Showing papers on "Ocean acidification published in 2022"
TL;DR: The model provides a framework for understanding the environmental sensitivity of marine calcifiers, past mass extinctions, and resilience in 21st century acidifying oceans and frames questions about the past, present, and future of CaCO3 biomineralizing organisms.
Abstract: Calcium carbonate (CaCO3) biomineralizing organisms have played major roles in the history of life and the global carbon cycle during the past 541 Ma. Both marine diversification and mass extinctions reflect physiological responses to environmental changes through time. An integrated understanding of carbonate biomineralization is necessary to illuminate this evolutionary record and to understand how modern organisms will respond to 21st century global change. Biomineralization evolved independently but convergently across phyla, suggesting a unity of mechanism that transcends biological differences. In this review, we combine CaCO3 skeleton formation mechanisms with constraints from evolutionary history, omics, and a meta-analysis of isotopic data to develop a plausible model for CaCO3 biomineralization applicable to all phyla. The model provides a framework for understanding the environmental sensitivity of marine calcifiers, past mass extinctions, and resilience in 21st century acidifying oceans. Thus, it frames questions about the past, present, and future of CaCO3 biomineralizing organisms.
50 citations
45 citations
35 citations
TL;DR: In this paper , a systematic review and meta-analysis aim to critically re-evaluate the prevailing paradigm of negative effects of ocean acidification on calcifiers, finding that over 70% of the observations in growth and calcification are non-negative, implying that the acclimation capacity of many calcifiers to Ocean acidification is mediated by phenotypic plasticity (e.g., physiological, mineralogical, structural, and molecular adjustments), transgenerational plasticity, increased food availability, or species interactions.
Abstract: Ocean acidification is considered detrimental to marine calcifiers, but mounting contradictory evidence suggests a need to revisit this concept. This systematic review and meta-analysis aim to critically re-evaluate the prevailing paradigm of negative effects of ocean acidification on calcifiers. Based on 5153 observations from 985 studies, many calcifiers (e.g., echinoderms, crustaceans, and cephalopods) are found to be tolerant to near-future ocean acidification (pH ≈ 7.8 by the year 2100), but coccolithophores, calcifying algae, and corals appear to be sensitive. Calcifiers are generally more sensitive at the larval stage than adult stage. Over 70% of the observations in growth and calcification are non-negative, implying the acclimation capacity of many calcifiers to ocean acidification. This capacity can be mediated by phenotypic plasticity (e.g., physiological, mineralogical, structural, and molecular adjustments), transgenerational plasticity, increased food availability, or species interactions. The results suggest that the impacts of ocean acidification on calcifiers are less deleterious than initially thought as their adaptability has been underestimated. Therefore, in the forthcoming era of ocean acidification research, it is advocated that studying how marine organisms persist is as important as studying how they perish, and that future hypotheses and experimental designs are not constrained within the paradigm of negative effects.
35 citations
TL;DR: In this article , the authors explore the consistency and robustness of scientific evidence over the past decade regarding direct effects of ocean acidification on fish behavior and provide quantitative evidence that the research to date on this topic is characterized by a decline effect, where large effects in initial studies have all but disappeared in subsequent studies over a decade.
Abstract: Ocean acidification—decreasing oceanic pH resulting from the uptake of excess atmospheric CO2—has the potential to affect marine life in the future. Among the possible consequences, a series of studies on coral reef fish suggested that the direct effects of acidification on fish behavior may be extreme and have broad ecological ramifications. Recent studies documenting a lack of effect of experimental ocean acidification on fish behavior, however, call this prediction into question. Indeed, the phenomenon of decreasing effect sizes over time is not uncommon and is typically referred to as the “decline effect.” Here, we explore the consistency and robustness of scientific evidence over the past decade regarding direct effects of ocean acidification on fish behavior. Using a systematic review and meta-analysis of 91 studies empirically testing effects of ocean acidification on fish behavior, we provide quantitative evidence that the research to date on this topic is characterized by a decline effect, where large effects in initial studies have all but disappeared in subsequent studies over a decade. The decline effect in this field cannot be explained by 3 likely biological explanations, including increasing proportions of studies examining (1) cold-water species; (2) nonolfactory-associated behaviors; and (3) nonlarval life stages. Furthermore, the vast majority of studies with large effect sizes in this field tend to be characterized by low sample sizes, yet are published in high-impact journals and have a disproportionate influence on the field in terms of citations. We contend that ocean acidification has a negligible direct impact on fish behavior, and we advocate for improved approaches to minimize the potential for a decline effect in future avenues of research.
23 citations
TL;DR: In this article , the effects of global environmental factors like warming and acidification on marine capture fisheries and aquaculture industry are discussed in a holistic manner taking into account growth, survival, behavioural response, prey predator dynamics, calcification, biomineralization, reproduction, physiology, thermal tolerance, molecular level responses as well as immune system and disease susceptibility.
19 citations
TL;DR: In this paper, the effects of global environmental factors like warming and acidification on marine capture fisheries and aquaculture industry are discussed in a holistic manner taking into account growth, survival, behavioural response, prey predator dynamics, calcification, biomineralization, reproduction, physiology, thermal tolerance, molecular level responses as well as immune system and disease susceptibility.
19 citations
TL;DR: In this article , the authors explore the sources of reactive oxygen species (ROS) and their roles in the oceans, how the dynamics of ROS might change in the future, and how this change might impact the ecology and chemistry of the future ocean.
Abstract: Reactive oxygen species (ROS) are omnipresent in the ocean, originating from both biological (e.g., unbalanced metabolism or stress) and non-biological processes (e.g. photooxidation of colored dissolved organic matter). ROS can directly affect the growth of marine organisms, and can also influence marine biogeochemistry, thus indirectly impacting the availability of nutrients and food sources. Microbial communities and evolution are shaped by marine ROS, and in turn microorganisms influence steady-state ROS concentrations by acting as the predominant sink for marine ROS. Through their interactions with trace metals and organic matter, ROS can enhance microbial growth, but ROS can also attack biological macromolecules, causing extensive modifications with deleterious results. Several biogeochemically important taxa are vulnerable to very low ROS concentrations within the ranges measured in situ, including the globally distributed marine cyanobacterium Prochlorococcus and ammonia-oxidizing archaea of the phylum Thaumarchaeota. Finally, climate change may increase the amount of ROS in the ocean, especially in the most productive surface layers. In this review, we explore the sources of ROS and their roles in the oceans, how the dynamics of ROS might change in the future, and how this change might impact the ecology and chemistry of the future ocean.
17 citations
TL;DR: Foraminiferal δ13C records from a marine continental margin section, which reveal a 1.0 to 1.5 ǫ negative pre-onset excursion (POE), and concomitant rise in sea surface temperature of at least 2°C and a decline in ocean pH, suggest a rapid (< ocean mixing time scales) carbon release, followed by recovery driven by deep-sea mixing as mentioned in this paper .
Abstract: The Paleocene-Eocene Thermal Maximum (PETM) is recognized by a major negative carbon isotope (δ13C) excursion (CIE) signifying an injection of isotopically light carbon into exogenic reservoirs, the mass, source, and tempo of which continue to be debated. Evidence of a transient precursor carbon release(s) has been identified in a few localities, although it remains equivocal whether there is a global signal. Here, we present foraminiferal δ13C records from a marine continental margin section, which reveal a 1.0 to 1.5‰ negative pre-onset excursion (POE), and concomitant rise in sea surface temperature of at least 2°C and a decline in ocean pH. The recovery of both δ13C and pH before the CIE onset and apparent absence of a POE in deep-sea records suggests a rapid (< ocean mixing time scales) carbon release, followed by recovery driven by deep-sea mixing. Carbon released during the POE is therefore likely more similar to ongoing anthropogenic emissions in mass and rate than the main CIE.
17 citations
17 citations
TL;DR: In this article , the elemental ratio of silicon to nitrogen (N) of sinking biogenic matter was found to increase by 17 ± 6 per cent under the year 2100, when ocean acidification was predicted.
Abstract: Abstract Diatoms account for up to 40% of marine primary production 1,2 and require silicic acid to grow and build their opal shell 3 . On the physiological and ecological level, diatoms are thought to be resistant to, or even benefit from, ocean acidification 4–6 . Yet, global-scale responses and implications for biogeochemical cycles in the future ocean remain largely unknown. Here we conducted five in situ mesocosm experiments with natural plankton communities in different biomes and find that ocean acidification increases the elemental ratio of silicon (Si) to nitrogen (N) of sinking biogenic matter by 17 ± 6 per cent under $${{p}}_{{{\rm{CO}}}_{2}}$$ p CO 2 conditions projected for the year 2100. This shift in Si:N seems to be caused by slower chemical dissolution of silica at decreasing seawater pH. We test this finding with global sediment trap data, which confirm a widespread influence of pH on Si:N in the oceanic water column. Earth system model simulations show that a future pH-driven decrease in silica dissolution of sinking material reduces the availability of silicic acid in the surface ocean, triggering a global decline of diatoms by 13–26 per cent due to ocean acidification by the year 2200. This outcome contrasts sharply with the conclusions of previous experimental studies, thereby illustrating how our current understanding of biological impacts of ocean change can be considerably altered at the global scale through unexpected feedback mechanisms in the Earth system.
TL;DR: In this paper , the authors focus on physiological variation among community members and the energetic demands and trophic mismatches generated by environmental changes in marine ecosystems and highlight how key species interactions that are sensitive to environmental change can operate as ecological leverage points through which small changes in abiotic conditions are amplified into large changes.
Abstract: Marine ecosystems are increasingly impacted by global environmental changes, including warming temperatures, deoxygenation, and ocean acidification. Marine scientists recognize intuitively that these environmental changes are translated into community changes via organismal physiology. However, physiology remains a black box in many ecological studies, and coexisting species in a community are often assumed to respond similarly to environmental stressors. Here, we emphasize how greater attention to physiology can improve our ability to predict the emergent effects of ocean change. In particular, understanding shifts in the intensity and outcome of species interactions such as competition and predation requires a sharpened focus on physiological variation among community members and the energetic demands and trophic mismatches generated by environmental changes. Our review also highlights how key species interactions that are sensitive to environmental change can operate as ecological leverage points through which small changes in abiotic conditions are amplified into large changes in marine ecosystems.
TL;DR: In this paper , the elemental ratio of silicon to nitrogen (N) of sinking biogenic matter was found to increase by 17 ± 6 per cent under the year 2100, when ocean acidification was predicted.
Abstract: Abstract Diatoms account for up to 40% of marine primary production 1,2 and require silicic acid to grow and build their opal shell 3 . On the physiological and ecological level, diatoms are thought to be resistant to, or even benefit from, ocean acidification 4–6 . Yet, global-scale responses and implications for biogeochemical cycles in the future ocean remain largely unknown. Here we conducted five in situ mesocosm experiments with natural plankton communities in different biomes and find that ocean acidification increases the elemental ratio of silicon (Si) to nitrogen (N) of sinking biogenic matter by 17 ± 6 per cent under $${{p}}_{{{\rm{CO}}}_{2}}$$ p CO 2 conditions projected for the year 2100. This shift in Si:N seems to be caused by slower chemical dissolution of silica at decreasing seawater pH. We test this finding with global sediment trap data, which confirm a widespread influence of pH on Si:N in the oceanic water column. Earth system model simulations show that a future pH-driven decrease in silica dissolution of sinking material reduces the availability of silicic acid in the surface ocean, triggering a global decline of diatoms by 13–26 per cent due to ocean acidification by the year 2200. This outcome contrasts sharply with the conclusions of previous experimental studies, thereby illustrating how our current understanding of biological impacts of ocean change can be considerably altered at the global scale through unexpected feedback mechanisms in the Earth system.
TL;DR: In a recent review as discussed by the authors, a sharpened focus on physiological variation among community members and the energetic demands and trophic mismatches generated by environmental changes was proposed to predict the emergent effects of ocean change.
Abstract: Marine ecosystems are increasingly impacted by global environmental changes, including warming temperatures, deoxygenation, and ocean acidification. Marine scientists recognize intuitively that these environmental changes are translated into community changes via organismal physiology. However, physiology remains a black box in many ecological studies, and coexisting species in a community are often assumed to respond similarly to environmental stressors. Here, we emphasize how greater attention to physiology can improve our ability to predict the emergent effects of ocean change. In particular, understanding shifts in the intensity and outcome of species interactions such as competition and predation requires a sharpened focus on physiological variation among community members and the energetic demands and trophic mismatches generated by environmental changes. Our review also highlights how key species interactions that are sensitive to environmental change can operate as ecological leverage points through which small changes in abiotic conditions are amplified into large changes in marine ecosystems. Expected final online publication date for the Annual Review of Marine Science, Volume 14 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
TL;DR: It is shown that elevated pCO2 induced common molecular responses related to circadian rhythm and immune system but different magnitudes of molecular response across the six species, with some species possessing evolved molecular toolkits to cope with future OA.
Abstract: Ocean acidification (OA) is postulated to affect the physiology, behavior, and life‐history of marine species, but potential for acclimation or adaptation to elevated pCO2 in wild populations remains largely untested. We measured brain transcriptomes of six coral reef fish species at a natural volcanic CO2 seep and an adjacent control reef in Papua New Guinea. We show that elevated pCO2 induced common molecular responses related to circadian rhythm and immune system but different magnitudes of molecular response across the six species. Notably, elevated transcriptional plasticity was associated with core circadian genes affecting the regulation of intracellular pH and neural activity in Acanthochromis polyacanthus. Gene expression patterns were reversible in this species as evidenced upon reduction of CO2 following a natural storm‐event. Compared with other species, Ac. polyacanthus has a more rapid evolutionary rate and more positively selected genes in key functions under the influence of elevated CO2, thus fueling increased transcriptional plasticity. Our study reveals the basis to variable gene expression changes across species, with some species possessing evolved molecular toolkits to cope with future OA.
TL;DR: In this article , the authors evaluated the impact of ocean acidification and microplastics on the health of a mussel species (Mytilus coruscus) by assessing its physiological performance, immunity and byssus properties.
TL;DR: In this article , the authors present the synthesis of 6 case studies from the North Atlantic Ocean and the Mediterranean Sea, revealing that food supply controlled by export production and turbulent hydrodynamics at the seabed exerted the strongest impact on coral vitality during the past 20,000 years, whereas locally low oxygen concentrations in the bottom water can act as an additional relevant stressor.
Abstract: Cold-water corals (CWCs) are the engineers of complex ecosystems forming unique biodiversity hotspots in the deep sea. They are expected to suffer dramatically from future environmental changes in the oceans such as ocean warming, food depletion, deoxygenation, and acidification. However, over the last decades of intense deep-sea research, no extinction event of a CWC ecosystem is documented, leaving quite some uncertainty on their sensitivity to these environmental parameters. Paleoceanographic reconstructions offer the opportunity to align the on- and offsets of CWC proliferation to environmental parameters. Here, we present the synthesis of 6 case studies from the North Atlantic Ocean and the Mediterranean Sea, revealing that food supply controlled by export production and turbulent hydrodynamics at the seabed exerted the strongest impact on coral vitality during the past 20,000 years, whereas locally low oxygen concentrations in the bottom water can act as an additional relevant stressor. The fate of CWCs in a changing ocean will largely depend on how these oceanographic processes will be modulated. Future ocean deoxygenation may be compensated regionally where the food delivery and food quality are optimal.
TL;DR: In this article , the authors report rapid acidification in the Arctic Ocean, with rates three to four times higher than in other ocean basins, and attribute it to changing sea ice coverage on a decadal time scale.
Abstract: The Arctic Ocean has experienced rapid warming and sea ice loss in recent decades, becoming the first open-ocean basin to experience widespread aragonite undersaturation [saturation state of aragonite (Ωarag) < 1]. However, its trend toward long-term ocean acidification and the underlying mechanisms remain undocumented. Here, we report rapid acidification there, with rates three to four times higher than in other ocean basins, and attribute it to changing sea ice coverage on a decadal time scale. Sea ice melt exposes seawater to the atmosphere and promotes rapid uptake of atmospheric carbon dioxide, lowering its alkalinity and buffer capacity and thus leading to sharp declines in pH and Ωarag. We predict a further decrease in pH, particularly at higher latitudes where sea ice retreat is active, whereas Arctic warming may counteract decreases in Ωarag in the future. Description Acceleration in the Arctic The Arctic is warming at a rate faster than any comparable region on Earth, with a consequently rapid loss of sea ice there. Qi et al. found that this sea ice loss is causing more uptake of atmospheric carbon dioxide by surface water and driving rapid acidification of the western Arctic Ocean, at a rate three to four times higher than that of the other ocean basins. They attribute this finding to melt-driven addition of freshwater and the resulting changes in seawater chemistry. —HJS The western Arctic Ocean is rapidly acidifying due to sea ice loss.
TL;DR: The results suggested that the relative abundance of probiotic bacteria decreased upon ocean acidification, which favored the proliferation of pathogenic species in the intestine of oysters.
TL;DR: Analysis of macromolecular content of selected individual diatom taxa from a natural Antarctic phytoplankton community exposed to a gradient of fCO2 levels suggests a shift away from lipid-rich large diatoms towards a community dominated by smaller taxa, but with higher lipid and protein stores than their present-day contemporaries, a response that could have cascading effects on food web dynamics in the Antarctic marine ecosystem.
Abstract: Primary production in the Southern Ocean is dominated by diatom-rich phytoplankton assemblages, whose individual physiological characteristics and community composition are strongly shaped by the environment, yet knowledge on how diatoms allocate cellular energy in response to ocean acidification (OA) is limited. Understanding such changes in allocation is integral to determining the nutritional quality of diatoms and the subsequent impacts on the trophic transfer of energy and nutrients. Using synchrotron-based Fourier transform infrared microspectroscopy, we analysed the macromolecular content of selected individual diatom taxa from a natural Antarctic phytoplankton community exposed to a gradient of fCO2 levels (288-1263 µatm). Strong species-specific differences in macromolecular partitioning were observed under OA. Large taxa showed preferential energy allocation towards proteins, while smaller taxa increased both lipid and protein stores at high fCO2 . If these changes are representative of future Antarctic diatom physiology, we may expect a shift away from lipid-rich large diatoms towards a community dominated by smaller taxa, but with higher lipid and protein stores than their present-day contemporaries, a response that could have cascading effects on food web dynamics in the Antarctic marine ecosystem.
TL;DR: In this paper, the effects of Cu exposure on two bivalve species (clams and scallops) for 28 days at a series of gradient pH levels (pH 8.1, 7.8, and 7.6).
TL;DR: In this paper , the intestinal microflora of the Pacific oyster Crassostrea gigas reared at seawater with pH values of 8.1 (control group), 7.8 (AC78 group) and 7.4 (AC74 group) were characterized and compared using 16S rRNA gene sequencing.
TL;DR: In this article , the authors systematically analyzed the different aspects of ocean acidification research in the Mediterranean region based on two sources: the United Nation's International Atomic Energy Agency's (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey.
Abstract: Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts are likely exacerbated in the semi-enclosed and highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These gaps are at tributed to both the uneven capacity for OA research that exists between Mediterranean countries, as well as to the subtle and long-term biological, physical and chemical interactions that define OA impacts. In this paper, we systematically analyzed the different aspects of OA research in the Mediterranean region based on two sources: the United Nation’s International Atomic Energy Agency’s (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey. Our analysis shows that 1) there is an uneven geographic capacity in OA research, and illustrates that both the Algero-Provencal and Ionian sub-basins are currently the least studied Mediterranean areas, 2) the carbonate system is still poorly quantified in coastal zones, and long-term time-series are still sparse across the Mediterranean Sea, which is a challenge for studying its variability and assessing coastal OA trends, 3) the most studied groups of organisms are autotrophs (algae, phanerogams, phytoplankton), mollusks, and corals, while microbes, small mollusks (mainly pteropods), and sponges are among the least studied, 4) there is an overall paucity in socio-economic, paleontological, and modeling studies in the Mediterranean Sea, and 5) in spite of general resource availability and the agreement for improved and coordinated OA governance, there is a lack of consistent OA policies in the Mediterranean Sea. In addition to highlighting the current status, trends and gaps of OA research, this work also provides recommendations, based on both our literature assessment and a survey that targeted the Mediterranean OA scientific community. In light of the ongoing 2021-2030 United Nations Decade of Ocean Science for Sustainable Development, this work might provide a guideline to close gaps of knowledge in the Mediterranean OA research. Systematic Review Registration https://www.oceandecade.org/
TL;DR: In this article , the effects of Cu exposure on two bivalve species (clams and scallops) for 28 d, at a series of gradient pH levels (pH 8.1, 7.8, and 7.6).
TL;DR: In this paper , the single and combined effects of nanoplastics and ocean acidification on the sub-Antarctic pteropod Limacina retroversa were investigated under laboratory conditions, using two surface charged polystyrene nanoparticles (PS NPs) as a proxy for nanoplastic.
TL;DR: In this article , the authors developed a framework to analyze the broad macro-physiological and molecular responses over a wide pH range in juvenile oyster, identifying low tipping points for physiological traits at pH 7.3-6.9 that coincide with a major reshuffling in membrane lipids and transcriptome.
Abstract: Studies on the impact of ocean acidification on marine organisms involve exposing organisms to future acidification scenarios, which has limited relevance for coastal calcifiers living in a mosaic of habitats. Identification of tipping points beyond which detrimental effects are observed is a widely generalizable proxy of acidification susceptibility at the population level. This approach is limited to a handful of studies that focus on only a few macro-physiological traits, thus overlooking the whole organism response. Here we develop a framework to analyze the broad macro-physiological and molecular responses over a wide pH range in juvenile oyster. We identify low tipping points for physiological traits at pH 7.3-6.9 that coincide with a major reshuffling in membrane lipids and transcriptome. In contrast, a drop in pH affects shell parameters above tipping points, likely impacting animal fitness. These findings were made possible by the development of an innovative methodology to synthesize and identify the main patterns of variations in large -omic data sets, fitting them to pH and identifying molecular tipping points. We propose the broad application of our framework to the assessment of effects of global change on other organisms.
TL;DR: In this paper, the physiological and biochemical response of intertidal green seaweed Ulva compressa to elevated pCO2 induced acidification was examined, and the results indicated that U. compressa will benefit from seawater acidification by improving productivity.
TL;DR: A comprehensive overview of the interplay between ocean deoxygenation and marine life across space and time is presented in this article , where the current knowledge gaps and future steps for deoxyogenation research are discussed.
Abstract: Global ocean O2 content has varied significantly across the eons, both shaping and being shaped by the evolutionary history of life on planet Earth. Indeed, past O2 fluctuations have been associated with major extinctions and the reorganization of marine biota. Moreover, its most recent iteration—now anthropogenically driven—represents one of the most prominent challenges for both marine ecosystems and human societies, with ocean deoxygenation being regarded as one of the main drivers of global biodiversity loss. Yet ocean deoxygenation has received far less attention than concurrent environmental variables of marine climate change, namely, ocean warming and acidification, particularly in the field of experimental marine ecology. Together with the lack of consistent criteria defining gradual and acute changes in O2 content, a general lack of multifactorial studies featuring all three drivers and their interactions prevents an adequate interpretation of the potential effects of extreme and gradual deoxygenation. We present a comprehensive overview of the interplay between O2 and marine life across space and time and discuss the current knowledge gaps and future steps for deoxygenation research. This work may also contribute to the ongoing call for an integrative perspective on the combined effects of these three drivers of change for marine organisms and ecosystems worldwide.
TL;DR: In this paper , the authors used experimental manipulations to test the hypotheses that ocean warming and acidification would negatively affect habitat-forming coralline algal turfs and the diverse molluscan assemblages they support.
TL;DR: In this paper , a meta-analysis of studies measuring the direct effect of ocean acidification and ocean warming on marine organisms was conducted, and the authors found that higher trophic level species display greater tolerance to acidification but greater sensitivity to warming.