Present and future changes in seawater chemistry due to ocean acidification

Abstract. Although future changes in the seawater carbonate chemistry are well constrained, their impact on marine organisms and ecosystems remains poorly known. The biological response to ocean acidification is a recent field of research as most purposeful experiments have only been carried out in the late 1990s. The potentially dire consequences of ocean acidification attract scientists and students with a limited knowledge of the carbonate chemistry and its experimental manipulation. Hence, some guidelines on carbonate chemistry manipulations may be helpful for the growing ocean acidification community to maintain comparability. Perturbation experiments are one of the key approaches used to investigate the biological response to elevated pCO2. They are based on measurements of physiological or metabolic processes in organisms and communities exposed to seawater with normal or altered carbonate chemistry. Seawater chemistry can be manipulated in different ways depending on the facilities available and on the question being addressed. The goal of this paper is (1) to examine the benefits and drawbacks of various manipulation techniques and (2) to describe a new version of the R software package seacarb which includes new functions aimed at assisting the design of ocean acidification perturbation experiments. Three approaches closely mimic the on-going and future changes in the seawater carbonate chemistry: gas bubbling, addition of high-CO2 seawater as well as combined additions of acid and bicarbonate and/or carbonate.

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Exploring B/Ca as a pH proxy in bivalves: relationships between <i>Mytilus californianus</i> B/Ca and environmental data from the northeast Pacific

Biogeosciences Discussions ◽

10.5194/bgd-8-5587-2011 ◽

2011 ◽

Vol 8 (3) ◽

pp. 5587-5616 ◽

Cited By ~ 4

Author(s):

S. J. McCoy ◽

L. F. Robinson ◽

C. A. Pfister ◽

J. T. Wootton ◽

N. Shimizu

Keyword(s):

Ocean Acidification ◽

Water Chemistry ◽

Growth Rates ◽

Environmental Parameters ◽

Environmental Data ◽

Mytilus Californianus ◽

Seawater Chemistry ◽

Northeast Pacific ◽

Ion Probe ◽

Seawater Environment

Abstract. A distinct gap in our ability to understand changes in coastal biology that may be associated with recent ocean acidification is the paucity of directly measured ocean environmental parameters at coastal sites in recent decades. Thus, many researchers have turned to sclerochronological reconstructions of water chemistry to document the historical seawater environment. In this study, we explore the relationships between B/Ca and pH to test the feasibility of B/Ca measured on the ion probe as a pH proxy in the California mussel, Mytilus californianus. We compare the M. californianus B/Ca record to directly measured environmental data during mussel growth 1999–2009 to determine the correlation between B/Ca and seawater chemistry and discuss methods for assigning sample chronology when sampling an organism with variable growth rates.

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Applying organized scepticism to ocean acidification research

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw010 ◽

2016 ◽

Vol 73 (3) ◽

pp. 529-536 ◽

Cited By ~ 45

Author(s):

Howard I. Browman

Keyword(s):

Ocean Acidification ◽

Science Studies ◽

The Body ◽

Marine Science ◽

Negative Effects ◽

Theme Issue ◽

Seawater Chemistry ◽

History Of Research ◽

History Of ◽

Do So

Abstract “Ocean acidification” (OA), a change in seawater chemistry driven by increased uptake of atmospheric CO2 by the oceans, has probably been the most-studied single topic in marine science in recent times. The majority of the literature on OA report negative effects of CO2 on organisms and conclude that OA will be detrimental to marine ecosystems. As is true across all of science, studies that report no effect of OA are typically more difficult to publish. Further, the mechanisms underlying the biological and ecological effects of OA have received little attention in most organismal groups, and some of the key mechanisms (e.g. calcification) are still incompletely understood. For these reasons, the ICES Journal of Marine Science solicited contributions to this special issue. In this introduction, I present a brief overview of the history of research on OA, call for a heightened level of organized (academic) scepticism to be applied to the body of work on OA, and briefly present the 44 contributions that appear in this theme issue. OA research has clearly matured, and is continuing to do so. We hope that our readership will find that, when taken together, the articles that appear herein do indeed move us “Towards a broader perspective on ocean acidification research”.

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Mangrove habitats provide refuge from climate change for reef-building corals

Biogeosciences Discussions ◽

10.5194/bgd-11-5053-2014 ◽

2014 ◽

Vol 11 (3) ◽

pp. 5053-5088 ◽

Cited By ~ 3

Author(s):

K. K. Yates ◽

C. S. Rogers ◽

J. J. Herlan ◽

G. R. Brooks ◽

N. A. Smiley ◽

...

Keyword(s):

Climate Change ◽

Ocean Acidification ◽

Coral Bleaching ◽

Anthropogenic Impacts ◽

Management Strategies ◽

Reef Coral ◽

Scleractinian Corals ◽

Seawater Chemistry ◽

Recent Climate ◽

Resiliency Factors

Abstract. Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business as usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef, coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove–coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove shaded and exposed (unshaded) areas. At least 33 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies was living shaded by mangroves, and no shaded colonies bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies bleached. A combination of substrate and habitat heterogeniety, proximity of different habitat types, hydrographic conditions, and biological influences on seawater chemistry generate chemical conditions that buffer against ocean acidification. This previously undocumented refuge for corals provides evidence for adaptation of coastal organisms and ecosystem transition due to recent climate change. Identifying and protecting other natural, non-reef coral refuges is critical for sustaining corals and other reef species into the future.

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Revisiting four scientific debates in ocean acidification research

Biogeosciences ◽

10.5194/bg-9-893-2012 ◽

2012 ◽

Vol 9 (3) ◽

pp. 893-905 ◽

Cited By ~ 78

Author(s):

A. J. Andersson ◽

F. T. Mackenzie

Keyword(s):

Ocean Acidification ◽

Shallow Water ◽

Experimental Manipulation ◽

Mineral Dissolution ◽

Negative Effects ◽

Saturation State ◽

Seawater Chemistry ◽

Co2 Gas ◽

Scientific Investigations ◽

Scientific Debates

Abstract. In recent years, ocean acidification has gained continuously increasing attention from scientists and a number of stakeholders and has raised serious concerns about its effects on marine organisms and ecosystems. With the increase in interest, funding resources, and the number of scientific investigations focusing on this environmental problem, increasing amounts of data and results have been produced, and a progressively growing and more rigorous understanding of this problem has begun to develop. Nevertheless, there are still a number of scientific debates, and in some cases misconceptions, that keep reoccurring at a number of forums in various contexts. In this article, we revisit four of these topics that we think require further thoughtful consideration including: (1) surface seawater CO2 chemistry in shallow water coastal areas, (2) experimental manipulation of marine systems using CO2 gas or by acid addition, (3) net versus gross calcification and dissolution, and (4) CaCO3 mineral dissolution and seawater buffering. As a summation of these topics, we emphasize that: (1) many coastal environments experience seawater pCO2 that is significantly higher than expected from equilibrium with the atmosphere and is strongly linked to biological processes; (2) addition of acid, base or CO2 gas to seawater can all be useful techniques to manipulate seawater chemistry in ocean acidification experiments; (3) estimates of calcification or CaCO3 dissolution based on present techniques are measuring the net of gross calcification and dissolution; and (4) dissolution of metastable carbonate mineral phases will not produce sufficient alkalinity to buffer the pH and carbonate saturation state of shallow water environments on timescales of decades to hundreds of years to the extent that any potential negative effects on marine calcifiers will be avoided.

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Technical Note: Approaches and software tools to investigate the impact of ocean acidification

Biogeosciences ◽

10.5194/bg-6-2121-2009 ◽

2009 ◽

Vol 6 (10) ◽

pp. 2121-2133 ◽

Cited By ~ 109

Author(s):

J.-P. Gattuso ◽

H. Lavigne

Keyword(s):

Ocean Acidification ◽

Biological Response ◽

Experimental Manipulation ◽

Technical Note ◽

Carbonate Chemistry ◽

R Software ◽

Seawater Chemistry ◽

Seawater Carbonate Chemistry ◽

Gas Bubbling ◽

The Impact

Abstract. Although future changes in the seawater carbonate chemistry are well constrained, their impact on marine organisms and ecosystems remains poorly known. The biological response to ocean acidification is a recent field of research as most purposeful experiments have only been carried out in the late 1990s. The potentially dire consequences of ocean acidification attract scientists and students with a limited knowledge of the carbonate chemistry and its experimental manipulation. Hence, some guidelines on carbonate chemistry manipulations may be helpful for the growing ocean acidification community to maintain comparability. Perturbation experiments are one of the key approaches used to investigate the biological response to elevated pCO2. They are based on measurements of physiological or metabolic processes in organisms and communities exposed to seawater with normal or altered carbonate chemistry. Seawater chemistry can be manipulated in different ways depending on the facilities available and on the question being addressed. The goal of this paper is (1) to examine the benefits and drawbacks of various manipulation techniques and (2) to describe a new version of the R software package seacarb which includes new functions aimed at assisting the design of ocean acidification perturbation experiments. Three approaches closely mimic the on-going and future changes in the seawater carbonate chemistry: gas bubbling, addition of high-CO2 seawater as well as combined additions of acid and bicarbonate and/or carbonate.

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Chemical characterization of the Punta de Fuencaliente CO<sub>2</sub>-enriched system (La Palma, NE Atlantic Ocean): a new natural laboratory for ocean acidification studies

Biogeosciences ◽

10.5194/bg-18-1673-2021 ◽

2021 ◽

Vol 18 (5) ◽

pp. 1673-1687

Author(s):

Sara González-Delgado ◽

David González-Santana ◽

Magdalena Santana-Casiano ◽

Melchor González-Dávila ◽

Celso A. Hernández ◽

...

Keyword(s):

Ocean Acidification ◽

Marine Ecosystem ◽

Chemical Characterization ◽

Seawater Chemistry ◽

Volcanic Origin ◽

La Palma ◽

Ne Atlantic Ocean ◽

Marine Realm ◽

Carbon Dioxide Co2

Abstract. We present a new natural carbon dioxide (CO2) system located off the southern coast of the island of La Palma (Canary Islands, Spain). Like CO2 seeps, these CO2 submarine groundwater discharges (SGDs) can be used as an analogue to study the effects of ocean acidification (OA) on the marine realm. With this aim, we present the chemical characterization of the area, describing the carbon system dynamics, by measuring pH, AT and CT and calculating Ω aragonite and calcite. Our explorations of the area have found several emission points with similar chemical features. Here, the CT varies from 2120.10 to 10 784.84 µmol kg−1, AT from 2415.20 to 10 817.12 µmol kg−1, pH from 7.12 to 8.07, Ω aragonite from 0.71 to 4.15 and Ω calcite from 1.09 to 6.49 units. Also, the CO2 emission flux varies between 2.8 and 28 kg CO2 d−1, becoming a significant source of carbon. These CO2 emissions, which are of volcanic origin, acidify the brackish groundwater that is discharged to the coast and alter the local seawater chemistry. Although this kind of acidified system is not a perfect image of future oceans, this area of La Palma is an exceptional spot to perform studies aimed at understanding the effect of different levels of OA on the functioning of marine ecosystems. These studies can then be used to comprehend how life has persisted through past eras, with higher atmospheric CO2, or to predict the consequences of present fossil fuel usage on the marine ecosystem of the future oceans.

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Ocean pH fluctuations affect mussel larvae at key developmental transitions

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.2381 ◽

2018 ◽

Vol 285 (1893) ◽

pp. 20182381 ◽

Cited By ~ 19

Author(s):

L. Kapsenberg ◽

A. Miglioli ◽

M. C. Bitter ◽

E. Tambutté ◽

R. Dumollard ◽

...

Keyword(s):

Ocean Acidification ◽

Larval Development ◽

Shell Growth ◽

Larval Shell ◽

Abnormal Development ◽

Life History Stage ◽

Carbonate Chemistry ◽

Developmental Processes ◽

Seawater Chemistry ◽

The Impact

Coastal marine ecosystems experience dynamic fluctuations in seawater carbonate chemistry. The importance of this variation in the context of ocean acidification requires knowing what aspect of variability biological processes respond to. We conducted four experiments (ranging from 3 to 22 days) with different variability regimes (pH T 7.4–8.1) assessing the impact of diel fluctuations in carbonate chemistry on the early development of the mussel Mytilus galloprovincialis . Larval shell growth was consistently correlated to mean exposures, regardless of variability regimes, indicating that calcification responds instantaneously to seawater chemistry. Larval development was impacted by timing of exposure, revealing sensitivity of two developmental processes: development of the shell field, and transition from the first to the second larval shell. Fluorescent staining revealed developmental delay of the shell field at low pH, and abnormal development thereof was correlated with hinge defects in D-veligers. This study shows, for the first time, that ocean acidification affects larval soft-tissue development, independent from calcification. Multiple developmental processes additively underpin the teratogenic effect of ocean acidification on bivalve larvae. These results explain why trochophores are the most sensitive life-history stage in marine bivalves and suggest that short-term variability in carbonate chemistry can impact early larval development.

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Diverse coral communities in mangrove habitats suggest a novel refuge from climate change

Biogeosciences ◽

10.5194/bg-11-4321-2014 ◽

2014 ◽

Vol 11 (16) ◽

pp. 4321-4337 ◽

Cited By ~ 28

Author(s):

K. K. Yates ◽

C. S. Rogers ◽

J. J. Herlan ◽

G. R. Brooks ◽

N. A. Smiley ◽

...

Keyword(s):

Climate Change ◽

Ocean Acidification ◽

Coral Bleaching ◽

Anthropogenic Impacts ◽

Management Strategies ◽

Reef Coral ◽

Scleractinian Corals ◽

Seawater Chemistry ◽

Recent Climate ◽

Resiliency Factors

Abstract. Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business-as-usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove–coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality, and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove-shaded and exposed (unshaded) areas. Over 30 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies were living shaded by mangroves, and no shaded colonies were bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies were bleached. A combination of substrate and habitat heterogeneity, proximity of different habitat types, hydrographic conditions, and biological influences on seawater chemistry generate chemical conditions that buffer against ocean acidification. This previously undocumented refuge for corals provides evidence for adaptation of coastal organisms and ecosystem transition due to recent climate change. Identifying and protecting other natural, non-reef coral refuges is critical for sustaining corals and other reef species into the future.

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Ocean acidification impacts on coastal ecosystem services due to habitat degradation

Emerging Topics in Life Sciences ◽

10.1042/etls20180117 ◽

2019 ◽

Vol 3 (2) ◽

pp. 197-206 ◽

Cited By ~ 26

Author(s):

Jason M. Hall-Spencer ◽

Ben P. Harvey

Keyword(s):

Ocean Acidification ◽

Carbon Dioxide Emissions ◽

Habitat Degradation ◽

Scale Up ◽

Rapid Change ◽

Coastal Protection ◽

Seawater Chemistry ◽

Goods And Services ◽

The Tropics ◽

Fossil Fuel Emissions

Abstract The oceanic uptake of anthropogenic carbon dioxide emissions is changing seawater chemistry in a process known as ocean acidification. The chemistry of this rapid change in surface waters is well understood and readily detectable in oceanic observations, yet there is uncertainty about the effects of ocean acidification on society since it is difficult to scale-up from laboratory and mesocosm tests. Here, we provide a synthesis of the likely effects of ocean acidification on ecosystem properties, functions and services based on observations along natural gradients in pCO2. Studies at CO2 seeps worldwide show that biogenic habitats are particularly sensitive to ocean acidification and that their degradation results in less coastal protection and less habitat provisioning for fisheries. The risks to marine goods and services amplify with increasing acidification causing shifts to macroalgal dominance, habitat degradation and a loss of biodiversity at seep sites in the tropics, the sub-tropics and on temperate coasts. Based on this empirical evidence, we expect ocean acidification to have serious consequences for the millions of people who are dependent on coastal protection, fisheries and aquaculture. If humanity is able to make cuts in fossil fuel emissions, this will reduce costs to society and avoid the changes in coastal ecosystems seen in areas with projected pCO2 levels. A binding international agreement for the oceans should build on the United Nations Sustainable Development Goal to ‘minimise and address the impacts of ocean acidification’.

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