Impact of micro and nanoplastics on aquaculture animals: a systematic review

The pervasive contamination of aquatic environments by microplastics (MPs) and nanoplastics (NPs) presents a growing concern for the aquaculture industry, with potential impacts on animal and/or human health and ecosystem sustainability. This review evaluates the existing literature on the effects of micro- and nanoplastics (MNPs) on key aquaculture species, drawing from both laboratory studies and field data across a range of freshwater and marine environments. Field data on MNP concentrations in aquaculture environments reveal that polypropylene and polyethylene fibers are the most commonly found forms. Laboratory studies, however, often employ higher doses and different particle types, raising concerns about the ecological relevance of experimental conditions. Despite this disparity, our analysis shows that waterborne MNPs primarily elicit oxidative stress, whereas dietary exposures not only induce oxidative stress but are also strongly associated with histopathological damage and reduced growth. Our review also examines the toxicological mechanisms of MNP exposure, highlighting the roles of particle characteristics as key factors influencing toxicity. We further highlight potential mitigation strategies, such as dietary interventions with probiotics, vitamin C, and chlorella, which show promise in reducing the harmful effects of MNPs. This review emphasizes the critical need for more ecologically relevant, long-term studies, a deeper understanding of route-specific effects, and the development of standardized testing protocols to enhance the accuracy and applicability of MNP risk assessments and inform sustainable aquaculture practices.