O aumento das emissões de gás carbônico atmosférico proveniente de atividades antrópicas desde a Revolução Industrial teve como consequência uma maior participação de águas superficiais no processo de sequestro de dióxido de carbono, a fim de amenizar o efeito estufa. A principal consequência do aumento de captura de gás carbônico pelos oceanos é um fenômeno denominado acidificação oceânica. Alguns poluentes presentes na água, como por exemplo fármacos e produtos de cuidados pessoais (FPCPs) podem sofrer alterações na sua mobilidade e biodisponibilidade por conta da diminuição do pH do meio. Atualmente a quantidade de dados sobre os efeitos e o risco ambiental de FPCPs em organismos marinhos ainda é escassa. Diante deste cenário o presente estudo teve como objetivo analisar a ocorrência, o comportamento e a biodisponibilidade do fármaco orfenadrina frente a diferentes cenários de acidificação oceânica. O fármaco orfenadrina, empregado como relaxante muscular e amplamente consumido foi observado em todos os pontos de amostragem das áreas de influência dos emissários submarinos de Santos e Guarujá – SP, com concentrações que variaram LOQ a 0,5 ng/g em sedimentos. Os resultados do ensaio de toxicidade com água empregando ouriços do mar (Echinometra lucunter) nos diferentes pHs 8,0; 7,6; 7,3 apresentaram valores de CEO de 0,05mg/L e o EpH50 foi estabelecido em 7,30. Quanto aos ensaios com mexilhões Perna perna foram observados efeitos em concentrações ambientalmente relevantes, com CEO de 200 ng/g. Os resultados dos ensaios feitos para a avaliação do desenvolvimento embriolarval em água indicaram que tanto o processo de acidificação quanto o aumento da concentração afetam o desenvolvimento dos embriões de ouriço do mar. Já nos ensaios com P. perna foi possível verificar ainda que a presença do fármaco de caráter básico reduziu os efeitos da acidificação oceânica. Os resultados da análise de bioacumulação detectaram a presença da orfenadrina em todos os tecidos analisados. A análise dos ensaios de citotoxicidade nesta ocasião refutou a hipótese inicial do estudo, visto que a presença do fármaco de caráter básico reduziu os efeitos da acidificação oceânica. Neste sentido, fica evidente necessidade de se aprofundar os estudos sobre toxicologia relacionada a fármacos sob cenários de acidificação em ambiente marinho.
- Ocean acidification scenarios were assessed with mussel in presence of crack-cocaine.
- Lysosomal membrane stability, lipid peroxidation, and DNA strand breaks in Perna perna revealed toxicity increase.
- Adverse effects of acidification were detected for pH below 6.5.
- At pH 7.5–6.5 adverse effects are related to combined stressors (CO2 and cocaine).
The increasing CO2-concentrations in the atmosphere promote ocean acidification. Seawater chemistry changes interact with contaminants, such as illicit drugs in the coastal zones. This work evaluates impacts of pH decrease and crack-cocaine exposure on the commercial mussel Perna perna through biomarker responses (lysosomal membrane stability, lipid peroxidation, and DNA strand breaks). The organisms were exposed to different crack-cocaine concentrations (0.5, 5.0, and 50 μg L−1) combined with different pH values (8.3, 8.0, 7.5, 7.0, 6.5, and 6.0) for 96 h. Crack-cocaine in the different acidification scenarios triggered cyto-genotoxicity, which affected the overall health of mussels exposed to cocaine environmentally relevant concentration. This study produced the first data on biomarker responses associated with CO2-induced acidification and illicit drugs (crack-cocaine) in marine organisms.
- Skeletonema costatum was tolerant to low and moderate benzo(a)pyrene concentrations.
- The high benzo(a)pyrene concentration remarkably inhibited growth and photosynthesis.
- Negative effects of ocean acidification were detected at the high benzo(a)pyrene level.
The combined effects of polycyclic aromatic hydrocarbons and seawater acidification are poorly understood. Hence, we exposed the bloom-forming diatom Skeletonema costatum to four concentrations (0, 0.1, 1 and 10 μg L-1) of benzo(a)pyrene and two pCO2 levels (400 and 1000 μatm) to investigate its physiological performance. The growth and photosynthesis of S. costatum were tolerant to low and moderate benzo(a)pyrene concentrations regardless of the pCO2 level. However, the highest benzo(a)pyrene concentration had remarkably adverse effects on most parameters, decreasing the growth rate by 69%. Seawater acidification increased the sensitivity to high light stress, as shown by the lower relative maximum electron transport rate and light saturation point at the highest benzo(a)pyrene concentration. Our results suggested that benzo(a)pyrene could be detrimental to diatoms at a habitat-relevant level, and seawater acidification might further decrease its light tolerance, which would have important ramifications for the community structure and primary production in coastal waters.
This study investigated the effect of an organic pollutant (Bisphenol A, an endocrine-disrupting chemical) on the stability of a mixture of nanoparticles (NPs). Experiments were conducted in seawater chemistry condition with TiO2/ZnO NP concentration ratio: 0.01, 10.1, 1, 10,100; pH: 7.4 and 8.1; BPA concentration: 1 and 10μg/L. The presence of BPA was found to increase the size of NP. Lower pH of 7.4 increased size of NPs from 3 to 297% (at 1 μg/L BPA; NP ratio = 0.1 to 100). Aggregation rate constant values ranged between 0.17 and 1.81nm/sec in pH 7.4 suspension and between 0.48 and 56nm/sec in pH 8.1 suspension. Factors such as pH and NP mass concentration had major effects on size change for suspension having the same ratio of TiO2/ZnO. NP aggregate was comprised of 97% ZnO NP, 3% TiO2 NP and had 1.39mg/kg BPA. Overall, this study found dominance of van der Waals forces of attraction in mixture suspension of NPs and BPA. The obtained result on NP persistence in seawater can now be used in estimating exposure doses of a mixture of nanoparticles during inadvertent exposure.
Emerging pollutants, such as pharmaceuticals from human waste, are continuously released into aquatic systems. Although pharmaceuticals alone can adversely impact marine organisms, the bioavailability of many pharmaceuticals are dependent on ambient physical conditions, like pH. As few studies have considered the interactive effects of pharmaceutical pollution and anthropogenic ocean acidification, this study investigated the behavioral response of larval sea urchins (Heliocidaris crassispina) and ascidians (Styela plicata) to environmentally-relevant concentrations of fluoxetine (10 and 100 ng L-1) under ambient (pH 8.0) and acidified conditions (pH 7.7). Larval ascidians reared at pH 8.0 exhibited swam in slower, more directed paths with increasing fluoxetine. Interestingly, this effect was absent at pH 7.7. On the other hand, I only observed independent effects of fluoxetine and acidification on urchin swimming behavior. My findings highlight the importance of using behavioral endpoints when assessing the realistic sub-lethal organismal and ecological impacts of anthropogenic stressors, and that considering differences in species traits may allow for the generation of more realistic predictions of the impact of emerging pollutants under future climate scenarios.
The Great Barrier Reef (GBR) is threatened by climate change and local pressures, including contaminants in nearshore habitats. This study investigated the combined effects of a GBR-relevant contaminant, the herbicide diuron, under current and two future climate scenarios on the coral Acropora millepora. All physiological responses tested (effective quantum yield (ΔF/Fm′), photosynthesis, calcification rate) were negatively affected with increasing concentrations of diuron. Interactive effects between diuron and climate were observed for all responses; however, climate had no significant effect on ΔF/Fm′ or calcification rates. Photosynthesis was negatively affected as the climate scenarios were adjusted from ambient (28.1 °C, pCO2 = 397 ppm) to RCP8.5 2050 (29.1 °C, pCO2 = 680 ppm) and 2100 (30.2 °C, pCO2 = 858 ppm) with EC50 values declining from 19.4 to 10.6 and 2.6 μg L−1 diuron in turn. These results highlight the likelihood that water quality guideline values may need to be adjusted as the climate changes.
- Environmental triclosan levels alter the reproductive output of R. philippinarum.
- Environmental triclosan levels reduce body mass in R. philippinarum.
- R. decussatus growth was resilient to environmental changes.
- Worst case scenario (TCS and climate change) will affect Manila clam production.
We built a simulation model based on Dynamic Energy Budget theory (DEB) to assess the growth and reproductive potential of the native European clam Ruditapes decussatus and the introduced Manila clam Ruditapes philippinarum under current temperature and pH conditions in a Portuguese estuary and under those forecasted for the end of the 21st c. The climate change scenario RCP8.5 predicts temperature increase of 3 °C and a pH decrease of 0.4 units. The model was run under additional conditions of exposure to the emerging contaminant triclosan (TCS) and in the absence of this compound. The parameters of the DEB model were calibrated with the results of laboratory experiments complemented with data from the literature available for these two important commercial shellfish resources. For each species and experimental condition (eight combinations), we used data from the experiments to produce estimates for the key parameters controlling food intake flux, assimilation flux, somatic maintenance flux and energy at the initial simulation time. The results showed that the growth and reproductive potential of both species would be compromised under future climate conditions, but the effect of TCS exposure had a higher impact on the energy budget than forecasted temperature and pH variations. The egg production of R. philippinarum was projected to suffer a more marked reduction with exposure to TCS, regardless of the climatic factor, while the native R. decussatus appeared more resilient to environmental causes of stress. The results suggest a likely decrease in the rates of expansion of the introduced R. philippinarum in European waters, and negative effects on fisheries and aquaculture production of exposure to emerging contaminants (e.g., TCS) and climate change.
Ocean warming and acidification can cause deleterious effects on marine biota, which may be potentialized when associated with metal pollution. Thus, the aim of this work was to evaluate the effects of pH decrease, temperature increase and lead contamination on fertility rate and embryo-larval development of Echinometra lucunter. Gametes and embryos were exposed at pH 8.2…
- Copepods were subjected to OA and Hg pollution under multigenerational exposure.
- OA reduced Hg accumulation and its toxicity to the growth/reproduction in copepods.
- Copepod proteome enabled its physiological resilience to decreasing pH.
- Proteomics indicated many toxic events, ensuring Hg toxicity to the copepod’s traits.
- Proteome compensation was accounting for the alleviative effect of OA on Hg toxicity.
Here, we examined the combinational effect of ocean acidification (OA) and mercury (Hg) in the planktonic copepod Pseudodiaptomus annandalei in cross-factored response to different pCO2 (400, 800 μatm) and Hg (control, 1.0 and 2.5 μg/L) exposures for three generations (F0-F2), followed by single-generation recovery (F3) under clean condition. Several phenotypic traits and Hg accumulation were analyzed for F0-F3. Furthermore, shotgun-based quantitative proteomics was performed for F0 and F2. Our results showed that OA insignificantly influenced the traits. During F0-F2, combined exposure reduced Hg accumulation as compared with the counterpart Hg treatment, supporting the mitigating effect of OA on Hg toxicity in copepods. Proteomics analysis indicated that the copepods probably increased energy production/storage and stress response to ensure physiological resilience against OA. However, Hg induced many toxic events (e.g., energy depletion and degenerated organomorphogenesis/embryogenesis for F0; cell cycle arrest and detrimental stress-defense for F2), which were translated to the population-level adverse outcome, i.e., compromised growth/reproduction. Particularly, compensatory proteome response was identified (e.g., increased immune defense for F0; energetic compensation and enhanced embryogenesis for F2), accounting for a negative interaction between OA and Hg. Together, this study provides the molecular mechanisms behind the effects of OA and Hg pollution in marine copepods.
This study evaluates the impacts of 16 different leachates of plastic-made packaging on marine species of different trophic levels (bacteria, algae, echinoderms). Standard ecotoxicological endpoints (inhibition of bioluminescence, inhibition of growth, embryo-toxicity) and alterations of ecologically significant parameters (i.e., echinoderms’ body-size) were measured following exposure under different pH water conditions: marine standard (pH 8.1) and two increasingly acidic conditions (pH 7.8 and 7.5) in order to evaluate possible variations induced by ocean acidification. The results obtained in this study evidence that the tested doses are not able to significantly affect bacteria (Vibrio fischeri) and algae (Phaeodactylum tricornutum). On the contrary, Paracentrotus lividus larvae were significantly affected by several packaging types (13 out of 16) with meaningless differences between pH conditions.
This study assessed the interactive effects of near-future coastal acidification in combination with varying sub lethal metal concentrations on the haemolymph osmolality of Dotilla fenestrata. Crabs were exposed to acute combination of near-future pH scenarios of estuarine systems (7.2, 7.4 and 7.6) by bubbling CO2 into holding tanks and metal concentrations (Cd = 0.50, 0.75, and 1.00 mg/l), (Pb = 6.50, 8.50 and 10.50 mg/l) and (Cd & Pb = 4.50, 5.75 and 7.00 mg/l) at 32 psu salinity and 18 °C for 96 h and compared with the control group that were acclimated in water medium (salinity 32 psu, temperature 18 °C and pH 8.1). Mean haemolymph osmolality of crabs exposed to a combination of varying pH and metal concentrations were not significantly different (ANOVA HSD: df 9; p > 0.05) from the crabs acclimated close to background water parameters. The study showed that near-future coastal pH has no significant effect on the haemolymph osmolality of the crab Dotilla exposed to sublethal concentrations of Cd and Pb at salinity level of 32 ppt.
- This work focusses on the effect of a multi-stressor environment in sea urchin.
- Embryo-larval bioassays were used to determine growth and morphometric parameters.
- A lower water pH (7.6) reduced larval growth and caused deformities.
- Microplastics aggravate the effect of water acidification in sea urchin larvae.
- High temperatures caused an additional stress and reduced larvae stomach volume.
The aim of this work was to estimate the potential risk of the combined effect of global change factors (acidification, temperature increase) and microplastic (MP) pollution on the growth and development of the sea urchin P. lividus. Embryo-larval bioassays were conducted to determine growth and morphology after 48 h of incubation with MP (1000 and 3000 particles/mL); with filtered sea water at pH = 7.6; and with their combinations. A second experiment was conducted to study the effect of pH and MP in combination with a temperature increase of 4 °C compared to control (20 °C). We found that the inhibition of growth in embryos reared at pH = 7.6 was around 75%. Larvae incubated at 3000 MP particles/mL showed a 20% decrease in growth compared to controls. The exposure to MP also induced an increase in the postoral arm separation or rounded vertices. The combined exposure to a pH 7.6 and MP caused a significant decrease of larval growth compared to control, to MP and to pH 7.6 treatments. Morphological alterations were observed in these treatments, including the development of only two arms. Increasing the temperature resulted in an increased growth in control, in pH 7.6 and pH 7.6 + MP3000 treatments, but the relative stomach volume decreased. However, when growth parameters were expressed per Degree-Days the lower growth provoked by the thermal stress was evidenced in all treatments. In this work we demonstrated that MP could aggravate the effect of a decreased pH and that an increase in water temperature generated an additional stress on P. lividus larvae, manifested in a lower growth and an altered development. Therefore, the combined stress caused by ocean warming, ocean acidification, and microplastic pollution, could threaten sea urchin populations leading to a potential impact on coastal ecosystems.
• Determined bioaccumulation and tissue distribution of cadmium alone and in combination with pH in Eriocheir sinensis
• Cadmium bioaccumulation decreased as gill > hepatopancreas > muscle
• The highest cadmium residue concentration was detected in 14 days
• With reduced values of pH, cadmium bioaccumulation decreased in tissues
• Lower pH reduced the toxicity of cadmium to Eriocheir sinensis
In this study, Chinese mitten crabs (Eriocheir sinensis) were exposed to various combinations of reduced pH (7.8, 7.3, and 6.5) and cadmium (Cd; 0 and 1 mg·L−1) for 7, 14, and 21 days. The reduced pH and 1 mg·L−1 Cd treatment significantly decreased the Cd concentration in crab tissues in the order of pH 7.8 > pH 7.3 > pH 6.5. The exposure to Cd resulted in edema, tubular vacuolization in epithelial cells, and hepatic duct degeneration in the hepatopancreas and indistinct cellular structure and disconnected epithelial layer in the gills. However, low pH alleviated the toxic effects of Cd on the tissues. In gill and hepatopancreas tissues, low pH and Cd exposure caused a significant increase in superoxide dismutase and catalase activities and oxidized glutathione content, but metallothionein activity was not affected. In contrast, the activity of glutathione-S-transferase decreased. Thus, indirect effects of pH on metal accumulation and antagonistic toxicities were observed in E. sinensis, and reduced pH and Cd exposure modulated the oxidative balance via different mechanisms.
Ocean-warming and acidification jeopardize Antarctic marine species, adapted to cold and constant conditions and naturally exposed to high pro-oxidant pressures and cadmium (Cd) bioavailability. The aim of this study was to investigate if projected temperature increase and pH reduction may affect the accumulation and the effects of Cd in the rockcod Trematomus bernacchii. Organisms were exposed for 14 days to six scenarios, combining environmental or increased temperature (−1 °C, +1 °C) and control or reduced pH (8.05, 7.60), either with or without Cd (40 µg/L). Responses in liver and gills were analyzed at different levels, including mRNA and functional measurements of metallothioneins and of a wide battery of antioxidants, integrated with the evaluation of the total antioxidant capacity and onset of oxidative damages. In the gills, metallothioneins and mRNA of antioxidant genes (nrf2, keap1, cat, gpx1) increased after Cd exposure, but such effects were softened by warming and acidification. Antioxidants showed slighter variations at the enzymatic level, while Cd caused glutathione increase under warming and acidified scenarios. In the liver, due to higher basal antioxidant protection, limited effects were observed. Genotoxic damage increased under the combined stressors scenario. Overall results highlighted the modulation of the oxidative stress response to Cd by multiple stressors, suggesting the vulnerability of T. bernacchii under predicted ocean change scenarios.
- MP/NP at the poles should be addressed with chemical and climate stressors.
- MP/NP and anthropogenic stress interactions may vary seasonally and locally.
- MP/NP research should focus on polar species enduring high anthropogenic stress.
Polar marine ecosystems may have higher sensitivity than other ecosystems to plastic pollution due to recurrent physical and biological features; presence of ice and high UV radiation, slow growth rates and weak genetic differentiation of resident biota, accumulation of persistent organic pollutants and heavy metals, and fast rates of warming and global ocean acidification. Here, we discuss potential sources of and exposure to micro- and nano-plastic in polar marine ecosystems and potential mixture effects of micro- and nano-plastic coupled with chemical and climate related stressors. We address the anthropogenic contaminants likely to be ‘high risk’ for interactions in Arctic and Antarctic waters for reasons such as accumulation under sea-ice, a known sink for plastic particulates. Consequently, we address the potential for localised plastic-chemical interactions and possible seasonal fluctuations in interactions associated with freeze-thaw events. The risks for keystone polar species are also considered, incorporating the behavioural and physiological traits of biota and addressing potential ‘hotspot’ areas. Finally, we discuss a possible direction for future research.
- Effects of Cu2+ and elevated atmospheric CO2 on young sporophytes of Sargassum fusiforme were investigated.
- At elevated CO2, growth inhibition and pigment damage caused by Cu2+ remain at the same level.
- Elevated CO2 alleviates the Cu-induced suppression on photosystem.
- Elevated CO2 down-regulates the enzymatic antioxidant system against Cu2+.
Little attention has been given to the combined effects of elevated atmospheric CO2-induced ocean acidification (OA) and heavy metal pollution on marine macroalgae at the young stage. This study investigated the mutual effects of copper (Cu) and elevated CO2 on the young sporophytes of brown macroalgae Sargassum fusiforme. A matrix of four copper concentrations, 0, 0.025, 0.075 and 0.15 mg‧L-1, and two levels of CO2 (ambient CO2: 400 μatm; elevated CO2: 1,000 μatm) were used. High concentration of copper exposure greatly depressed photosynthesis and growth of the young sporophytes of S. fusiforme by reducing the apparent photosynthetic efficiency (ɑ), maximum net photosynthetic oxygen evolution rate (Pmax), maximum photochemical quantum yield (Fv/Fm) and pigments content (Chl a and Car). While elevated CO2 alone had obscure impact on this alga. However, the inhibition of Cu stress on Fv/Fm was weakened by elevated CO2, which also decreased the light compensation point (Ic). Meanwhile, the Cu2+-induced ascent in the dark respiration rate (Rd) and superoxide dismutase (SOD) activity was mitigated under the growth with elevated CO2, suggesting an alleviated oxidative stress. Overall, we propose that, under CO2 enrichment condition, the young sporophytes of S. fusiforme may increase photosynthesis efficiency and synthesize less enzymatic antioxidants in face of increasing Cu stress.
- Photosynthetic yield is affected by low pH in assays with and without Irgarol.
- Membrane damage and antioxidant activities increased in low pH added to Irgarol.
- H2O2 content and lipid peroxidation were not affected by low pH isolated.
- U.lactuca is tolerant to low pH by triggering photoprotector mechanisms.
- Protective mechanisms could not avoid the simultaneous effects of low pH and Irgarol.
Anthropogenic changes such as ocean acidification, eutrophication, and the release of hazardous chemicals affect coastal environments and aquatic organisms. We investigated the effects of seawater pH (7.4 and 8.2) isolated and in combination with Irgarol on Ulva lactuca. Stress indicators such as membrane damage, lipid peroxidation, and hydrogen peroxide content were assessed. In addition, chlorophyll fluorescence and antioxidant enzyme activities were measured. The photosynthetic yield was affected by low pH in assays with and without Irgarol. However, the combination of low pH and Irgarol promoted photoinhibition, besides the induction of non-photochemical quenching (NPQ) and changes in photosynthetic pigment contents. The induction of NPQ was directly influenced by low pH. The membrane damage was increased in low pH with and without Irgarol exposure. Total soluble protein and carbohydrate contents decreased in low pH, and in presence of Irgarol. The H2O2 content and lipid peroxidation were not affected by low pH. In contrast, Irgarol exposure strongly increased lipid peroxidation in both pHs, suggesting a possible synergistic effect. To avoid the harmful effects of high H2O2, U. lactuca increased antioxidant enzyme activities in treatments under low pH and in presence of Irgarol. Our results indicate that U. lactuca is tolerant to low pH by inducing NPQ, changing pigment contents, and increasing antioxidant defenses. In contrast, these protective mechanisms could not avoid the harmful effects of the combination with Irgarol.
- Combined effects of carbamazepine and reduced pH were investigated in M. galloprovincialis.
- Hypercapnia had a limited influence on carbamazepine accumulation.
- Interactive effects were observed at both transcriptional and cellular level.
- Immune system, cellular homeostasis and oxidative processes were mostly affected.
- Weighted elaboration of results revealed higher hazard by multiple stressors.
Contaminants of emerging concern and ocean changes are key environmental stressors for marine species with possibly synergistic, but still unexplored, deleterious effects. In the present study the influence of a simulated ocean acidification scenario (pH = 7.6) was investigated on metabolism and sub-lethal effects of carbamazepine, CBZ (1 µg/L), chosen as one of the most widely diffused pharmaceuticals in marine organisms. A multidisciplinary approach was applied on mussels, M. galloprovincialis, integrating measurement of drug bioaccumulation with changes in the whole transcriptome, responsiveness of various biochemical and cellular biomarkers including immunological parameters, lipid and oxidative metabolism, onset of genotoxic effects. Chemical analyses revealed a limited influence of hypercapnia on accumulation and excretion of CBZ, while a complex network of biological responses was observed in gene expression profile and functional changes at cellular level. The modulation of gamma-aminobutyric acid (GABA) pathway suggested similarities with the Mechanism of Action known for vertebrates: immune responses, cellular homeostasis and oxidative system represented the processes targeted by combined stressors. The overall elaboration of results through a quantitative Weight of Evidence model, revealed clearly increased cellular hazard due to interactions of CBZ with acidification compared to single stressors.
Commonly affected by changes in climate and environmental conditions, coastal areas are very dynamic environments where shellfish play an important ecological role. In this study, the oxidative stress and genotoxic responses of mussels (Mytilus galloprovincialis) exposed to paralytic shellfish toxin (PST) – producing dinoflagellates Gymnodinium catenatum were evaluated under i) current conditions (CC: 19 °C; pH 8.0), ii) warming (W: 24 °C; pH 8.0), iii) acidification (A:19 °C; pH 7.6) and iv) combined effect of warming and acidification (WA: 24 °C; pH 7.6). Mussels were fed with G. catenatum for 5 days, and to a non-toxic diet during the following 10 days. A battery of oxidative stress biomarkers and comet assay was performed at the peak of toxin accumulation and at the end of the post-exposure phase. Under CC, gills and hepatopancreas displayed different responses/vulnerabilities and mechanisms to cope with PST. While gills presented a tendency for lipid peroxidation (LPO) and genetic damage (expressed by the Genetic Damage Indicator – GDI), hepatopancreas seems to better cope with the toxins, as no LPO was observed. However, the mechanisms involved in hepatopancreas protection were not enough to maintain DNA integrity. The absence of LPO, and the antioxidant system low responsiveness, suggests DNA damage was not oxidative. When exposed to toxic algae under W, toxin-modulated antioxidant responses were observed in both gills and hepatopancreas. Simultaneous exposure to the stressors highlighted gills susceptibility with a synergistic interaction increasing DNA damage. Exposure to toxic algae under A led to genotoxicity potentiation in both organs. The combined effect of WA did not cause relevant interactions in gills antioxidant responses, but stressors interactions impacted LPO and GDI. Antioxidant responses and LPO pointed out to be modulated by the environmental conditions in hepatopancreas, while GDI results support the dominance of toxin-triggered process. Overall, these results reveal that simultaneous exposure to warming, acidification and PSTs impairs mussel DNA integrity, compromising the genetic information due to the synergetic effects. Finally, this study highlights the increasing ecological risk of harmful algal blooms to Mytilus galloprovinciallis populations.
The oceans are undergoing physical and biogeochemical changes in response to the increasing atmospheric CO2 load and increased ocean uptake, such as surface warming, reduced oxygen and a reduction in calcium carbonate and pH saturation levels. Changes in the pH and chemical composition of seawater can modify the speciation of contaminants, interfering with their bioavailability and toxicity. The present study aimed to evaluate the sublethal effect of the illicit drug crack-cocaine at different concentrations (0.5; 5; 50 µg / L) combined with ocean acidification by CO2 at pH values of 8.1; 7.5; 7.0; 6.5 and 6.0. For this purpose, an analysis of the biomarker of neurotoxic effect acetylcholinesterase (AChe) was performed on mussels Perna perna. The inhibition of AChe after exposure to crack at pH 7.5, 7.0 and 6.5 was preliminarily observed, demonstrating a combined effect of crack-cocaine and pH reduction, which can be observed in future scenarios of acidification in coastal zones contaminated by illicit drugs.