scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Future ocean acidification will be amplified by hypoxia in coastal habitats

01 Nov 2013-Marine Biology (Springer Berlin Heidelberg)-Vol. 160, Iss: 8, pp 1875-1888
TL;DR: Coastal ocean acidification experimental designs need to be closely adjusted to carbonate system variability within the specific habitat, as the magnitude of expected changes in pCO2 in these regions indicates that coastal systems may be more endangered by future global climate change than previously thought.
Abstract: Ocean acidification is elicited by anthropogenic carbon dioxide emissions and resulting oceanic uptake of excess CO2 and might constitute an abiotic stressor powerful enough to alter marine ecosystem structures. For surface waters in gas-exchange equilibrium with the atmosphere, models suggest increases in CO2 partial pressure (pCO2) from current values of ca. 390 μatm to ca. 700–1,000 μatm by the end of the century. However, in typically unequilibrated coastal hypoxic regions, much higher pCO2 values can be expected, as heterotrophic degradation of organic material is necessarily related to the production of CO2 (i.e., dissolved inorganic carbon). Here, we provide data and estimates that, even under current conditions, maximum pCO2 values of 1,700–3,200 μatm can easily be reached when all oxygen is consumed at salinities between 35 and 20, respectively. Due to the nonlinear nature of the carbonate system, the approximate doubling of seawater pCO2 in surface waters due to ocean acidification will most strongly affect coastal hypoxic zones as pCO2 during hypoxia will increase proportionally: we calculate maximum pCO2 values of ca. 4,500 μatm at a salinity of 20 (T = 10 °C) and ca. 3,400 μatm at a salinity of 35 (T = 10 °C) when all oxygen is consumed. Upwelling processes can bring these CO2-enriched waters in contact with shallow water ecosystems and may then affect species performance there as well. We conclude that (1) combined stressor experiments (pCO2 and pO2) are largely missing at the moment and that (2) coastal ocean acidification experimental designs need to be closely adjusted to carbonate system variability within the specific habitat. In general, the worldwide spread of coastal hypoxic zones also simultaneously is a spread of CO2-enriched zones. The magnitude of expected changes in pCO2 in these regions indicates that coastal systems may be more endangered by future global climate change than previously thought.
Citations
More filters
Journal ArticleDOI
TL;DR: In this paper, the authors argue that ocean acidification from anthropogenic CO2 emissions is largely an open ocean syndrome and that a concept of anthro- pogenic impacts on marine pH, which is applicable across the entire ocean, from coastal to open-ocean environments, provides a superior framework to consider the multiple components of the anthropogenic perturbation of marine pH trajectories.
Abstract: Ocean acidification due to anthropogenic CO2 emissions is a dominant driver of long-term changes in pH in the open ocean, raising concern for the future of calcifying organisms, many of which are present in coastal habitats. However, changes in pH in coastal ecosystems result from a multitude of drivers, including impacts from watershed pro- cesses, nutrient inputs, and changes in ecosystem structure and metabolism. Interaction between ocean acidification due to anthropogenic CO2 emissions and the dynamic regional to local drivers of coastal ecosystems have resulted in complex regulation of pH in coastal waters. Changes in the watershed can, for example, lead to changes in alkalinity and CO2 fluxes that, together with metabolic processes and oceanic dynamics, yield high-magnitude decadal changes of up to 0.5 units in coastal pH. Metabolism results in strong diel to seasonal fluctuations in pH, with characteristic ranges of 0.3 pH units, with metabolically intense habitats exceeding this range on a daily basis. The intense variability and multiple, complex controls on pH implies that the concept of ocean acidification due to anthropogenic CO2 emissions cannot be transposed to coastal ecosystems directly. Furthermore, in coastal ecosys- tems, the detection of trends towards acidification is not trivial and the attribution of these changes to anthropogenic CO2 emissions is even more problematic. Coastal ecosystems may show acidification or basification, depending on the balance betweenthe invasionof coastal waters byanthropogenic CO2, watershed export of alkalinity, organic matter and CO2 ,a nd changes in the balance between primary production, respira- tion and calcification rates in response to changes in nutrient inputs and losses of ecosystem components. Hence, we contend that ocean acidification from anthropogenic CO2 is largely an open-ocean syndrome and that a concept of anthro- pogenic impacts on marine pH, which is applicable across the entire ocean, from coastal to open-ocean environments, provides a superior framework to consider the multiple components of the anthropogenic perturbation of marine pH trajectories. The concept of anthropogenic impacts on seawater pH acknowledges that a regional focus is neces- sary to predict future trajectories in the pH of coastal waters and points at opportunities to manage these trajec- tories locally to conserve coastal organisms vulnerable to ocean acidification.

575 citations


Cites background from "Future ocean acidification will be ..."

  • ...…Table 2), driven by the metabolic signal to seasonal and decadal oscillations with amplitudes >0.3 pH units (e.g. Borges and Gypens 2010; Provoost et al. 2010; Barton et al. 2012; Cai et al. 2011; Hofmann et al. 2011; Mercado and Gordillo 2011; Waldbusser et al. 2011; Melzner et al. 2013; Fig....

    [...]

Journal ArticleDOI
TL;DR: The find that multi-stressor experiments have rarely incorporated naturalistic physicochemical variation into their designs, and the importance of doing so to make ecologically relevant inferences about physiological responses to global change is emphasized.
Abstract: Abiotic conditions (e.g., temperature and pH) fluctuate through time in most marine environments, sometimes passing intensity thresholds that induce physiological stress. Depending on habitat and season, the peak intensity of different abiotic stressors can occur in or out of phase with one another. Thus, some organisms are exposed to multiple stressors simultaneously, whereas others experience them sequentially. Understanding these physicochemical dynamics is critical because how organisms respond to multiple stressors depends on the magnitude and relative timing of each stressor. Here, we first discuss broad patterns of covariation between stressors in marine systems at various temporal scales. We then describe how these dynamics will influence physiological responses to multi-stressor exposures. Finally, we summarize how multi-stressor effects are currently assessed. We find that multi-stressor experiments have rarely incorporated naturalistic physicochemical variation into their designs, and emphasize the importance of doing so to make ecologically relevant inferences about physiological responses to global change.

425 citations

Journal ArticleDOI
TL;DR: It is concluded that benthic stages of M. edulis tolerate high ambient pCO2 when food supply is abundant and that important habitat characteristics such as species interactions and energy availability need to be considered to predict species vulnerability to ocean acidification.
Abstract: Ocean acidification is expected to decrease calcification rates of bivalves. Nevertheless in many coastal areas high pCO2 variability is encountered already today. Kiel Fjord (Western Baltic Sea) is a brackish (12-20 g kg-1) and CO2 enriched habitat, but the blue mussel Mytilus edulis dominates the benthic community. In a coupled field and laboratory study we examined the annual pCO2 variability in this habitat and the combined effects of elevated pCO2 and food availability on juvenile M. edulis growth and calcification. In the laboratory experiment, mussel growth and calcification were found to chiefly depend on food supply, with only minor impacts of pCO2 up to 3350 μatm. Kiel Fjord was characterized by strong seasonal pCO2 variability. During summer, maximal pCO2 values of 2500 μatm were observed at the surface and >3000 μatm at the bottom. However, the field growth experiment revealed seven times higher growth and calcification rates of M. edulis at a high pCO2 inner fjord field station (mean pCO2 ca. 1000 μatm) in comparison to a low pCO2 outer fjord station (ca. 600 μatm). In addition, mussels were able to outcompete the barnacle Amphibalanus improvisus at the high pCO2 site. High mussel productivity at the inner fjord site was enabled by higher particulate organic carbon concentrations. Kiel Fjord is highly impacted by eutrophication, which causes bottom water hypoxia and consequently high seawater pCO2. At the same time, elevated nutrient concentrations increase the energy availability for filter feeding organisms such as mussels. Thus M. edulis can dominate over a seemingly more acidification resistant species such as A. improvisus. We conclude that benthic stages of M. edulis tolerate high ambient pCO2 when food supply is abundant and that important habitat characteristics such as species interactions and energy availability need to be considered to predict species vulnerability to ocean acidification.

405 citations


Cites background from "Future ocean acidification will be ..."

  • ...In Kiel Fjord, high seawater pCO2 results from aerobic degradation of organic matter in the water masses below the thermocline, an effect which is enhanced by strong eutrophication during the last 50 years (Babenerd, 1991; Melzner et al. 2012)....

    [...]

  • ...Shallow temperate estuaries such as the Western Baltic Sea, with a strong seasonal vertical stratification due to salinity and tem- perature gradients are characterized by higher and more fluctuating seawater pCO2 (Thomsen et al., 2010; Melzner et al., 2012, Haynert et al., 2012)....

    [...]

  • ...Future ocean acidification might lead to very high summer and autumn seawater pCO2 in such habitats, with regular occurrence of pCO2 levels >2000 latm likely by the year 2100 (Melzner et al., 2012)....

    [...]

  • ...Future ocean acidification might lead to very high summer and autumn seawater pCO2 in such habitats, with regular occurrence of pCO2 levels >2000 latm likely by the year 2100 (Melzner et al., 2012)....

    [...]

  • ...In Kiel Fjord, high seawater pCO2 results from aerobic degradation of organic matter in the water masses below the thermo- cline, an effect which is enhanced by strong eutrophica- tion during the last 50 years (Babenerd, 1991; Melzner et al. 2012)....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the potential for acidification in eutrophic estuaries was assessed during the onset, peak, and demise of low oxygen conditions in systems across the northeast US including Narragansett Bay (RI), Long Island Sound (CT-NY), Jamaica Bay (NY), and Hempstead Bay ( NY).
Abstract: Increased nutrient loading into estuaries causes the accumulation of algal biomass, and microbial degradation of this organic matter decreases oxygen levels and contributes towards hypoxia. A second, often overlooked consequence of microbial degradation of organic matter is the production of carbon dioxide (CO 2 ) and a lowering of seawater pH. To assess the potential for acidification in eutrophic estuaries, the levels of dissolved oxygen (DO), pH, the partial pressure of carbon dioxide ( p CO 2 ), and the saturation state for aragonite ( Ω aragonite ) were horizontally and vertically assessed during the onset, peak, and demise of low oxygen conditions in systems across the northeast US including Narragansett Bay (RI), Long Island Sound (CT–NY), Jamaica Bay (NY), and Hempstead Bay (NY). Low pH conditions ( p CO 2 , (>3000 μatm), were acidic pH ( Ω aragonite

400 citations

Journal ArticleDOI
TL;DR: The present review presents a clear message that ocean acidification may cause significant effects on fish across multiple physiological systems, suggesting that pH compensation does not necessarily confer tolerance as downstream consequences and tradeoffs occur.
Abstract: Most fish studied to date efficiently compensate for a hypercapnic acid-base disturbance; however, many recent studies examining the effects of ocean acidification on fish have documented impacts a...

359 citations

References
More filters
01 Jan 2007
TL;DR: The first volume of the IPCC's Fourth Assessment Report as mentioned in this paper was published in 2007 and covers several topics including the extensive range of observations now available for the atmosphere and surface, changes in sea level, assesses the paleoclimatic perspective, climate change causes both natural and anthropogenic, and climate models for projections of global climate.
Abstract: This report is the first volume of the IPCC's Fourth Assessment Report. It covers several topics including the extensive range of observations now available for the atmosphere and surface, changes in sea level, assesses the paleoclimatic perspective, climate change causes both natural and anthropogenic, and climate models for projections of global climate.

32,826 citations

Book
01 Jan 2007
TL;DR: In this article, the authors present a historical overview of climate change science, including changes in atmospheric constituents and radiative forcing, as well as changes in snow, ice, and frozen ground.
Abstract: Summary for policymakers -- Technical summary -- Historical overview of climate change science -- Changes in atmospheric constituents and radiative forcing -- Observations: atmospheric surface and climate change -- Observations: changes in snow, ice, and frozen ground -- Observations: ocean climate change and sea level -- Paleoclimate -- Coupling between changes in the climate system and biogeochemistry -- Climate models and their evaluation -- Understanding and attributing climate change -- Global climate projections -- Regional climate projections -- Annex I: Glossary -- Annex II: Contributors to the IPCC WGI Fourth Assessment Report -- Annex III: Reviewers of the IPCC WGI Fourth Assessment Report -- Annex IV: Acronyms.

7,738 citations

BookDOI
27 Jan 1999
TL;DR: The Automatic Determination of Dissolved Organic Carbon (DOC) by Wet Chemical Oxidation is described in this paper, along with the results of HPLC analysis of photosynthetic pigments.
Abstract: Sampling and Sampling Techniques. Filtration and Storage. Determination of Salinity. Determination of Oxygen. Determination of Hydrogen Sulphide. Determination of Thiosulphate and Sulfur. Determination of pH. Determination of Alkalinity and Total Carbonate. Determination of pCO2. Determination of Nutrients. Determination of Major Constituents. Determination of Trace Elements. Determination of Natural Radioactive Tracers. In Situ Registration of pH and Oxygen. Determination of Dissolved Organic Carbon (DOC) by High Temperature Combustion. The Automatic Determination of Dissolved Organic Carbon (DOC) by Wet Chemical Oxidation. Determination of Particulate Organic Carbon and Nitrogen. Preparation of Lipophilic Organic Seawater Concentrates. Adsorption Chromatography of Organic Seawater Concentrates. Clean-up of Organic Seawater Concentrates by HPLC. Fluorimetric Determination of Dissolved Petroleum Residues. Determination of Selected Organochlorines in Seawater. Determination of Volatile Halocarbons in Seawater. Determination of Dimethlysulfide. Determination of Marine Humics. Determination of Amino Acids and Carbohydrates. HPLC Analysis of Photosynthetic Pigments.

7,247 citations

01 Jan 2008
TL;DR: The formation of dead zones has been exacerbated by the increase in primary production and consequent worldwide coastal eutrophication fueled by riverine runoff of fertilizers and the burning of fossil fuels as discussed by the authors.
Abstract: Dead zones in the coastal oceans have spread exponentially since the 1960s and have serious consequences for ecosystem functioning. The formation of dead zones has been exacerbated by the increase in primary production and consequent worldwide coastal eutrophication fueled by riverine runoff of fertilizers and the burning of fossil fuels. Enhanced primary production results in an accumulation of particulate organic matter, which encourages microbial activity and the consumption of dissolved oxygen in bottom waters. Dead zones have now been reported from more than 400 systems, affecting a total area of more than 245,000 square kilometers, and are probably a key stressor on marine ecosystems.

4,686 citations

Journal ArticleDOI
15 Aug 2008-Science
TL;DR: Dead zones in the coastal oceans have spread exponentially since the 1960s and have serious consequences for ecosystem functioning, exacerbated by the increase in primary production and consequent worldwide coastal eutrophication fueled by riverine runoff of fertilizers and the burning of fossil fuels.
Abstract: Dead zones in the coastal oceans have spread exponentially since the 1960s and have serious consequences for ecosystem functioning. The formation of dead zones has been exacerbated by the increase in primary production and consequent worldwide coastal eutrophication fueled by riverine runoff of fertilizers and the burning of fossil fuels. Enhanced primary production results in an accumulation of particulate organic matter, which encourages microbial activity and the consumption of dissolved oxygen in bottom waters. Dead zones have now been reported from more than 400 systems, affecting a total area of more than 245,000 square kilometers, and are probably a key stressor on marine ecosystems.

4,667 citations


Additional excerpts

  • ...metazoan communities cannot survive (Diaz and Rosenberg 2008)....

    [...]