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 'toxicants'
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
Multi-level holobiont dysregulation increases the ecological risk of combined ocean acidification and benzo[a]pyrene pollution to the reef-building coral Porites lutea
Published 17 March 2026 Science ClosedTags: archaea, biological response, BRcommunity, community composition, corals, laboratory, molecular biology, multiple factors, North Pacific, otherprocess, photosynthesis, physiology, phytoplankton, prokaryotes, toxicants
Highlights
- Combined ocean acidification and BaP induce holobiont dysregulation, evidencing by a decoupled Symbiodiniaceae proliferation and a collapse of the archaeal Nanoarchaeota-Halobacterota symbiosis.
- The coral host shifts its defense strategy from antioxidant capacity to cellular homeostasis, while the bacterial community increases functional redundancy, revealing a costly acclimation mechanism.
- The multi-level dysregulation demonstrates an underestimated ecological risk, highlighting that current single-stressor risk assessments are inadequate for protecting corals under complex pollution scenarios.
Abstract
Reef-building corals are increasingly threatened by the combined effects of global climate change and localized organic pollutants. However, the holistic impacts of co-exposure to ocean acidification (OA) and benzo[a]pyrene (BaP) on coral holobionts remain poorly understood. Here, we investigated the multi-level responses of the reef-building coral Porites lutea to short-term (7-day) exposure to OA (pH 7.80), BaP (10 µg/L), and their combination, by integrating physiological measurements with microbiome profiling (ITS2 and 16S rRNA). We found that combined stress was associated with a dysregulated response in Symbiodiniaceae, characterized by a significant increase in cell density without a parallel rise in chlorophyll content, suggesting a possible compensatory but inefficient proliferation response. Despite this, the dominant symbiont Cladocopium C15 remained stable. The bacterial diversity increased (e.g., enrichment of Ruegeria and Acanthopleuribacter, decline of Endozoicomonas), which may suggest enhanced functional redundancy, while the archaeal community was significantly restructured, most notably a marked decline of the putative obligate Nanoarchaeota–Halobacterota symbiosis. At the host level, combined stress was associated with suppressed antioxidant enzyme activities (SOD/POD) but upregulated genes related to protein folding (Hsp90) and calcium homeostasis (NCX1, VAMP4). These findings suggest a complex holobiont reconfiguration under combined stress, involving a stabilized core symbiont, altered microbiomes, and a shifted host defense strategy. Our study suggests that the ecological risk of combined OA and organic pollution may not be extrapolated from single-stressor responses, indicating the need to incorporate multi-stressor frameworks into coral reef risk assessments.
Continue reading ‘Multi-level holobiont dysregulation increases the ecological risk of combined ocean acidification and benzo[a]pyrene pollution to the reef-building coral Porites lutea’Ocean acidification enhances TiO2 nanoparticle toxicity in Oryzias melastigma: dominant role of size effects in driving bioaccumulation and hepatotoxicity
Published 21 October 2025 Science ClosedTags: biological response, fish, laboratory, molecular biology, multiple factors, physiology, toxicants
Highlights
- OA reduces TiO₂ NPs aggregation/sedimentation, increasing NP bioaccumulation
- NPs preferentially accumulate in liver, inducing hepatotoxicity via oxidative stress
- Size effect outweighs biological resistance as primary NP toxicity driver under OA
- Combined OA-NPs suppress hepatic genes, activate senescence and cell death pathways
- First evidence quantifying hydrodynamic size dominance in OA-enhanced NP toxicity
ABSTRACT
Ocean acidification (OA) and engineered nanoparticles (NPs) pollution represent two critical global environmental challenges. Marine organisms are suffering from their combined stress. However, few studies address their combined effects, and the toxicity mechanisms of NPs under OA are largely unresolved. In this study, we investigated the responses of the marine medaka Oryzias melastigma to environmentally relevant concentration of TiO2 NPs (1.0 mg/L) under OA (pH 7.40). We found that OA alleviated the aggregation and sedimentation of NPs, and decreased the resistance ability of the marine medaka to NPs stress, leading to elevated bioaccumulation of TiO2 NPs. Notably, NPs preferentially accumulated in the liver, inducing hepatotoxicity through oxidative stress and histopathological and ultrastructural damage. Critically, an integrated biomarker approach quantified the relative contributions of size effects (58%) and biological resistance (42%) to NP toxicity under OA, demonstrating that hydrodynamic size dominates toxicity outcomes. Transcriptomic analysis further revealed suppressed hepatic gene transcription and translation, alongside activated cellular senescence and programmed cell death pathways under combined exposure. These findings provide critical insight into the combined toxicity mechanisms of NPs and OA, significantly advancing our understanding of the profound risks that NPs pose to marine ecosystems under OA conditions.
Continue reading ‘Ocean acidification enhances TiO2 nanoparticle toxicity in Oryzias melastigma: dominant role of size effects in driving bioaccumulation and hepatotoxicity’The impact of an early exposure to 17α-ethynylestradiol on the physiology of the three-spined stickleback (Gasterosteus aculeatus) under current and future climatic scenarios
Published 9 October 2025 Science ClosedTags: biological response, fish, laboratory, molecular biology, morphology, mortality, multiple factors, reproduction, temperature, toxicants
Highlights
- RCP8.5 scenario modulated some of the long-lasting physiological responses to EE2.
- RCP8.5-EE2 group led to sex and tissue specific responses.
- RCP8.5-EE2 scenario resulted in lower body length at five months post-contamination.
- RCP8.5 reduced survival rate of embryo-larval but not juvenile stages.
- Early-life exposure to EE2 led to stickleback feminisation.
- Early-life exposure to EE2, led to long-lasting effect on stickleback physiological responses.
Abstract
Ocean warming and acidification are climate change related drivers that impact the physiology of marine organisms and their ability to cope with future environments. Marine ecosystems are also facing pollution from an ever-growing diversity of chemical contaminants, including endocrine disruptors. A common example is the 17α-ethynylestradiol (EE2), which can affect the endocrine regulation of fish and hence potentially impact their fitness. Thus, fish have to cope to multiple climatic and chemical stresses that can interact, influencing the overall impact on fish physiology. In this study, we investigated whether the direct and carry-over effect of early exposure to EE2 (15 ng.L−1; one month during embryo-larval development) are modulated by the RCP8.5 scenario (+3°C; -0.4 pH unit). Five months post-contamination, we measured survival, growth and reproductive axis of prepubertal sticklebacks. Our findings revealed that the survival of juveniles, when exposed to EE2 during early development, is reduced under Current but not RCP8.5 scenario. Furthermore, under RCP8.5-EE2, a significantly lower body length was observed. Sex and tissue specific responses in terms of the expression profiles of genes related to development and sexual maturation was reported. Interestingly, significant interaction between RCP8.5 and EE2 was observed for the expression of ovarian aromatase (cyp19a1a), suggesting a long-lasting estrogenic effect under RCP8.5 scenario. Additionally, the skewed sex ratios and the presence of intersex individuals in both scenarios early exposed to EE2 suggested a feminization due to EE2, which could potentially disrupt sexual maturation and future reproduction. Hence, the early EE2 exposure had carry-over physiological effects on sticklebacks, and these effects can be modulated by the climate scenario. This underscores the importance of conducting long-term multi-stress studies to comprehensively understand the vulnerability on fish populations in future environments.
Continue reading ‘The impact of an early exposure to 17α-ethynylestradiol on the physiology of the three-spined stickleback (Gasterosteus aculeatus) under current and future climatic scenarios’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’Effect of acidification on the chronic toxicity of diclofenac to Daphnia magna
Published 28 July 2025 Science ClosedTags: biological response, laboratory, multiple factors, phytoplankton, reproduction, toxicants
Highlights
- Chronic diclofenac (DCF) exposure was tested in Daphnia magna at pH 7.0 and 8.7.
- An unexpected pH increase in M4 medium was observed during the experiment.
- The NOEC (no observed effect concentration) of DCF was 5 mg l-1 at pH 8.7.
- Initial pH 7.0 prolonged the time to release of the first hatchlings.
- At 1.3 mg l-1 DCF, fewer neonates were observed at pH 7.0 than at pH 8.7.
Abstract
Pharmaceuticals, as ionizable compounds, are a challenging group of pollutants to analyze because the pH of the environment can alter its ecotoxicological features. However, changes in the toxicity of pharmaceuticals toward aquatic organisms were observed even when there was no change in the ionization of the molecules with a pH shift. Therefore, we conducted a study that aimed to check how pH influences the chronic toxicity of diclofenac (DCF, pKa ≈ 4.0) toward Daphnia magna at two pH levels, 7.0 and 8.7, where DCF is obtained as relatively polar anion. The performance of the experiment with OECD 211 was found to be challenging because of the medium pH shift during the exposure test. Acidification increased the toxicity of DCF, reducing the number of neonates (at a concentration of 1.3 mg l-1) and showing a tendency towards delayed hatching and reduced number of hatchings. In addition, the acidification itself also changes D. magna reproduction, affecting the number of hatchings and the first day of hatching. We conclude that the pH, as a factor of toxicity modulation for ionizable compounds, needs to be evaluated and presented in scientific protocols.
Continue reading ‘Effect of acidification on the chronic toxicity of diclofenac to Daphnia magna’Biomarkers responses in the amphipod Tiburonella viscana exposed to the biocide DCOIT and CO2-induced ocean acidification
Published 10 March 2025 Science ClosedTags: biological response, crustaceans, laboratory, multiple factors, physiology, South Atlantic, toxicants, zooplankton
Highlights
- Biomarkers responses in amphipods assessed in sediment testing with the biocide DCOIT;
- Environmentally relevant concentrations of DCOIT produced biomarker responses;
- Enzymatic activities of GST and AChe were reported, including LPO and DNA damage;
- Biomarkers responses were observed in CO2-induced acidification conditions.
Abstract
Anthropogenic carbon dioxide emissions (CO2) have led to climate change and marine acidification, with an estimated decrease in ocean surface pH of 0.3-0.4 units by the end of the current century. Chemical pollution also contributes to biodiversity loss in marine environments. This issue is particularly critical in areas under pressure from shipping activities, where the introduction of new antifouling system formulations poses a major threat to non-target species. The biocide DCOIT is the most widely used alternative to organotin compounds due to its rapid degradation in seawater. The toxicity of waterborne DCOIT to marine organisms has been documented, but sediment-bound effects are limited to apical responses and pH scenarios corresponding to current levels. In this study, we determine in a combined way, the toxicity of DCOIT under marine acidification scenarios assessing biomarker responses in the burrowing amphipod Tiburonella viscana as a parameter of sublethal effects in solid phase exposures. Environmental relevant concentrations of DCOIT caused inhibition of the enzyme glutathione S-transferases (GST), changed acetylcholinesterase-like activity (AChE), and increased DNA damage at pHs of 7.7 and 7.4. For lipid peroxidation (LPO), increased levels caused by DCOIT were found for both control (8.1) and intermediate (7.7) conditions of pH. Our data provides evidence of oxidative and genotoxic effects induced by DCOIT, with activation of detoxification and defense mechanisms in T. viscana. These results are important for ecological risk assessment and managing of antifouling paint biocides in multiple stressors scenarios.
Continue reading ‘Biomarkers responses in the amphipod Tiburonella viscana exposed to the biocide DCOIT and CO2-induced ocean acidification’Adaptive resilience of sea urchins against seawater acidification: a study on egg quality and offspring performance within a volcanic vents area
Published 20 February 2025 Science ClosedTags: adaptation, biological response, echinoderms, field, multiple factors, otherprocess, reproduction, toxicants, vents
Highlights
- Sea urchins were collected within and outside a volcanic carbon vents area
- Egg quality was investigated revealing differences in size and energetic profile
- Offspring performances were tested at 2 pH levels both with and without herbicide
- Sea urchins from the Vents area showed better offspring performance
- Glyphosate-AMPA mixture caused additional but limited effects compared to pH.
Abstract
Local adaptation plays a critical role in an organism’s ability to survive and reproduce in diverse environmental conditions, potentially improving an organism’s response to stressful conditions such as ocean acidification or pollution. In this study, the effects of lower pH coupled with the presence of environmental contaminants were assessed on sea urchins (Paracentrotus lividus) collected outside and inside a volcanic CO2-vent system, where the mean ambient pH is 8.1 and 7.7, respectively.
Both groups of sea urchins were spawned, and offspring were reared at pH 8.1 and 7.7, and in the presence or absence of a mixture of 100 μg/L of glyphosate and its main metabolite aminomethylphosphonic acid. Offspring performance metrics (development, abnormalities, and growth) were investigated under the different exposure conditions. The exposure to reduced pH affected the development and larval growth in echinoplutei obtained from adults of both sites, although to a different extent. Chemicals mixture had an additive effect in slowing embryo development.
Results revealed that sea urchins living within the lower pH Vents area exhibited significantly higher egg quality, which likely enhanced embryonic development, reduced abnormalities, and increased larval size compared to their counterparts outside the Vents system, both in the presence and absence of contaminants. Findings suggest that sea urchins living within the CO2-Vents system developed adaptations to thrive under lower pH conditions. Elevated egg quality and improved offspring performance suggest organisms’ resilience to environmental stressors associated with seawater acidification. Although insights gained from this study are preliminary, mostly due to the limited number of replicates in the egg biochemical analysis, they contribute to unveiling the adaptive capabilities of sea urchins in facing ongoing ocean acidification challenges.
Continue reading ‘Adaptive resilience of sea urchins against seawater acidification: a study on egg quality and offspring performance within a volcanic vents area’Toxicity of PAHs-enriched sediments on meiobenthic communities under ocean warming and CO2-driven acidification scenarios
Published 6 January 2025 Science ClosedTags: annelids, biological response, BRcommunity, community composition, crustaceans, laboratory, mollusks, multiple factors, nematodes, otherprocess, platyhelminthes, sediment, South Atlantic, tardigrada, temperature, toxicants, zooplankton
Highlights
- Temperature rise reduced the densities of Copepoda and certain Nematoda groups.
- CO2 acidification prevented some Nematoda groups from increasing at high temperatures.
- CO2 acidification reduced Copepoda and nauplii densities, but increased Ostracoda.
- Complex interactions increased certain meiobenthic groups exposed to sediment PAHs.
- Global change and pollution showed interactive effects in meiobenthic communities.
Abstract
This study aimed to assess the interactive effects of CO2-driven acidification, temperature rise, and PAHs toxicity on meiobenthic communities. Laboratory microcosms were established in a full factorial experimental design, manipulating temperature (25 °C and 27 °C), pH (8.1 and 7.6), and PAH contamination (acenaphthene + benzo(a)pyrene spiked sediments and negative control). Temperature rise and CO2-driven acidification led to a decrease in the densities of Copepoda. The density of nematodes Pseudochromadora and Daptonema also decreased, while Sphaerotheristus and Sabatieria densities increased, particularly in the absence of CO2-driven acidification. Ostracoda densities increased in the acidified scenario. PAH contamination resulted in decreased Daptonema densities but increased Turbellaria and certain Nematoda genera (e.g. Pseudochromadora). Overall, the results indicate that the changes of meiobenthic communities caused by CO2 acidification, warming, and PAH contamination are shaped by the vulnerability and tolerance of each taxonomic group, alongside indirect effects observed in Nematoda assemblages.
Continue reading ‘Toxicity of PAHs-enriched sediments on meiobenthic communities under ocean warming and CO2-driven acidification scenarios’Synergistic effects of ocean acidification and sulfamethoxazole on immune function, energy allocation, and oxidative stress in Trochus niloticus
Published 9 December 2024 Science ClosedTags: biological response, mollusks, multiple factors, physiology, respiration, toxicants
Highlights
- Dual stress of OA and SMX may harm survival and reproduction in T. niloticus.
- OA increased immune and antioxidant responses in T. niloticus.
- SMX exposure boosted antioxidant responses and oxygen consumption.
- Exposure to OA combined with SMX impaired cellular energy allocation in T. niloticus.
Abstract
Ocean acidification, a major consequence of climate change, poses significant threats to marine organisms, particularly when combined with other environmental stressors such as chemical pollution. This study investigated the physiological responses of Trochus niloticus to a 28-day exposure of ocean acidification and/or sulfamethoxazole, a commonly detected antibiotic in the South China Sea. Exposure to either acidification or sulfamethoxazole individually triggered adaptive responses through immune activation, antioxidant reactions, and metabolic adjustments. However, concurrent exposure resulted in significant adverse effects, including compromised immunity, oxidative damage, and disrupted energy budget. These findings provide new insights into how ocean acidification interacts with antibiotic pollution to synergistically impact marine gastropods, suggesting that multiple stressors may pose greater threats to T. niloticus populations than single stressors alone.
Continue reading ‘Synergistic effects of ocean acidification and sulfamethoxazole on immune function, energy allocation, and oxidative stress in Trochus niloticus’Ocean acidification enhances the tolerance of dinoflagellate Prorocentrum donghaiense to nanoplastic-induced oxidative stress by modulating photosynthetic performance
Published 28 November 2024 Science ClosedTags: biological response, BRcommunity, growth, laboratory, multiple factors, North Pacific, photosynthesis, phytoplankton, toxicants
Introduction: The impact of ocean acidification (OA) and nanoplastics (NPs) on harmful algal blooms (HAB) has emerged as a major global concern. However, the combined effects of OA and NPs on the HAB species are poorly understood.
Methods: In this study, dinoflagellate Prorocentrum donghaiense, a typical HAB species, was exposed to varying concentrations of NPs (108.15 ± 8.52 nm) (0, 5, 10, and 15 mg L−1) and CO2 (low CO2: 417 ppm, pH: 8.00 and high CO2: 1045 ppm, pH: 7.73) for seven days to investigate the combined effects of OA and NPs.
Results and discussion: The findings revealed that NPs inhibited the growth of P. donghaiense by inducing oxidative stress, as indicated by elevated malondialdehyde (MDA) content and decreased carotenoid/chlorophyll-a ratio, even though photochemical efficiency (φP0, ψ0, and φE0), rETRmax and α were enhanced in response to NPs stress. However, OA promoted the growth and alleviated the adverse effects of NPs on P. donghaiense by increasing photochemical efficiency (φP0, ψ0, and φE0) and energy flux (RC/CS0, TR0/CS0, ET0/CS0) and enhancing the antioxidant ability (increased superoxide dismutase, and decreased MDA). P. donghaiense showed enhanced tolerance to NPs under simulated OA conditions. These findings enhance our knowledge of the HAB species response to NPs pollution under future OA scenarios.
Continue reading ‘Ocean acidification enhances the tolerance of dinoflagellate Prorocentrum donghaiense to nanoplastic-induced oxidative stress by modulating photosynthetic performance’Impacts of UV-filter pollution and low pH: sperm and adult biomarkers in the mussel Mytilus galloprovincialis in a multi-stressor context
Published 7 November 2024 Science ClosedTags: biological response, laboratory, Mediterranean, mollusks, multiple factors, North Atlantic, physiology, reproduction, toxicants
Highlights
- Low pH emerged as a main driver of responses, amplifying UV-filters’ effects on both biological levels.
- Sperm quality was relatively unaffected by UV-filters but significantly impacted by pH 7.7.
- Exposure to low pH resulted in redox imbalance and reduced lipid peroxidation levels in sperm cells.
- UV-filters, alone or combined with low pH, increased adults’ metabolic activity and energy storage.
- Activation of antioxidant and biotransformation defense systems, with increased ACP activity across all treatments.
Abstract
In an era of unprecedented environmental changes, understanding the combined effects of multiple stressors on species’ performance is urgent. The increasing UV-filter incorporation in daily-life products raises concerns about their potential impact on marine-coastal environments upon release. As stressors rarely act alone, global change-induced factors, such as ocean acidification (OA), can amplify ecological hazards promoted by contaminants in coastal realms. This study investigated the combined impacts of UV-filters 4-methylbenzylidene camphor (4-MBC) and benzophenone-3 (BP-3), at ecologically relevant concentrations (1 and 10 µg/L), under two target pH levels (8.2 and 7.7, reflecting a ∆pH of 0 and -0.3 relative to the average pH at the sampling site), on the biochemical performance and male reproductive health of the mussel Mytilus galloprovincialis. Using sperm and adult assays alongside a multi-biomarker approach, the study revealed that pH was the primary driver of the decline in mussel physiological and biochemical performances, further intensifying UV-filters’ impacts. While sperm cells showed adaptive responses to low pH conditions alone, characterized by reduced lipid peroxidation (LPO) levels and superoxide anion overproduction, adult mussels experienced more pronounced effects, particularly under simultaneous exposure to low pH and UV-filters. Specifically, the adults exhibited distinct bioconcentration patterns under low pH, along with enhanced cellular metabolic activity and energy-demand compensatory processes, activation of biotransformation pathways, and regulation of antioxidant defenses. Given the ecological and socio-economic importance of M. galloprovincialis and its demonstrated vulnerability to these stressors, these findings highlight the need for further studies on potential transgenerational impacts and evolutionary implications for mussel populations.
Continue reading ‘Impacts of UV-filter pollution and low pH: sperm and adult biomarkers in the mussel Mytilus galloprovincialis in a multi-stressor context’Effects of single or combined exposure to tralopyril and ocean acidification on energy metabolism response and sex development in Pacific oysters (Crassostrea gigas)
Published 5 November 2024 Science ClosedTags: biological response, laboratory, mollusks, multiple factors, physiology, reproduction, toxicants
Highlights
- Tralopyril and OA stimulate energy metabolism gene expression in the C. gigas.
- Under the stress of ocean acidification, C. gigas tend to develop into females.
- C. gigas are able to restore normal energy metabolism from a state of stress after depuration.
Abstract
The combined effects of the novel antifouling biocide tralopyril (TP) nitrile and ocean acidification (OA) on marine organisms are still not well understood, despite the increasing attention given to the toxic effects of emerging pollutants and OA on marine organisms in recent years. In this study, Crassostrea gigas (C. gigas) was exposed to TP, OA, and a combination of TP and OA for 21 days with a 14-day depuration. This study investigated the inter-tissue variability in energy metabolism responses and the impacts on gonadal development in C. gigas under both single and combined exposures to TP and OA. The results indicate that TP exposure and OA resulted in up-regulation of energy metabolism genes in the C. gigas, with tissues exhibiting enhanced aerobic metabolism. Furthermore, OA influences the sex determination of C. gigas, promoting the development of female individuals. Moreover, following depuration, C. gigas is able to restore normal energy metabolism and sexual development through the accumulation of suitable energy reserves. This study provides a valuable reference for the environmental and ecological risk assessment of TP, addressing the research gap in understanding the combined toxicity of TP and OA on aquatic organisms.
Continue reading ‘Effects of single or combined exposure to tralopyril and ocean acidification on energy metabolism response and sex development in Pacific oysters (Crassostrea gigas)’Environmental behavior and toxic effects of micro(nano)plastics and engineered nanoparticles on marine organisms under ocean acidification: a review
Published 5 November 2024 Science ClosedTags: biological response, BRcommunity, growth, morphology, multiple factors, physiology, reproduction, review, toxicants
Ocean acidification (OA) driven by human activities and climate change presents new challenges to marine ecosystems. At the same time, the risks posed by micro(nano)plastics (MNPs) and engineered nanoparticles (ENPs) to marine ecosystems are receiving increasing attention. Although previous studies have uncovered the environmental behavior and the toxic effects of MNPs and ENPs under OA, there is a lack of comprehensive literature reviews in this field. Therefore, this paper reviews how OA affects the environmental behavior of MNPs and ENPs, and summarizes the effects and the potential mechanisms of their co-exposure on marine organisms. The review indicates that OA changes the marine chemical environment, thereby altering the behavior of MNPs and ENPs. These changes affect their bioavailability and lead to co-exposure effects. This impacts marine organisms’ energy metabolism, growth and development, antioxidant systems, reproduction and immunity. The potential mechanisms involved the regulation of signaling pathways, abnormalities in energy metabolism, energy allocation, oxidative stress, decreased enzyme activity, and disruptions in immune and reproductive functions. Finally, based on the limitations of existing research, actual environment and hot issues, we have outlined future research needs and identified key priorities and directions for further investigation. This review deepens our understanding of the potential effects of MNPs and ENPs on marine organisms under OA, while also aiming to promote further research and development in related fields.
Continue reading ‘Environmental behavior and toxic effects of micro(nano)plastics and engineered nanoparticles on marine organisms under ocean acidification: a review’Elevated pCO2 may increase the edible safety risk of clams exposed to toxic Alexandrium spp.
Published 2 October 2024 Science ClosedTags: biological response, BRcommunity, growth, laboratory, mollusks, multiple factors, North Pacific, nutrients, physiology, phytoplankton, toxicants
Highlights
- High pCO2 diversely affects PSTs production of various Alexandrium spp.
- Elevated pCO2 alters PSTs composition and toxicity in clams than in algae.
- High pCO2 is beneficial to bioaccumulation of highly toxic PST in clams.
- Elevated pCO2 inhibits elimination of highly toxic PST components in clams.
- High pCO2 enhances PSTs toxicity in clams exposed to different Alexandrium spp.
Abstract
Toxic harmful algal blooms (HABs) have received increasing attention owing to their threat to the health of aquatic life and seafood consumers. This study evaluated the impacts of elevated atmospheric partial pressure of CO2 (pCO2) on the production of paralytic shellfish toxins (PSTs) in different Alexandrium spp. strains, together with its further effects on the bioaccumulation/elimination dynamics of PSTs in bivalves contaminated with PSTs from toxic dinoflagellates. Our results showed that elevated pCO2 stimulated the growth of the two Alexandrium spp. (A. catenella and A. pacificum) isolated from the northern and southern coastal areas of China, respectively, and affected PST production including content and toxicity of the two strains differently. Further PSTs bioaccumulation/elimination in PSTs-contaminated Manila clam, Ruditapes philippinarum under high pCO2 also occurred. It is worth noting the biotransformation of neosaxitoxin (NEO) with high toxicity through trophic transfer with effect of elevated pCO2. When in microalgae cultured under the control (410 ppm) and elevated pCO2 conditions (495 and 850 ppm), the proportion of NEO in the PST content produced by A. catenella was reduced from 11.1 to 6.4 and 2.6 %, while the proportion of NEO in A. pacificum was increased from 3.1 to 3.6 and 4.7 %, respectively. NEO accounted for >50 % of total PST contents in clams, which were biotransformed via transfer from dinoflagellates and higher pCO2 enhanced this biotransformation leading to increased NEO accumulation. The negatively affected elimination of PSTs, especially NEO, in clams fed with A. catenella or A. pacificum, indicates that the detoxification of PSTs-contaminated clams may be more difficult under elevated pCO2. This study provides reference for developing models to assess the safety of bivalves under the co-stress of environmental change and toxic HABs, suggesting that ocean acidification may lead to the higher safety risk of Manila clams exposed to toxic HAB dinoflagellates.
Continue reading ‘Elevated pCO2 may increase the edible safety risk of clams exposed to toxic Alexandrium spp.’Growth, photosynthetic and nutrition characteristics of Pyropia haitanensis in response to the effects of increased CO2 and chloramphenicol
Published 27 May 2024 Science ClosedTags: algae, biological response, chemistry, laboratory, multiple factors, North Pacific, performance, photosynthesis, physiology, toxicants
Pyropia haitanensis was cultured under two CO2 (410 (LC), 1000 (HC) μL L-1) concentrations and six chloramphenicol (CAP)-methanol solutions (0, 0+methanol, 10, 50, 100, 250 μg mL-1) to investigate the effects of elevated CO2 and CAP on its growth, photosynthesis and biochemical characteristics. HC had no obvious effects on the growth rate (RGR) with CAP in the range of 10 to 100 μg mL-1, but the decrease of RGR by HC was statistically significant with the CAP dosage at 250 μg mL-1. HC had no significant effect on net photosynthetic rates (Pn) in the present of CAP (10-250 μg mL-1). CAP greatly reduced net photosynthesis as well as the maximal photochemical yield (Fv/Fm) and photosynthetic efficiency (αETR). In contrast, the maximum relative electron transport rates (rETRm) were almost constant with the CAP dosage from 10 to 100 μg mL-1. HC significantly increased the energy fluxes (per RC) for absorption (ABS/RC), trapping (TRo/RC) and transport fluxes (ETo/RC) with the dosage of CAP at 250 μg mL-1. Principal component analysis (PCA) indicated that CAP was positively correlated with the synthesis of free amino acids (FAA), contents of umami-, sweet- and essential AA were significantly enhanced with the interaction of HC and higher CAP dosage at 100 μg mL-1, which led to the variation of flavor in algae. Furthermore, phycobiliproteins and soluble protein (SP) contents were remarkably reduced by CAP. Contents of chlorophyll a (Chl a), carotenoids (Car), soluble carbohydrates (SC) and C/N ratios were almost unchanged among treatments. The study indicates that future ocean acidification has no obvious effects on the biomass productivity of P. haitanensis, maintained steady photosynthetic activities with the CAP (within 100 μg mL-1) and induces better flavor. The data obtained have important theoretical relevance for in-depth understanding of algal responses to global changes and oceanic contamination.
Continue reading ‘Growth, photosynthetic and nutrition characteristics of Pyropia haitanensis in response to the effects of increased CO2 and chloramphenicol’Impacts of microplastic and seawater acidification on unicellular red algae: growth response, photosynthesis, antioxidant enzymes, and extracellular polymer substances
Published 17 May 2024 Science ClosedTags: abundance, algae, biological response, growth, laboratory, multiple factors, otherprocess, physiology, toxicants
Highlights
- Single and combined effects of MPs and OA on P. purpureum were investigated.
- μm MPs significantly promoted algal growth at concentrations of 5-100 mg L−1.
- 1μm MPs caused negative effect on microalgae at medium and high concentrations.
- Seawater acidification mitigated the impacts of MPs on microalgae.
Abstracts
Microplastics (MPs) pollution and seawater acidification have increasingly become huge threats to the ocean ecosystem. Their impacts on microalgae are of great importance, since microalgae are the main primary producers and play a critical role in marine ecosystems. However, the impact of microplastics and acidification on unicellular red algae, which have a unique phycobiliprotein antenna system, remains unclear. Therefore, the impacts of polystyrene-MPs alone and the combined effects of MPs and seawater acidification on the typical unicellular marine red algae Porphyridium purpureum were investigated in the current study. The result showed that, under normal seawater condition, microalgae densities were increased by 17.75-41.67% compared to the control when microalgae were exposed to small-sized MPs (0.1 μm) at concentrations of 5-100 mg L−1. In addition, the photosystem II and antioxidant enzyme system were not subjected to negative effects. The large-sized MPs (1 μm) boosted microalgae growth at a low concentration of MPs (5 mg L−1). However, it was observed that microalgae growth was significantly inhibited when MPs concentration increased up to 50 and 100 mg L−1, accompanied by the remarkably reduced Fv/Fm value and the elevated levels of SOD, CAT enzymes, phycoerythrin (PE), and extracellular polysaccharide (EPS). Compared to the normal seawater condition, microalgae densities were enhanced by 52.11-332.56%, depending on MPs sizes and concentrations, due to the formed CO2-enrichment condition and appropriate pH range. PE content in microalgal cells was significantly enhanced, but SOD and CAT activities as well as EPS content markedly decreased under acidification conditions. Overall, the impacts of seawater acidification were more pronounced than MPs impacts on microalgae growth and physiological responses. These findings will contribute to a substantial understanding of the effects of MPs on marine unicellular red microalgae, especially in future seawater acidification scenarios.
Continue reading ‘Impacts of microplastic and seawater acidification on unicellular red algae: growth response, photosynthesis, antioxidant enzymes, and extracellular polymer substances’
