scholarly journals Continuous Monitoring and Future Projection of Ocean Warming, Acidification, and Deoxygenation on the Subarctic Coast of Hokkaido, Japan

2021 ◽  
Vol 8 ◽  
Author(s):  
Masahiko Fujii ◽  
Shintaro Takao ◽  
Takuto Yamaka ◽  
Tomoo Akamatsu ◽  
Yamato Fujita ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Ocean Acidification ◽  
Continuous Monitoring ◽  
Critical Level ◽  
Marine Organisms ◽  
Ocean Warming ◽  
Future Projection ◽  
Do Concentration ◽  
Biogeochemical Parameters ◽  
The Impact

As the ocean absorbs excessive anthropogenic CO2 and ocean acidification proceeds, it is thought to be harder for marine calcifying organisms, such as shellfish, to form their skeletons and shells made of calcium carbonate. Recent studies have suggested that various marine organisms, both calcifiers and non-calcifiers, will be affected adversely by ocean warming and deoxygenation. However, regardless of their effects on calcifiers, the spatiotemporal variability of parameters affecting ocean acidification and deoxygenation has not been elucidated in the subarctic coasts of Japan. This study conducted the first continuous monitoring and future projection of physical and biogeochemical parameters of the subarctic coast of Hokkaido, Japan. Our results show that the seasonal change in biogeochemical parameters, with higher pH and dissolved oxygen (DO) concentration in winter than in summer, was primarily regulated by water temperature. The daily fluctuations, which were higher in the daytime than at night, were mainly affected by daytime photosynthesis by primary producers and respiration by marine organisms at night. Our projected results suggest that, without ambitious commitment to reducing CO2 and other greenhouse gas emissions, such as by following the Paris Agreement, the impact of ocean warming and acidification on calcifiers along subarctic coasts will become serious, exceeding the critical level of high temperature for 3 months in summer and being close to the critical level of low saturation state of calcium carbonate for 2 months in mid-winter, respectively, by the end of this century. The impact of deoxygenation might often be prominent assuming that the daily fluctuation in DO concentration in the future is similar to that at present. The results also suggest the importance of adaptation strategies by local coastal industries, especially fisheries, such as modifying aquaculture styles.

scholarly journals Seasonal calcium carbonate undersaturation in shelf waters of the Western Arctic Ocean; how biological processes exacerbate the impact of ocean acidification

2012 ◽  
Vol 9 (10) ◽  
pp. 14255-14290 ◽  
Author(s):  
N. R. Bates ◽  
M. I. Orchowska ◽  
R. Garley ◽  
J. T. Mathis
Keyword(s):  
Calcium Carbonate ◽  
Ocean Acidification ◽  
Arctic Ocean ◽  
The Arctic ◽  
Biological Processes ◽  
Subsurface Waters ◽  
Bottom Waters ◽  
Western Arctic ◽  
The Impact ◽  
Surface And Subsurface Waters

Abstract. The Arctic Ocean accounts for only 4% of the global ocean area but it contributes significantly to the global carbon cycle. Recent observations of seawater carbonate chemistry in shelf waters of the Western Arctic from 2009 to 2011 indicate that extensive areas of the benthos are exposed to bottom waters that are seasonally undersaturated with respect to calcium carbonate (CaCO3) minerals, particularly aragonite. Our observations indicate seasonal reduction of saturation states (Ω) for calcite (Ωcalcite) and aragonite (Ωaragonite) in the subsurface in the Western Arctic by as much as 0.9 and 0.6, respectively. Such data indicates that bottom waters of the Western Arctic shelves are already potentially corrosive for biogenic and sedimentary CaCO3 for several months each year. Seasonal changes in Ω are imparted by a variety of factors such as phytoplankton photosynthesis, respiration/remineralization of organic matter and air-sea gas exchange of CO2 – combined these processes either increase or enhance Ω in surface and subsurface waters, respectively. These seasonal physical and biological processes also act to mitigate or enhance the impact of Anthropocene ocean acidification (OA) on Ω in surface and subsurface waters, respectively. Future monitoring of the Western Arctic shelves is warranted to assess the present and future impact on Ω values from ocean acidification and seasonal biological/physical processes on Arctic marine ecosystems.

Electrochemical Characteristics of BIS 2062 Carbon Steel Under Simulated Ocean Acidification Scenario

2020 ◽  
Author(s):  
K R DEVIKA ◽  
P MUHAMED ASHRAF
Keyword(s):  
Climate Change ◽  
Carbon Steel ◽  
Ocean Acidification ◽  
Marine Environment ◽  
Research Paper ◽  
Marine Organisms ◽  
Natural Seawater ◽  
Electrochemical Characteristics ◽  
Boat Building ◽  
The Impact

Dear Professor,<div><p>I am herewith enclosing a research paper entitled “<b>Electrochemical characteristics of BIS 2062 carbon steel under simulated ocean acidification scenario.</b>” authored by Devika KR, and me. </p> <p>The research paper highlights the behavior of carbon steel in acidified natural seawater. Ocean acidification is a burning issue under climate change. Several studies have undertaken to understand the behavior marine organisms and marine environment. No studies have initiated regarding the deterioration of materials due to ocean acidification. Large number of materials were deployed in the ocean with different objectives. These materials are under risk as the ocean acidification continues. We believe this is the first attempt to study the impact of ocean acidification on carbon steel. </p> <p>The study conducted to evaluate the impact of ocean acidification on BIS 2062 boat building steel. The results showed that the carbon steel will deteriorate 2 to 3 times higher when pH was changed from 8.05 to 7.90. The data highlights the immediate need to redesign the marine materials within 1-2 decade. The paper also highlights the possible mechanism of deterioration under different pH scenario.</p><p>Thanking you</p><p>Sincerely</p><p>ashrafp</p><br></div>

scholarly journals The Impact of Ocean Acidification on Reproduction, Early Development and Settlement of Marine Organisms

Water ◽  
2011 ◽  
Vol 3 (4) ◽  
pp. 1005-1030 ◽  
Author(s):  
Pauline M. Ross ◽  
Laura Parker ◽  
Wayne A. O’Connor ◽  
Elizabeth A. Bailey
Keyword(s):  
Ocean Acidification ◽  
Early Development ◽  
Marine Organisms ◽  
The Impact

The impact of ocean warming on marine organisms

2014 ◽  
Vol 59 (5-6) ◽  
pp. 468-479 ◽  
Author(s):  
Cui-Luan Yao ◽  
George N. Somero
Keyword(s):  
Marine Organisms ◽  
Ocean Warming ◽  
The Impact

Comparing the impact of high CO2 on calcium carbonate structures in different marine organisms

2011 ◽  
Vol 7 (6) ◽  
pp. 565-575 ◽  
Author(s):  
Helen S. Findlay ◽  
Hannah L. Wood ◽  
Michael A. Kendall ◽  
John I. Spicer ◽  
Richard J. Twitchett ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Marine Organisms ◽  
High Co2 ◽  
The Impact

scholarly journals Calcium carbonate production response to future ocean warming and acidification

2011 ◽  
Vol 8 (6) ◽  
pp. 11863-11897
Author(s):  
A. J. Pinsonneault ◽  
H. D. Matthews ◽  
E. D. Galbraith ◽  
A. Schmittner
Keyword(s):  
Calcium Carbonate ◽  
Co2 Emissions ◽  
Climate Model ◽  
Surface Air Temperature ◽  
Ocean Warming ◽  
Total Carbon ◽  
Global Ocean ◽  
Saturation State ◽  
Carbonate Production ◽  
The Impact

Abstract. Anthropogenic carbon dioxide (CO2) emissions are acidifying the ocean, affecting calcification rates in pelagic organisms and thereby modifying the oceanic alkalinity cycle. However, the responses of pelagic calcifying organisms to acidification vary widely between species, contributing uncertainty to predictions of atmospheric CO2 and the resulting climate change. Meanwhile, ocean warming caused by rising CO2 is expected to drive increased growth rates of all pelagic organisms, including calcifiers. It thus remains unclear whether anthropogenic CO2 will ultimately increase or decrease the globally-integrated pelagic calcification rate. Here, we assess the importance of this uncertainty by introducing a variable dependence of calcium carbonate (CaCO3) production on calcite saturation state (ΩCaCO3) in the University of Victoria Earth System Climate Model, an intermediate complexity coupled carbon-climate model. In a series of model simulations, we examine the impact of this parameterization on global ocean carbon cycling under two CO2 emissions scenarios, both integrated to the year 3500. The simulations show a significant sensitivity of the vertical and surface horizontal alkalinity gradients to the parameterization, as well as the removal of alkalinity from the ocean through CaCO3 burial. These sensitivities result in an additional oceanic uptake of carbon when calcification depends on ΩCaCO3 (of up to 13 % of total carbon emissions), compared to the case where calcification is insensitive to acidification. In turn, this response causes a reduction of global surface air temperature of up to 0.4 °C in year 3500, a 13 % reduction in the amplitude of warming. Narrowing these uncertainties will require better understanding of both temperature and acidification effects on pelagic calcifiers. Preliminary examination suggests that alkalinity observations can be used to constrain the range of uncertainties and may exclude large sensitivities of CaCO3 production on ΩCaCO3.

scholarly journals Summertime calcium carbonate undersaturation in shelf waters of the western Arctic Ocean – how biological processes exacerbate the impact of ocean acidification

2013 ◽  
Vol 10 (8) ◽  
pp. 5281-5309 ◽  
Author(s):  
N. R. Bates ◽  
M. I. Orchowska ◽  
R. Garley ◽  
J. T. Mathis
Keyword(s):  
Calcium Carbonate ◽  
Ocean Acidification ◽  
Arctic Ocean ◽  
Biological Processes ◽  
Western Arctic Ocean ◽  
Subsurface Waters ◽  
Bottom Waters ◽  
Western Arctic ◽  
The Impact ◽  
Surface And Subsurface Waters

Abstract. The Arctic Ocean accounts for only 4% of the global ocean area, but it contributes significantly to the global carbon cycle. Recent observations of seawater CO2-carbonate chemistry in shelf waters of the western Arctic Ocean, primarily in the Chukchi Sea, from 2009 to 2011 indicate that bottom waters are seasonally undersaturated with respect to calcium carbonate (CaCO3) minerals, particularly aragonite. Nearly 40% of sampled bottom waters on the shelf have saturation states less than one for aragonite (i.e., Ωaragonite < 1.0), thereby exposing the benthos to potentially corrosive water for CaCO3-secreting organisms, while 80% of bottom waters present had Ωaragonite values less than 1.5. Our observations indicate seasonal reduction of saturation states (Ω) for calcite (Ωcalcite) and aragonite (Ωaragonite) in the subsurface in the western Arctic by as much as 0.8 and 0.5, respectively. Such data indicate that bottom waters of the western Arctic shelves were already potentially corrosive for biogenic and sedimentary CaCO3 for several months each year. Seasonal changes in Ω are imparted by a variety of factors such as phytoplankton photosynthesis, respiration/remineralization of organic matter and air–sea gas exchange of CO2. Combined, these processes either increase or enhance in surface and subsurface waters, respectively. These seasonal physical and biological processes also act to mitigate or enhance the impact of Anthropocene ocean acidification (OA) on Ω in surface and subsurface waters, respectively. Future monitoring of the western Arctic shelves is warranted to assess the present and future impact of ocean acidification and seasonal physico-biogeochemical processes on Ω values and Arctic marine ecosystems.

scholarly journals Electrochemical Characteristics of BIS 2062 Carbon Steel Under Simulated Ocean Acidification Scenario

2020 ◽  
Author(s):  
K R DEVIKA ◽  
P MUHAMED ASHRAF
Keyword(s):  
Climate Change ◽  
Carbon Steel ◽  
Ocean Acidification ◽  
Marine Environment ◽  
Research Paper ◽  
Marine Organisms ◽  
Natural Seawater ◽  
Electrochemical Characteristics ◽  
Boat Building ◽  
The Impact

Dear Professor,<div><p>I am herewith enclosing a research paper entitled “<b>Electrochemical characteristics of BIS 2062 carbon steel under simulated ocean acidification scenario.</b>” authored by Devika KR, and me. </p> <p>The research paper highlights the behavior of carbon steel in acidified natural seawater. Ocean acidification is a burning issue under climate change. Several studies have undertaken to understand the behavior marine organisms and marine environment. No studies have initiated regarding the deterioration of materials due to ocean acidification. Large number of materials were deployed in the ocean with different objectives. These materials are under risk as the ocean acidification continues. We believe this is the first attempt to study the impact of ocean acidification on carbon steel. </p> <p>The study conducted to evaluate the impact of ocean acidification on BIS 2062 boat building steel. The results showed that the carbon steel will deteriorate 2 to 3 times higher when pH was changed from 8.05 to 7.90. The data highlights the immediate need to redesign the marine materials within 1-2 decade. The paper also highlights the possible mechanism of deterioration under different pH scenario.</p><p>Thanking you</p><p>Sincerely</p><p>ashrafp</p><br></div>

scholarly journals Ocean acidification but not warming alters sex determination in the Sydney rock oyster, Saccostrea glomerata

2018 ◽  
Vol 285 (1872) ◽  
pp. 20172869 ◽  
Author(s):  
Laura M. Parker ◽  
Wayne A. O'Connor ◽  
Maria Byrne ◽  
Michael Dove ◽  
Ross A. Coleman ◽  
...  
Keyword(s):  
Sex Determination ◽  
Ocean Acidification ◽  
Sex Ratios ◽  
Marine Organisms ◽  
Reproductive Capacity ◽  
Larval Supply ◽  
Rock Oyster ◽  
Saccostrea Glomerata ◽  
The Impact

Whether sex determination of marine organisms can be altered by ocean acidification and warming during this century remains a significant, unanswered question. Here, we show that exposure of the protandric hermaphrodite oyster, Saccostrea glomerata to ocean acidification, but not warming, alters sex determination resulting in changes in sex ratios. After just one reproductive cycle there were 16% more females than males. The rate of gametogenesis, gonad area, fecundity, shell length, extracellular pH and survival decreased in response to ocean acidification. Warming as a sole stressor slightly increased the rate of gametogenesis, gonad area and fecundity, but this increase was masked by the impact of ocean acidification at a level predicted for this century. Alterations to sex determination, sex ratios and reproductive capacity will have flow on effects to reduce larval supply and population size of oysters and potentially other marine organisms.

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