Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas)

Moura, Cláudia; Silva, Diogo M.; Espincho, Francisca; Rodrigues, Sabrina M.; Pereira, Rúben; Almeida, C. Marisa R.; Ramos, Sandra; Freitas, Vânia

doi:10.3390/environments12080254

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Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas)

by

Cláudia Moura

¹,

Diogo M. Silva

^1,2,

Francisca Espincho

¹

,

Sabrina M. Rodrigues

^1,2

,

Rúben Pereira

^1,2,

C. Marisa R. Almeida

^1,3

,

Sandra Ramos

^1,4 and

Vânia Freitas

^1,*

¹

Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal

²

Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira nº 228, 4050-313 Porto, Portugal

³

Chemistry and Biochemistry Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal

⁴

Biology Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal

^*

Author to whom correspondence should be addressed.

Environments 2025, 12(8), 254; https://doi.org/10.3390/environments12080254

Submission received: 25 June 2025 / Revised: 22 July 2025 / Accepted: 23 July 2025 / Published: 25 July 2025

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Plastic Contamination)

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Abstract

This study assessed the presence, abundance, and characteristics of microplastics (MPs) in farmed Pacific oysters (Crassostrea gigas) and evaluated the efficacy of depuration in reducing MPs under laboratory-controlled and commercial conditions. Oysters cultivated in the Lima estuary (NW Portugal) were sampled in autumn and winter, along with adjacent surface water and sediment, to investigate potential contamination sources. MP concentrations in oysters varied temporally, with higher levels in October 2023 (0.48 ± 0.34 MPs g⁻¹ ww) than in February 2024 (0.09 ± 0.07 MPs g⁻¹ ww), while the environmental levels remained stable across dates. All MPs were fibres, predominantly transparent, followed by blue and black. Fourier-Transform Infrared Spectroscopy (FTIR) confirmed cellulose and polyethylene terephthalate (PET) as dominant polymers in oysters and environmental samples. No clear correlation was found between MPs in oysters and surrounding compartments. Laboratory depuration reduced MPs by 78% within 48 h, highlighting its potential as a mitigation strategy. However, depuration was less effective under commercial conditions, possibly due to lower initial contamination levels. These findings suggest that oysters may act as a vector for human exposure to MPs via seafood consumption. While depuration shows promise in reducing contamination, further research is needed to optimise commercial protocols and enhance the safety of aquaculture products.

Keywords: oysters; aquaculture; estuary; microplastics; microfibres; depuration; seafood safety

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MDPI and ACS Style

Moura, C.; Silva, D.M.; Espincho, F.; Rodrigues, S.M.; Pereira, R.; Almeida, C.M.R.; Ramos, S.; Freitas, V. Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas). Environments 2025, 12, 254. https://doi.org/10.3390/environments12080254

AMA Style

Moura C, Silva DM, Espincho F, Rodrigues SM, Pereira R, Almeida CMR, Ramos S, Freitas V. Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas). Environments. 2025; 12(8):254. https://doi.org/10.3390/environments12080254

Chicago/Turabian Style

Moura, Cláudia, Diogo M. Silva, Francisca Espincho, Sabrina M. Rodrigues, Rúben Pereira, C. Marisa R. Almeida, Sandra Ramos, and Vânia Freitas. 2025. "Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas)" Environments 12, no. 8: 254. https://doi.org/10.3390/environments12080254

APA Style

Moura, C., Silva, D. M., Espincho, F., Rodrigues, S. M., Pereira, R., Almeida, C. M. R., Ramos, S., & Freitas, V. (2025). Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas). Environments, 12(8), 254. https://doi.org/10.3390/environments12080254

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Assessing Microplastic Contamination and Depuration Effectiveness in Farmed Pacific Oysters (Crassostrea gigas)

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