Micro/nanoplastics in aquaponic systems: Sources, features and their effects on the immune system of fish

Abstract

Plastic debris in aquatic ecosystems undergoes weathering and degradation, breaking down into micro/nanoplastics (MNPs) that inflict physical damage or chemical toxicity upon ingestion by fish. The fish immune system exerts a key role in responding to and defending against pathogens and adverse environments, making it essential to assess the impact of MNPs on the fish immune system. Fish ingest MNPs through respiration, food intake, and bioaccumulation, which can impose a toxic burden on immune organs such as the gut, liver, kidneys, and spleen. MNPs exert toxic effects by destroying immune cells and altering gene expression. Notably, MNPs may synergize with environmental pollutants, including heavy metals, persistent organic pollutants, and pathogens, leading to more severe immune damage in fish. Additionally, the limitations of current research and future research directions are discussed, alongside feasible mitigation strategies for reducing plastic pollution.