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- Perfluorooctane sulfonic acid (PFOS) adsorbed to polyethylene microplastics: accumulation and ecotoxicological effects in the clam Scrobicularia planaPublication . Islam, Naimul; FONSECA, TAINÁ; Vilke, Juliano Marcelo; Gonçalves, Joanna M.; Pedro, Paulo; Keiter, Steffen; Cunha, Sara C.; Fernandes, José O.; Bebianno, Maria JoãoMicroplastics are widespread in the marine environment, whereby organisms’ uptake these tiny particles, presenting adverse biological responses. Plastic debris also act as a vector of many contaminants which intensify their effects to marine organisms that depend on type, size, shape and chemical properties. This study aimed to assess the accumulation and potential toxicity of different sizes of microplastics with and without adsorbed perfluorooctane sulfonic acid (PFOS) in the clam Scrobicularia plana. Clams were exposed to 1 mg L-1 of virgin and PFOS (70.2 ± 12.4 μg g−1) contaminated lowdensity polyethylene microplastics of two different sizes (4-6 and 20-25 μm) over 14 days. Microplastic and PFOS accumulation and filtration rate were determined along with a multi biomarker approach to access the biological effects of microplastics accumulation. Biomarkers include oxidative stress (superoxide dismutase, catalase, glutathione peroxidases), biotransformation enzymes (glutathione-S-transferases) activity, neurotoxicity (acetylcholinesterase activity), oxidative damage and apoptosis. Microplastics and PFOS accumulated were microplastic size dependent but not PFOS dependent and filtration rate was reduced at the end of the exposure. Reactive oxygen species in gills and digestive gland were generated as a result of exposure to both types of microplastics, confirming the disturbance of the antioxidant system. Larger microparticles lead to stronger impacts, when compared to smaller ones which was also supported by Integrated Biomarker Responses index calculated for both tissues. An anti-apoptotic response was detected in digestive glands under exposure to any of the MPs treatments as a probable mechanism associated to carcinogenic responses derived from MPs uptake.
- Looking beyond the obvious: the ecotoxicological impact of the leachate from fishing nets and cables in the marine mussel Mytilus galloprovincialisPublication . Vilke, Juliano Marcelo; GARCIA DA FONSECA, TAINÁ; Dias de Alkimin, Gilberto; Ribeiro Gonçalves, Joanna Melissa; Edo Cuesta, Carlos; d’ Errico, Giuseppe; Seilitz, Fredric Södergren; Rotander, Anna; Benedetti, Maura; Regoli, Francesco; Lüchmann, Karim H.; Bebianno, MariaOnce in the marine environment, fishing nets and cables undergo weathering, breaking down into micro and nano -size particles and leaching plastic additives, which negatively affect marine biota. This study aims to unravel the ecotoxicological impact of different concentrations of leachate obtained from abandoned or lost fishing nets and cables in the mussel Mytilus galloprovincialis under long-term exposure (28 days). Biochemical biomarkers linked to antioxidant defense system, xenobiotic biotransformation, oxidative damage, genotoxicity, and neurotoxicity were evaluated in different mussel tissues. The chemical nature of the fishing nets and cables and the chemical composition of the leachate were assessed and metals, plasticizers, UV stabilizers, flame retardants, antioxidants, dyes, flavoring agents, preservatives, intermediates and photo initiators were detected. The leachate severely affected the antioxidant and biotransformation systems in mussels' tissues. Following exposure to 1 mg center dot L -1 of leachate, mussels' defense system was enhanced to prevent oxidative damage. In contrast, in mussels exposed to 10 and 100 mg center dot L -1 of leachate, defenses failed to overcome pro -oxidant molecules, resulting in genotoxicity and oxidative damage. Principal component analysis (PCA) and Weight of Evidence (WOE) evaluation confirmed that mussels were significantly affected by the leachate being the hazard of the leachate concentrations of 10 mg center dot L -1 ranked as major, while 1 and 100 mg center dot L -1 was moderate. These results highlighted that the leachate from fishing nets and cables can be a threat to the heath of the mussel M. galloprovincialis .
- Are mixtures of micro/nanoplastics more toxic than individual micro or nanoplastic contamination in the clam ruditapes decussatus?Publication . Ventura, Emma; Ribeiro Gonçalves, Joanna Melissa; Vilke, Juliano Marcelo; d'Errico, Giuseppe; Benedetti, Maura; Regoli, Francesco; Bebianno, MariaThe abundance of micro (MPs) and nano (NPs) sized plastic particles in the ocean is concerning due to their harmful effects on marine life. The interactions between MPs and NPs in the marine environment and their impact on marine biota remain not fully understood. This study contributes with new insights into the interaction between polystyrene NPs (PSNPs) and polyethylene MPs (PEMPs) on the clam Ruditapes decussatus . Results showed ingestion of MPs and NPs by clams, with PSNPs demonstrating higher toxicity in hemolymph. While no genotoxicity was observed, clams treated with MPs and the mixture showed increased acetylcolinesterase (AchE) activity over time. Additionally, the antioxidant defense system mitigated oxidative stress, suggesting effective neutralization of reactive oxygen species. Hazard assessment indicated the greatest impact on clam digestive glands after ten days of exposure, with an antagonistic interaction between MPs and NPs noted.
- Dominant effects of the antiepileptic drug carbamazepine over climate change stressors on mytilus galloprovincialis toxicityPublication . Nascimento Bajwa, Farhat-Un-Nisá; Cunha, Marta; Vilke, Juliano Marcelo; Dias Duarte Fragoso, Bruno; Borges, Rodrigo; Soares, Amadeu M. V. M.; Freitas, Rosa; GARCIA DA FONSECA, TAINÁPharmaceuticals have become ubiquitous in marine realms, raising concerns about their ecological effects. This study investigates the ecotoxicological impact of the antiepileptic drug carbamazepine on marine mussels (Mytilus galloprovincialis) under increased seawater temperature and salinity, reflecting projected climate change scenarios. Mussels were exposed to carbamazepine (CBZ, 5 μg L− 1 ) for 28 days in both current (17 ◦C and salinity 35) and predicted (23 ◦C and salinity 40) conditions. A multiple-biomarker approach was employed to assess alterations in energy balance, antioxidant and biotransformation systems, membrane damage, neurotoxicity, and genotoxicity in gills and digestive glands. The results indicated that CBZ caused significant oxidative stress, disruption in energy metabolism, and neurotoxic and genotoxic effects, regardless of the combination of stressors. Moreover, biomarkers were modulated by the time of exposure, suggesting a time-specific response in mussels exposed to either a single or multiple stressors. The findings underscore the complex interplay between pharmaceutical pollution and climate change stressors. This study provides crucial insights into the toxicity of pharmaceuticals in marine environments under future climate change scenarios. To our knowledge, this is the first study to investigate the effects of CBZ on marine mussels in conjunction with the simultaneous rise in seawater temperature and salinity.
- Metal ecotoxicity in sea anemones: accumulation, effects, and knowledge gapsPublication . Vilke, Juliano Marcelo; Power, Deborah Mary; Vieira de Sousa, Cármen Sofia; Mestre, NéliaMetals are a major class of legacy pollutants that end up in marine ecosystems, posing a significant threat to marine biota, including sea anemones. The current review critically synthesises studies published over the last 50 years on the uptake, tissue distribution, and biological effects of 20 metals across 18 sea anemone species in both field and laboratory settings, including interactions with climate change stressors (salinity and pH). Field studies have focused on bioaccumulation and report the high capacity of sea anemones to accumulate metals, mainly iron and barium, primarily in the pedal disk. Laboratory exposure studies reveal a dose- and timedependent accumulation and highlight that symbionts take up and store essential metals (Cu, Fe, and Mn) due to their key biological roles. Available data point to Exaiptasia pallida as a promising model for metal ecotoxicology. Across studies, metals elicit alterations at molecular to behavioural/morphological levels, including transcriptome reprogramming, oxidative stress, and detoxification failures, as well as genotoxicity, cellular injury, immune dysfunction, metabolic and morphological disruption, reproductive impairment, and bleaching, which are generally amplified by climate change stressors. Ultimately, this review identifies key knowledge gaps and outlines future research directions on metal ecotoxicity in sea anemones. Collectively, these insights position sea anemones as informative sentinels of metal contamination in marine ecosystems.