Effects Of Ocean Acidification Research Articles

Aquaculture and climate change: a data-driven analysis

Abstract As climate change increasingly impacts the aquaculture industry, it poses challenges to production quality, management, and sustainability. This study provides a scientometric analysis of 47 years of research on aquaculture and climate change, analysing 4,785 articles and 224,895 references through CiteSpace software. The study highlights enduring themes such as “ocean acidification” and “global warming,” alongside emerging concerns like “deforestation” and “nutrient runoff,” reflecting new research directions. Notably, “seasonal variations” persist as a key focus due to their significant impact on aquaculture practices. Fourteen research clusters were identified, revealing a diverse array of topics from environmental performance to the effects of blue food systems and ocean acidification on marine life. Clusters related to “carbon sequestration,” “seaweed farming,” and “integrated multi-trophic aquaculture (IMTA)” emphasise the shift toward innovative practices aimed at mitigating climate impacts and enhancing sustainability. The analysis shows a need for more collaborative research, particularly from leading contributors such as the USA, Europe and Australia with underrepresented regions like Southeast Asia and Africa, to develop resilient aquaculture systems capable of adapting to climatic challenges. It advocates for the integration of new technologies and the exploration of sustainable aquaculture practices that minimise environmental impacts while enhancing global food security. This approach sets a direction for future research to promote adaptive strategies and technological innovations in aquaculture.

Toward an ecologically realistic experimental system to investigate the multigenerational effects of ocean warming and acidification on benthic invertebrates

AbstractHuman activities over the past 150 yr have led to significant carbon dioxide (CO2) emissions, causing global warming and ocean acidification. Surface ocean temperature has risen by 0.93°C since 1850, with projections of an additional +1.42°C to 3.47°C by 2080–2099. Ocean acidification, driven by CO2 absorption, has already lowered seawater pH by 0.1 units, affecting calcifying organisms, including shelled mollusks. Long‐term multigenerational studies on mollusk responses to both ocean acidification and warming, under realistic environmental conditions, are scarce. To address this knowledge gap, two mobile experimental units that can be deployed at the vicinity of shellfish farming areas were developed within the framework of the CocoriCO2 project. The experimental systems were designed to manipulate temperature and pH as offsets from ambient conditions. The experimental units have shown their effectiveness in terms of controlling and maintaining pH and temperature to assess the multigenerational effects of ocean warming and acidification on benthic invertebrates. Finally, the developed experimental systems can be modified easily to provide an educated assessment of the impact of other relevant environmental changes such as deoxygenation and changes in salinity.

From Individual Calcifiers to Ecosystem Dynamics: Ocean Acidification Effects on Urchins and Abalone.

A central question in ecology is: to what extent do trophic interactions govern the structure and function of communities? This question is becoming more pressing as trophic interactions shift with rapid climate change. Sea urchins and abalone are key invertebrates in the habitats in which they reside. Sea urchins are critical members of exemplar trophic cascades in kelp forests due to their impact on kelp establishment and maintenance; yet their populations are controlled by predators, such as sea otters and sunflower sea stars. Abalone compete with urchins for macroalgal food resources and therefore can help regulate urchin populations in kelp forests. Given that both urchin tests and abalone shells used for predator defense are comprised of calcium carbonate, much research has been conducted on the impacts of ocean acidification (OA) on these calcified structures. A growing body of literature has shown that urchin tests are less calcified and break with less force under OA conditions. Less is known about abalone, but their shells also appear to respond negatively to OA. Using kelp forest communities as exemplar ecosystems, we discuss the morphological, biomechanical, and physiological responses to OA in urchins and abalone and consider how these individual level responses scale to trophic interactions and ultimately whole ecosystem processes. Although the impacts of OA on the calcified structures used for defense have been well studied, calcified mechanisms for food consumption, such as the Aristotle's lantern of urchins, are much less understood. Thus, examining both the feeding and defense sides of trophic interactions would greatly improve our understanding of OA responses across individual to ecosystem level scales. More generally, measurements of morphological, biomechanical, and physiological responses to OA can be made in individuals to help predict higher level ecological responses, which would greatly contribute to broader predictions of whole ecosystem responses to OA.

The Science, Engineering, and Validation of Marine Carbon Dioxide Removal and Storage.

Scenarios to stabilize global climate and meet international climate agreements require rapid reductions in human carbon dioxide (CO2) emissions, often augmented by substantial carbon dioxide removal (CDR) from the atmosphere. While some ocean-based removal techniques show potential promise as part of a broader CDR and decarbonization portfolio, no marine approach is ready yet for deployment at scale because of gaps in both scientific and engineering knowledge. Marine CDR spans a wide range of biotic and abiotic methods, with both common and technique-specific limitations. Further targeted research is needed on CDR efficacy, permanence, and additionality as well as on robust validation methods-measurement, monitoring, reporting, and verification-that are essential to demonstrate the safe removal and long-term storage of CO2. Engineering studies are needed on constraints including scalability, costs, resource inputs, energy demands, and technical readiness. Research on possible co-benefits, ocean acidification effects, environmental and social impacts, and governance is also required.

A numerical model sheds new light on the effects of ocean acidification on an indicator species.

A Lagrangian Individual Based Model (IBM) offers new insights into the effects of ocean acidification on pteropods by providing detailed life histories of individuals. A thorough analysis of the results makes it possible to attribute the effects of ocean acidification to different mechanisms.

Impact of ocean acidification on microzooplankton grazing dynamics

This study examines the potential impacts of projected atmospheric carbon dioxide (pCO2) levels reaching 800 ppm by the end of the century, focusing on ocean acidification effects on marine ecosystems in the coastal areas of Bohai. We investigated how acidification affects the grazing patterns of microzooplankton using dilution techniques and ecophysiological methods. Our findings indicate that acidic conditions shift the phytoplankton community structure, changing dominant species. Elevated CO2 concentrations reduced grazing pressure on phytoplankton, with less steep declines in growth rates at 800 ppm CO2 (spring: 2.43 d−1 vs. 2.16 d−1, summer: −0.46 d−1 vs. −0.73 d−1, autumn: −0.45 d−1 vs. −0.90 d−1) and significant decreases in grazing pressure percentages (%Pp from 0.84 to 0.58 and %Pi from 0.64 to 0.46). Short-term acid exposure significantly increased superoxide dismutase activity in both microplankton (from 0.03 to 0.08 U mg−1, p<0.01) and nanoplankton (from 0.05 to 0.09 U mg−1, p<0.001), indicating an adaptive response to oxidative stress. These results highlight that elevated CO2 levels primarily boost phytoplankton growth by reducing microzooplankton grazing pressure, resulting in higher growth rates and a shift towards smaller-sized phytoplankton, reflecting complex short-term ecological responses to acidification. Further research is needed to understand the long-term effects of ocean acidification on microzooplankton and their role in marine secondary productivity.

Interactive effects of ocean acidification and nitrate on Ulva lactuca

Interactive effects of ocean acidification and nitrate on Ulva lactuca

Evaluating the time to detect biological effects of ocean acidification and warming: an example using simulations of purple sea urchin settlement

Ocean acidification (OA) and ocean warming driven by climate change are important stressors for marine species and systems, but documenting and detecting their long-term impacts on biological responses outside of laboratory settings are challenging due to natural variability caused by complex processes and interactions. We used settlement of purple sea urchins Strongylocentrotus purpuratus in the Southern California Bight (USA) over 6 yr as an example data set to parameterize a simulation model for exploring the time needed to detect environmental effects on a biological response. A generalized linear model was used to describe an index of urchin settlement as functions of pH, sea surface temperature (SST), sea surface salinity (SSS), and spatio-temporal factors, demonstrating that settlement was negatively associated with pH (i.e. lower settlement at higher pH) and positively associated with SST and SSS. Monte Carlo simulations were developed from this base model under a variety of alternative scenarios to estimate the time to detect: (1) annual trends in pH and SST time series, (2) pH and SST effects on urchin settlement, and (3) annual trends in urchin settlement. Time to detect pH and SST effects was predominantly influenced by the underlying strength of the relationships and the model uncertainty. Time to detect annual trends in settlement was more sensitive to the severity of long-term OA and warming trends, which had cumulative (at times opposing) effects. This study highlights the variable time scales (2-60+ yr) that may be necessary to detect biological responses to OA and ocean warming and the sensitivity to different assumptions of the study system.

Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer

Reef-building corals live in highly hydrodynamic environments, where water flow largely controls the complex chemical microenvironments surrounding them—the concentration boundary layer (CBL). The CBL may be key to alleviate ocean acidification (OA) effects on coral colonies by partially isolating them. However, OA effects on coral CBL remain poorly understood, particularly under different flow velocities. Here, we investigated these effects on the reef-building corals Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. We preconditioned corals to a control (pH 8.0) and OA (pH 7.8) treatment for four months and tested how low flow (2 cm s−1) and moderate flow (6 cm s−1) affected O2 and H+ CBL traits (thickness, surface concentrations, and flux) inside a unidirectional-flow chamber. We found that CBL traits differed between species and flow velocities. Under OA, traits remained generally stable across flows, except surface pH. In all species, the H+ CBL was thin and led to lower surface pH. Still, low flow thickened H+ CBLs and increased light elevation of surface pH. In general, our findings reveal a weak to null OA modulation of the CBL. Moreover, the OA-buffering capacity by the H+ CBL may be limited in coral species, though low flow could enhance CBL sheltering.

Are physiological and ecosystem-level tipping points caused by ocean acidification? A critical evaluation

Abstract. Ocean acidification (OA) is predicted to cause profound shifts in many marine ecosystems by impairing the ability of calcareous taxa to calcify and grow and by influencing the physiology of many others. In both calcifying and non-calcifying taxa, ocean acidification could further impair the ability of marine life to regulate internal pH and thus metabolic function and/or behaviour. Identifying tipping points at which these effects will occur for different taxa due to the direct impacts of ocean acidification on organism physiology is difficult because they have not adequately been determined for most taxa nor for ecosystems at higher levels. This is due to the presence of both resistant and sensitive species within most taxa. However, calcifying taxa such as coralline algae, corals, molluscs, and sea urchins appear to be most sensitive to ocean acidification. Conversely, non-calcareous seaweeds, seagrasses, diatoms, cephalopods, and fish tend to be more resistant or even benefit from the direct effects of ocean acidification, though the effects of ocean acidification are more subtle for these taxa. While physiological tipping points of the effects of ocean acidification either do not exist or are not well defined, their direct effects on organism physiology will have flow-on indirect effects. These indirect effects will cause ecological tipping points in the future through changes in competition, herbivory, and predation. Evidence for indirect effects and ecological change is mostly taken from benthic ecosystems in warm temperate–tropical locations in situ that have elevated CO2. Species abundances at these locations indicate a shift away from calcifying taxa and towards non-calcareous taxa at high-CO2 concentrations. For example, lower abundance of corals and coralline algae and higher covers of non-calcareous macroalgae, often turfing species, are often found at elevated CO2. However, there are some locations where only minor changes or no detectable changes occur. Where ecological tipping points do occur, it is usually at locations with naturally elevated mean pCO2 concentrations of 500 µatm or more, which also corresponds to just under that concentration where the direct physiological impacts of ocean acidification are detectable in the most sensitive taxa in laboratory research (coralline algae and corals). Collectively, the available data support the concern that ocean acidification will most likely cause ecological change in the near future in most benthic marine ecosystems, with tipping points in some ecosystems as low as 500 µatm pCO2. However, further research is required to more adequately quantify and model the extent of these impacts in order to accurately project future marine ecosystem tipping points under ocean acidification.

Increasing impacts of ocean acidification on coral reefs under global warming

The rapid increase in atmospheric CO2 concentration in recent decades has influenced the marine system to a great extent with ocean acidification being one of the consequences. Ocean acidifications impact on calcifying marine organisms has long been the subject of scientific studies. To determine the effect of ocean acidification on hard coral reefs, we analyzed five ocean coastal regions, comparing the trend in regional surface hydrogen ion activity with the change in hard coral coverage. In each region, we included both historical measured data and predicted data using RCP models as an implication of the potential future. The outcome does not provide substantial evidence to confirm the hypothesis linking the two variables. Additionally, the direct association between these variables cannot be ascertained due to the influence of uncontrolled factors such as local pollution, ocean warming, and ocean currents.

The investigation on stress mechanisms of Sepia esculenta larvae in the context of global warming and ocean acidification

Sepia esculenta is a tasty and nutritious cephalopod. But the trend toward global warming is accelerating with massive emissions of greenhouse gases. An increase in seawater temperature and a decrease in pH are a great challenge for artificial breeding and culture of S. esculenta. In this study, we investigated the contingency mechanism of S. esculenta larvae under both high temperature and low pH conditions by transcriptome analysis. A total of 1235 DEGs were identified. functional enrichment analysis results suggest that high temperature and low pH conditions led to malignant proliferation in exceptional cells of S. esculenta larvae. A comprehensive analysis of the KEGG signaling pathway and protein-protein interaction network (PPI) identified sixteen key genes under both high temperature and low pH conditions. The three genes with the highest quantities of interactions or involved in more KEGG signaling pathways were identified as hub genes affecting normal physiological processes in S. esculenta. In this study, the effects of global warming and ocean acidification on the metabolism and immunity of S. esculenta larvae were preliminarily investigated to provide necessary help for S. esculenta captive breeding in the face of global climate change.

Combining mesocosms with models reveals effects of global warming and ocean acidification on a temperate marine ecosystem.

Ocean warming and species exploitation have already caused large-scale reorganization of biological communities across the world. Accurate projections of future biodiversity change require a comprehensive understanding of how entire communities respond to global change. We combined a time-dynamic integrated food web modeling approach (Ecosim) with previous data from community-level mesocosm experiments to determine the independent and combined effects of ocean warming, ocean acidification and fisheries exploitation on a well-managed temperate coastal ecosystem. The mesocosm parameters enabled important physiological and behavioral responses to climate stressors to be projected for trophic levels ranging from primary producers to top predators, including sharks. Through model simulations, we show that under sustainable rates of fisheries exploitation, near-future warming or ocean acidification in isolation could benefit species biomass at higher trophic levels (e.g., mammals, birds, and demersal finfish) in their current climate ranges, with the exception of small pelagic fishes. However, under warming and acidification combined, biomass increases at higher trophic levels will be lower or absent, while in the longer term reduced productivity of prey species is unlikely to support the increased biomass at the top of the food web. We also show that increases in exploitation will suppress any positive effects of human-driven climate change, causing individual species biomass to decrease at higher trophic levels. Nevertheless, total future potential biomass of some fisheries species in temperate areas might remain high, particularly under acidification, because unharvested opportunistic species will likely benefit from decreased competition and show an increase in biomass. Ecological indicators of species composition such as the Shannon diversity index decline under all climate change scenarios, suggesting a trade-off between biomass gain and functional diversity. By coupling parameters from multilevel mesocosm food web experiments with dynamic food web models, we were able to simulate the generative mechanisms that drive complex responses of temperate marine ecosystems to global change. This approach, which blends theory with experimental data, provides new prospects for forecasting climate-driven biodiversity change and its effects on ecosystem processes.

The review of how ocean acidification affect organisms and ecological environment

The pH of our sea water is decreasing nowadays. Therefore, ocean acidification has gradually become a problem that people have to face. Human activities since Industrial Revolution are making sea water more and more acidic. Human activity has done some damage to the environment that will directly or indirectly increases the amount of hydrogen ions in seawater, which will finally make the seawater more acidic. One of the result of this changes is ocean acidification. People should start playing attention on this problem. If people do not intervene in advance to acidify the oceans, this issue can cause some consequences that will hurt our environment. The following is the main content of this paper. The reason why carbon dioxide can cause ocean acidification, effects of ocean acidification on Marine ecological environment, the shape of Balanophyllias bones changes in different PH environment and Changes in metabolic pathways of phytoplankton under ocean acidification.

The combined effects of ocean warming and ocean acidification on Pacific cod (Gadus macrocephalus) early life stages

The eastern North Pacific is simultaneously experiencing ocean warming (OW) and ocean acidification (OA), which may negatively affect fish early life stages. Pacific cod (Gadus macrocephalus) is an economically and ecologically important species with demonstrated sensitivity to OW and OA, but their combined impacts are unknown. Through a ~ 9-week experiment, Pacific cod embryos and larvae were reared at one of six combinations of three temperatures (3, 6, 10 °C) and two CO2 levels (ambient: ~ 360 μatm; high: ~ 1560 μatm) in a factorial design. Both embryonic and larval mortality were highest at the warmest temperature. Embryonic daily mortality rates were lower under elevated CO2 and there was no effect of CO2 level on larval daily mortality rates. Growth rates of young larvae (0 to 11 days post-hatch) were faster at warmer temperatures and at high CO2 levels, but growth during the 11–28 days post-hatch interval increased by temperature alone. The condition of larvae decreased with age, but less markedly under high CO2 levels. However, at 6 °C, fish incubated in ambient CO2 remained in higher condition than fish in the high CO2 treatment throughout the experiment. Overall, temperature had the greater influence on Pacific cod early life stages across each measurement endpoint, while CO2 effects were more modest and inconsistent. Subtle developmental differences in larval Pacific cod could be magnified later in life and important in the context of recruitment. These results show the complexity of stage- and trait-specific responses to and value of investigating the combined effects of co-occurring climatic stressors.

An in-depth assessment of the long-term effects of global ocean acidification on marine ecosystems

The main goal of this study is to establish the long-term effects that ocean acidification has on the biogeochemical processes that involve carbon, nitrogen, and phosphorus in marine ecosystems. Even though scientists have learned a lot about how ocean acidification affects marine species as evidenced by a wide body of literature on the subject, there are still a lot of areas that require further investigation. For example, there exists a dearth of academic studies on the long-term effects of ocean acidification. More study needs to be done to establish what the long-term and cumulative effects of acidity are, especially in terms of how well different species can adapt. A research design that combines laboratory experiments and field surveys has been identified for this study. In order to gain a comprehensive understanding of how ocean acidification affects marine ecosystems, field surveys will be done at the places chosen for the study. A statistical analysis will be done on the pH readings and carbonate ion concentrations. The goal of this process is to identify patterns and links that may point to probable cause-and-effect links between changes in the chemistry of the ocean and the reported changes in life. The results and discussion intend to give a full analysis and evaluation of how acidification of the world's oceans affects marine ecosystems. This will be done by showing, interpreting, and comparing all the important data and findings. The results of this study are critical for establishing how ocean acidification affects marine ecosystems in the long run.

The incorporation of strontium and barium into the otoliths of the flounder Paralichthys olivaceus at early life stages demonstrates resilience to ocean acidification.

Ocean acidification could modify the bioavailability and chemical properties of trace elements in seawater, which could affect their incorporation into the calcareous structures of marine organisms. Fish otoliths, biomineralized ear stones made by aragonite, are suspended within the endolymph fluid of teleosts, indicating that the elemental incorporation of otoliths might also be susceptible to ocean acidification. In this study, we evaluated the combined effects of CO2-induced ocean acidification (pH 8.10, 7.70, and 7.30, corresponding to ocean acidification scenarios under the representative concentration pathway 8.5 model as projected by the Intergovernmental Panel on Climate Change) and water elemental concentrations of strontium (Sr) and barium (Ba; low, medium, and high) on elemental incorporation into otoliths of the flounder Paralichthys olivaceus at early life stages. Our results revealed that the elemental incorporation of Sr and Ba into otoliths was principally dependent on the corresponding water elemental concentrations rather than on ocean acidification. Moreover, the partition coefficients (DMe) of Sr and Ba may stabilize after dynamic equilibrium is reached as the water elemental concentration increases, but are not affected by ocean acidification. Therefore, the incorporation of Sr and Ba into otoliths of the flounder at early life stages may not serve as an effective indicator of ocean acidification. In other words, the findings suggest that ocean acidification does not impact the incorporation of Sr and Ba incorporation into otoliths when tracing the temperature or salinity experiences of the flounder. Our findings will provide new knowledge for understanding the potential ecological effects of ocean acidification on the recruitment dynamics of fish species.

Responses of marine trophic levels to the combined effects of ocean acidification and warming.

Marine organisms are simultaneously exposed to anthropogenic stressors associated with ocean acidification and ocean warming, with expected interactive effects. Species from different trophic levels with dissimilar characteristics and evolutionary histories are likely to respond differently. Here, we perform a meta-analysis of controlled experiments including both ocean acidification and ocean warming factors to investigate single and interactive effects of these stressors on marine species. Contrary to expectations, we find that synergistic interactions are less common (16%) than additive (40%) and antagonistic (44%) interactions overall and their proportion decreases with increasing trophic level. Predators are the most tolerant trophic level to both individual and combined effects. For interactive effects, calcifying and non-calcifying species show similar patterns. We also identify climate region-specific patterns, with interactive effects ranging from synergistic in temperate regions to compensatory in subtropical regions, to positive in tropical regions. Our findings improve understanding of how ocean warming, and acidification affect marine trophic levels and highlight the need for deeper consideration of multiple stressors in conservation efforts.

Effects of Ocean Acidification and Summer Thermal Stress on the Physiology and Growth of the Atlantic Surfclam (Spisula solidissima)

Effects of Ocean Acidification and Summer Thermal Stress on the Physiology and Growth of the Atlantic Surfclam (Spisula solidissima)

Origin and Formation Mechanism of the Late Permian Black Siliceous Rocks in the Lower Yangtze Region.

The Late Permian witnessed a Permian Chert Event (PCE) and distinctive oceanic geochemical fluctuations, such as an ocean acidification event, large-scale volcanic eruption, and rapid global warming. However, the links between siliceous rock formation mechanism, ocean, and climate changes are rarely discussed. In this article, two well-preserved deeper-water sections of the Dalong Formation from the Lower Yangtze region in southeast China are selected for analysis. To document the coeval oceanic changes, we present thin section authentication, scanning electron microscope (SEM) observation, and multiple geochemical proxies, including total organic carbon contents (TOC), major element contents, trace element contents, and rare earth element contents (REEs). The results show that siliceous rocks are mainly of biological origin in this region. The low content of MgO (0.10-0.94%, mean = 0.36%) in the Fantiansi section of Tongling area indicates that it is affected by regional hydrothermal fluids. The correlation between Al2O3/TiO2, Al2O3 versus SiO2 /Al2O3, and TiO2/ΣREEs indicates that the Late Permian was greatly influenced by the continuous input of terrigenous materials. The correlations of MnO/TiO2, LaN/CeN, Ce/Ce*, and LREE/HREE imply that the Dalong Formation siliceous rocks were deposited in a continental margin setting. Redox geochemical data (EFU, EFMo, and EFV) imply the water column experienced widespread anoxic/euxinic during the Late Permian, which aided in the preservation of organic matter following biological decay. The accumulation of siliceous rocks is related to South China experiencing a hot tropical climate, coastal upwelling and continental weathering-enriched marine nutrients, fostering high primary productivity, and benefiting abundant siliceous zooplankton. Volcanic and regional hydrothermal activity further enhanced nutrient flux, and the simultaneous ocean acidification event provided favorable chemical conditions for the preservation of silica, leading to the formation of siliceous rocks in the Dalong Formation.