Microplastics in Semi-Technified Nile Tilapia (Oreochromis niloticus) Aquaculture Farms in the Central Region of the State of Veracruz, Mexico

Microplastic contamination in aquaculture systems represents an emerging challenge with environmental, production, and food safety implications. The aim was to evaluate the prevalence of microplastics in the muscle tissue of Nile tilapia (Oreochromis niloticus) from ten semi-technified aquaculture farms located in the central region of Veracruz, Mexico. Five specimens per farm were collected, and 5 g of muscle tissue per organism were processed via 30% KOH digestion, vacuum filtration, and density separation. Particle identification was conducted through stereomicroscopy based on morphological and chromatic criteria. A total of 67 microplastics were detected, with a mean of particles per farm. The highest abundance was recorded at farm F-06 (23.88%), while the lowest corresponded to F-10 (2.99%). All identified particles were fibres, with blue being the predominant colour (47.76%), followed by black and purple. Statistical analysis via ANOVA showed no significant differences between farms, and Tukey’s test confirmed a homogeneous distribution among the evaluated units. The results suggest that microplastic contamination in semi-intensive systems is influenced by shared environmental sources and the deployment of plastic materials during the production process. This finding underscores the necessity of integrating microplastic monitoring into aquaculture biosecurity and food safety programmes.