Evaluating heavy metal levels in green mussels (Perna viridis, Linnaeus, 1758) across major farms in Samar, Philippines

Do polybrominated diphenyl ethers cause adverse effects in the freshwater bioindicator zebra mussel (Dreissena polymorpha Pallas, 1771)? An acute and subchronic biomarker assessment.

Exploring the effect of microparticles on bivalves: Exposure of Mytilus galloprovincialis and Ruditapes philippinarum to both microplastics and silt.

In the present study, the effects of emerging and legacy pollutants such as hazardous microplastics (hMP) and toxic elements (As, Cd, Hg and Pb) were investigated in wild Mediterranean mussel Mytilus galloprovincialis (n=40) from three estuaries with different anthropogenic uses in the Asturias region (SW Bay of Biscay). The expression levels of six candidate genes related with oxidative stress and/or heavy metal detoxification (sod1, sod2, cat, hsp70, mt10 & mt20) were measured using qPCR. The relationship between their expression levels, the Condition Index (CI), and the concentration of these concurrent pollutants was assessed through linear mixed models (LMM). PERMANOVA revealed significant differences between polluted and clean locations for both pollutants and gene expression levels in mussels. However, no differences were found between Nalón and Sella estuaries despite their distinct historical uses and pollution levels, suggesting recovery in post-mining times. Overall, the expression of the antioxidant gene sod2 and the detoxification genes mt10 and mt20 were upregulated in mussels from the most industrialized and heavy metal polluted estuary of Avilés, with Cd and Pb significantly predicting mt10 and mt20 increase. Hg and the hMP content significantly explained the expression patterns of sod1 and sod2 genes. To the best of our knowledge, this is the first study examining the combined molecular effects of legacy and emerging pollutants on wild populations of the bioindicator Mediterranean mussel. Additionally, it represents the first application of this molecular approach to monitor the ecological status of estuaries in the region that could be applied elsewhere.

This study set out to investigate the effects of the organophosphate insecticide chlorpyrifos (CPF) on certain biochemical parameters of the freshwater mussel Unio elongatulus eucirrus. Mussels were exposed to varying concentrations of CPF (10, 20, and 40 µg·L-1) for duration of 96 hours. Samples were collected from the mussels at the 24th and 96th hours of the experiment. The results indicated that exposure to CPF concentrations led to a decline in the activities of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities and, accompanied by an increase in malondialdehyde (MDA), and decreased reduced glutathione (GSH) levels in mussels. In conclusion, the present study demonstrates that CPF caused AChE inhibition, formation of oxidative stress, and negative effects on certain antioxidant parameters in the freshwater mussel U. elongatulus eucirrus.

Combined effects of a pharmaceutical pollutant, gemfibrozil, and abiotic stressors (warming and air exposure) on cellular stress responses of the blue mussels Mytilus edulis.

Mussels (Donax sp.) are marine shellfish that tend to be contaminated with heavy metals as they are filter feeders. Heavy metal levels can be reduced by immersion in sequestrants. This study aimed to measure the effectiveness of the optimal sequestrant to reduce heavy metal levels in mussels. This experimental study was conducted at the Food Technology Laboratory of Padjadjaran University in January-April 2024 using samples of mussels (Donax sp.) from Cirebon, Indonesia. The data processing method used was a Randomized Group Design with five treatments consisting of soaking mussels in distilled water, 25% citric acid, 25% tamarind, 25% tomato, and 25% Pidada; each repeated 3x. The results showed that the most optimal organic sequestrant in reducing heavy metals was Pidada fruit with the effectiveness of reducing cadmium metal 21,195%, lead metal 6,543%, total citric acid 0.552%, water content 76.953%, and antioxidant activity based on IC50 value of 19,537 ppm with a very strong category. In conclusion, the Pidada fruit is the most optimal organic sequestrant for reducing heavy metal levels in mussels (Donax sp.) and has very strong antioxidant activity, making it effective for reducing heavy metal contamination.

The present study aimed to assess the oxidative stress potential of Mytilus galloprovincialis across four sites along the Algerian west coast from March 2022 to June 2022. Among these sites, three were previously identified as contaminated, while the Barbadjanie site was considered isolated and distant from pollution sources. We measured glutathione (GSH) and malondialdehyde (MDA) levels, as well as the specific activities of glutathione S-transferase (GST) and catalase (CAT) in the digestive glands of the mussels. Our findings revealed a significant decrease in GSH levels in mussels from the contaminated sites, indicating reduced antioxidant capacity. In contrast, MDA levels, GST, and CAT activities exhibited significant increases (P< 0.05) in the same mussels, suggesting heightened oxidative stress and increased cellular damage. To further evaluate the impact of pollution, we applied the Integrated Biomarker Response (IBR) index to the four biomarkers measured. The IBR analysis showed the lowest score for mussels from Barbadjanie, confirming its relatively low pollution impact, and the highest score for mussels from Beni Saf Port, indicating severe pollution effects. This multi-biomarker approach was effective in demonstrating oxidative stress responses in mussels, highlighting its reliability in assessing the impacts of environmental pollution on aquatic organisms. The study underscores the importance of using comprehensive biomonitoring tools to evaluate ecological health and pollution effects in marine environments.

Microplastics, an emerging pollutant, have garnered widespread attention due to potential repercussions on human health and the environment. Given the critical role of seafood in food security, growing concerns about microplastics might be detrimental to meeting future global food demand. This study employed a discrete choice experiment to investigate Chilean consumers’ preferences for technology aimed at mitigating microplastic levels in mussels. Using a between-subjects design with information treatments, we examined the impact of informing consumers about potential human health and environmental effects linked to microplastics pollution on their valuation for the technology. We found that the information treatments increased consumers’ willingness to pay for mussels. Specifically, consumers were willing to pay a premium of around US$ 4 for 250 g of mussel meat with a 90 % depuration efficiency certification. The provision of health impact information increased the price premium by 56 %, while the provision of environmental information increased it by 21 %. Furthermore, combined health and environmental information significantly increased the probability of non-purchasing behavior by 22.8 % and the risk perception of microplastics for human health by 5.8 %. These results emphasized the critical role of information in shaping consumer preferences and provided evidence for validating investment in research and development related to microplastic pollution mitigation measures.

Modulation of thermal stress response by prostaglandins in gills of the blue mussel Mytilus edulis

Intra-annual variation in microplastics in mussels (Mytilus galloprovincialis) inhabiting an urbanized bay of South Korea

This study aimed to assess the spatiotemporal bioavailability of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in wild adult mussels, Mytilus galloprovincialis, collected along the Portuguese Atlantic coast between 2009 and 2020. The work is part of a national environmental monitoring program. The purpose was to evaluate the dioxins’ temporal trends, the human and ecological risks, and the correlation between mussels’ location and the main pollutant sources in Portugal. The levels and congener patterns of the most toxicity-relevant 17 PCDD/Fs and 12 dl-PCBs were determined, with the dl-PCBs dominant. The sum of Σ17PCDD/Fs and Σ12dl-PCBs values ranged from 2.0 to 4.0 ng WHO-TEQ kg−1, (wet weight basis), below the limits established by the European Commission for contamination in fish and fishery products (6.5 ng per kg−1). The study included five years – 2009, 2010, 2016, 2018 and 2020 –, allowing to verify the impact of European Directive 2013/39/UE against the pollution of water in Portugal; it was observed that dioxin levels in mussels diminished over the time. Statistical analysis allowed verification of different spatial trends of dl-PCB profiles along the Portuguese Atlantic coast. The mono-ortho dl-PCB pentachlorinated congener IUPAC #118 prevailed in 2009 and 2018 in all sampling sites, and it was predominant in 2010, 2016 and 2020, followed by the congeners IUPAC #105, #156 and #167. The IUPAC #167, #169 and #123 were the most abundant hexachlorinated congeners, and the IUPAC #77 the most abundant tetrachlorinated congener. This work emphasises the importance of monitoring dioxins and mapping the congeners in Atlantic coastal ecosystems, to contribute to their elimination.

Twenty-five years of paralytic shellfish poisoning (PSP) toxicity in Galician bivalves have been studied. PSP was detected in 4785 out of 73,740 samples of the commercially important bivalve species analyzed from 1995 to 2020. Its general prevalence in the area was 6.5%. Only 1.6% of all samples tested were over the regulatory limit (incidence). The maximum level of PSP in the area, 40,800 µg STX 2HCl-eq kg-1, was recorded in raft mussels from Bueu (PON-II, Pontevedra) in December 2005. The highest maximum PSP values were found in mussels, which were mostly affected by Gymnodinium catenatum, but not those of prevalence and incidence which were recorded in clams, mostly affected by Alexandrium. Average levels in mussels were higher than in any other studied species. Spatially, in general, the prevalence, incidence, maximum, and average PSP toxicity during episodes tend to decrease from south to northeast, but some hot points with high levels can be identified. PCA analysis separates the southern rías, associated to G. catenatum blooms, from the middle and northern ones, associated to Alexandrium blooms. Along the year, two main peaks of the four variables are observed, the first one in late autumn-winter and the other in summer, the summer peak being much more important for the infaunal species than for raft mussels. In the seasonal pattern obtained by time series analysis of the average PSP toxicity, the autumn-winter peak was only maintained (and very reduced) in the southern rías, indicating that this peak is seasonally much less important than the summer peak. The observed seasonality is expected based on the timing of the blooms of the two PSP-producing phytoplankton groups present in the area. Over the 25 years of monitoring, large differences in PSP toxicity have been observed. Apart from some special years, an ascending trend in prevalence and incidence seems to be present from 2011 to 2020. No trend seems to exist during the same period for average or maximum toxicity.

A new sensitive and selective gas chromatography tandem mass spectrometry (GC-MS/MS) method was developed for the analysis of 26 polycyclic aromatic hydrocarbons (PAHs), including 16 Environmental Protection Agency (EPA) and 15 + 1 European Union (EU) PAHs, in mussel samples from aquaculture farms in Thermaikos and Strymonian Gulf, Central Macedonia Region, in three sampling periods. Concentrations were found at moderate to low values at all sampling sites, without exceeding maximum levels set by EU. Low molecular weight PAHs were predominant in all samples. Seasonal variation of the concentrations was observed; values were slightly higher in the winter period. Use of diagnostic ratios for potential sources of PAHs showed both petrogenic and pyrolitic origin. In comparison to other related studies of mussels from the Mediterranean Sea, Greek mussels cultivated in the studied gulfs are low in contaminants due to minimal environmental pollution effects. Low concentrations of PAHs are in compliance with the low values of other POPs which were found in the mussels.

This study assessed the impact of increasing seawater surface temperature (SST) and toxic algal abundance (TAA) on the accumulation, tissue distribution and elimination dynamics of paralytic shellfish toxins (PSTs) in mussels. Mytilus coruscus were fed with the PSTs-producing dinoflagellate A. catenella under four simulated environment conditions. The maximum PSTs concentration was determined to be 3548 µg STX eq.kg−1, which was four times higher than the EU regulatory limit. The increasing SST caused a significant decline in PSTs levels in mussels with rapid elimination rates, whereas high TAA increased the PSTs concentration. As a result, the PSTs toxicity levels decreased under the combined condition. Additionally, toxin burdens were assessed within shellfish tissues, with the highest levels quantified in the hepatopancreas. It is noteworthy that the toxin burden shifted towards the mantle from gill, muscle and gonad at the 17th day. Moreover, variability of PSTs was measured, and was associated with changes in each environmental factor. Hence, this study primarily illustrates the combined effects of SST and TAA on PSTs toxicity, showing that increasing environmental temperature is of benefit to lower PSTs toxicity with rapid elimination rates.

The short-term effects of coastal untreated effluents from Ushuaia Bay, Beagle Channel, on the biochemical and physiological biomarkers of Mytilus chilensis were assessed. An integrated biomarker response (IBR) index was calculated as a helpful tool to represent the general stress of the experimental organisms. Cultured mussels were exposed during 96 h to three coastal sites impacted by sewage effluents. At the beginning (T0) and every 24 h, mussels were subsampled from each site and different biochemical and physiological biomarkers were determined. There was no mortality registered in the experiments during the 96 h. However, biochemical and physiological biomarkers presented significant variations. Lipid peroxidation mean levels in mussels decreased in mantle and increased in digestive gland with respect to T0 in almost all cases. Acetylcholinesterase activity was inhibited in all sites, reaching a maximal decrease of 35% with respect to T0. Catalase remained stable and glutathione-S-transferase was activated. Oxygen consumption and ammonia excretion rates increased in organisms from two sites and, consequently, O:N ratio decreased, denoting a symptom of stress. IBR values showed the existence of different stress levels between exposed and unexposed mussels. These results exhibited an alteration of the general metabolism of mussels exposed for a short period of time to untreated coastal wastewater, suggesting the use of these organisms as early indicators of changes in the environmental quality of coastal waters of Ushuaia Bay.

Heavy metal spatial and temporal trends (2008–2018) in clams and mussel from Adriatic Sea (Italy): Possible definition of forecasting models

Trematode prevalence and abundance in hosts are known to be affected by biotic drivers as well as by abiotic drivers. In this study, we used the unique salinity gradient found in the south-western Baltic Sea to: (i) investigate patterns of trematode infections in the first intermediate host, the periwinkle Littorina littorea and in the downstream host, the mussel Mytilus edulis, along a regional salinity gradient (from 13 to 22) and (ii) evaluate the effects of first intermediate host (periwinkle) density, host size and salinity on trematode infections in mussels. Two species dominated the trematode community, Renicola roscovita and Himasthla elongata. Salinity, mussel size and density of infected periwinkles were significantly correlated with R. roscovita, and salinity and density correlated with H. elongata abundance. These results suggest that salinity, first intermediate host density and host size play an important role in determining infection levels in mussels, with salinity being the main major driver. Under expected global change scenarios, the predicted freshening of the Baltic Sea might lead to reduced trematode transmission, which may be further enhanced by a potential decrease in periwinkle density and mussel size.

Organic pollutants (PCBs, PCDD/Fs, PAHs) and toxic metals in farmed mussels from the Gulf of Naples (Italy): Monitoring and human exposure

To encourage the applicability of nano-adsorbent materials for heavy metal ion removal from seawater and limit any potential side effects for marine organisms, an ecotoxicological evaluation based on a biological effect-based approach is presented. ZnCl2 (10 mg L−1) contaminated artificial seawater (ASW) was treated with newly developed eco-friendly cellulose-based nanosponges (CNS) (1.25 g L−1 for 2 h), and the cellular and tissue responses of marine mussel Mytilus galloprovincialis were measured before and after CNS treatment. A control group (ASW only) and a negative control group (CNS in ASW) were also tested. Methods: A significant recovery of Zn-induced damages in circulating immune and gill cells and mantle edges was observed in mussels exposed after CNS treatment. Genetic and chromosomal damages reversed to control levels in mussels’ gill cells (DNA integrity level, nuclear abnormalities and apoptotic cells) and hemocytes (micronuclei), in which a recovery of lysosomal membrane stability (LMS) was also observed. Damage to syphons, loss of cilia by mantle edge epithelial cells and an increase in mucous cells in ZnCl2-exposed mussels were absent in specimens after CNS treatment, in which the mantle histology resembled that of the controls. No effects were observed in mussels exposed to CNS alone. As further proof of CNS’ ability to remove Zn(II) from ASW, a significant reduction of >90% of Zn levels in ASW after CNS treatment was observed (from 6.006 to 0.510 mg L−1). Ecotoxicological evaluation confirmed the ability of CNS to remove Zn from ASW by showing a full recovery of Zn-induced toxicological responses to the levels of mussels exposed to ASW only (controls). An effect-based approach was thus proven to be useful in order to further support the environmentally safe (ecosafety) application of CNS for heavy metal removal from seawater.