Understanding how shellfish growers adapt to environmental and socioeconomic stressors is critical for food security, especially with growing impacts from climate change. However, we know relatively little about the supporting factors that lead shellfish growers who experience stressors to make adaptive choices. Through interviews conducted with US West Coast (California and Oregon) shellfish farm owners and managers (growers), we document environmental and socioeconomic stressors that growers experience and investigate whether they can adapt, react, or cope (ARC response) to these stressors. We further identify growers’ strategies for adaptation and link these strategies to theoretical adaptive capacity domains (ie, assets, flexibility, social organization, learning, agency, and governance) using qualitative comparative analysis (QCA). We found regulatory stressors were the most impactful to growers overall. These stressors caused financial burdens and time delays to operations for growers in both states. Ocean acidification and/or hypoxia (OAH) was the most frequently reported environmental stressor. Ocean acidification and/or hypoxia impacts include increased mortality and shellfish die-off events. Out of 125 responses to stressors, growers were able to adapt in just over half of stressor responses (54.4%). Agency, flexibility, learning, and social organization supported adaptation most frequently, while governance was employed the least. Growers responded with cope responses (35.2%) more frequently than react responses (10.4%). Growers combined adaptive capacity domains in various ways to adapt. For example, the adaptive capacity domain of agency was frequently employed, but almost always in combination with other adaptive capacity domains (eg, assets, governance, flexibility, and learning). This study demonstrates that US West Coast shellfish growers combine adaptive capacity domains in creative ways to form adaptive pathways and illuminates pathways to better support adaptive capacity in shellfish aquaculture.
Continue reading ‘Pathways to adaptation for shellfish aquaculture on the U.S. West Coast’Posts Tagged 'mitigation'
Pathways to adaptation for shellfish aquaculture on the U.S. West Coast
Published 2 March 2026 Science ClosedTags: fisheries, mitigation, North Pacific, socio-economy
Blue carbon ecosystems and coral reefs as coupled nature-based climate solutions
Published 20 February 2026 Science ClosedTags: mitigation, review
Restoring coastal ecosystems offers more than just carbon storage: it can also help bring coral reefs back to life. This Perspective explores how the carbon captured by mangroves and other blue carbon systems could be used to support reef restoration, creating a powerful synergy between climate action and marine conservation. By aligning ecological benefits with innovative funding strategies, this approach offers a practical path towards more resilient coastlines and more durable climate solutions.
Continue reading ‘Blue carbon ecosystems and coral reefs as coupled nature-based climate solutions’Seaweeds (Ulva, Gracilaria) significantly increase the growth rates of North Atlantic oysters, scallops, and clams grown in an aquaculture setting
Published 17 February 2026 Science ClosedTags: algae, biological response, BRcommunity, chemistry, fisheries, laboratory, mitigation, mollusks, morphology
Highlights
- Seaweeds significantly increased the growth rates of oysters by 20–70%, of clams by 60–70%, and of scallops by 130–140%.
- Seaweeds caused significant increases in pH, DO, and the saturation state of calcium carbonate (Ω).
- Seaweeds caused a significant increase in the concentrations of suspended chlorophyll a.
- Co-culture of seaweeds with bivalves accelerates the growth rate of bivalves by increasing pH, DO, Ω, and food availability.
Abstract
While bivalve populations are threatened by climate change stressors including ocean acidification and hypoxia, the photosynthetic activity of seaweeds can raise the pH and dissolved oxygen (DO) of seawater, combatting these stressors. Here, three commercially important North Atlantic bivalves (Eastern oysters, Crassostrea virginica; hard clams, Mercenaria mercenaria; bay scallops, Argopecten irradians) were grown in the presence and absence of two common seaweeds (Ulva sp. and Gracilaria sp.) in replicated 300 L outdoor aquaculture tables with flow-through seawater. Environmental conditions including pH, DO, and chlorophyll a were continuously monitored and levels of dissolved inorganic carbon and the complete carbonate chemistry of seawater were quantified. The presence of seaweeds significantly increased shell- and tissue-based growth rates of oysters by 20–70%, of clams by 60–70%, and of scallops by 130–140% (p < 0.05) with both seaweeds being similarly effective. Both seaweed species caused significant increases in pH, DO, and the saturation state of calcium carbonate (Ω) during the day (p < 0.05) whereas differences at night were muted with night-time Ωaragonite levels being at or below saturation in all treatments. In some experiments, the presence of seaweeds caused a significant increase in the concentrations of suspended chlorophyll a, suggesting that seaweeds increased the total amount and diversity of food available to bivalves. Collectively, this study demonstrates that the co-culture of seaweeds with bivalves in a land-based aquaculture setting can significantly accelerate the growth rate of bivalves by increasing pH, DO, Ω, and food availability.
Continue reading ‘Seaweeds (Ulva, Gracilaria) significantly increase the growth rates of North Atlantic oysters, scallops, and clams grown in an aquaculture setting’Effectiveness and scalability of coastal nature-based solutions under climate impact drivers: a systematic review
Published 30 January 2026 Science ClosedTags: mitigation, policy, review
Highlights
- A structured review filters 117 coastal NbS studies to 35 CID-relevant and 14 implementation-informative cases
- Coastal NbS are evaluated through their implementation components under multiple climate impact drivers
- NbS foundational and measurement processes dominate reviewed NbS practices, while learning, governance, and economic processes remain weak
- Scalability emerges from processes completeness rather than ecosystem type or NbS intervention design
- Key implementation gaps are identified that limit the resilience, transferability, and policy uptake of coastal NbS
Abstract
Nature-based Solutions (NbS) are increasingly promoted for enhancing coastal resilience to climate change, yet most evaluations focus on biophysical outcomes while overlooking the project-level processes that influence long-term effectiveness and scalability. This study applies an implementation-based analytical framework to assess how coastal NbS respond to multiple Climate Impact Drivers (CIDs), including sea-level rise, ocean warming, storm intensity, precipitation variability, and ocean acidification.
A structured qualitative review of 117 coastal NbS studies was conducted, of which 35 were CID-relevant and only 14 contained sufficient process-level information for detailed analysis. Eight Implementation Components (ICs)—baseline assessment, stakeholder engagement, comparative analysis, economic analysis, performance indicators, monitoring, adaptive management, scalability and replicability—were identified and analysed using Jaccard similarity indices to quantify their co-occurrence. These ICs are related to implementation planning, governance, monitoring, learning, and scalability. The ICs were further mapped to the International Union for Conservation of Nature (IUCN) Global Standard for NbS to evaluate their conceptual alignment with recognised quality criteria.
Results show that ICs such as baseline assessment, monitoring, and performance indicators dominate current NbS practice, whereas learning-orientated and enabling processes—particularly comparative analysis, adaptive management, stakeholder engagement, and economic assessment—are weakly integrated. This structural imbalance limits cross-site learning, adaptive capacity, and scalability under interacting climate pressures. NbS interventions exhibiting more complete process architectures demonstrate greater alignment with IUCN criteria related to governance, feasibility, and long-term sustainability.
The study demonstrates that scalability is an emergent property of process completeness rather than a function of ecosystem type or intervention outcomes. This study establishes a quantitative-conceptual framework that integrates CIDs, ICs, and NbS standards, offering a transferable methodology for identifying implementation deficiencies and enhancing the design of resilient, policy-relevant coastal NbS.
Continue reading ‘Effectiveness and scalability of coastal nature-based solutions under climate impact drivers: a systematic review’Aquaculture of seaweeds (Saccharina latissima, Ulva spp., Gracilaria spp.) significantly improves the growth of co-cultivated bivalves in mesotrophic, but not eutrophic, estuaries
Published 29 December 2025 Science ClosedTags: algae, biological response, BRcommunity, chemistry, field, fisheries, mitigation, mollusks, morphology, North Atlantic
The co-cultivation of seaweeds with bivalve shellfish is a potential strategy for protecting bivalve crops against anthropogenic coastal acidification and hypoxia. We co-cultivated seaweeds and bivalves using a succession of seaweed species according to season (winter, Saccharina latissima → spring, Ulva spp. → summer, Gracilaria spp.) together with eastern oysters (Crassostrea virginica) and blue mussels (Mytilus edulis). Bivalves and seaweeds were deployed in two estuaries that contrasted in trophic state, one mesotrophic and one eutrophic. In all five experiments in the mesotrophic system, cocultivation with seaweeds significantly increased weight- and/or shell-based growth of bivalves (p < 0.05). Growth rate increases for C. virginica were modest, with weight-based growth improving by 17–21% and shell-based growth improving by 3–27% with seaweed co-culture of all macroalgal species. For M. edulis, the effect was large; co-culture with S. latissima caused 47% and 114% increases in shell- and weight-based growth rates, respectively. In the four experiments in the eutrophic estuary, co-culture with seaweeds did not significantly improve bivalve growth. Seaweed cultivation significantly improved water quality metrics (increased pH and dissolved oxygen (DO); p < 0.05 in all cases) in and around the seaweed sites at both locations, although increases in pH and DO were modest, and even in control treatments, there were no prolonged periods of harmful pH or DO levels. An abundance of macroalgal detritus may have bolstered the diets of co-cultivated bivalves in the mesotrophic estuary, a hypothesis supported by lower chlorophyll a concentration, and therefore lower planktonic food levels, at that site. Given that seaweeds display species-specific allelopathic effects against phytoplankton, it is also possible that the presence of seaweeds altered the phytoplankton community to the benefit of the bivalves. Regardless, the findings here demonstrate that co-cultivation with seaweeds can accelerate the growth of bivalves.
Continue reading ‘Aquaculture of seaweeds (Saccharina latissima, Ulva spp., Gracilaria spp.) significantly improves the growth of co-cultivated bivalves in mesotrophic, but not eutrophic, estuaries’A global meta-analysis reveals consistently negative effects of ocean acidification on marine cultured bivalves: implications for future bivalve aquaculture
Published 16 December 2025 Science ClosedTags: biological response, calcification, fisheries, growth, mitigation, mollusks, mortality, performance, physiology, reproduction, review
The exponential rise in atmospheric CO₂ driven by human activities is accelerating climate change and causing ocean acidification (OA). While the effects of elevated CO₂ on a wide range of marine species have been well documented, the implications of OA for bivalve aquaculture have received comparatively little attention. Using a multi-level meta-analytical approach, we evaluated the impacts of two elevated pCO₂ levels—classified as high and extreme—on cultured bivalves, based on 266 observations from 24 species across tropical and temperate regions. Overall, both elevated pCO₂ levels negatively affected bivalves, reducing survival, growth, feeding rates, development, and calcification. Larvae were generally more vulnerable than juveniles and adults. Our analyses further indicated that temperate bivalves were more sensitive to OA than tropical and subtropical counterparts. Among taxa, clams were the most vulnerable under high CO₂ emission scenarios, whereas scallops were the most sensitive under extreme pCO₂ levels. We also discuss potential mitigation strategies for the bivalve aquaculture industry. With advancements in local and regional monitoring, coupled with targeted measures such as buffering sites, selective breeding, and integrated multi-trophic aquaculture, the adverse effects of OA on bivalve farming could be mitigated.
Continue reading ‘A global meta-analysis reveals consistently negative effects of ocean acidification on marine cultured bivalves: implications for future bivalve aquaculture’Perceptions of oyster farmers on adopting environmental monitoring technologies to mitigate ocean acidification: a case study in Bahía San Quintín, México
Published 19 November 2025 Science ClosedTags: fisheries, mitigation, North Pacific, socio-economy
Coastal ecosystems face multiple stressors, and their responses are magnified by global stressors associated with climate change, such as warming and ocean acidification (OA). Oyster farming are vulnerable to the effects of these stressors. Environmental monitoring technologies have been proposed as an adaptive strategy to OA. This study examined the perceptions of the oyster farmers in Bahía San Quintín, Mexico, toward this strategy. Through surveys and workshops, we identified the main challenges oyster farmers face in their industry, their level of awareness about OA, and their openness to adopting new technologies. Most respondents (66 %) did not recognize OA, which suggests that they had a low perception of its risks and its potential consequences for their activities. The most frequent problems were environmental issues (48 %), such as extreme temperature events, biofouling, and predation, followed by limited technical and financial resources (34 %). Recognizing the negative effect that high temperatures have on their activity, especially during El Niño Southern Oscillation (ENSO) events, is a positive outcome, as it allows them to adopt strategies to cope with OA. The main barriers to adopt new technologies were related to management issues (56 %), including a lack of economic resources. We recommend that interactions between oyster producers, academia, and governmental actors must be strengthened to promote environmental monitoring, thus improving their adaptive capacity and reducing potential impacts of stressors on their industry, such as climate change and OA. This study case is a valuable reference for other oyster farming communities in similar environmental and socio-economic contexts.
Continue reading ‘Perceptions of oyster farmers on adopting environmental monitoring technologies to mitigate ocean acidification: a case study in Bahía San Quintín, México’Spaces of anthropogenic CO2 emissions compatible with climate boundaries
Published 14 November 2025 Science ClosedTags: chemistry, globalmodeling, mitigation, modeling
Climate boundaries are planetary boundaries for the climate system: limits within which humanity can sustainably prosper. Here we introduce a modelling framework to analyse global warming, ocean acidification, sea-level rise and Arctic sea-ice melt. Using a reduced-form model, we map out anthropogenic CO2 emissions, carbon dioxide removal and solar radiation management pathways compatible with these boundaries. We define safety levels as the probability to stay within one or several boundaries considering physical uncertainty. If CO2 emissions peak in 2030, net-zero CO2 is reached in 2050, and carbon dioxide removal capacity is 10 PgC yr−1, without solar radiation management, remaining within the global warming boundary of 2 °C exhibits a safety level of 80%. When all four boundaries are considered together, the safety level drops to 35%. Our results highlight key trade-offs in mitigation options and suggest a need to assess climate boundaries holistically to develop sustainable future strategies.
Continue reading ‘Spaces of anthropogenic CO2 emissions compatible with climate boundaries’Japan shellfish farmer perceptions of ocean acidification, adaptive strategies and comparison with global shellfish farmers
Published 24 October 2025 Science ClosedTags: fisheries, mitigation, North Pacific, policy, socio-economy
Ocean acidification (OA) poses significant threats to shellfish aquaculture. Although governments and organizations around the globe are taking actions to mitigate the impacts of OA, few studies directly report shellfish farmer perceptions of OA and corresponding responses. In this study, we document Japanese shellfish (oyster) commercial farmer perceptions of, and adaptive strategies for OA with respect to oyster aquaculture. We also review and compare our results with existing studies of shellfish commercial farmer perceptions of OA in three regions, including the United States (U.S.), the Mediterranean region and British Columbia, Canada. We found variation in the perceptions of OA around the globe; it is common among all shellfish farmers to have difficulty distinguishing OA from other environmental stressors. OA adaptive strategies from shellfish farmers were only reported for the U.S. (in the literature), and Japan (this study). Acknowledging the diverse geographical and cultural backgrounds, we discussed the similarity and difference of adaptive strategies between the U.S. (as a post-event case with documented OA-related shellfish mortality) and Japan (as a pre-event case) to cope with OA. For example, farmers from both countries suggest, or are already utilizing flexibility in farm management and applying knowledge through hands-on learning. While U.S. farmers rely on networking with different stakeholders to learn about OA knowledge and solutions while Japanese farmers do not. Learning from the strategies that U.S. farmers applied to adapt to OA events, several areas of policies and actions (e.g., financial support, collaboration with scientists and OA awareness enhancement) were identified to better support and empower Japanese shellfish farmers to adapt to future OA scenarios. However, future study on suitability and transferability of implementing policies and actions in Japan is required due to different geographical and cultural contexts.
Continue reading ‘Japan shellfish farmer perceptions of ocean acidification, adaptive strategies and comparison with global shellfish farmers’Dulse seaweed Devaleraea mollis mitigates effects of ocean acidification on larval Pacific oysters Magallana gigas
Published 21 October 2025 Science ClosedTags: algae, biological response, BRcommunity, chemistry, laboratory, mitigation, molecular biology, mollusks, morphology, North Pacific, reproduction
Ocean acidification (OA), driven by upwelling and climate change, can negatively impact the ecological and economic contribution of marine calcifiers along coasts worldwide. OA interferes with calcification, particularly in early life stages, causing mortality, reduced growth, and morphological abnormalities in shellfish such as the Pacific oyster (Magallana gigas). This issue is gaining traction as climate change intensifies, placing shellfish in wild populations and farms alike at risk. Macroalgal photosynthesis by seaweed such as Pacific dulse (Devaleraea mollis) has been proposed to provide small-scale OA refuges, but few controlled experiments quantify this effect, and none have focused on larval shellfish. This study examines the potential for Pacific dulse to mitigate OA and its effects on Pacific oyster larvae. Under continuous light for 23 days, the presence of dulse resulted in a consistent increase in seawater aragonite saturation state by 0.1-0.9, and pH by 0.1-0.5 units, depending on OA condition. Newly fertilized oysters were reared for 48 hours in the absence or presence of dulse under treatments corresponding to ambient (pH 7.8, 450 μatm CO₂), future OA (pH 7.6, 800 μatm CO₂), and future OA + upwelling (pH 7.4, 1200 μatm CO₂) seawater conditions. Dulse fully mitigated OA effects on larval size that ranged from decreases of 5% to 10%. Under the future OA + upwelling treatment, dulse presence reduced the odds of underdeveloped oyster larvae at 14 hours post fertilization (hpf), and larvae with hinge abnormalities at 24 hpf, by over 50%. Dulse induced minor changes to immune response gene expression at 48 hpf. These findings highlight the benefits of seaweed when adjacent to organisms sensitive to OA. These findings will be particularly useful for shellfish farms, habitat restoration efforts, and ocean stewardship practices as a potential mitigation strategy under the changing climate.
Continue reading ‘Dulse seaweed Devaleraea mollis mitigates effects of ocean acidification on larval Pacific oysters Magallana gigas’Macroalgae farming increases DO and pH, reduces pCO2 and nutrients, and enhances blue carbon potential
Published 17 October 2025 Science ClosedTags: algae, biogeochemistry, biological response, chemistry, field, fisheries, mitigation, North Pacific
Edible macroalgal cultivation is increasingly promoted as a nature-based solution to mitigate coastal eutrophication and improve seawater quality. However, the species-specific impacts and spatial extent of these ecological effects remain poorly understood, particularly in semi-enclosed bays with complex hydrodynamics. This study aims to quantify the biogeochemical influence of two widely cultivated species—Porphyra haitanensis and Hizikia fusiformis—on seawater carbonate chemistry and nutrient levels in Yueqing Bay, eastern China. High-resolution field surveys were conducted at 52 stations, enabling direct comparisons between cultivated and non-cultivated waters. Geostatistical modeling, including spherical semivariograms and Empirical Bayesian Kriging, was applied to delineate species-specific influence zones and quantify changes in key water quality parameters. P. haitanensis farming induced broad, kilometer-scale improvements in seawater chemistry, including elevated dissolved oxygen (DO) (+ 2.72%) and pH (+ 0.09 units), and significantly lower partial pressure of CO2 (pCO2) (− 118 µatm), relative to distant reference sites (all p < 0.05). A slight increase in total phosphorus (TP) (+ 0.007 mg L− 1) was also observed, likely reflecting nearby riverine inputs. In contrast, H. fusiformis cultivation produced more localized (< 100 m) but significant changes, including reductions in dissolved inorganic carbon (DIC) (− 1.84 mg L− 1) and pCO2 (− 82.6 µatm), alongside increases in DO (+ 1.72%), pH (+ 0.02 units), and chlorophyll-a (Chl-a) (+ 0.72 µg L− 1) (all p < 0.05). These results provide the first fine-scale, species-resolved spatial assessment of macroalgal farming effects on water quality in a semi-enclosed bay. By quantifying distance-dependent ecological responses, this study offers science-based guidance for spatial planning, nutrient management, and blue carbon integration—particularly as the routine harvest of biomass facilitates net carbon export from coastal waters. These findings highlight the potential of macroalgal farming as a scalable, multifunctional nature-based solution for sustainable aquaculture and climate mitigation.
Continue reading ‘Macroalgae farming increases DO and pH, reduces pCO2 and nutrients, and enhances blue carbon potential’Impact of ocean acidification on the biology of marine bivalves
Published 14 October 2025 Science ClosedTags: biological response, mitigation, mollusks, physiology, reproduction, review
Ocean acidification, resulting from increased atmospheric CO₂ levels, poses a significant threat to marine ecosystems, particularly to shell-forming organisms such as marine bivalves. This review synthesizes current knowledge regarding the impacts of ocean acidification on bivalves, including oysters, clams, and mussels, focusing on their physiology, development, and ecological interactions. Acidification impairs shell formation, disrupts energy metabolism, alters feeding and respiration patterns, and inhibits the growth and recruitment of larvae. These changes can destabilize bivalve populations and impair the ecosystem services they offer, such as water filtration, habitat creation, and support for fisheries and aquaculture. The report discusses potential strategies to mitigate the impacts of climate change, including the reduction of carbon emissions, selective breeding, and habitat management. This underscores the necessity of interdisciplinary research to comprehend the long-term impacts of climate change and to promote sustainable resource management that benefits the environment.
Continue reading ‘Impact of ocean acidification on the biology of marine bivalves’New Jersey ocean acidification action plan
Published 3 October 2025 Science ClosedTags: mitigation, North Atlantic, policy, socio-economy
The NJDEP created an Ocean Acidification Action Plan to address ocean and coastal acidification. Left unchecked, this global issue will negatively impact the balance of the ecosystem as well as the state’s fish and shellfish industries. Shellfish are particularly vulnerable through the impacts of acidification on shell formation.
The New Jersey Ocean Acidification Action Plan identifies steps that the NJDEP has already taken that can help mitigate ocean and coastal acidification and outlines the Department’s next steps to better understand the current conditions and prepare for additional impacts of ocean and coastal acidification.
Continue reading ‘New Jersey ocean acidification action plan’In-situ measurements reveal alkalinity release from cold-temperate seagrass meadows
Published 25 September 2025 Science ClosedTags: biological response, chemistry, field, mitigation, North Atlantic, phanerogams
Highlights
- Cold-temperate seagrass meadows are net sources of alkalinity
- Alkalinity generation exceeds soil organic carbon accumulation by fourfold
- Seagrasses buffer ocean acidification locally during the day
- Alkalinity generation in seagrasses is lower than in mangroves and saltmarshes
Abstract
Understanding the carbon sequestration potential of blue carbon ecosystems is important to inform climate policies and to guide restoration and protection efforts. Alkalinity generation is an often overlooked carbon sequestration mechanism, especially in seagrass meadows. Here, we quantified total alkalinity (TA) and dissolved inorganic carbon (DIC) fluxes in two cold-temperate Zostera marina seagrass meadows in Sweden using 24-hour in-situ chamber incubations at the end of the high-productivity season. The seagrass meadows were similar net sources of TA (16 ± 45 mmol m-2 d-1 in Smalsund, 17 ± 16 mmol m-2 d-1 in Bökevik), whereas DIC fluxes were highly variable (34 ± 59 mmol m-2 d-1 in Smalsund, -43 ± 35 mmol m-2 d-1 in Bökevik). Fluxes followed a diurnal cycle consistent with photosynthesis-respiration cycles. As a result, seagrass meadows ameliorated ocean acidification locally during the day, but not during the night. The large CO2 uptake provided higher buffering levels compared to mangroves and saltmarshes. The TA fluxes were comparable to those reported for Mediterranean and tropical seagrass meadows, but 16-times lower than in mangrove forests and 5-times lower than in saltmarshes. Alkalinity generation in these cold-temperate seagrasses exceeded soil organic carbon stocks accumulation by fourfold, potentially contributing to their carbon sequestration potential and warranting inclusion in seagrass meadow carbon budgets.
Continue reading ‘In-situ measurements reveal alkalinity release from cold-temperate seagrass meadows’The impacts of ocean acidification on coral reefs in the Red Sea and ways to address it – a review
Published 17 September 2025 Science ClosedTags: biological response, BRcommunity, corals, mitigation, physiology, Red Sea, review
Ocean acidification (OA) is an escalating environmental challenge that poses significant threats to marine ecosystems, especially coral reefs. The Red Sea, characterized by its distinct marine biodiversity and climatic conditions, is becoming increasingly susceptible to the effects of (OA). This review investigates the impact of ocean acidification on coral reefs in the Red Sea, emphasizing physiological, ecological, and socio-economic consequences. Alterations in seawater chemistry, notably a reduction in pH and the availability of carbonate ions, impede coral calcification, disrupt symbiotic relationships, and contribute to coral bleaching. The review also highlights the vulnerability of coral species in the Red Sea, which is further exacerbated by local stressors such as temperature variations, pollution, and overfishing. Additionally, it examines various strategies to mitigate these impacts, including active coral reef restoration, genetic adaptation research, the creation of marine protected areas, and the mitigation of local environmental stressors. Addressing ocean acidification in the Red Sea necessitates a combination of global and regional initiatives aimed at reducing (CO2) emissions, alongside local conservation measures to enhance the resilience of coral reef ecosystems. This review highlights the critical need for interdisciplinary research and cooperative efforts to protect the future of coral reefs in the region.
Continue reading ‘The impacts of ocean acidification on coral reefs in the Red Sea and ways to address it – a review’Effect of ocean acidification on the metabolism and behavior of tropical sea cucumbers
Published 16 September 2025 Science ClosedTags: biological response, echinoderms, mitigation, performance, physiology, respiration, review
In recent years, CO₂ emitted by human activities has continued to rise. The ocean absorbs these CO₂ and has caused seawater acidification. It is expected that the pH of the sea surface will drop by 0.3~0.4 by the end of this century. Tropical sea cucumbers are the “engineers” of the subsea ecosystem, promoting organic degradation and nutrient circulation through feeding disturbances. This study reviews the effects of marine acidification on the metabolism and behavior of tropical sea cucumbers. Studies have shown that under low pH conditions, sea cucumbers have increased respiratory metabolic pressure, digestive enzyme activity is reduced, and more energy is used to maintain the acid-base balance in the body, and their growth and reproduction are limited. At the same time, sea cucumber feeding rate and defense behavior are inhibited, and habitat distribution may change. These changes will have a chain effect on tropical ecosystems such as coral reefs, weaken the nutrient circulation function, and affect ecological balance. In-depth research on the impact mechanism of marine acidification on sea cucumbers will help predict the response of marine ecosystems under climate change and provide scientific basis for resource conservation and aquaculture management.
Continue reading ‘Effect of ocean acidification on the metabolism and behavior of tropical sea cucumbers’Selective breeding boosts oyster resilience to ocean acidification via energy budget modulation
Published 12 September 2025 Science ClosedTags: biological response, fisheries, growth, laboratory, mitigation, mollusks, mortality, North Pacific, physiology
Natural pH variability in coastal-estuarine systems exacerbates OAX events through frequent pCO2 spikes, posing severe threats to bivalves and ecosystems they support. While selective breeding has improved growth performance in oysters, its capacity to enhance tolerance to acidic stress remains poorly understood. Here, we evaluated the physiological performance of wild and recently selectively bred oyster variety (Guihao No. 1) under the simulation of recurrent OAX scenarios. In comparison to wild oysters, selectively bred oysters exhibited significantly higher survival rates, fast shell growth, and improved condition index. Energy metabolism suggests that selective breeding confers enhanced stress resilience in oysters by optimizing feeding capacity, increasing oxygen uptake, and reducing ammonia excretion rates. This metabolic efficiency supports more effective protein and glycogen turnover, as evidenced by elevated O:N ratios, and ultimately results in higher SFG. PCA analysis demonstrated that enhanced energy metabolism (CMA, NKA), antioxidant capacity (low MDA), and immune activity (high ACP, AKP) contributed to improved growth and resilience of selectively bred oysters when exposed to OAX, whereas wild oysters showed metabolic suppression and oxidative damage. These results highlight the role of selective breeding in promoting stress tolerance through optimized energy allocation and defense mechanisms, offering valuable guidance for climate-resilient oyster aquaculture in acidifying oceans.
Continue reading ‘Selective breeding boosts oyster resilience to ocean acidification via energy budget modulation’Ocean acidification: impacts on marine ecosystems and deep-sea carbon sequestration
Published 10 September 2025 Science ClosedTags: biogeochemistry, biological response, fisheries, mitigation, review
Carbon dioxide (CO₂) is a major greenhouse gas that plays an essential role in Earth’s climate system. Oceans help climate stability by absorbing about 30% of the anthropogenic CO₂ emissions. However, this process leads to ocean acidification (OA) and reduces the availability of carbonate ions, which are necessary for organisms that build shells and skeletons, such as corals, mollusks, and certain plankton. Since the Industrial Revolution, ocean pH has dropped by approximately 0.1 units, a significant shift that threatens marine ecosystems. OA affects marine organisms in multiple ways. Calcifying species struggle to form shells, leading to reduced survival and disrupted food webs. Coral reefs, often called the “rainforests of the sea” due to their exceptional biodiversity, are particularly vulnerable, and their decline results in biodiversity and habitat loss. Phytoplankton, the foundation of the marine food web and the ocean’s biological carbon pump, also respond in mixed ways; some benefit from higher CO₂, while others are negatively affected, reducing ocean productivity and carbon cycling. OA weakens the ocean’s biological carbon pump, reducing long-term carbon storage in the deep sea. It also contributes to harmful algal blooms, which can contaminate seafood and pose human health risks. Economically, OA threatens global seafood production, especially shellfish and crustaceans, jeopardizing food security and coastal livelihoods. This paper explores the biological, ecological, and economic impacts of OA and discusses mitigation strategies such as reducing CO₂ emissions, protecting blue carbon ecosystems, controlling coastal pollution, and supporting adaptive aquaculture. Addressing OA is essential to protect marine biodiversity, sustain seafood resources, and maintain climate stability.
Continue reading ‘Ocean acidification: impacts on marine ecosystems and deep-sea carbon sequestration’Emergent seasonal hypoxia and acidification risks induced by seaweed and fish polyculture in the world’s largest seaweed farm
Published 26 August 2025 Science ClosedTags: chemistry, field, fisheries, mitigation, North Pacific
Scientific Significance Statement
Seaweed farming is increasingly recognized as a promising strategy for marine carbon dioxide removal (mCDR). However, its ecological sustainability, particularly in semi-enclosed bays, remains uncertain. Using data collected from Sansha Bay, Fujian, China, the world’s largest seaweed farming site, our study reveals an inherent trade-off: in highly sheltered coastal environments, especially when integrated with algae-fish polyculture, seaweed farming can induce significant hypoxia and acidification risks through organic carbon degradation. Carbon isotopic tracing further demonstrates that seasonal shifts in organic carbon sources—from fish feed in autumn to macroalgal detritus in spring—diminish the potential of macroalgal-based carbon sequestration. These findings emphasize the complexity of coastal carbon management and highlight the critical importance of considering ecosystem health—including the system’s capacity to maintain oxygen and pH stability and sustain biogochemical functioning—when implementing seaweed-based carbon sequestration strategies.
Abstract
Seaweed farming is increasingly promoted as a carbon sequestration strategy, but its effectiveness relies on carbon burial and export to deep waters. Seaweed farms commonly occupy semi-enclosed bays, causing continuous accumulation of organic carbon (OC) and its degradation products, potentially undermining carbon sequestration and driving hypoxia and acidification. These ecological impacts may be amplified in fish–algae polyculture systems, yet they remain unclear. We investigated carbon cycling in Sansha Bay, China, the world’s largest seaweed farm and intensive algae–fish polyculture site. During aquaculture seasons, bottom waters experienced rapid OC decomposition, causing severe oxygen depletion and acidification. Vertical mixing spread these effects throughout the water column, turning surface waters into net CO2 sources. δ13CDIC carbon isotopic analyses indicated seasonal shifts in dominant OC sources, from fish feed in autumn to macroalgal detritus in spring. These findings underscore the importance of evaluating the sustainability of coastal systems when pursuing seaweed-based carbon sequestration.
Renewable energy innovation seen as key to slowing ocean warming and acidification
Published 19 August 2025 Media coverage ClosedTags: mitigation
While reading about growing trends affecting a sustainable future, you’ve probably encountered articles warning of adverse ocean warming and acidification patterns. The issues affect marine life and risk the biodiversity of some of the world’s largest bodies of water. However, greenhouse gas emissions — including those linked to fossil fuel usage — are among the biggest contributors to these problems. Could renewable energy and related technologies ease the pressures on sea life?
…
Reducing fossil fuel dependence could meaningfully improve these worrying ocean-related trends. Increased demands from concerned citizens who care about the planet and its oceans should encourage authorities to act faster than they otherwise might.
One possibility might be to use oceans to accelerate renewable energy transitions. A 2025 study revealed coastal areas in South Africa and eastern Florida as among the best places for capturing kinetic energy from currents and finding new renewable sources. The data indicated locations in those sites had power densities surpassing 2,500 watts per square meter, equivalent to 2.5 times more energy than places identified as excellent wind farm candidates.
Offshore wind farms already show the promising feasibility of ocean-located renewable sites. However, this study’s angle provides an additional possibility that taps into natural forces. The more people learn about diverse options, the easier it will be to focus on those with the most potential.
…
Continue reading ‘Renewable energy innovation seen as key to slowing ocean warming and acidification’
