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

Microplastic (MP) pollution raises urgent concerns about the environmental well-being and the safety of the food supply for humans. Mussels are essential filter-feeding organisms that may be highly susceptible to MPs uptake due to their global distribution and sedentary lifestyle. There is also a knowledge gap regarding MP levels in commercially-farmed and wild-sourced mussels for human consumption, creating gaps in risk identification for food safety. This study aims to fill this gap in understanding by (a) investigating the presence and abundance of MPs in both wild and aquacultured mussels collected from six different stations in the Sea of Marmara, (b) comparing the levels of MPs between aquacultured and wild mussels, and (c) evaluating the potential health risks associated with the consumption of these contaminated mussels. Polymer types were verified by ATR-FTIR (Attenuated Total Reflectance Fourier Transform- Infrared Spectroscopy), and 6 different polymers have been identified. Among the total 753 identified MPs, the majority (79.8%) were fibers, with the predominant size range (42.4%) falling between 0.1 and 0.5 mm. Consuming wild mussels was associated with a 187.6% higher risk of MP intake compared to aquaculture. A consumer can potentially be exposed to 133.11 to 844.86 MP particles when consuming a 100 g serving of mussels, with risks becoming more significant as portion sizes increase, as is the case in some countries where portions reach 225 g. In this study, detailed information is presented on MP pollution in both wild and aquacultured mussels from Sea of Marmara, providing valuable insights for ensuring food safety, effective management and control of MP pollution in this region.

The effect of different types of microplastic and acute cadmium exposure on the Mytilus galloprovincialis (Lamarck, 1819).

Microplastic (MP) pollution is a pressing issue for both environmental health and the safety of human food sources. This study provides a comprehensive analysis of the effects of MPs on Mediterranean mussels (Mytilus galloprovincialis, Lamarck 1819), focusing on the food safety risks associated with MP and cadmium (Cd) exposure in these organisms intended for consumption. The retention of different polymer types of MPs in mussels was specifically evaluated, and the influence of Cd on MP retention across these polymers was investigated. Mussels were exposed to polystyrene (PS), polypropylene (PP), and polyethylene terephthalate (PET) MPs individually and in combination with the toxic metal Cd for a duration of 7 days. Antioxidant enzymes, oxidative stress parameters, and digestive system enzyme activities, selected as biomarkers for Cd and MPs pollution, were assessed. Furthermore, human consumption risk evaluations and limits regarding mussel intake were analysed in terms of food safety. The results suggest that exposure to Cd, MPs, or their combination induces oxidative stress, tissue damage, and neurotoxicity. Alterations in digestive enzyme activities could impact the mussels' energy acquisition from food and their capacity to conserve energy reserves. The estimated daily intake (EDI), provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), and target cancer risk (TCR) levels for all groups surpassed established limits, implying a significant health risk for humans consuming these products. These results underscore the potential health risks for humans associated with consuming mussels exposed to Cd and/or MPs and provide valuable data for monitoring pollution levels and ecological risks in aquatic organisms. Additionally, our findings reveal that the retention of Cd in mussel tissues varies significantly after exposure, with combinations of PET and Cd showing lower levels of Cd accumulation compared to other groups, suggesting a differential interaction that influences Cd retention.

Evaluation of biotoxins and toxic metal risks in mussels from the Sea of Marmara following marine mucilage.

The mucilage phenomenon observed in the Sea of Marmara in 2021, has raised public concern about seafood safety. Mediterranean mussels serve as a vehicle in food chain, enabling the transfer of pollutants. Farmed and wild mussels were collected from 4 different stations throughout the fishing season. Biotoxins causing amnesic, paralytic, or diarrhetic shellfish poisonings (ASP, PSP, or DSP) were examined during monthly samplings. Potential health risks posed by cadmium, lead and arsenic were assessed. Health risks were evaluated considering 150 g/week mussel consumption, accounting for the different age groups of consumers (50, 60, 70 kg). Estimated Weekly Intake calculations of metals were determined to be lower than Provisional Tolerable Weekly Intake at all age groups throughout the sampling period in all stations. Target Hazard QuotientCd of mussels captured from Istanbul Strait was always determined <1, while it was equal to 1 for 50 kg individuals in Gelibolu samples. All THQAs were >1. Target carcinogenic Risk was evaluated for Pb and iAs, which were found to be negligible and acceptable, respectively. No biotoxins responsible for ASP, PSP, or DSP were detected. Hg levels were under detectable limits. Excluding Cd, the results did not reveal any risks associated with mussel consumption during mucilage.

Assessment of health risks due to toxic metals in demersal fish captured from Saros and Edremit Bays, Northern Aegean Sea.

Bays are vulnerable ecosystems generally located near densely populated areas where toxic metals tend to accumulate and stay longer, affecting marine life. This study aimed to investigate the age-based health risks arising from Hg, Cd, Pb, and As in demersal fish captured from two major bays in the Aegean Sea. For this purpose, red mullet, whiting, piper gurnard, and tub gurnard, frequently consumed species, were caught from Saros and Edremit Bays. Toxic metal concentrations were determined from the muscle tissue of fish. Health risk assessments were conducted by the estimation of weekly intake (EWI), provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), total THQ (TTHQ), and target carcinogenic risk (TR). Red mullet from Edremit Bay was the species with the highest toxic metal levels, which were 1.597 mg/kg, 0.041 mg/kg, 0.070 mg/kg, and 19.351 mg/kg for Hg, Cd, Pb, and As, respectively. Whiting from Edremit Bay had higher mean concentrations of Hg and As than those from Saros Bay. The levels of Hg, Pb, and As (0.328, 0.043, and 0.574 mg/kg) in the tub gurnard were higher in comparison with the piper gurnard (0.252, 0.020, and 0.382 mg/kg) caught in the same station in Saros. TTHQs of red mullet and whiting from the same bay were found to be > 1, indicating potential health risks for all nine age categories studied. On the other hand, TTHQs of all species from Saros Bay were determined to be > 1 for the first four age categories, which might trigger health risks for children and adolescents. According to the TR index for Pb, no risk was determined for the fish from both bays. However, TR calculations for inorganic As indicated high cancer risk in most of the age categories for red mullet and whiting from Edremit Bay. To sum up, the results revealed that the fish captured from Edremit Bay posed serious health risks in terms of Hg and As concentrations for all nine age categories. Surveillance and monitoring of toxic metal levels in demersal fish and population-based health risk evaluation are vital in heavily populated bays.

Determination of mineral composition in three commercial fish species (Solea solea, Mullus surmuletus, and Merlangius merlangus).

This study was monitored to determine the changes in the micromineral and macromineral composition of common sole (Solea solea), striped red mullet (Mullus surmuletus), and whiting (Merlangius merlangus) throughout the year. Macromineral concentrations in edible parts of fish species were 444-1,559 mg/kg for Na, 1,975-5,130 mg/kg for K, 228-658 mg/kg for Mg, 187-1,105 mg/kg for Ca, and 2,341-7,341 for P, respectively. The highest mercury contents were found in the autumn months. While the highest protein and lowest fat values were found in the summer, the highest ash contents were found in the spring. Mercury content was found to be over the legislative limits in autumn samples for common sole and in summer for striped red mullet. Lead and cadmium contents of striped red mullet were found to be over the legislative limits throughout year.

Seasonal variations in the macronutrient mineral and proximate composition of two clams (Chamelea gallina and Donax trunculus).

Two bivalve's species (Chamelea gallina and Donax trunculus) were investigated in terms of proximate and mineral compositions (sodium, potassium, magnesium, calcium, iodine and selenium) throughout the year. The concentrations of minerals were determined using inductively coupled plasma mass spectrometry. Ranges of moisture, protein, fat, ash and carbohydrate contents were 82.70-86.57%, 6.86-8.99%, 0.58-1.20%, 2.44-2.95% and 2.70-4.50% for C. gallina, and were 81.09-85.55%, 8.13-10.61%, 0.69-1.33%, 3.19-4.06% and 2.31-3.18% for D. trunculus, respectively. The highest sodium, potassium, magnesium, calcium, iodine and selenium contents for two species were found in the summer, followed by spring, autumn and winter. The concentrations of metals in two tissues exceeded the acceptable levels for a food source for human consumption.

Effect of frying, grilling, and steaming on amino acid composition of marine fishes.

Amino acid and proximate compositions were determined in six raw and cooked marine fish species that are commonly consumed in Turkey. The changes in amino acid and proximate content were found to be significant for all cooking methods in all fish species. Cooking did, in general, significantly increase the contents of essential, semiessential, and other amino acids compared with raw fish species. Grilled Atlantic bonito, anchovy, and bluefish and fried mullet and hake appeared to be more valuable fish dishes for obtaining the officially recommended appropriate daily intake of essential amino acids for humans. Moisture, fat, ash, and carbohydrate contents of raw fish ranged between 48.01% and 83.05%, 0.87% and 30.48%, 1.10% and 1.61%, and 0.09% and 8.70%, respectively. All fresh fish investigated were high in protein: 11.20-17.14 g/100 g. Wide variations in protein content (18.11-25.65 g/100 g) between species and methods of cooking were observed. Fried fish had intermediate fat values, whereas grilled and steamed fishes had a comparatively low value.