Microplastic pollution in wild and aquacultured Mediterranean mussels from the Sea of Marmara: Abundance, characteristics, and health risk estimations

Environmental stress responses to marine mucilage: Oxidative damage in economically important seafood from the Sea of Marmara

Marine mucilage, a gelatinous organic substance driven by nutrient enrichment and rising sea temperature, poses significant threats to marine biodiversity and fisheries. This study examines the oxidative stress responses in four seafood species: deep-water rose shrimp (Parapenaeus longirostris), common sole (Solea solea), European anchovy (Engraulis encrasicolus), and Atlantic horse mackerel (Trachurus trachurus) in Sea of Marmara, Türkiye, between September 2021 to April 2022. Biomarkers of oxidative stress-reduced glutathione (GSH), lipid peroxidation (LPO), and antioxidant enzyme activities (glutathione reductase, glutathione-S-transferase, and superoxide dismutase), were analyzed in muscle tissues to evaluate species-specific resilience to mucilage. Findings revealed distinct variations among species. Deep-water rose shrimp demonstrated the highest GSH level and lowest LPO level, indicating robust oxidative stress defense. In contrast, pelagic species, including European anchovy and Atlantic horse mackerel, exhibited decreased GSH and elevated LPO levels and variability antioxidant enzyme activities, reflecting greater sensitivity to environmental stress. During the marine mucilage, in addition to mucilage distribution, fluctuations in seawater temperature (between 7.4°C and 24.4°C), and physiological stress caused seasonal changes in various enzymatic activities of the fish species investigated in our study. These results highlight the risks posed by marine mucilage to seafood safety and the ecological balance of marine environments. The vulnerability of pelagic species, combined with their economic and nutritional importance, underscores the urgency of mitigation strategies. This study emphasizes the need for integrated "One Health" approaches to safeguard ecosystem health and food security in the region.

Microplastics levels in cultured or harvested mollusks non-depurated and commercially depurated at different times

Microplastics (MPs) are emerging pollutants found worldwide, not only in environmental matrices but also in the food web. The present study aimed to establish better removal rates of MPs in cultivated or harvested edible bivalves currently on the market. Samples of three species (mussels, oysters and wedge clams) were collected from a producer at three different depuration times. The most abundant (>90 %) detected morphology corresponded to fibers. Standard depuration rates were 50 %, 26 % and 26 % reduction of MPs in mussels, oysters and wedge clams, respectively. In turn, extending the depuration treatment did not significantly improve the depuration rate. The total ingestion of MPs through the consumption of these species was estimated for the adult population in a range between 2508 and 4692 items, depending on the depuration stage. This means a yearly mean accumulated consumption of 4.5, 2.4, and 2.7 m of fibers for non-depurated, standard and extended depurated mollusks, respectively.

Beneath the surface: Exploring microplastic intricacies in Anadara granosa

Anadara granosa or blood cockles have been reported to be a candidate for biomonitoring agents due to their sedimentary nature and their nutrient uptake mechanisms. Yet, this bivalve is still regarded as a delicacy in Asian cuisine. Malaysia is the largest exporter of this sea product that contaminated cockles may also be experienced by the importing countries. However, the bioaccumulation of microplastics in A. granosa cultivated in Malaysia has not been extensively studied. It is crucial to comprehend the risk posed to humans by consuming A. granosa in their diet. Therefore, the purpose of this research is to investigate the levels of microplastic accumulation in A. granosa from major exporters in Peninsular Malaysia, to evaluate the associated risk of microplastics on the species, and to estimate daily human consumption of microplastics through the consumption of A. granosa. The abundance of microplastics was quantified through the use of a stereo microscope, and the polymer type was determined using FTIR and micro-FTIR. Findings from this investigation revealed that all samples of A. granosa were contaminated with microplastics, with the highest levels of accumulation found in bivalves collected from the west coast (0.26 ± 0.15 particles/g) of Peninsular Malaysia. Fragment and fiber microplastics, measuring between 0.05 and 0.1 mm in size, were found to be the most prevalent in A. granosa, with blue being the dominant identified colour and rayon being the most common polymer type. Microplastic risk assessment due to the presence of polyacrylate, polycarbonate (PC), and polymethyl methacrylate (PMMA) resulted in a high risk of contamination for A. granosa. It was further determined that the current estimated dietary intake (EDI) suggests that consumers of A. granosa uptake approximately 21.8-93.5 particles/person/year of microplastics. This study highlights that A. granosa accumulates microplastics, which could potentially result in bioaccumulation and biomagnification in humans through consumption.

Microplastics in retail shellfish from a seafood market in eastern Thailand: Occurrence and risks to human food safety

This study aimed to investigate the presence of microplastics in three economically essential shellfish species: green mussels, cockles and spotted babylon. The average abundance of microplastics ranged from 2.41 to 2.84 particles/g wet weight. The predominant shape was fiber, with colors ranging from black-grey to transparent. The size of the microplastics discovered was <1.0 mm. Polystyrene and polyethylene were the most detected types in mussels and cockles, while linen was the predominant type in spotted babylon. The Thai population's estimated annual intake (EAI) of microplastics through shellfish consumption ranged from 20.23 to 1178.42 particles/person/year. The potential human health risks were evaluated using the polymer hazard index (PHI), which led to risk categories III-IV. These findings, along with others from the literature, indicate that shellfish consumption may pose risks to human health, depending on the species consumed and the origin of the specimens.