Microplastics (MPs) are recognized as a global concern, with specific attention shifted towards marine MPs pollution. This particular study investigates the abundance and distribution of crude oil-loaded microplastics (COMPs) along the Chennai coastline, Tamil Nadu, India and evaluates their combined toxicological effects with ocean acidification on Artemia franciscana. Spatial analysis revealed that Ennore Creek exhibited the highest MP concentration (10.82 ± 0.2 items/L). Polypropylene was recorded as the predominant polymer type followed by low density polyethylene and polyethylene terephthalate, with particle size ranging from 250 to 500 µm. COMPs were detected across all sampling sites, with concentrations declining from Ennore Creek (0.21 ± 0.03 items/L) to Kasimedu Beach (0.10 ± 0.02 items/L). The adsorption of crude oil on MPs is primarily mediated by physical interaction with multi-layer adsorption behaviour. The results highlighted that increase in MP concentration and decrease in seawater pH significantly induced acute toxicity and oxidative stress responses in A. franciscana. At pH 7.8, experimental groups exposed to 0.5 mg/mL of COMPs developed higher ROS, SOD and catalase activity (p<0.001). Whereas control groups alone showed significant increase in oxidative stress responses at lower pH level such as pH 7.8 and 8.0. Combined exposure of COMPs and low pH conditions significantly increased oxidative damages in A. franciscana and affected its hatching ability. The observations from this study emphasize the urgent need for integrated monitoring and further research to explore combined toxicological effects of MPs and ocean acidification to other marine organisms as well.
Continue reading ‘Combined ecotoxicity of microplastics and crude oil co-pollutants: occurrence, distribution and its synergistic impact with ocean acidification on Artemia franciscana’Posts Tagged 'plastics'
Combined ecotoxicity of microplastics and crude oil co-pollutants: occurrence, distribution and its synergistic impact with ocean acidification on Artemia franciscana
Published 3 April 2026 Science ClosedTags: biological response, crustaceans, Indian, laboratory, multiple factors, physiology, plastics, reproduction, toxicants, zooplankton
Photoaged microplastics disrupt the response of marine medaka (Oryzias melastigma) to ocean acidification: perspectives from energy metabolism and ammonia production
Published 2 February 2026 Science ClosedTags: biological response, fish, laboratory, molecular biology, multiple factors, North Pacific, physiology, plastics, respiration
Ocean acidification (OA) and microplastics (MPs, <5 mm) are co-occurring stressors that threaten marine ecosystems. Although the marine environment contains multiple pollutants, OA can alter the environmental behavior of MPs, influencing their toxicity and environmental fate. Therefore, investigating the interactive effects of OA and MPs is essential. Fish can activate physiological compensatory mechanisms to adapt to OA; however, it remains unclear how MPs affect these mechanisms. In this study, marine medaka were exposed to acidified seawater (pH 7.70) containing environmentally relevant concentrations of MPs (0.1 mg/L) for 90 days to investigate the disruptive effects of MPs on responses to OA. The results showed that while OA triggered compensatory energy metabolism reprogramming to enhance ammonia production, MPs disrupted this process, reducing the TCA cycle intermediate α-ketoglutarate. This α-ketoglutarate deficiency limited the glutamate supply for ammonia production. Simultaneous inhibition of glutamate dehydrogenase activity further limited glutamate availability. As a result, MPs reduced the level of ammonia production by 25.29%, compromising the ability to neutralize excess H+. Crucially, photoaging exacerbated this toxicity, leading to a 32.04% reduction in ammonia production. This study demonstrates that MPs interfere with fish responses to OA via α-ketoglutarate-mediated metabolic reprogramming, highlighting a vulnerability in marine organisms facing climate change scenarios.
Continue reading ‘Photoaged microplastics disrupt the response of marine medaka (Oryzias melastigma) to ocean acidification: perspectives from energy metabolism and ammonia production’From pollution to ocean warming: the climate impacts of marine microplastics
Published 9 January 2026 Science ClosedTags: multiple factors, plastics, review
Highlights
- MPs disrupt nutrient cycling and influence climate-related processes.
- MPs interact with ocean warming and acidification, amplifying ecological impacts.
- Combined effects of MPs, warming, and acidification threaten marine ecosystem stability.
- MP pollution hinders progress toward multiple UN SDG targets.
Abstract
Despite being a critical global issue, the role of microplastics (MPs) in climate change has received limited attention. Climate disruption and plastic pollution are two major environmental challenges that intersect in complex ways. MPs influence biogeochemical processes, disrupt oceanic carbon pumps, and contribute directly to greenhouse gas (GHG) emissions. In marine ecosystems, MPs alter the natural carbon sequestration by affecting phytoplankton and zooplankton, which are key agents of carbon cycling. Additionally, the plastisphere, a microbial community colonizing MPs, plays a significant role in GHG production due to its diverse microbial networks. This review highlights the close relationship between MP pollution and climate change, suggesting that MPs may significantly contribute to climate change and potentially further affect ocean health in the form of ocean warming and ocean acidification. Given the interconnected nature of these challenges, a holistic and integrated strategy is essential to effectively address them. Furthermore, this article examines MP pollution through the lens of the UN Sustainable Development Goals (SDGs) and human rights, recognizing that MP pollution can hinder the implementation of sustainable strategies and action plans necessary for achieving the SDGs.
Continue reading ‘From pollution to ocean warming: the climate impacts of marine microplastics’Ocean acidification enhances microplastic uptake and alters physiological responses in Manila clams
Published 6 January 2026 Science ClosedTags: biological response, laboratory, mollusks, multiple factors, North Pacific, physiology, plastics, respiration
Highlights
- Ocean acidification (OA) impairs particle selection, increasing microplastic ingestion.
- Microplastic retention in clams is higher under acidified conditions.
- Stress-related suppression of filtration and respiration is diminished under OA.
- OA and microplastics interact, highlighting multi-stressor ecological risks.
Abstract
Microplastic (MP) pollution and ocean acidification (OA) are co-occurring stressors in coastal ecosystems, yet their combined effects on bivalves remain unclear. We investigated how OA influences MP ingestion, excretion, and physiological performance in the Manila clam Ruditapes philippinarum. Clams were exposed to two pH levels (8.1 and 7.6) for 10 days and three MP concentrations (0, 10, and 1000 items/L) during the final three days. MP accumulation in gills/labial palps and digestive tracts, MP content in excreted material, and filtration and respiration rates were measured. Acidified conditions impaired particle selection, leading to greater MP accumulation in the digestive tract, whereas MP excretion was unaffected. Filtration and respiration were maintained at higher levels under OA, suggesting suppressed stress responses. These results demonstrate that OA enhances MP retention and modulates physiological stress reactions, highlighting synergistic effects that may influence energy balance and ecosystem functioning under future ocean conditions.
Continue reading ‘Ocean acidification enhances microplastic uptake and alters physiological responses in Manila clams’Warming coupled with elevated pCO2 modulates microplastic inhibition in a commercial red alga Pyropia haitanensis
Published 5 December 2025 Science ClosedTags: algae, biological response, growth, laboratory, multiple factors, North Pacific, photosynthesis, physiology, plastics, temperature
Highlights
- Microplastics exert concentration-dependent negative effects on Pyropia haitanensis.
- Warming (24 °C) exacerbated microplastic-induced growth inhibition at ambient CO₂ level.
- High CO₂ inhibited growth at 20 °C but enhanced it at 24 °C under high microplastic stress.
Abstract
Ocean acidification, warming, and microplastics are pervasive stressors in coastal ocean, yet their combined effects on economically important seaweed Pyropia haitanensis remain unclear. To investigate how elevated pCO2, warming, and microplastics interact to affect physiology of P. haitanensis, we cultured thalli at ambient (418 μatm, AC) and elevated (1000 μatm, HC) CO2 levels with two temperatures (20 and 24 °C), and a gradient of microplastics (0.025, 2.5, 25, 50, 100 mg L−1) in a controlled indoor experiment. Our results indicate that microplastics imposed a strong, concentration-dependent stress on P. haitanensis, consistently reducing relative growth rate (RGR), Fv/Fm, photosynthetic pigments (chlorophyll a, carotenoids, and phycobiliproteins), and cellular reserves (soluble protein and carbohydrates), with the strongest inhibition observed at concentration of 100 mg L−1. However, while the increased temperature (24 °C) promoted the content of pigments and soluble protein of the thalli, it decreased the content of soluble carbohydrate among the microplastic concentrations regardless of pCO2 levels. It is noteworthy that under ambient pCO2 level, elevated temperature exacerbated the growth inhibition caused by microplastics, resulting in the highest inhibition rate of 57 % occurring at 100 mg L−1. In contrast, this temperature-aggravated microplastic toxicity was mitigated by high pCO2 levels, with the inhibition rate of 32 % at the highest microplastic concentration. These findings reveal that while elevated pCO2 and warming can modulate microplastic stress via physiological reallocation, persistent declines in photochemical efficiency and light-harvesting pigments may constrain yield and nutritional quality of P. haitanensis where microplastics are high in coastal aquaculture area.
Continue reading ‘Warming coupled with elevated pCO2 modulates microplastic inhibition in a commercial red alga Pyropia haitanensis’The multiple responses of Mytilus galloprovincialis in the multi-stressor scenario: impacts of low pH, low dissolved oxygen, and microplastics
Published 18 November 2025 Science ClosedTags: biological response, laboratory, Mediterranean, mollusks, multiple factors, oxygen, physiology, plastics, respiration
Highlights
- Low pH, low dissolved oxygen (DO), and microplastics (MPs) did not notably affect organismal parameters or ETS activity.
- Stressors significantly affected hemocytes, genotoxicity, and gill metabolites individually and interactively.
- Hemolymph phagocytic activity, granulocyte/hyalinocyte ratio, and mantle lipid peroxidation were partly affected.
- Metabolomic analyses showed that mussel gills are valuable indicators of metabolic status under stress.
Abstract
Along with high temperatures, acidification, deoxygenation, and microplastics (MPs) pollution represent key drivers in coastal marine ecosystems. Sessile invertebrates living in coastal habitats are primarily exposed to the combination of these drivers, often at severe levels. Here, we investigated the individual and combined impacts of low pH (pHT: 7.35), low dissolved oxygen (DO) (1.91 mg L−1), and MP (26 μg L−1) in the Mediterranean mussel Mytilus galloprovincialis by measuring organismal and cellular parameters after a 15-day exposure period. Organismal parameters (respiration rate, ammonia excretion rate, absorption efficiency) as well as electron transport system (ETS) activity were not impacted by the stressors, either individually or combined. At the cellular level, however, we observed significant effects of these stressors individually and interactively on the hemocyte count, hemocyte viability, genotoxicity (comet assay), and gill metabolite profiles. In addition, we observed partial effects on the hemolymph phagocytic activity (PA) and granulocyte/hyalinocyte (G/H) ratio, and mantle lipid peroxidation (LPO). Metabolomics results manifested that the gill of mussels can serve as a valuable indicator of metabolic status under the stress of low pH, low DO and MP. Metabolites involved in osmoregulation, membrane stability, oxidative stress, energy, amino acid and nitrogen metabolism were significantly affected by the stressors, with low DO being the main driver of metabolic changes. We suggest that the individual and variable interactions of these stressors negatively impact M. galloprovincialis, except for the organismal and, to some extent, biochemical parameters.
Continue reading ‘The multiple responses of Mytilus galloprovincialis in the multi-stressor scenario: impacts of low pH, low dissolved oxygen, and microplastics’Oxidative stress and histological alterations in coral Briareum violacea co-exposed to ocean acidification and microplastic stressors
Published 17 October 2025 Science ClosedTags: biological response, BRcommunity, corals, laboratory, morphology, multiple factors, North Pacific, performance, physiology, phytoplankton, plastics
Ocean acidification and microplastic pollution are two major stressors threatening coral health, yet their combined impacts and underlying mechanisms remain poorly understood. This study investigated the combined effects of ocean acidification and microplastics exposure to coral health. Briareum violacea was exposed to pH at 7.7, 7.5, and 7.3 combined with polyethylene microplastic (PE-MP; 50 mg/L) for 21 days. Polyp length and behavioral adaptability were monitored daily, while coral was collected on days 14 and 21 to assess Symbiodiniaceae density, antioxidant enzyme activity, and histopathological alterations. Results showed that combined exposure to different pH (7.7, 7.5, and 7.3) and PE-MP significantly impaired coral condition, reduced polyp length and Symbiodiniaceae density, along with intensified oxidative stress and tissue damage compared to single stressors. These findings underscore coral vulnerability under combined stressors, emphasizing the necessity for future research to address long-term ecological consequences and resilience mechanisms in coral reef ecosystems.
Continue reading ‘Oxidative stress and histological alterations in coral Briareum violacea co-exposed to ocean acidification and microplastic stressors’Microplastic exposure under future oceanic conditions further threatens an endangered coral, Acropora cervicornis
Published 22 September 2025 Science ClosedTags: biological response, BRcommunity, corals, laboratory, morphology, multiple factors, photosynthesis, physiology, phytoplankton, plastics, South Atlantic, temperature
Microplastic pollution is ubiquitous in the oceans. However, little is known about the physiological impact of microplastics on corals, particularly under predicted future ocean conditions. This study investigated the individual impacts of microplastic exposure (MP) and predicted future ocean conditions [ocean acidification and warming (OAW)] as well as the combination of these stressors (OAW+MP) on the growth and physiology of Acropora cervicornis, a threatened Caribbean coral and its associated symbiont, Symbiodiniaceae. After 22 days, the OAW+MP treatment resulted in more pronounced physiological changes than either stressor individually or the control. OAW conditions alone had minimal impacts, despite A. cervicornis generally being sensitive to thermal stress. The OAW+MP treatment and the MP treatment also disrupted the host-symbiont relationship evidenced by the higher symbiont densities relative to the control and the OAW treatments. Additionally, the OAW+MP treatment resulted in lower chlorophyll a per symbiont cell. Microplastic handling is energetically costly, possibly leading to changes in host-symbiont signaling. Photosynthetic efficiency was only marginally lower in the OAW+MP treatment, and values did not indicate photosystem damage. Negative host health impacts were found with the OAW+MP treatment exhibiting lower skeletal growth compared to the control and lower host protein concentrations compared to the OAW treatment. These results indicate that although short term microplastic exposure alone may not pose a significant threat to coral health, when adding additional stressors, it can further threaten the health and recovery of this already vulnerable species.
Continue reading ‘Microplastic exposure under future oceanic conditions further threatens an endangered coral, Acropora cervicornis’Mathematical analysis on the effects of microplastic pollution and ocean acidification on coral reefs in aquatic ecosystem
Published 10 September 2025 Science ClosedTags: biological response, BRcommunity, communitymodeling, corals, modeling, multiple factors, plastics
This study explores the complex interplay between microplastic contamination and ocean acidification in influencing coral reef ecosystems through the development of a mathematical model with time-varying parameters. The model ensures positivity and boundedness to accurately represent ecological dynamics, and stability analyses provide insights into system behavior under various environmental conditions. Numerical simulations validate the theoretical results and reveal that microplastic accumulation in marine environments significantly hinders coral reef establishment while contributing to elevated oceanic carbon dioxide levels. These rising CO2 levels, primarily driven by anthropogenic emissions, lead to accelerated ocean acidification, further degrading coral reefs. Model predictions indicate that, if unchecked, the current trends in microplastic pollution and ocean acidification will result in a 50% reduction in coral reef coverage within four decades. However, the findings suggest that limiting microplastic input into aquatic ecosystems could mitigate these adverse effects, preserving reef health and slowing acidification. By quantifying the relationship between microplastic pollution, ocean acidification, and coral reef dynamics, this study provides a robust framework for understanding and addressing critical threats to marine ecosystems.
Continue reading ‘Mathematical analysis on the effects of microplastic pollution and ocean acidification on coral reefs in aquatic ecosystem’Molecular markers of stress in the sea urchin embryo test: analysing the effect of climate change and pollutant mixtures on Paracentrotus lividus larvae
Published 15 August 2025 Science ClosedTags: biological response, echinoderms, laboratory, molecular biology, morphology, multiple factors, North Atlantic, plastics, reproduction, temperature, toxicants
Highlights
- Combined effects of ocean stressors on sea urchin larvae were analysed.
- RNA-seq revealed key transcriptional changes under stressor combinations.
- Larval growth and deformities worsened with acidification and warming.
- Biomarkers for early detection of stress in marine larvae were identified.
- Insights contribute to predicting organismal responses to climate change.
Abstract
Climate change and pollution represent critical stressors for marine ecosystems, particularly for calcifying organisms such as the sea urchin Paracentrotus lividus. This study examines the combined effects of ocean acidification (OA), ocean warming (OW), and microplastics (MP) loaded with chlorpyrifos (CPF), a broad-spectrum organophosphate insecticide, on sea urchin larvae, evaluating growth and molecular endpoints. Experimental treatments simulated future ocean conditions predicted for 2100, exposing larvae to varying temperature and pH levels, alongside CPF-contaminated MP. RNA sequencing (RNA-seq) was utilized to assess gene expression changes, revealing significant transcriptional shifts in metabolic, cellular, and developmental pathways. Morphological responses showed reduced larval growth, exacerbated under OA and OW conditions. Molecular analyses identified key upregulated pathways associated with stress response, including nitrogen metabolism and extracellular matrix remodelling, while downregulated genes involved DNA stability, cell cycle regulation, and enzymatic activities. These findings suggest a dual compensatory and deleterious response to combined stressors. Notably, temperature acted as a modulator of stressor effects, amplifying oxidative stress and metabolic costs at higher temperatures. Potential biomarkers, such as genes involved in actin regulation and embryonic development, were identified, offering possible tools for early detection of environmental stress. This study highlights the compounded impacts of anthropogenic and climate-induced stressors on marine invertebrates, emphasizing the need for integrative molecular approaches in ecotoxicology. Our findings contribute to the understanding of organismal adaptation and vulnerability in the face of global climate change and pollution, informing conservation strategies for marine ecosystems.
Continue reading ‘Molecular markers of stress in the sea urchin embryo test: analysing the effect of climate change and pollutant mixtures on Paracentrotus lividus larvae’Decreased dimethylsulfide and increased polybrominated methanes: potential climate effects of microplastic pollution in acidified ocean
Published 3 July 2025 Science ClosedTags: biogeochemistry, biological response, community composition, laboratory, multiple factors, otherprocess, phytoplankton, plastics
Microplastic (MP) pollution and ocean acidification (OA) are pressing marine environmental concerns, but their combined impacts on short-lived biogenic climate-active gases and the resulting climate effects remain unclear. To address this gap, a ship-based microcosm experiment was conducted, where OA and MP pollution were simulated under in situ conditions to explore their effects on the production of dimethylsulfide (DMS), bromoform (CHBr3), and dibromomethane (CH2Br2). The results indicated that both MP and OA inhibited phytoplankton growth and DMS concentration, with OA inducing further reductions in the production rate and yield of DMS. MP addition led to extra dissolved organic matter, and the acidified condition enhanced bromoperoxidase activity, both of which promoted the production of CHBr3 and CH2Br2. When OA and MP addition were combined, DMS concentrations decreased by 61%, whereas CHBr3 and CH2Br2 concentrations increased by 132% and 45%, respectively. Based on the results, MP pollution under OA conditions might directly reduce DMS accumulation or decrease the formation of DMS-derived sulfate aerosols by increasing CHBr3 and CH2Br2 levels, which finally weaken DMS’s climate-cooling capabilities. This study underscores the potential for MP pollution in future acidified oceans to exacerbate global warming by disrupting the cycle of marine biogenic climate-active gases.
Continue reading ‘Decreased dimethylsulfide and increased polybrominated methanes: potential climate effects of microplastic pollution in acidified ocean’
