Microplastics and their impact on marine ecosystems: a review study.

Introduction. Microplastics are widespread across marine ecosystems and may affect biodiversity and food safety. Evidence points to bioaccumulation, trophic transfer, and organism-level effects that warrant an integrated synthesis. Objetives: To characterise polymers and particle forms reported in marine species, identify affected organs and biological responses, and appraise implications for ecological risk and potential human exposure. Materials and Methods. A systematic search in Scopus used a PICOC-derived TITLE-ABS-KEY equation with Boolean operators OR and AND. Limits were final-stage, open-access articles published from 2020 to 2024. Screening by title and abstract preceded full-text assessment against predefined criteria, following PRISMA. The search retrieved 241 records, yielding 42 eligible studies. NOAA’s NCEI dataset on oceanic microplastic pollution for 2017 to 2024 was analysed descriptively to contextualise trends. Results. Fibres were the dominant particle form. Polyethylene, polyester, and polyethylene terephthalate were the most frequently identified polymers. The gastrointestinal tract and gills were the principal sites of accumulation. Reported effects included oxidative stress, histopathological alterations, and reduced nutrient absorption. Evidence of bioaccumulation and trophic transfer indicates plausible pathways to human exposure via seafood. Conclusions. Current literature confirms pervasive microplastic contamination, polymer and form-specific patterns, and consistent organ-level impacts in marine fauna. Methodological heterogeneity limits comparability. Standardised protocols and expanded monitoring in understudied oceans are priorities for robust risk assessment and management.