This review synthesizes studies published up to 2025 on cobalt (Co) and nickel (Ni) contamination in marine and coastal environments, identified through major scientific databases. After duplicate removal, 183 unique studies were included. Of these, 142 reported Co and/or Ni concentrations in water and/or sediments, 18 included organism-based data, and 28 were laboratory-based investigations. Environmental concentrations ranged from 0.0001 to 101 μg/L for Co and from 0.001 to 550 μg/L for Ni, whereas laboratory exposures ranged from 0.035 to 171,660 μg/L for Co and from 0.12 to 162,985 μg/L for Ni. Most studies addressed bioaccumulation and toxicity in marine invertebrates, particularly bivalves, copepods, corals, and other taxa. Bivalves, including Mytilus galloprovincialis, M. edulis, and M. trossulus, were the most frequently investigated organisms because of their filter-feeding behaviour, broad distribution, and established value as bioindicators. Under controlled exposure, M. galloprovincialis accumulated up to 33 μg/g Co and 25 μg/g Ni in tissues. Overall, Co and Ni exposure induced oxidative stress, enzymatic alterations, and cellular damage, affecting fertilisation, embryonic and larval development, growth, calcification, and reproduction. However, responses varied according to metal, dose, species, and endpoint. In corals, adverse effects were mainly associated with Co or high Ni concentrations, whereas low to moderate Ni exposure often stimulated calcification, growth, photosynthetic performance, or symbiont-related responses. Given the increasing industrial and municipal releases, especially from lithium-ion battery production, this review highlights the need for improved monitoring, source control, wastewater treatment, metal speciation assessment, and long-term ecological risk evaluation.

As demand for rare earth elements (REEs) rises and environmental concerns about the extraction of primary resources grow, biological methods for removing these elements have gained significant attention as eco-friendly alternatives. This study assessed the ability of the green macroalga Ulva lactuca to remove europium (Eu) from aqueous solutions, evaluated the cellular partition of this element and investigated the toxicological effects of Eu exposure on its biochemical performance. U. lactuca was exposed to variable concentrations of Eu (ranging from 0.5 to 50 mg/L), and the amount of Eu in both the solution and algal biomass was analyzed after 72 h. The results showed that U. lactuca successfully removed 85 to 95% of Eu at low exposure concentrations (0.5-5.0 mg/L), with removal efficiencies of 75% and 47% at 10 and 50 mg/L, respectively. Europium accumulated in algal biomass in a concentration-dependent manner, reaching up to 22 mg/g dry weight (DW) at 50 mg/L. The distribution of Eu between extracellular and intracellular fractions of U. lactuca demonstrated that at higher concentrations (5.0-50 mg/L), 93-97% of Eu remained bound to the extracellular fraction, whereas intracellular uptake accounted for approximately 20% at the lowest concentration (0.5 mg/L). Biochemical analyses showed significant modulation of antioxidant defenses. Superoxide dismutase activity increased at 10 and 50 mg/L, while catalase and glutathione peroxidase activities were enhanced at lower concentrations (0.5-1.0 mg/L) and inhibited at higher exposures. Lipid peroxidation levels remained similar to controls at most concentrations, with no evidence of severe membrane damage except at the highest Eu level. Overall, the results demonstrate that U. lactuca is an efficient and resilient biological system for Eu removal, combining high sorption capacity with controlled biochemical responses. These findings highlight its potential application in environmentally sustainable remediation strategies for REE-contaminated waters, while also providing insights into Eu toxicity and cellular partitioning mechanisms in marine macroalgae.

The rapid expansion of lithium-ion battery production has heightened the environmental relevance of lithium (Li) and nickel (Ni), sparking concerns about their potential release into aquatic ecosystems. This study investigated the ecotoxicological effects of Li and Ni, individually and in combination, as well as post-exposure recovery processes, in two ecologically and commercially important bivalves, the mussel Mytilus galloprovincialis and the clam Ruditapes philippinarum. Specimens were subjected to a 14-day exposure phase followed by a 14-day recovery period under clean water conditions. A comprehensive biomarker approach was applied to assess energy metabolism, antioxidant and detoxification responses, cellular damage, and neurotoxicity. Distinct species-specific response patterns were observed. Despite higher metal accumulation, mussels displayed relatively stable biochemical profiles during both exposure and recovery, indicating a higher capacity to withstand metal-induced stress. In contrast, clams showed pronounced activation of antioxidant and detoxification pathways, which was insufficient to fully restore biochemical parameters to control levels within the recovery period, resulting in persistent oxidative stress and energetic imbalance. Nickel induced stronger biological effects than Li, and combined exposure to both metals produced the most pronounced impacts, particularly in clams. Overall, the contrasting responses of mussels and clams reflect differences in exposure pathways and physiological strategies, highlighting their complementary value as bioindicators. These findings emphasise the importance of incorporating recovery dynamics into ecotoxicological assessments to better evaluate ecosystem vulnerability to emerging metal contaminants.

Studying the cumulative impacts of interacting stressors is essential for predicting ecosystem-wide risks from anthropogenic stressors, yet multi-stressor experiments remain scarce. Here, we investigated how lead (Pb) contamination influences survival and cross-tolerance to salinity and thermal stress in Arctic blue mussels (Mytilus edulis). Mussels were exposed to environmentally relevant Pb concentrations, followed by sequential exposure to varying salinities (5-25) and aerial temperatures (5-36 °C). Survival patterns were assessed, and transcriptomic responses were analysed using RNA sequencing. Heat-induced mortality occurred across treatments, and Pb exposure elevated baseline mortality. However, elevated tissue Pb concentrations significantly attenuated temperature-driven mortality, indicating partial cross-tolerance between contamination and thermal stress. Reduced salinity increased vulnerability to heat stress and weakened the protective effect of Pb. Transcriptomic analyses revealed upregulation of cellular stress-response pathways, including detoxification-related genes, consistent with transcriptional front-loading mechanisms underpinning cross-tolerance. Gene expression responses were modest overall, reflecting the high physiological plasticity of Mytilus mussels. Our findings demonstrate that pollution can alter thermal sensitivity in non-additive ways, complicating predictions of organismal responses to environmental changes. Thus, accounting for multi-stressor interactions is critical to understand species resilience in a rapidly changing world.

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants of increasing concern in aquatic ecosystems, yet their interactions with climate-related stressors remain insufficiently understood. This study evaluated whether prior exposure to a moderately elevated temperature modifies the sub-cellular responses of the Mediterranean mussel Mytilus galloprovincialis to two long-chain perfluoroalkyl carboxylic acids, perfluoroundecanoic acid (PFUnDA) and perfluorotetradecanoic acid (PFTeDA). Mussels were pre-exposed to 23 °C for 6 days and then exposed for 14 days at 17 °C to PFUnDA or PFTeDA at a nominal concentration of 20 ng/L. A multi-biomarker approach showed that PFAS exposure at 17 °C induced moderate biochemical changes, mainly involving metabolic depression and antioxidant modulation, with limited oxidative damage. In contrast, thermally pre-exposed mussels displayed higher metabolic activity, increased energy consumption, stronger antioxidant and detoxification responses, and reduced cellular energy allocation, indicating a more energetically demanding physiological state. The strongest integrated response was observed in PFTeDA-exposed mussels after thermal pre-exposure, suggesting compound-specific effects consistent with chain-length-related physicochemical behaviour. However, because exposure concentrations were nominal and internal PFAS burdens were not measured, this interpretation should be considered a mechanistic inference rather than direct evidence of differential bioaccumulation. Overall, these findings indicate that thermal history can reshape sublethal PFAS responses in marine mussels and highlight the need to incorporate stressor sequence, internal exposure and food availability into future ecological risk assessments under climate change.

Although the use of ultraviolet (UV) filters in personal care products is steadily increasing, their ecological consequences remain poorly characterized despite evidence of persistence and bioaccumulation in marine systems. In parallel, climate change stressors such as rising temperatures and fluctuations in salinity are known to modulate the toxicity of contaminants and the physiological tolerance of marine organisms. The combined action of these factors can intensify biological stress, highlighting the need for studies that evaluate pollutant effects under realistic multi-stressor scenarios. This study investigated the biochemical effects of octinoxate (also known as ethylhexyl methoxycinnamate, EHMC), a widely used organic UV filter, on the sea urchin Paracentrotus lividus under environmentally relevant conditions. A 28-day laboratory exposure was conducted using three EHMC concentrations (50, 500, and 5000 ng/L) under control conditions (17 °C, salinity 35) and climate change scenarios (21 °C, salinity 40). Multiple biomarkers were analysed, including metabolic activity, antioxidant and biotransformation responses, redox balance, cellular damage, and neurotoxicity. Results showed that the biochemical responses of P. lividus were significantly influenced by environmental conditions. Combined exposure to EHMC and elevated temperature (21 °C) induced marked oxidative stress, metabolic alterations, and shifts in detoxification responses. These effects were less pronounced under increased salinity, though still detectable. The present findings emphasize the heightened vulnerability of marine invertebrates to chemical pollutants under climate stress. Furthermore, the present study highlights the importance of integrating multiple stressors into ecotoxicological assessments and supports the use of bioindicator species, such as P. lividus, for more realistic environmental risk evaluations. Given that UV filters remain understudied contaminants and that data on their effects in echinoderms are still almost nonexistent, this work provides a timely contribution and highlights a critical knowledge gap that warrants urgent scientific attention.

Non-enzymatic oxidative stress biomarkers such as thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), and reduced glutathione (GSH) are among the most widely applied endpoints in aquatic biomonitoring and ecotoxicology, with relevance for assessing pollution across coastal, estuarine, and marine ecosystems. Despite decades of use, however, their translation into robust environmental monitoring tools remains constrained by analytical and interpretative bottlenecks, including poor interlaboratory comparability, lack of harmonized sampling and storage procedures, matrix interferences, inconsistent normalization strategies, and insufficient quality assurance frameworks. This review critically examines the use of non-enzymatic oxidative stress biomarkers in aquatic systems, shifting the focus from biomarker relevance toward methodological and technological barriers that currently limit operational deployment. We synthesize evidence on methodological variability, analytical artefacts, and confounding factors affecting biomarker responses across biological matrices and environmental contexts. Our analysis highlights that TBARS, PC, and GSH are highly sensitive indicators of oxidative damage associated with exposure to diverse contaminant classes, including metals, organic pollutants, and complex contaminant mixtures. However, substantial heterogeneity in analytical approaches and experimental designs across studies continues to hinder interstudy comparability and the establishment of ecologically meaningful baseline values. Finally, we propose a technology-oriented roadmap for improving biomarker standardization and field applicability, including minimum reporting requirements, validation priorities, and scalable analytical strategies such as miniaturized assays, microfluidic platforms, biosensing technologies, and smartphone-based detection systems. Overall, the integration of these approaches may facilitate the transition of non-enzymatic oxidative biomarkers from research endpoints to standardized and operational tools for environmental monitoring and decision-making in aquatic ecosystems.

In this study, we investigated the combined effects of enrofloxacin (ENR; 5 and 500 ng/L) and temperature (17°C, ambient; 21°C, warming) on physiological and biochemical responses of clams. Biomarkers of antioxidant and biotransformation defense (CAT, TAC, GSTs, and CbEs), oxidative damage (LPO and protein carbonyls), metabolic activity (respiration rate and ETS), and energy reserves (proteins, carbohydrates, and lipids) were measured, and results were integrated through multivariate analysis (principal coordinate analysis, PCoA) and the IBR index. At 17°C, ENR exposure elicited moderate adjustments, including GSTs induction and ETS stimulation at high concentration, indicating that clams could sustain the additional metabolic demand associated with detoxification. At 21°C, however, antioxidant defenses were destabilized: GSTs activity was markedly reduced while CAT was strongly induced, pointing to a compensatory but unbalanced response. This was accompanied by a mismatch in energy metabolism, as respiration rate increased without ETS stimulation, leading to the mobilization of carbohydrate and lipid reserves. Although oxidative damage remained limited, with only a significant rise in LPO at low ENR concentration under warming, the IBR index confirmed higher biological stress at 21°C across treatments. Overall, our findings show that elevated temperatures amplify the physiological impact of ENR exposure by impairing detoxification pathways and accelerating energetic costs. These results highlight temperature as a critical factor modulating the resilience of bivalves to pharmaceutical pollutants, with implications for coastal ecosystems under climate change scenarios.

Carbon-based materials like activated carbon (AC) are frequently applied for water treatments and remediation. The increasing use and functionalization of AC, especially with the recent mandate to implement quaternary treatments to remove organic micropollutants (Directive 2024/3019), may inadvertently introduce AC or leachate products to aquatic bodies. Such occurrences pose potential risks to inhabiting organisms, which have been understudied. This study assessed the environmental safety of an AC obtained from spent brewery grains (SBG)-a lignocellulosic biomass-through microwave pyrolysis with potassium carbonate activation. The resulting AC (SBG-AC) was washed, sieved (powder, particle size ≤ 180 µm), and tested for its ecotoxicological effects on the marine mussel Mytilus galloprovincialis at doses of 5, 25, and 50 mg/L. After 28 days of exposure (with weekly water renewal), biochemical parameters related to the mussels' metabolic capacity and oxidative status were evaluated. Exposure to SBG-AC stimulated the energy metabolism in M. galloprovincialis, at the expense of internal energy reserves (such as glycogen). Although SBG-AC exposure induced antioxidant responses, the significant increase in lipid peroxidation and protein carbonylation at the higher doses (particularly 50 mg/L) suggests that these protective mechanisms were insufficient to prevent oxidative damage. Overall, while SBG-AC offers an effective alternative for water treatment, its ecotoxicity at higher doses raises concerns, emphasizing the need for careful risk assessment and containment measures.

Long-chain per- and polyfluoroalkyl substances (PFAS) are persistent, bioaccumulative pollutants posing risks to marine life. This study quantified biochemical, physiological, and histopathological effects of four long-chain PFAS (PFUnDA, PFDoA, PFTriDA, PFTeDA) on the mussel Mytilus galloprovincialis. The Integrated Biomarker Response (IBR) index was used to assess the overall organismal stress. Longer-chain PFAS (PFTriDA, PFTeDA) triggered metabolic activation, increasing respiration and electron transport system activity, with protein and lipid accumulation and carbohydrate depletion. Antioxidant defenses were modulated in a compound-specific manner, and increased lipid peroxidation in several treatments indicated that these responses were not always sufficient to prevent oxidative damage. Biotransformation-related enzyme responses were also compound-specific, suggesting differential activation of detoxification pathways among PFAS treatments. Acetylcholinesterase inhibition suggested potential functional neurotoxicity. Histopathological index, especially in gills and digestive gland, showed higher values under PFTriDA and PFTeDA exposures, corroborated biochemical findings, mainly characterized by digestive tubule atrophy, brown cell aggregates in primary tubule epithelia, fibrous tissue formation in connective areas, and enlarged central vessels in gills. Overall, PFAS toxicity was chain length-dependent, with PFTriDA and PFTeDA eliciting the strongest oxidative, metabolic, and neurotoxic effects. These findings provide an integrated description of sublethal biological responses to selected long-chain perfluorocarboxylic acids in bivalves and support further investigation of chain-length-related effects using molecular and pathway-specific approaches.

Climate change may exacerbate extreme weather events, leading to severe salinity fluctuations in coastal waters and enhancing the mobility of land-based pollutants such as aminomethylphosphonic acid (AMPA), the main breakdown product of glyphosate. Although the individual effects of salinity stress and AMPA are increasingly characterized, their combined impact on marine organisms is still poorly investigated. This study aimed to assess, for the first time, the effects of different salinity scenarios (35, 25, 15) on the toxicity of environmentally realistic concentrations of AMPA (0.5 μg/L) in Mytilus galloprovincialis. A wide panel of cholinergic functions, immunological responses, antioxidant defences and oxidative damage, peroxisomal proliferation, and energy metabolism was evaluated after 21 days of exposure, and the results elaborated using weighted criteria to provide hazard classification based on magnitude and toxicological relevance of observed effects. Results indicated that AMPA exposure significantly influenced cholinergic responses, detoxification mechanisms and antioxidant defences. Beyond the direct effects, salinity modulated AMPA toxicity, either exacerbating or counteracting specific effects on immune function, oxidative balance, and metabolic homeostasis, with tissue-specific patterns. The Weight of Evidence approach assigned a higher hazard classification to combined stressor scenarios, further corroborating the importance of exploring interactive toxicological effects. Overall, this work provided a novel integrative toxicological profiling of AMPA under climate change-driven salinity stress, emphasizing the need to consider the interactions between multiple co-occurring stressors in environmental risk assessment frameworks.

The rapid growth of electronic waste, including fluorescent lamp waste (FLW), has led to an increase in elements like yttrium (Y) and other rare earth elements (REE) in aquatic environments due to improper waste management. However, there are no guidelines for permissible concentrations of these elements in the environment. This study examines the biochemical impacts of varying Y concentrations (50, 100, and 200µgL-1), mimicking a FLW discharge, on the gills and digestive glands of Mytilus galloprovincialis exposed for 14 days. Energy reserves, antioxidant and biotransformation enzymes, lipid peroxidation (LPO), and neurotoxicity were measured. Results showed a limited antioxidant capacity in the gills at the highest Y concentration. Additionally, increased LPO levels in both organs suggest oxidative stress-induced damage. The study underscores the need for regulations to address Y contamination from FLW and safeguard aquatic ecosystems, proposing a reference value for permissible concentrations based on the observed effects.

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals known for their persistence and bioaccumulation, leading to widespread environmental contamination. Despite their recognised environmental risks, particularly to aquatic wildlife, including marine invertebrates, detailed impact studies are limited. PFAS can be categorised according to the length of the compound chain, with short-chain PFAS announced as a safer alternative to the more commonly used long-chain PFAS. However, recent evidence suggests that also short-chain PFAS pose significant environmental risks. The present study evaluated the adverse effects of six PFAS compounds—two short-chain (PFHxA, 6:2 FTA) and four long-chain (PFUnDA, PFDoA, PFTriDA, PFTeDA)— on the digestive gland and gills of mussels, Mytilus galloprovincialis, using in vitro assays. The results showed organ-specific responses: the digestive gland was more sensitive to PFHxA, with increased catalase activity and decreased total antioxidant capacity, and cellular damage was observed only at higher concentrations of PFTriDA. Gills were more affected by PFDoA and PFTeDA, with inhibited antioxidant enzyme activity and increased oxidative stress. PFHxA and PFTriDA also showed inhibition of acetylcholinesterase activity. 6:2 FTA had the lowest effects for both organs, while PFHxA was the most harmful. These findings underscore the need for thorough risk assessments of PFAS, considering both chain length and organ-specific effects.

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 biological 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, 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.

Cobalt (Co) pollution in aquatic ecosystems is rising due to its increased use in battery production. This study examines organ-specific biochemical responses of the mussel Mytilus galloprovincialis to Co exposure under three different salinities (20, 30, and 40) over 14 and 28 days. Mussels were exposed to 100 μg/L Co, and biomarkers of metabolism, oxidative stress, detoxification, and neurotoxicity were analyzed in the digestive gland, gills, mantle, and muscle. Exposure duration had a stronger influence on biochemical responses than salinity or Co contamination. A time-dependent response was evident, particularly in the digestive gland and gills. Higher Co accumulation was observed at salinity 20, suggesting that ionic competition affects metal uptake. After 28 days, superoxide dismutase and glutathione peroxidase activities increased, while total antioxidant capacity decreased, indicating oxidative stress. Biotransformation enzyme activities peaked at 14 days but were later inhibited, suggesting an early failure in detoxification. The gills were strongly associated with oxidative stress markers, while the digestive gland played a key role in detoxification. Acetylcholinesterase activity was consistently higher in the gills, indicating an enhanced neurotoxic response. These findings demonstrate that exposure duration is a primary determinant of cobalt-induced biochemical alterations in marine bivalves and should be explicitly integrated into risk assessment frameworks, particularly under variable salinity conditions that modulate metal bioavailability and toxicity.

Marine heatwaves (MHWs), characterized by prolonged periods of elevated sea temperatures, pose significant threats to marine ecosystems, particularly affecting the physiology and behavior of marine organisms, including crustaceans. This study investigates the physiological and biochemical responses of males and females of Carcinus maenas crabs, after an acute exposure to an MHW, focusing on energy metabolism, oxidative status, and potential neurotoxicity. Specimens were exposed to controlled laboratory conditions simulating a temperature increase from 17 °C to 23 °C, and responses were analyzed in gills and hepatopancreas. Results revealed sex-specific differences in thermal stress resilience, with males showing higher glycogen storage in gills after MHW exposure, while females exhibited a significant reduction in glycogen reserves and an increase in antioxidant enzyme activity. Superoxide dismutase and glutathione reductase activities were notably elevated in females subjected to MHW, suggesting a more robust antioxidant response to counteract oxidative stress. Additionally, acetylcholinesterase activity, an indicator of neurotoxicity, was significantly reduced in females post-MHW, hinting at potential neurotoxic effects. Despite these biochemical changes, lipid peroxidation levels remained stable across both sexes and tissues, indicating that short-term MHW exposure did not cause significant oxidative damage to cell membranes. This study highlights the importance of considering sex differences in assessing the impacts of climate change-induced stressors on marine organisms, as males and females display distinct metabolic and physiological strategies for coping with thermal stress.

The widespread use of gadolinium (Gd) in medical and industrial applications, especially as a contrast agent in magnetic resonance imaging (MRI), has led to its increasing presence in surface waters, disrupting natural geochemical cycles and posing risks to aquatic ecosystems. Addressing this challenge, recent studies have explored the potential of magnetic materials, such as spinel ferrite nanoparticles, in the removal of Gd from contaminated water sources. The present study specifically focused on the use of MnFe2O4 nanoparticles to remove Gd from contaminated solutions, employing response surface methodology (RSM) to optimize sorption conditions. Key variables evaluated included salinity (0–30 g/L), initial Gd concentration (1–5 μmol/L), and sorbent dose (20–180 mg/L), at a fixed pH of 6. The results revealed that salinity had a minimal impact on Gd sorption, likely due to the high sorbent mass used. Optimal conditions were identified as a sorbent dose of 165 mg/L, an initial Gd concentration of 1.3 μmol/L, and a salinity level of 13.4 g/L, at pH 6. The process was efficient and rapid, achieving over 90% Gd removal within 1 h in both freshwater and saline conditions, and over 75% removal in mineral water within 3 h. The high efficiency and celerity of this method suggest that MnFe2O4 nanoparticles are a promising solution for treating Gd-contaminated hospital effluents. Future research should focus on validating these results in real-world effluent matrices and addressing the environmental and economic aspects of large-scale implementation, thereby contributing to sustainable water remediation strategies.

Technological proliferation relies on critical elements such as rare earth elements (REEs) and raises environmental problems associated with raw material extraction, industrial manufacturing, and the informal management of the growing e-waste. Algae are good bioindicators of contamination and have shown promise as biosorbents for remediating metal-contaminated environments. However, the effects of REEs on algae are still poorly documented and understood. This study investigated the uptake of yttrium (Y)—one of the most frequently used REEs, particularly in fluorescent lamps—by Ulva sp., as well as its effects on total chlorophyll content, relative growth rate, and biochemical performance. The algae were exposed to Y for 72 h at environmentally relevant concentrations, including levels found in e-waste leachates (0.5, 5.0, 50, and 500 mg/L). Ulva sp. removed 86% of Y within 72 h, with a bioconcentration factor of up to 621. EDTA analysis revealed that over 90% of yttrium was retained on the algal surface. SEM-EDS mapping showed crystal structures on the algae where Y was present. While the relative growth rate was unaffected by the tested Y gradient, photosynthesis was significantly impaired at 500 mg/L. Despite the activation of defence mechanisms, cell damage was observed at most Y concentrations tested, highlighting the potential risks associated with the presence of REEs in aquatic environments.

Platinum group elements (PGEs), namely platinum (Pt), palladium (Pd), and rhodium (Rh), are increasingly recognized as emerging contaminants due to their extensive use in automotive catalysts, industry, and medicine. Their continuous release and accumulation in aquatic environments have raised ecotoxicological concerns, yet experimental data on their biological and interactive effects remain scarce. This study provides one of the first comprehensive evaluations of the sublethal and mixture effects of Pt, Pd, and Rh on the marine mussel Mytilus galloprovincialis, a sentinel species. Mussels were chronically exposed for 28 days to environmentally relevant concentrations (2, 20, and 200 μg/L) of each metal and to binary and ternary mixtures (20 μg/L each). A suite of biochemical biomarkers was analyzed, covering energy metabolism, antioxidant defenses, detoxification, and cellular damage, enabling a mechanistic understanding of metal-specific and mixture effects. Distinct dose-dependent responses emerged: Pt at low levels stimulated metabolism and antioxidant activity; Pd at high levels impaired energy reserves and mitochondrial efficiency; Rh caused oxidative damage to lipids and proteins. The Independent Action model revealed that interaction type and magnitude varied among mixtures. Synergistic effects predominated in Pt+Pd and Pt+Rh (≈50 % of biomarkers), while Pd+Rh showed mainly additive or synergistic patterns, and the ternary mixture (Pt+Pd+Rh) displayed mostly additive responses (50 %). Multivariate (PCO) and integrative (IBRv2) analyses confirmed distinct biochemical fingerprints for each exposure. Overall, this study pioneers the mechanistic evaluation of PGEs mixtures in marine organisms, highlighting their emerging and complex ecotoxicological risks.

Electronic waste (E-waste) has become a significant environmental challenge in recent decades due to the rapid increase in electronic device production and the subsequent disposal of obsolete products. E-waste contains hazardous materials, including metals like chromium (Cr) and rare earth elements (REEs) such as terbium (Tb), which can leach into aquatic ecosystems and cause severe ecological damage. With global temperatures projected to rise due to climate change, the interaction between these contaminants and increasing temperatures could heighten risks to aquatic life. This study examines the combined effects of Cr and Tb on the biochemical and physiological responses of the Manila clam (Ruditapes philippinarum), a species commonly used as a bioindicator of environmental stress. Clams were exposed to Cr, Tb, and their mixture at two temperatures (18 and 21 degrees C) over 28 days to assess how warming influences metal toxicity. The overall biochemical response of the clams was evaluated using Principal Coordinate Ordination (PCO). The results showed that at 21 degrees C, the biochemical effects were significantly exacerbated, particularly with the inhibition of antioxidant and biotransformation enzymes compared to those exposed at 18 degrees C. This suggests that oxidative stress impaired the enzymatic activity of the clams, especially under simultaneous exposure to both metals. These findings highlight the increased risk of metal toxicity in a warming world, emphasizing the need for integrated management strategies that address both e-waste and climate change. By providing critical insights into the combined effects of contaminants and temperature, this research aims to inform more effective regulatory policies to protect aquatic ecosystems.