The increase in the human population has created pressure, due to the high consumption of natural resources, to meet basic needs. Poor waste management resulting from human activities has caused plastics to become pollutants that are present around the planet, including aquatic environments. The degradation of plastics through physicochemical processes has resulted in the presence of microplastics (particles < 5 mm), which have been found in species for human consumption and economic importance, including tilapia. In the last decade, research has shown the presence of microplastics in tilapia collected from different water bodies and aquaculture ponds, as well as in fish markets. In addition to this, there are studies that demonstrate that exposure to microplastics can have negative effects on the health of tilapia. The aim of this review is to compile and analyze the available information on microplastic contamination in Oreochromis spp., as well as in their environment, due to their importance as a species for human consumption.

Emerging contaminants (ECs) represent a growing environmental problem due to their presence in various environmental matrices. In Mexico, research on ECs remains limited. This scoping review, conducted in accordance with the PRISMA-ScR guidelines, analyzes their environmental fate during the period 2004–2025, considering their distribution in surface and groundwater, sediments, and influents and effluents from wastewater treatment plants (WWTPs). The reviewed studies demonstrate the presence of pharmaceutically active compounds (PhACs), endocrine-disrupting compounds (EDCs), personal care products, phthalates, bisphenols, pesticides, illicit drugs, xanthines, perfluoroalkyl and polyfluoroalkyl substances (PFAS), metabolites, and industrial compounds. The Apatlaco, Cuautla, and Santa Catarina rivers exhibit the greatest diversity of ECs, while groundwater shows evidence of infiltration of PhACs, phthalates, bisphenols, and triclosan, associated with urban, industrial, and tourist discharges. In sediments, PhACs and EDCs accumulate at concentrations in the ng/g range, while phthalates reach concentrations of thousands of ng/g, indicating their affinity for the solid phase. At Mexican wastewater treatment plants, conventional treatment methods do not completely remove ECs, allowing residual amounts to be discharged into receiving bodies of water. Overall, national monitoring should be expanded to include metabolites, transformation products, and advanced treatment assessment.

Microplastic pollution poses an emerging risk to aquaculture systems and food security. Nile tilapia (Oreochromis niloticus), one of the most widely farmed freshwater species globally, can be exposed to these particles through water, feed, and aquaculture infrastructure. This systematic review aimed to synthesize the scientific evidence regarding the sources, characteristics, and effects of microplastics in tilapia aquaculture. The PRISMA 2020 guidelines were followed, and a literature search was conducted across Scopus, SpringerLink, Google Scholar, and ResearchGate for the period 2016-2025. Following the selection process, 34 studies were included in the qualitative synthesis. The results demonstrate that microplastics in O. niloticus are widespread globally, having been recorded in natural, aquaculture, and experimental systems. Fibers and fragments, composed mainly of polyethylene, polypropylene, and PET, predominate; these are associated with both external sources (wastewater, urban activities, and textiles) and internal sources (wear and tear of netting, pipes, equipment, and contaminated feed). Most studies document accumulation in the gastrointestinal tract, although particles have also been detected in the gills, liver, and muscle, suggesting a potential risk to human health. Furthermore, physiological effects such as digestive disturbances, oxidative stress, and reduced growth have been reported. Overall, the evidence confirms that microplastics are a significant contaminant in tilapia aquaculture and highlights the necessity to implement mitigation strategies and standardize assessment methodologies.

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.

The Mexican axolotl is an aquatic species endemic to Mexico that has recently attracted increasing interest in both aquaculture and conservation; however, Information on the Mexican axolotl Ambystoma mexicanum remains limited, this study evaluated the effect of three stocking densities on growth, survival, Fulton’s condition factor (K), and proximate composition of A. mexicanum. Juveniles (28.7 ± 0.31 g initial wet weight) were assigned to three densities: D3 (3 individuals/40 L), D6 (6 individuals/40 L), and D9 (9 individuals/40 L), The experiment lasted seven weeks at 19 °C, using a commercial diet containing 55% protein. Final length, wet weight, specific growth rate (SGR), Fulton’s condition factor, size heterogeneity, coefficient of variation, and proximate composition were evaluated. No significant differences were detected among treatments in final length, Fulton’s K, size heterogeneity, coefficient of variation, protein, lipid, or moisture content. In contrast, final weight and SGR differed significantly among densities. Individuals at D3 achieved the highest final weight and SGR, whereas those at D9 showed lower values. Although D9 allows a greater number of individuals to be reared per unit volume, its lower growth performance does not support considering it the most efficient production alternative based on the variables evaluated. Nevertheless, rearing juvenile A. mexicanum at nine individuals per 40 L may offer an option for improving space utilization in captive production and ex situ conservation under the conditions evaluated.

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 (ρ = 0.523, p = 0.121). These findings provide baseline information on the occurrence of particles suspected of being microplastics in edible muscle tissue and, in practical terms, support the incorporation of their surveillance into future aquaculture monitoring programmes, including water, feed, sediment, and production materials, to identify potential exposure pathways. Spectroscopic confirmation via FTIR or Raman spectroscopy will be necessary to determine polymeric composition and strengthen future environmental and food safety assessments.