Posts Tagged 'growth'

Changes in photosynthesis and grazing facilitate growth of a mixotrophic protist under ocean acidification and warming

Published 22 July 2026 Science Closed
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Summary

  • Mixotrophic protists capable of both photosynthesis and phagotrophy are key members of marine plankton communities. Yet, little is known about their responses to the combination of ocean acidification and warming.
  • A marine mixotrophic chrysophyte, Ochromonas CCMP2951, was subjected to two levels of pCO2 (300 and 800 ppm, resulting in pH of 8.2 and 7.8) and temperature (21°C and 26°C) in a factorial design.
  • Enhanced growth rates were observed in both the high CO2 and high temperature treatments, while cell size significantly decreased with temperature. Strongly decreased cellular phosphorus content led to increased N : P and C : P ratios of Ochromonas with temperature. Furthermore, warming increased grazing rates, while elevated CO2 reduced the Chl content but increased photosynthetic carbon acquisition, albeit only at low temperature. The combination of warming and elevated CO2 had antagonistic effects on the balance between autotrophic and heterotrophic carbon acquisition, keeping the net role of this mixotroph in the marine carbon cycle stable.
  • Altogether, both the direct stimulation of growth and the indirect effects of altered stoichiometry may favor mixotrophs under future ocean conditions. However, their contribution to future carbon cycling in complex natural communities will need further study.

Graphical Abstract

Grazing rates of Ochromonas CCMP2951 expressed as carbon obtained per mean cell volume (a) and Caut/het-photosynthetically fixed carbon divided by carbon obtained through grazing (b) in the four experimental treatments.

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The effects of decreased pH and increased temperature on survival and shell development of the larvae of the endemic Hawaiian oyster Dendostrea sandvichensis

Published 17 July 2026 Science Closed
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Climate change models predict future ocean-wide decreases in pH and increases in temperature, posing a serious threat to calcifying marine invertebrates. In Hawaiʻi, local seawater temperature and pH are predicted to change even more rapidly. The Hawaiian oyster Dendostrea sandvichensis, an endemic species, remains understudied despite its ecological roles in reef- building, biofiltration, and as a food source. While previous studies have revealed the alarming impacts of ocean acidification and warming on bivalves, little is known about how the planktonic larvae of D. sandvichensis will respond to projected climate conditions.

To investigate these effects, the larvae of D. Sandvichensis were reared under present-day conditions in Pearl Harbor, HI (pH 8.1, 26.5 °C) and projected future conditions (pH 7.7, 30.0°C) for one week. Shell growth, density, and degradation were then measured using micro-CT, confocal, and scanning electron microscopy. Additionally, two larval husbandry methods were evaluated, with a static-flow system paired with UV water treatment yielding approximately 11- fold higher survival than an open-flow system. Elevated temperature reduced larval survival (~67%) compared to ambient conditions. Reduced pH significantly decreased shell length (~11.8μm), while both stressors reduced shell density in Experiment 3. Shell density decreased by ~12% under elevated temperature, ~18% under reduced pH, and ~43% under the combined stressors, and was accompanied by increased shell degradation and abnormalities.

These findings indicate that elevated temperature and reduced pH impact larval oysters through multiple pathways, including reduced survival and compromised shell integrity. This study provides new insights into the vulnerability of an endemic Hawaiian species and essential data for predicting its resilience under future climate change scenarios.

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Interactive effects of triclosan, microplastic vectors, and ocean warming–acidification on sea urchin embryo development

Published 6 July 2026 Science Closed
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Highlights

  • Microplastics modulate triclosan toxicity in a concentration-dependent manner.
  • Microplastic loads reverse triclosan attenuation affecting larval development.
  • Acidification amplifies triclosan–microplastic toxicity in sea urchin embryos.
  • Ocean Warming modulates toxicity; degree-day normalization reveals hidden stress.

Abstract

Understanding how emerging contaminants interact with climate-driven stressors is essential for accurate ecological risk assessment in coastal ecosystems. This study evaluates the individual and combined effects of triclosan (TC), polyethylene microplastics (MP), ocean warming (OW), and ocean acidification (OA) on the early development of Paracentrotus lividus embryos. A tiered experimental design was implemented to: (i) characterize TC dose–response curves alone and in combination with increasing concentrations of MP (300–3000 particles mL−1), and (ii) assess how OW (24 °C) and OA (pH 7.6) modulate contaminant toxicity. TC showed concentration-dependent growth inhibition, while MP exhibited a biphasic interaction with TC: at moderate concentrations, MP increased EC10 values and steepened dose–response slopes, consistent with contaminant sorption reducing freely dissolved TC. At 3000 particles mL−1, this trend reversed, lowering EC50 values and enhancing toxicity. Morphometric analyses revealed that co-exposure to TC alone and with MP loads impaired arm elongation, increased body-width ratios, and reduced stomach volume, indicating compromised feeding and skeletal development. Climate stressors significantly altered toxicological outcomes. OA strongly amplified the combined toxicity of TC + MP, reducing larval growth to near-zero levels, whereas OW alone did not exacerbate toxicity and partially mitigated OA-driven effects in MP-TC treated groups. Degree-day normalization demonstrated that warming accelerates development but reduces growth efficiency across treatments. Overall, these results reveal threshold-dependent MP–TC interactions and highlight acidification as a critical amplifier of contaminant effects. Incorporating realistic MP–pollutant interactions and climate variables is crucial for improving hazard assessments under future ocean scenarios.

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Impact of water quality and gear type on Eastern oyster (Crassostrea virginica) growth in Narragansett Bay, RI

Published 1 July 2026 Science Closed
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Oyster aquaculture is expanding in Rhode Island, yet key farming regions in the lower West Passage of Narragansett Bay (WPNB) lack the in-situ, high-temporal resolution monitoring needed to evaluate emerging stressors and support production. At the same time, the industry is undergoing rapid technological development aimed at improving production while reducing labor and overall costs. In recent years, a low maintenance, alternative surface gear was introduced in WPNB; however, its impact on oyster performance relative to traditional cultivation methods has not been quantified. This study established a 1.5-year continuous water quality time series in WPNB and paired these observations with physiological assessments of Crassostrea virginica grown in three cultivation methods (i.e., traditional surface, alternative surface, and bottom gear). This work aimed to better understand the impact of environmental variability and gear type on oyster health, growth, and survival. Multiparameter sondes and discrete bottle samples were used to monitor water quality and calculate carbonate saturation state (Ω) at a 4-acre oyster farm. Nine mesh bags containing early-life stage C. virginica (16 ± 0.4 mm; n = 300 per bag) were deployed in July 2025, with three replicate bags in each gear type. Subsamples (n = 15) from each gear type were collected over a 6-month period for morphometric measurements and scope for growth (SFG) determinations. Minimal differences in carbonate chemistry were observed among sampling sites and Ω remained supersaturated (Ω >1) for the majority of the study period, indicating that ocean acidification was not a major stressor for farmed oysters. Survival was highest (82 ± 4.5%) in surface gear types compared to bottom gear (27 ± 0.58%), while physical growth (shell and tissue) and SFG were largely similar among all gear types. These results suggest that the alternative surface gear may support comparable production and product quality to traditional gear types, while also reducing maintenance and labor demands. Overall, this study provides important physiological and biological context for oyster aquaculture while informing gear selection and farm management strategies.

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Acute low pH associated with coastal acidification is detrimental to larval development of the Cape urchin Parechinus angulosus

Published 26 June 2026 Science Closed
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Acidification in coastal habitats is increasing in duration and amplitude under the continued influence of ocean acidification and contributing coastal processes. The impacts of low pH conditions on calcifying organisms, especially echinoderms, is well established, with the early developmental stages being especially vulnerable. This is the first study to assess the impact of locally relevant coastal acidification scenarios on the early development of the Cape urchin Parechinus angulosus. Our findings suggest that the early larval stages of this species are unlikely to survive when exposed to low pH conditions, specifically during the onset of skeletogenesis. In our laboratory experiments, larvae that were exposed to the low pH treatment (pH 7.32) showed significantly reduced growth (GLMM, Time × Treatment interaction: β = −0.361 ± 0.019, z = −19.06, p < 0.001) and developmental regression compared with those from the control treatment (pH 7.95). Substantially slower growth rates were observed in the low pH treatment (length = 72.3 hpf0.18) compared with in the control treatment (length = 24.24 hpf0.54). There was also evidence of abnormal and delayed development and potential dissolution of skeletal structures under the low pH condition. However, fertilisation success and larval survival did not differ significantly between the experimental treatments, suggesting that developmental impacts of low pH over short durations, even though substantial, may be sublethal. The developmental impacts are likely to impair the transition of larvae to the adult stages, which may ultimately affect populations of this ecologically important species under future coastal acidification scenarios.

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Response of HAB-forming microalgae competition to ocean acidification, warming, and changing light fields

Published 17 June 2026 Science Closed
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In recent years, the East China Sea (ECS) has experienced frequent harmful algal blooms (HABs), driven by the complex interplay of climate change—specifically ocean warming and acidification—and eutrophication-induced light attenuation. Despite their ecological significance, the interactive effects of these environmental stressors on the competitive dynamics between bloom-forming microalgae remain poorly understood. This study aimed to elucidate how warming, reduced light, and elevated CO2 influence the competition between two dominant diatoms. We conducted controlled monoculture and mixed-culture experiments using two key species: Skeletonema costatum and Chaetoceros curvisetus. The experimental design incorporated varying levels of CO2, temperature, and light intensity to simulate future coastal scenarios. Growth rates, peak cell densities, and successional patterns were monitored to assess competitive outcomes under multiple stressors. Monoculture results indicated that high temperature and low light intensity promoted the growth of both species. However, in mixed cultures, these conditions significantly accelerated the time to reach peak density and induced a definitive successional shift from S. costatum to C. curvisetus. Notably, while the general successional pattern was consistent, elevated CO2 further enhanced the competitive advantage of C. curvisetus, particularly when combined with high-temperature and low-light scenarios. These findings suggest that the synergy of future warming, declining light availability, and intensified ocean acidification in the ECS will likely favor C. curvisetus over S. costatum. This shift may increase the frequency of HAB events dominated by C. curvisetus, driving significant climate-related restructuring of phytoplankton communities in coastal ecosystems.

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Response mechanism of Sepia esculenta larvae under global warming, ocean acidification and salinity fluctuation: Integrated biochemical and transcriptome profiling

Published 12 June 2026 Science Closed
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Highlights

  • Analysis based on global warming, ocean acidification and salinity fluctuation.
  • Multi-angle analysis of Sepia esculenta under temperature, pH and salinity stress.
  • Different stress enhanced the immune defense and antioxidant defense of S.esculenta.
  • The hub genes closely related to stress resistance were identified and screened out.

Abstract

The Sepia esculenta occupies a significant economic proportion in the squid family, and it is also the squid with the largest economic value in the northern sea area of China. With the occurrence of global warming, ocean acidification and ocean salinity fluctuations, it has caused serious negative effects on the development of the S. esculenta artificial breeding industry. Therefore, in the research, we employed weighted gene co-expression network analysis (WGCNA) to investigate the effects of three environmental factors, including salinity, temperature and pH, on the molecular mechanism of S. esculenta larvae, and proved the reliability of transcriptome results through physiological indicators. Enrichment analysis of each module indicated that environmental exposure markedly influenced immune function, oxidative stress responses, and other physiological processes in S. esculenta larvae. Our research elucidates the comprehensive response mechanism of S. esculenta under different environmental stresses, clarifies the significant molecular pathways essential for its growth and development.

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Ocean acidification effects on larval development and survival in commercially important shellfish

Published 10 June 2026 Science Closed
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This paper studies the consequences of ocean acidification (OA) on the growth and survival of the larvae of commercially significant shellfish species such as oysters, mussels, and scallops. The authors of the study are particularly concerned with the negative processes of OA with respect to the growth of larvae, shell development, and behavior, which result in decreased survival rates, particularly the consequences of the reduced availability of calcium carbonate on the weakening of shells and larvae, which are preyed upon. The paper also studies the interference with the behavior of larvae, particularly with respect to the adequate detection of sites to settle, which is harmful to recruitment success. Additionally, the study looks at the OA-induced metabolic stress, where the larvae are expected to expend higher energy to maintain homeostasis at the expense of growth and immunity. By focusing on this issue, the paper outlines the OA’s impacts on the shellfish populations and industries. The paper also looks at the available soft measures, such as the implementation of buffering solutions to limit the acidification in hatcheries, the use of genetic selection to incorporate acidification-resistant traits, and coastal management measures to limit local sources of acidification. The paper also suggests some potential new ways to increase the resilience of shellfish stock, including more flexible adaptive aquaculture practices. With commercial shellfish interests emerging, this paper fills some of the more critical gaps in the existing literature and offers insight into the impact of OA on the sustainability of the shellfish industry. It also provides OA mitigation strategies to preserve shellfish stocks in a changing climate.

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Feeding and excreting ecology in coastal systems

Published 26 May 2026 Science Closed
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Oysters (Crassostrea virginica) are critical foundation species in estuaries, providing numerous ecological and economic benefits. However, oyster populations have diminished worldwide. Effective oyster restoration and aquaculture require a mechanistic understanding of the physiological and environmental factors that govern oyster feeding, growth, and resilience under changing coastal conditions. We investigated how oyster ploidy and environmental conditions influenced oyster feeding and investigated how changes in abiotic conditions affected behavioral performance of oyster drills (Stramonita spp.), a key oyster predator. To better understand feeding responses and behaviors of both predator and prey we 1) used in-situ filter feeding assays to determine feeding differences existed amongst diploid and triploid oysters, 2) gathered a baseline for growth and in-situ feeding rates of oysters across Mississippi Sound in the Northern Gulf in the Spring, Summer, and Fall, 3) simulated present-day and projected future pH conditions (7.0-8.8) to analyze oyster feeding responses, and 4) introduced oyster drills to acidified conditions (7.0-8.8) to monitor behavior and foraging rates. Diploid oysters exhibited higher overall feeding rates, yet equivalent absorption efficiency between ploidies demonstrates a difference in energy allocation which might be the key to triploids’ ability to grow quickly. These findings highlight the role of intrinsic genetic and physiological traits in shaping oyster performance and provide a baseline for interpreting responses to environmental variability. Across spatial and seasonal variation in oyster in-situ feeding and growth across three contrasting sites in Mobile Bay and Mississippi Sound, in the Northern Gulf on the western border of Alabama and Mississippi, results revealed strong spatial and seasonal variability in feeding and growth. This was driven primarily by seston composition and salinity. Under present-day and projected future ocean acidification conditions, overall oyster feeding rates declined with lower pH’s, absorption efficiency remained stable, suggesting partial physiological compensation. These results indicate that pH can impose sublethal constraints on energy acquisition and growth, with individual variability at extreme pH highlighting potential acclimation or tolerance thresholds. When subjecting the oyster’s predator, the oyster drill, to similar pH conditions (7.0-8.8) experimental results indicate that decreased pH may increase drill foraging times. Behaviors like inactivity and climbing out of the water indicate a stress response under both high and low pH, demonstrating the complexity of predicting predator-prey outcomes under more acidic conditions. Collectively, these chapters demonstrate that oyster feeding, growth, and survival are shaped by both intrinsic traits, such as ploidy, and extrinsic factors including environmental variability and ocean acidification. Understanding the interplay between physiological plasticity, seston quality, and predator-prey interactions is essential for informing restoration and aquaculture strategies that sustain ecological function and the ecosystem services oysters provide.

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Controls on boron isotope ratios in marine bivalve shells: insights from a controlled experiment across pH and temperature gradients

Published 8 May 2026 Science Closed
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Documenting spatial and temporal patterns of ocean acidification and understanding the way marine organisms build carbonate skeletons is critical to assessing their potential vulnerability to present and future stressors. The boron isotopic composition (δ11Bc) of many marine carbonates provides insight into the pH at the site of calcification within biocalcifiers and, by extension, the pH of ambient seawater when the carbonate formed. The modification of seawater carbonate chemistry at the site of calcification by marine calcifiers and the utility of different taxa as paleo-pH proxy archives remains an area of active research. Despite the significance of marine bivalves to ecosystem function, high-resolution paleoclimatic studies, and the shellfish industry, their biocalcification mechanisms, controls on internal pH, and potential for reconstructing records of past seawater pH remain unclear. To address these gaps, a 20.5-week flowthrough tank experiment was conducted in which four species of commercially important bivalves from the northwest Atlantic Ocean were grown in tanks with controlled pHT (pH 7.4 to 8.0) and temperature conditions (6 to 12 °C). A total of 106 shell samples from 99 individuals of adult and juvenile Arctica islandica (ocean quahog), juvenile Mercenaria mercenaria (northern quahog or hard clam), juvenile Mya arenaria (soft-shell clam) and juvenile Placopecten magellanicus (Atlantic sea scallop) were analyzed from this controlled experiment to assess the seawater pH, temperature, and growth rate controls on shell δ11Bc.These four bivalve species, grown under identical, controlled conditions, showed differential responses to the same seawater temperature and pH, likely due to differences in how they regulate the pH of their internal fluids. Juvenile P. magellanicus and juvenile M. mercenaria demonstrated significant relationships (R≥0.60; p-value <0.006) between tank pHT and δ11Bc, suggesting potential utility as proxies for past ambient seawater pH. Conversely, the δ11Bc of juvenile A. islandica and juvenile M. arenaria did not yield a strong relationship with seawater pHT but instead yielded significant relationships with shell growth rate (linear extension), with a positive relationship for M. arenaria and a negative relationship for juvenile A. islandica. The δ11B results from the few (n=9) adult A. islandica shells measured show the most variability across the range of pH and temperatures (range of 16‰) and no significant relationship was found with seawater pH or growth rate. Despite rigorous oxidative cleaning of samples, the data suggest that adult A. islandica shells contain boron-rich organic phases resistant to traditional cleaning techniques. This suggests that the next step in the development of boron-based pH proxies in A. islandica requires additional research into robust cleaning and sampling methods of periostracum and other organics. Despite the need for further investigations to constrain growth rate effects and cleaning techniques in A. islandica and M. arenaria, there is potential for developing paleo-pH proxies from P. magellanicus and M. mercenaria to better understand spatial and temporal patterns of past, present and future ocean acidification.

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Climate change resilience and positive scope for growth in wild adult Sydney rock oysters, Saccostrea glomerata (Gould 1850)

Published 27 April 2026 Science Closed
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Oysters have ecological and economic importance worldwide as they provide ecosystem services and sustain profitable aquaculture industries. Calcifying bivalves including oysters have been found to be sensitive to ocean warming and acidification caused by anthropogenic climate change. This study tested whether adult wild Sydney rock oyster, Saccostrea glomerata, exposed to elevated pCO2 (331 μatm and 867 μatm) and temperature (24°C and 28°C) in an orthogonal design for five weeks, have resilience and can maintain sufficient scope for growth or are pushed into a suboptimal state. At the end of the exposure growth, condition index, clearance, ingestion and absorption efficiency and rates were measured and scope for growth calculated. Sydney rock oysters responded to elevated pCO2 and temperature with no change in overall growth or condition index, but significantly increased metabolic, clearance, ingestion, and absorption rates and positive Scope for Growth. Our results indicate that adult S. glomerata can cope with the moderate level of climate change stress predicted for 2100 through increased standard metabolic rate and increased energetic processes. If, however, food availability becomes limiting, and other environmental stressors interact with climate change stressors then resilience thresholds maybe breached for this economically, ecologically and indigenous significant and iconic oyster species.

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Seawater acidification accelerates growth but hastens decline in batch cultures of the marine diatom Thalassiosira pseudonana

Published 22 April 2026 Science Closed
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Diatoms are characterized by rapid cell division and a high capacity to adapt to environmental variability, and some species can form blooms when environmental conditions are favorable. Previous studies have largely focused on the bloom development phase, during which biomass accumulates rapidly, whereas the decline phase-despite its critical role in carbon export and microbial loop dynamics-has received far less attention. Here, we tracked changes in cell density and inorganic carbon utilization characteristics throughout the entire course of a simulated Thalassiosira pseudonana bloom under ambient (420 μatm) and elevated pCO2 (1000 μatm) conditions. Inhibitors of carbonic anhydrase and direct bicarbonate transporters were applied to investigate the characteristics of inorganic carbon utilization. The relationship between photosynthetic rate and inorganic carbon concentration was measured to assess inorganic carbon affinity. The simulated T. pseudonana bloom was characterized by rapid cell density accumulation, reaching a peak within 10 days, followed by a rapid decline without a distinct stationary phase. As the bloom progressed, photosynthetic rate and the maximum quantum yield of photosystem II declined, whereas the inorganic carbon affinity increased. Elevated CO2 enhanced growth and maximum quantum yield during the acceleration phase but resulted in an 86% higher fitted death rate during the decline phase. Regarding the relationship between photosynthetic rate and dissolved inorganic carbon concentration, elevated CO2 increased the maximum photosynthetic rate and half-saturation constant only during the acceleration phase. Collectively, these results indicate that seawater acidification can influence both biomass accumulation and decline intensity in diatom blooms, with potential consequences for carbon sequestration and its redistribution among biogeochemical pools.

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Effects of pH on phytoplankton growth and diversity in a tropical coastal ay: an experimental study

Published 14 April 2026 Science Closed
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This research was intended to investigate the effects of reduced pH on the growth rates and diversity of phytoplankton in the coastal waters of Visakhapatnam in the Bay of Bengal. A short-term (six days) microcosm experiment was conducted with different pH conditions such as ambient (control-in situ pH), pH 8.0 (0.2 pH units drop from in situ pH) and pH 7.8 (0.4 pH units drop from in situ pH) corresponding to low, medium, and high future pH decline scenarios, respectively, to study the direct acidification impact on phytoplankton. The results revealed that the phytoplankton communities exhibit a wide range of responses including changes in growth rate during incubation. From the two treatments, a more pronounced response was observed in pH 7.8 conditions compared to the present pH scenario. Some phytoplankton communities exhibited positive growth responses to acidification, while others showed negative reactions in terms of biodiversity. Notably, Pseudo-nitzschia sp. became dominant during acidification, whereas larger centric diatoms such as Skeletonema spp., Chaetoceros spp., Rhizosolenia sp., Dactyliosolen fragilissimus, and Ditylum brightwellii showed no significant growth response to upcoming acidified conditions. This indicates a diverse array of physiological tolerance among the plankton species to environmental shifts. This study recommends further research to explore the impact of ocean acidification on other planktonic species in the coastal waters of Bay of Bengal.

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Intracellular acid-base regulation mediates a trade-off between shell and somatic growth in a clam under ocean acidification

Published 9 April 2026 Science Closed
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Highlights

  • Clams actively regulate intracellular pH against ocean acidification via CAc
  • RNAi confirms CAc’s essential role in H+ efflux, measured by in vivo SIET.
  • A CAc-sAC-NKA network forms a conserved regulatory pathway for acid-base balance.
  • DEB model shows this pH defense sustains shell linear growth despite metabolic costs.

SUMMARY

Ocean acidification (OA) is predicted to threaten marine bivalves, casting them as passive victims of changing carbonate chemistry. Contributing to a revised understanding, we identified a conserved mechanism for acid-base regulation that supports intracellular resilience. Using the Manila clam Ruditapes philippinarum as a model, this study demonstrated that intracellular pH (pHi) homeostasis under elevated pCO2 was maintained through cytosolic carbonic anhydrase (CAc)-mediated H+ efflux. A causal link was established by combining in vivo scanning ion-selective electrode technique (SIET) with RNA interference (RNAi), where RpCAc knockdown suppressed H+ efflux and compromised pHi. A coordinated regulatory network involving CAc, soluble adenylyl cyclase (sAC), and Na+/K+-ATPase (NKA) was synergistically upregulated, suggesting an evolved adaptive pathway. Dynamic Energy Budget (DEB) modeling, calibrated with experimental data, revealed that this cellular compensation carries a high energetic cost, leading to a significant reallocation of resources: shell growth was maintained, but somatic growth was severely suppressed. These results elucidate a conserved cytoprotective mechanism that enables short-term tolerance of OA at a substantial somatic cost, redefining resilience to include energetic trade-offs.

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The impact of climate change on lobster production: a systematic synthesis of literature

Published 6 April 2026 Science Closed
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Climatic impact-drivers are projected to change in coastal and marine regions globally, especially towards the fisheries production of the commercially important global shellfish, such as lobster species. Thus, there is an immediate need for ongoing, rigorous systematic review that continuously assesses and analyzes the risk of climatic factors towards lobsters’ production (i.e., growth, reproduction, etc.). A global relevant literature was analyzed from the inception to 31st December 2024. The review targets commercially important lobster, across various life history stages. The current study presents a systematic analysis of the research articles on lobster growth, reproduction, and development from relevant literature through two main academic databases, Scopus (n = 284) and Web of Science (n = 310). During literature search, duplicate articles were removed manually (n = 177). A total of 46 research articles were generated from the strict systematic selection process at various life history stages of lobsters. Climate change elements such as temperature, salinity, carbon dioxide, pH, and hypoxia significantly impact ovigerous females, reproduction, hatching success, larval stages, and juvenile development of lobsters. As global climate change intensifies, the reproductive and developmental capacity of lobster populations may be increasingly compromised, particularly in early life history stages. To date, a comprehensive synthesis of reproductive and biological impacts across taxa and regions has been lacking. This review provides a foundational reference for future assessments and adaptation strategies for sustainable management of lobsters under climate change.

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Skeletal growth and loss of the cold-water coral Lophelia pertusa from multiple environmental drivers in a year-long experiment

Published 27 March 2026 Science Closed
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Colony-forming scleractinian cold-water corals (CWCs) are important ecosystem engineers, forming complex 3-dimensional habitats in the deep sea, which in turn sustain high biodiversity. They are threatened by future environmental changes such as ocean acidification, warming, deoxygenation, and food limitation, but little is known about the effect of these drivers in combination or on the long-term. We conducted a year-long aquarium experiment with Lophelia pertusa (syn. Desmophyllum pertusum) under projected end-of-century conditions, investigating the combined effect of differences in pH (8.1 and 7.7), temperature (9°C and 12°C), oxygen concentration (100% and 90%) and food supply (100% and 60%) on coral survival, growth, respiration rates, skeletal dissolution and energetic reserves. Growth rates of L. pertusa decreased significantly in both multiple driver treatments, resulting in negative and more variable growth rates. However, growth rates only started to decrease after 4.5 months, clearly showing a delayed response. In addition, survival rates and energetic reserves were slightly lower in multiple driver treatments, whereas L. pertusa was not affected by reduced oxygen concentration examined as a single factor. Negative growth rates in multiple driver treatments were driven by dissolution of bare skeletal parts due to reduced seawater pH and temporary aragonite undersaturation, visualised here through micro-computed tomography images. While live CWCs may be able to cope with projected future environmental changes over the timescale of 1 year, ocean acidification will lead to dissolution of the dead skeletal framework of CWC reefs and net loss, reducing the complexity and associated biodiversity of these reefs. However, the challenge remains in closing the gap between long-term experiments and the much longer-term chronic exposure of CWCs to projected environmental changes.

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CO2 rise modulates the physiological performance of the diatoms Thalassiosira pseudonana and Thalassiosira weissflogii to light challenge

Published 25 March 2026 Science Closed
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Highlights

  • Ocean acidification boosts diatom growth independent of CO2 ramping speed.
  • Acidification changed PSII repair and photoprotection strategies under high light.
  • Species-specific adaptive advantages altered in acidified, light-variable oceans.

Abstract

Diatoms are major contributors to marine primary productivity and typically dominate well-mixed coastal environments characterized by rapidly fluctuating light levels. Yet, how the ongoing ocean acidification (OA) caused by rising CO2 affects their capacity to exploit such variable light is not well known. In this study, the diatoms Thalassiosira pseudonana and Thalassiosira weissflogii were cultured under two CO2 acidification regimes (gradual increase from ambient 400 to 1000 ppmV in ∼200 ppmV increments vs. direct elevation from 400 to 1000 ppmV) and exposed to high light stress to assess comparative physiological responses. Both diatoms showed significant increases in maximum electron transfer rate and saturation light intensity, with T. weissflogii additionally exhibiting elevated PsbA and Rubisco content. Growth rates increased by 15 % and 27 % for T. pseudonana and T. weissflogii respectively, with no significant difference between direct versus gradual CO2 elevation treatments. T. pseudonana demonstrated higher intrinsic susceptibility to PSII photoinhibition than T. weissflogii, OA didn’t significantly alter the functional absorption cross-section for PSII photoinactivation in either species. Notably, OA decreased PSII repair rates in T. pseudonana, while T. weissflogii maintained repair capacity through increased PsbA content and sustained non-photochemical quenching. These findings suggest T. weissflogii may gain a competitive advantage in future acidified, light-variable oceans due to its enhanced photoprotection and PSII repair capacity, highlighting species-specific resilience to combined environmental stresses.

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Tolerance of egg and yolk-sac larval yellowfin sole (Limanda aspera) to ocean warming and acidification

Published 23 March 2026 Science Closed
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Yellowfin sole (Limanda aspera) support the largest flatfish fishery in the world and contribute substantially to the eastern Bering Sea (EBS) flatfish catch. The EBS has been warming and acidifying, trends that are expected to intensify into the future. Sustainable management of yellowfin sole requires an understanding of how yellowfin sole respond to environmental change, which can be assessed through controlled laboratory investigations. Across four independent trials, yellowfin sole embryos and larvae were incubated at one of six experimental treatments spanning three temperatures (9°C, 12°C, and 15°C) and two pCO2 target levels (low and high), and a range of organismal and physiological responses were measured. Embryonic daily mortality rates and metabolic rates increased with increasing temperature but were not affected by ocean acidification. At- hatch and at- yolk absorption, morphometric measurements (length, dry weight, myotome height, and yolk area) were temperature- sensitive, but the response differed across the four trials. There was a consistent increase in length- based growth and yolk absorption rates with increasing temperature across trials. All morphometric and rate- based measurements were not affected by ocean acidification. Yellowfin sole metabolic enzyme activities were measured at- yolk absorption. Lactate dehydrogenase (anaerobic metabolism) and β- hydroxyacyl CoA dehydrogenase (fatty acid metabolism) both increased with increasing temperature, indicating elevated energy demand. Citrate synthase (aerobic metabolism) declined with increasing pCO2 levels, indicating potential metabolic suppression. Overall, embryonic and larval yellowfin sole demonstrated relatively high tolerance to ocean warming and acidification. We hypothesize the variation in temperature responses across the trials may be driven by maternal effects, which could support tolerance to future ocean conditions.

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Novel in situ CO2 enrichment system reveals seagrass meadows are a refugium against coastal acidification for North Atlantic bivalves

Published 18 March 2026 Science Closed
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While the accumulation of anthropogenic CO2 in the atmosphere is causing a decline in global ocean pH, many eutrophic estuaries are already experiencing acidification due to accelerated respiration driving the consumption of dissolved oxygen (DO) and production of CO2, decreasing available carbonate ions (CO32-) and threatening marine calcifiers. Here, a novel in situCO2 enrichment system was constructed to examine the effects of coastal acidification on the growth and survival of two species of North Atlantic bivalves (Argopecten irradians and Crassostrea virginica) in two distinct estuarine habitats: a seagrass meadow and an unvegetated sandy bottom in an open water estuary. The in-situ system captured natural diel dynamics as ambient chambers displayed chemistry nearly identical to the surrounding water, while CO2-enriched, acidified chambers maintained a consistent ~Δ 0.3–0.5 pH offset. At the unvegetated sandy bottom site, A. irradians and C. virginica displayed significant reductions in growth and survival in the acidified chambers (pHT = 7.3–7.5; saturation state of aragonite, ΩAr = 0.6–0.9) relative to ambient conditions (pHT = 7.6–7.9; ΩAr = 1.6–2). At the seagrass site, while growth of A. irradians and C. virginica in the acidified treatments (pHT = 7.3–7.7; ΩAr = 0.7) receiving the same delivery of CO2 was, again, significantly slowed compared to the control (pHT = 7.5–8.1; ΩAr = 2 – 2.8), the growth reduction, mortality rates, and levels of acidification were attenuated compared to the sandy bottom experiment, evidencing the ability of seagrass to buffer seawater and serve as a potential acidification refuge for bivalves. Collectively, the novel experimental CO2 enrichment system constructed for this project demonstrates that coastal acidification can have deleterious effects on marine bivalve populations, and that future conditions as well as the habitat refuge offered by seagrasses must be considered when developing management and restoration plans for temperate estuaries. 

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Eco-evolutionary dynamics of planktonic calcifying communities under ocean acidification

Published 12 March 2026 Science Closed
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Increasing emissions of CO2 into the atmosphere are causing ocean acidification, threatening calcifying organisms. In this study, we model the physiological responses of coccolithophorids to acidification to understand the ecological and evolutionary outcomes of a system in interaction with zooplankton. Assuming a trade-off between growth and protection against grazing, we show that calcification has bivalent effects on transfers between two trophic levels and that acidity can strongly alter energy transfers. Taking into account the evolution of calcifying phenotypes in response to acidification, we show that the system outcome contrasts with previous results. While the effect of evolution depends on how calcification affects grazing, it nevertheless follows that acidification leads to a decrease in calcifying capacity. This evolutionary decrease may be progressive, but can also lead to tipping points where abrupt shifts may occur. Such a counter-selection of calcification in turn affects ecosystem functioning, enhancing energy transfers within the system and modifying carbon fluxes. We discuss how such eco-evolutionary changes may impact food webs integrity, carbon sequestration into the deep ocean and therefore endanger the carbon pump stability.

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