Assessment of Microplastic Contamination in Semi-Technified Nile Tilapia (Oreochromis niloticus) Aquaculture in Veracruz, Mexico

The presence of microplastics in aquaculture systems constitutes an environmental concern due to their potential occurrence in fish intended for human consumption. This study aimed to determine the presence, abundance, and morphological and chromatic characteristics of particles suspected of being microplastics in the edible muscle tissue of Nile tilapia (Oreochromis niloticus) obtained from ten semi-technified aquaculture farms in Veracruz, Mexico. Five fish were analysed from a single pond per farm (n = 50). Muscle tissue samples (5 g) were subjected to digestion with 30% KOH, vacuum filtration, and inspection under a stereomicroscope; identification was performed using visual criteria and the supplementary hot needle test. A total of 67 suspected particles were detected, with an overall abundance of 1.34 ± 1.60 particles/5 g of muscle tissue; 30 of the 50 fish contained at least one particle, corresponding to an observed prevalence of 60%. All particles exhibited fibrous morphology, with blue being predominant (47.76%), followed by black (19.40%) and purple (13.43%). Due to the clustered structure of the sampling design, variations among farms were interpreted descriptively. At the farm–pond unit level (n = 10), no statistically significant association was observed between compliance with Good Aquaculture Production Practices (GAPPs) and the mean abundance of particles (<!-- MathType@Translator@5@5@MathML2 (no namespace).tdl@MathML 2.0 (no namespace)@ -->