal flocculation occurs at the very lower (less than 2 ppt) salinity regimes.
Trace Metals Concentration in Shallow Well Water in Enugu Metropolispaperpublications3
Abstract: This work assesses the concentration of heavy metals in Enugu Municipal well-water considering the fact that some Enugu inhabitants depend on well-water as their major source of water supply. Water from twenty four (24) different hand dug wells from six locations were investigated for Zn, Cu, Pb, Mn, Cd, and Fe using Atomic Absorption Spectroscopy (AAS). The result of the study expressed as the means and standard deviations were compared to WHO and EU standards for drinking water, and it was found that well waters from Iva-Valley and Uwani areas suffer from Cd and Mn pollution. The remaining four locations (Emene, Asata, Abakpa Nike and Achara Layout) were all free from Cd and Mn pollution. Cu, Zn, Fe and Pb concentrations were either completely absent or below world threshold limits at all the locations.
Study of Seasonal Variations in Oxygen Consumption of Estuarine Clam, Meretri...ijtsrd
The estuarine clam, Meretrix meretrix was exposed to predetermined seasonal sublethal and lethal concentrations of CdCl2, 2½ H2O for 96 hrs. Experiments were conducted during summer, monsoon and winter by keeping control group of clams. Estuarine water parameters like temperature, pH, salinity, rainfall and dissolved oxygen were recorded. In the present study, it is found that, it has significant influence on rate of oxygen consumption and toxicity of cadmium chloride. During summer, clams from LC0 and LC50 group were treated with 1.1ppm and 1.8 ppm respectively. During monsoon LC0 and LC50 group were treated with 1.6 ppm and 2.0 ppm respectively. During winter clams from LC0 and LC50 group were exposed to 1.4 ppm and 2.1 ppm cadmium chloride respectively. During summer, as compared to control group, there were 3.83, 17.04, 16.77 and 10.63 increase in oxygen uptake at the end of 24, 36, 48, and 60 hrs. There were 0.35, 4.97 and 21.75 decrease at the end of 48, 72, 84 and 96 hrs. Moreover, similar trend of oxygen consumption was observed in LC0 and LC50 .group of clams in winter and monsoon season. During monsoon and winter clams from control group showed similar trend of oxygen uptake with less significant fluctuations. Clams from control group and LC0 and LC50 group showed less oxygen consumption during monsoon than summer and winter. Sanjay Kumbhar "Study of Seasonal Variations in Oxygen Consumption of Estuarine Clam, Meretrix Meretrix (Linnaeus, 1758) after Acute Exposure of Cadmium Chloride" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30543.pdf Paper Url :https://www.ijtsrd.com/biological-science/zoology/30543/study-of-seasonal-variations-in-oxygen-consumption-of-estuarine-clam-meretrix-meretrix-linnaeus-1758-after-acute-exposure-of-cadmium-chloride/sanjay-kumbhar
International Journal of Mathematics and Statistics Invention (IJMSI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJMSI publishes research articles and reviews within the whole field Mathematics and Statistics, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
An overview of the SABRE project - an integrated laboratory and field investigation with process modelling and performance assessment of DNAPL source zone bioremediation.
Twenty (20) sample regimes were collected for each sample matrix. The samples were pretreated and digested for the determination of selected heavy metals of interest (As, Cd. Cr, Hg, Ni and Pb. The results reveals that mean concentrations of elements in the water samples decreases in the sequence as follows Hg > Ni > Cr> Pb > As > Cd. This clearly confirmed that Hg has the highest concentration followed by Ni, with Cd being the least. The mean concentrations of elements in the cat fish organs flesh, Gills, Kidney and liver of Barkin-Ladi pond water samples are given in table 4 above. The results confirmed the differences of accumulation of element in different catfish organs. The element concentrations in the cat fish samples decreased in the sequence for the flesh as Ni > Cr >Pb > Hg > As > Cd, for the gills Ni > Hg > Cr > Pb > As > Cd, for kidney Ni > Pb > Hg > Cr > As > Cd, for liver Ni > Cr > Cd > Pb > Hg > As. A two-way ANOVA showed that there was no significant difference between the mean concentrations of elements in the organs of the same fish species, while there is significant difference in the mean concentration between the organs of the different fish species investigated. The correlation analysis was carried out to determine the relationship between the concentrations of element in water sample of the study area. The result above reveals that there is a significant correlation between Cd and Pb, and also there is a significant relationship between Cr and Ni elements. While no significant correlation was observed between the other pairs. These implied that the pairs either have the same source or chemical species. Generally, the ponds were shown to be polluted with heavy metals thus the risk of bioconcentration and bioaccumulation of these heavy metals in the aquatic lives, thus endangering human health directly when consumed or through the food chain.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Modeling of Predictive interaction of Water Parameters in Groundwaterijtsrd
The assessment presented in this article is centred on investigating the interaction of turbidity, total suspended solids and total dissolved solids interaction within the water bearing aquifer of Obite to Oboburu communities of Ogba/ Egbema/ Ndoni local government area of Rivers State, Nigeria. Experimental and modeled turbidity, total suspended solids and total dissolved solids investigated are within recommended standard of World Health Organization revealing the reliability of model equation in predicting groundwater parameters distribution upon influence of time, recharge, flow rate. Ottos C. G | Isaac E. O"Modeling of Predictive interaction of Water Parameters in Groundwater" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-3 , April 2018, URL: http://www.ijtsrd.com/papers/ijtsrd11292.pdf http://www.ijtsrd.com/engineering/civil-engineering/11292/modeling-of-predictive-interaction-of-water-parameters-in-groundwater/ottos-c-g
Ocean Acidification: Cause, Impact and mitigationIIT Kanpur
Ocean Acidification and the battle for Carbonate.
In this presentation the points covered are detailed briefing of ocean acidification, its causes, its impact on marine ecosystems and measures to mitigate this.
58 S C I E N T I F I C A M E R I C A N M A R C H 2 0 0 6.docxtroutmanboris
58 S C I E N T I F I C A M E R I C A N M A R C H 2 0 0 6
I
n 1956 Roger Revelle and Hans Suess, geochemists at
the Scripps Institution of Oceanography in California,
pointed out the need to measure carbon dioxide in the
air and ocean so as to obtain “a clearer understanding
of the probable climatic effects of the predicted great indus-
trial production of carbon-dioxide over the next 50 years.”
In other words, they wanted to fi gure out how dire the situ-
ation would be today. That they had to argue the importance
of such observations now seems astonishing, but at the time
scientists did not know for certain whether the carbon diox-
ide spewing out of tailpipes and smokestacks would indeed
accumulate in the atmosphere. Some believed that it would
all be absorbed benignly by the sea or be happily taken up by
growing plants on land.
Revelle and the young researcher he hired for this project,
the late Charles David Keeling, realized that they had to set
up equipment at remote locations, far from local sources and
sinks of carbon dioxide, which would cause the measure-
ments to vary erratically. One spot they chose was about as
far from industrial activity and vegetation as anyone could
get: the South Pole. Another was at a newly established
weather station atop Mauna Loa in Hawaii.
The Mauna Loa monitoring has continued (with just one
brief interruption) from 1958 to this day. Being not so remote
as Antarctica, Hawaii sees carbon dioxide levels rise and fall
sharply in step with the Northern Hemisphere’s growing sea-
son, but at the end of each and every year, the concentration
of this heat-trapping gas always ends up higher than it was 12
Much of the carbon dioxide given off from the burning of fossil fuels goes into the ocean, where it changes the
acid balance of seawater. The r eper cussions for marine lif e may be enor mous B Y S C O T T C . D O N E Y
The Dangers of
F
R
E
D
B
A
V
E
N
D
A
M
M
in
d
e
n
P
ic
tu
re
s
COP YRIGHT 2006 SCIENTIFIC A MERIC A N, INC.
w w w . s c i a m . c o m S C I E N T I F I C A M E R I C A N 59
months before. So it did not take long for the scientifi c com-
munity to realize that Revelle was right—much of the carbon
dioxide released into the atmosphere was destined to remain
there. But his calculations were also correct in showing that
a substantial fraction would end up in the sea. And it was clear
to Revelle long ago that the part that went into the ocean would
fundamentally alter the chemistry of seawater. Unlike some
aspects of climate change, the reality of this effect— essentially
the acidifi cation of the ocean—is not much debated, although
its full implications are just now being revealed.
How Unnatural?
t h e h a l f - c e n t u r y r e c o r d that Keeling produced is
extremely valuable, but it is too short to place the current
situation in context. Scientists have, however, been able to
obtain a longer-term perspe.
Study of Seasonal Variations in Oxygen Consumption of Estuarine Clam, Meretri...ijtsrd
The estuarine clam, Meretrix meretrix was exposed to predetermined seasonal sublethal and lethal concentrations of CdCl2, 2½ H2O for 96 hrs. Experiments were conducted during summer, monsoon and winter by keeping control group of clams. Estuarine water parameters like temperature, pH, salinity, rainfall and dissolved oxygen were recorded. In the present study, it is found that, it has significant influence on rate of oxygen consumption and toxicity of cadmium chloride. During summer, clams from LC0 and LC50 group were treated with 1.1ppm and 1.8 ppm respectively. During monsoon LC0 and LC50 group were treated with 1.6 ppm and 2.0 ppm respectively. During winter clams from LC0 and LC50 group were exposed to 1.4 ppm and 2.1 ppm cadmium chloride respectively. During summer, as compared to control group, there were 3.83, 17.04, 16.77 and 10.63 increase in oxygen uptake at the end of 24, 36, 48, and 60 hrs. There were 0.35, 4.97 and 21.75 decrease at the end of 48, 72, 84 and 96 hrs. Moreover, similar trend of oxygen consumption was observed in LC0 and LC50 .group of clams in winter and monsoon season. During monsoon and winter clams from control group showed similar trend of oxygen uptake with less significant fluctuations. Clams from control group and LC0 and LC50 group showed less oxygen consumption during monsoon than summer and winter. Sanjay Kumbhar "Study of Seasonal Variations in Oxygen Consumption of Estuarine Clam, Meretrix Meretrix (Linnaeus, 1758) after Acute Exposure of Cadmium Chloride" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30543.pdf Paper Url :https://www.ijtsrd.com/biological-science/zoology/30543/study-of-seasonal-variations-in-oxygen-consumption-of-estuarine-clam-meretrix-meretrix-linnaeus-1758-after-acute-exposure-of-cadmium-chloride/sanjay-kumbhar
International Journal of Mathematics and Statistics Invention (IJMSI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJMSI publishes research articles and reviews within the whole field Mathematics and Statistics, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
An overview of the SABRE project - an integrated laboratory and field investigation with process modelling and performance assessment of DNAPL source zone bioremediation.
Twenty (20) sample regimes were collected for each sample matrix. The samples were pretreated and digested for the determination of selected heavy metals of interest (As, Cd. Cr, Hg, Ni and Pb. The results reveals that mean concentrations of elements in the water samples decreases in the sequence as follows Hg > Ni > Cr> Pb > As > Cd. This clearly confirmed that Hg has the highest concentration followed by Ni, with Cd being the least. The mean concentrations of elements in the cat fish organs flesh, Gills, Kidney and liver of Barkin-Ladi pond water samples are given in table 4 above. The results confirmed the differences of accumulation of element in different catfish organs. The element concentrations in the cat fish samples decreased in the sequence for the flesh as Ni > Cr >Pb > Hg > As > Cd, for the gills Ni > Hg > Cr > Pb > As > Cd, for kidney Ni > Pb > Hg > Cr > As > Cd, for liver Ni > Cr > Cd > Pb > Hg > As. A two-way ANOVA showed that there was no significant difference between the mean concentrations of elements in the organs of the same fish species, while there is significant difference in the mean concentration between the organs of the different fish species investigated. The correlation analysis was carried out to determine the relationship between the concentrations of element in water sample of the study area. The result above reveals that there is a significant correlation between Cd and Pb, and also there is a significant relationship between Cr and Ni elements. While no significant correlation was observed between the other pairs. These implied that the pairs either have the same source or chemical species. Generally, the ponds were shown to be polluted with heavy metals thus the risk of bioconcentration and bioaccumulation of these heavy metals in the aquatic lives, thus endangering human health directly when consumed or through the food chain.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Modeling of Predictive interaction of Water Parameters in Groundwaterijtsrd
The assessment presented in this article is centred on investigating the interaction of turbidity, total suspended solids and total dissolved solids interaction within the water bearing aquifer of Obite to Oboburu communities of Ogba/ Egbema/ Ndoni local government area of Rivers State, Nigeria. Experimental and modeled turbidity, total suspended solids and total dissolved solids investigated are within recommended standard of World Health Organization revealing the reliability of model equation in predicting groundwater parameters distribution upon influence of time, recharge, flow rate. Ottos C. G | Isaac E. O"Modeling of Predictive interaction of Water Parameters in Groundwater" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-3 , April 2018, URL: http://www.ijtsrd.com/papers/ijtsrd11292.pdf http://www.ijtsrd.com/engineering/civil-engineering/11292/modeling-of-predictive-interaction-of-water-parameters-in-groundwater/ottos-c-g
Ocean Acidification: Cause, Impact and mitigationIIT Kanpur
Ocean Acidification and the battle for Carbonate.
In this presentation the points covered are detailed briefing of ocean acidification, its causes, its impact on marine ecosystems and measures to mitigate this.
58 S C I E N T I F I C A M E R I C A N M A R C H 2 0 0 6.docxtroutmanboris
58 S C I E N T I F I C A M E R I C A N M A R C H 2 0 0 6
I
n 1956 Roger Revelle and Hans Suess, geochemists at
the Scripps Institution of Oceanography in California,
pointed out the need to measure carbon dioxide in the
air and ocean so as to obtain “a clearer understanding
of the probable climatic effects of the predicted great indus-
trial production of carbon-dioxide over the next 50 years.”
In other words, they wanted to fi gure out how dire the situ-
ation would be today. That they had to argue the importance
of such observations now seems astonishing, but at the time
scientists did not know for certain whether the carbon diox-
ide spewing out of tailpipes and smokestacks would indeed
accumulate in the atmosphere. Some believed that it would
all be absorbed benignly by the sea or be happily taken up by
growing plants on land.
Revelle and the young researcher he hired for this project,
the late Charles David Keeling, realized that they had to set
up equipment at remote locations, far from local sources and
sinks of carbon dioxide, which would cause the measure-
ments to vary erratically. One spot they chose was about as
far from industrial activity and vegetation as anyone could
get: the South Pole. Another was at a newly established
weather station atop Mauna Loa in Hawaii.
The Mauna Loa monitoring has continued (with just one
brief interruption) from 1958 to this day. Being not so remote
as Antarctica, Hawaii sees carbon dioxide levels rise and fall
sharply in step with the Northern Hemisphere’s growing sea-
son, but at the end of each and every year, the concentration
of this heat-trapping gas always ends up higher than it was 12
Much of the carbon dioxide given off from the burning of fossil fuels goes into the ocean, where it changes the
acid balance of seawater. The r eper cussions for marine lif e may be enor mous B Y S C O T T C . D O N E Y
The Dangers of
F
R
E
D
B
A
V
E
N
D
A
M
M
in
d
e
n
P
ic
tu
re
s
COP YRIGHT 2006 SCIENTIFIC A MERIC A N, INC.
w w w . s c i a m . c o m S C I E N T I F I C A M E R I C A N 59
months before. So it did not take long for the scientifi c com-
munity to realize that Revelle was right—much of the carbon
dioxide released into the atmosphere was destined to remain
there. But his calculations were also correct in showing that
a substantial fraction would end up in the sea. And it was clear
to Revelle long ago that the part that went into the ocean would
fundamentally alter the chemistry of seawater. Unlike some
aspects of climate change, the reality of this effect— essentially
the acidifi cation of the ocean—is not much debated, although
its full implications are just now being revealed.
How Unnatural?
t h e h a l f - c e n t u r y r e c o r d that Keeling produced is
extremely valuable, but it is too short to place the current
situation in context. Scientists have, however, been able to
obtain a longer-term perspe.
The carbon regeneration in the water column of
the Cariaco Basin (Venezuela) was investigated
using a regression model of total alkalinity (TA)
and the concentration of total inorganic carbon
(TCO2
). Primary productivity (PP) was determined
from the inorganic carbon fraction assimilated
by phytoplankton and the variation of the 22 and
23°C isotherm was used as an indicator of coastal
upwelling. The results indicate that CO2
levels were
lowest (1962 µmol/kg) at the surface and increased
to 2451 µmol/kg below the oxic-anoxic redox
interface. The vertical regeneration distribution of
carbon was dominated (82%) by organic carbon
originating from the soft tissue of photosynthetic
organisms, whereas 18% originated from the
dissolution of biogenic calcite. The regeneration
of organic carbon was highest in the surface layer
in agreement with the primary productivity values.
However, at the oxic-anoxic interface a second more
intense maximum was detected (70-80%), generated
by chemotrophic respiration of organic material
by microorganisms. The percentages in the anoxic
layers were lower than in the oxic zone because
aerobic decomposition occurs more rapidly than
anaerobic respiration of organic material because
more labile fractions of organic carbon have already
been mineralized in the upper layers.
Miriam Kastner: Her findings on METHANE HYDRATES in Ocean Acidification Summ...www.thiiink.com
Atmospheric carbon dioxide (CO2) levels are rising as a result of human activities, such as fossil fuel burning, and are increasing the acidity of seawater. This process is known as ocean acidi cation. Historically, the ocean has absorbed approximately 30% of all CO2 released into the atmosphere
by humans since the start of the industrial revolution, resulting in a 26% increase in the acidity of the ocean1.
Ocean acidi cation causes ecosystems and marine biodiversity to change. It has the potential to affect food security and it limits the capacity of the ocean to absorb CO2 from human emissions. The economic impact of ocean acidi cation could be substantial.
Reducing CO2 emissions is the only way to minimise long-term, large-scale risks.
The carbon regeneration in the water column of
the Cariaco Basin (Venezuela) was investigated
using a regression model of total alkalinity (TA)
and the concentration of total inorganic carbon
(TCO2). Primary productivity (PP) was determined
from the inorganic carbon fraction assimilated
by phytoplankton and the variation of the 22 and
23°C isotherm was used as an indicator of coastal
upwelling. The results indicate that CO2 levels were
lowest (1962 μmol/kg) at the surface and increased
to 2451 μmol/kg below the oxic-anoxic redox
interface. The vertical regeneration distribution of
carbon was dominated (82%) by organic carbon
originating from the soft tissue of photosynthetic
organisms, whereas 18% originated from the
dissolution of biogenic calcite. The regeneration
of organic carbon was highest in the surface layer
in agreement with the primary productivity values.
However, at the oxic-anoxic interface a second more
intense maximum was detected (70-80%), generated
by chemotrophic respiration of organic material
by microorganisms. The percentages in the anoxic
layers were lower than in the oxic zone because
aerobic decomposition occurs more rapidly than
anaerobic respiration of organic material because
more labile fractions of organic carbon have already
been mineralized in the upper layers.
Chemical Fractionation Modeling of Plumes Indicates a Gas-rich, Moderately Al...Sérgio Sacani
Enceladus harbors an ocean beneath its ice crust that erupts spectacular plumes from fissures at the south pole. The
plume composition was measured by the Cassini spacecraft, and provides evidence for the ocean’s gas content,
salinity, pH, and potential for life. Understanding the ocean’s composition is complicated by physicochemical
processes that alter the plume composition during eruption, such as water vapor condensation in the icy fissures
and gas exsolution from the ocean surface. We developed a model that includes key fractionation processes, in
particular fractionation during gas exsolution, which has not been previously considered. Our model predicts a
moderately alkaline (pH 7.95–9.05), gas-rich ocean (∼10−5
–10−3 molal) with high concentrations of ammonium
ions (10−2
–10−1 molal). Our derived dissolved gas concentrations are higher than in recent studies because we
account for gas exsolution, which depletes gases in the plume compared to the ocean, and because our model
conserves mass flow rates between gas exsolution from the ocean and eruption from the tiger stripe fissures. We
find carbon dioxide and hydrogen concentrations that could provide sufficient chemical energy for oceanic life in
the form of hydrogenotrophic methanogens. Carbon dioxide concentrations of 10−5
–10−3 molal indicate a more
Earth-like pH than the pH ∼8.5–13.5 in previous studies. The inferred bulk ammonium and total inorganic carbon
concentrations are consistent with cometary levels. This corroborates evidence from cometary deuterium-hydrogen
(D/H) ratios that Enceladus formed from comet-like planetesimals. Our results suggest a gas-rich ocean that
inherited its high volatile concentrations from comet-like building blocks
This study aimed to understand the behavior of the carbonate system in the Cananéia-Iguape Estuarine-Lagoon Complex
(CIELC) to evaluate its potential as a source or sink for atmospheric CO2. This estuarine-lagoon complex is one of the most
extensive in Brazil, more than 100 km long and covers protected and sparsely inhabited regions of the state of São Paulo. This
system presents, in its southern portion, most preserved areas, and evident anthropogenic impact in the northern portion,
where an artificial canal was created in the second half of the 19th century, with the aim of shortening the navigation path link
the river to the estuarine system offering a passage to the sea, resulting in several modifications, both from a hydrodynamic
and biogeochemical mechanisms. Sampling of salinity (S), temperature (T), total alkalinity (TA), pH, dissolved oxygen (DO),
and nutrients (P and Si) were performed along the CIELC in the winter of 2012 and in the summer of 2013. S, TA, pH and
nutrients were used to support the understanding the behavior of the species in the carbonate system (CO2
, HCO3
-
, CO3
2-)
and related variables were used to calculating the partial pressure of CO2
(pCO2
). The data showed the difference in salinity
and carbonate members distinguished the northern and southern areas, the influence of the marine waters entrance by the
bars, and the predominance of the system as a source of CO2
, even in the most preserved area. However, the difference in this
behavior is most evident under anthropogenic pression offering risk of extreme changes in direction to the southern sector,
now observed until the intermediate point of the system. The recommendation is an urgency in monitoring this region to
minimizes futures environmental changes, as acidification and the increase as a source of CO2
1. John Sequeira
Oceanic Climate Change and its Organismal Effects
A State of the Art Review on Ocean Acidification
The Acidifying Depths: An Introduction
Considerable coverage has been given to the climate-altering effects of atmospheric CO2
for many years, and it has long been understood that the oceans are an effective CO2 sink. Yet a
deeper awareness of the extensive effects of carbon dioxide on our oceans has been, at times,
slow in coming to fruition. Ocean acidification, a term first coined in 2003 (Caldeira and
Wickett, 2003), might prove to be the most damaging of all of these. Modern laboratory
experimentation and in situ studies suggest that, despite variability among species response and
limitations to research, the effects of ocean acidification “due to historical fossil fuel emissions
will be felt for centuries” (Gattuso et al. 2012). A recent analysis of proxy records show that the
last time ocean acidification occurred at today’s rate was 252 MYA, at the Permo-Triassic
Boundary (Clarkson et al. 2015). It is estimated that 66% of terrestrial and 90% of ocean life
died in the greatest extinction event in the earth’s history.
The Chemistry of Acidification
It is estimated that around 30% of atmospheric CO2 is absorbed by the world’s oceans
(Beaufort et al., 2011). This carbon dioxide can either be photosynthesized by aquatic plants and
algae or result in acidification. Ocean acidification is the process by which the dissolution of
atmospheric carbon dioxide creates a decrease in oceanic pH (Honisch et al., 2015). Upon
dissolution, CO2 reacts with H2O to create carbonic acid (H2CO3). Carbonic acid is then capable
2. of disassociating to form HCO3
- (bicarbonate) which can further disassociate into 𝐶𝑂3
2−
(carbonate ions). Another result of this disassociation is a release of hydrogen ions (H+). pH (-
log H+) is the logarithmic potential to create hydrogen ions with a pH of 7.0 being a baseline.
Any value higher implies that the substance is a base, while lower values mean the substance is
an acid. An increase in H+ thus decreases the water’s pH, further acidifying it from its already
currently decreasing pH of 8.1 (at mid-latitude; the pH has been recorded at below 8.0 around the
equator and Antarctica in certain parts) (Ying et al., 2012). It is important to note that pre-
industrial levels stood at around 8.2; this represents a 30% increase in acidity since the mid-18th
century (Feely et al., 2009).
Acidification and Calcium Carbonate
A major effect of a decrease in pH is a decrease in the availability of calcium carbonate
(CaCO3). CaCO3 is formed from calcium atoms (Ca2
+) and carbonate ions (𝐶𝑂3
2−
) (Bednarsek et
al., 2014). As H+ are released, they recombine with available 𝐶𝑂3
2−
to form bicarbonate, thus
limiting the availability of CaCO3. However, CaCO3 is a crucial component of numerous marine
ecosystems. Aragonite, calcite, and high magnesium calcite are three naturally created
polymorphs of CaCO3, and numerous organisms use them to create and maintain their shells and
skeletons (for research purposes, it is important to note that aragonite is more soluble than calcite
and aragonite saturation rates are). A low CaCO3 saturation state implies that these organisms
(which include crucial groups such as crustaceans, mollusks, and corals) will not only not have
the means to create a secure calcium carbonate covering to protect them from predators, but also
that their rate of calcification will fall below the rising rate of dissolution caused by the more
acidic environment.
3. One such calcium carbonate precipitator is the shelled pteropod. As a planktonic
calcifier, pteropods construct their shells purely of aragonite and are one of the few pelagic
organisms to do so (Bednarsek et al., 2012). Because of this and the higher solubility of
aragonite, they are considered to be strong bioindicators of acidification. Laboratory experiments
in which pteropod samples were exposed to various CaCO3 saturation levels with all other
variables controlled showed that not only did the studied pteropods calcify at a lower rate, but
that their shells also exhibited a much higher dissolution rate when CO2 levels were elevated
(Bednarsek et al., 2014). Sample populations were incubated in tanks for up to 14 days and
exposed to three different levels of saturation (super-, transitional, and undersaturation), which
were created by supplying CO2 in 375, 500, 750, and 1200 ppm mixed ratios. Initial exposure to
undersaturated conditions resulted in immediate shell dissolution at the rate of 1.4% shell mass
per day. Extensive dissolution was apparent in samples held in aragonite-undersaturated tanks
for 14 days.
Figure 6. Dissolution is visible at sites 1, 4, 11, and 14 of the pteropod shell.
4. Increased dissolution and decreased calcification in low CaCO3 saturated waters is not a
guarantee, however. Research shows that though calcifying phytoplankton such as
coccolithophores and foraminifera may face hardship from decreased CaCO3 saturation states
(Pinsonneault et al., 2012), some species may actually increase calcification under particular
circumstances. Planktonic algae known as coccolithophores, “considered to be the most
productive calcifying organisms on Earth,” serve a dual purpose in our oceans (Raven et al.,
2005) (Hutchins, 2011). Through photosynthesis, this phytoplankton assimilates CO2 and
produces organic carbon. However, it can also convert dissolved inorganic carbon (DIC) into
overlapping calcite plates known as coccoliths. Coccolith production is influenced by a number
of factors, including temperature, salinity, and seasonality (i.e. pH levels and CaCO3 saturation
levels are both lowest in the winter). Furthermore, coccolithophore blooms are known to increase
the ocean’s albedo due to the reflective property of coccoliths (Tyrrell, 1999), adding further
import to their study.
In situ observation of E. huxleyi coccolithophores in the Bay of Biscay, a northeastern
Atlantic Ocean gulf off the coast of France, was performed over the course of one year (Smith et
al., 2012). Monthly samples were taken of coccolithophores and seawater carbonate chemistry,
as well as other environmental variables such as DIC and alkalinity levels. Perhaps because
strong related research into coccolithophore response pointed to a positive correlation between
decreased pH and decreased calcification (Beaufort et al., 2011), this study’s researchers put
forth a hypothesis that lightly calcified coccolithophores would dominate winter samples.
However, analysis of the collected data proved the exact opposite to be true. Over 90% of
coccolithophores collected during winter months were heavily calcified; just as markedly, less
than 10% of summer samples, when pH and CaCO3 levels are higher, exhibited the same rate of
5. calcification. Subsequent laboratory testing could not duplicate the results utilizing the same
environmental conditions.
Figure 7. Map A shows the path and timeline of sample collection along the Bay of Biscay.
Box B shows the heavily calcified form of E. huxleyi on the left, with a lesser calcified
sample on the right. Box C shows a heavily calcified coccolith on the left, and a nominally
calcified coccolith on the right. Increased calcification is apparent in the lack of a central hole
and a thickening of spokes connecting the center mass to the outer edge.
A Research Review
The previous study serves to highlight the variability of research results. As noted in the
introduction, ocean acidification has been a subject of study for just over a decade. In situ and
6. laboratory methodologies are both continuously being reworked so as to discover new
correlations and interactions in regard to decreasing global pH. Yet restrictions limit both in their
usefulness and feasibility at times.
A 2013 “snapshot” of then-current research highlighted some worthwhile concerns. The
majority of research then and now has been focused on single species responses (Dupont et al.,
2013). Most laboratory research falls into what the authors term as “stamp collecting”- that is,
experimentation is performed on a single species under very simplistic conditions with changes
generally being introduced to only one or two variables. However, any oceanic ecosystem is in a
state of constant flux, being affected by inflow and outflow of currents, nutrients, organisms, and
myriad other factors. As the above coccolithophore study showed, results that could not have
been predicted through laboratory testing could not be replicated in the lab either. Furthermore,
many studies examined for this paper failed to observe sample populations for multiple
generations. This limited scope in turn limits the possibility of ascertaining whether adaptive
processes can be adopted by a species in time to prevent a catastrophic extinction event.
It is imperative to understand, however, that despite sometimes very wide-ranging
deviations in results, a general consensus does exist. Gattuso, Mach, and Morgan formulated a
detailed survey composed of 22 declarative statements (Gattuso et al., 2012). They submitted this
survey to 53 experts, previously participants in a 2011 IPCC workshop in Okinawa, Japan,
organized by Working Groups I and II.
Results of the survey show that 90% of the experts agree with strong confidence that
ocean acidification caused by anthropogenic fossil fuel activities will continue to alter the
ocean’s chemistry for centuries. 14 of 19 experts knowledgeable on the subject confirmed with
high probability that “assuming business as usual…scenarios, anthropogenic ocean acidification
7. will continue at a rate faster than non-anthropogenic acidification has ever occurred in the past
55 Myr.” 26 of 28 surveyed experts expressed with strong confidence that “the magnitude of
future anthropogenic ocean acidification depends on CO2 pathways.”
Subsequent questions on specific biogeochemical issues achieved less solid consensus.
14 knowledgeable experts confirmed with strong to very strong confidence that acidification will
negatively affect calcification for most calcareous organisms. However, 21 instead placed some
to no confidence in this statement. “Anthropogenic ocean acidification will reduce biodiversity”
was said to be highly probably by four experts, while 14 responded with some or no confidence.
Despite this, 23 respondents placed high to very high probability on the statement that
anthropogenic “acidification will impact biogeochemical processes at the global scale.”
Refinements in research will have to be made to discover global trends related to pH and species
response. In this way, the science can be directed toward creating a more unified knowledge base
of and thus, approach to the issue of ocean acidification. As Dupont and Portner state:
“There is one overarching limitation. There is a lack of idea of and approach to
how the overarching principles of ocean acidification effects can be understood
across organism domains.”
Perhaps when this is accomplished, more relevant research can be performed, and the
results grouped together to be succinctly presented to policy makers and the public. Ocean
acidification may be an old story for Earth, but it is a new one for us and it is our immediate next
few steps which will affect the next millennia.
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