Effects of feeding habits, foraging habitats, and trophic levels on organ-specific accumulation of microplastics in marine fishes

Microplastics (MPs) are pervasive in marine environments, raising concern about their accumulation in fish organs. This review synthesized data from 35 studies on 160 marine species to assess organ-specific (gills vs. gastrointestinal tract, GIT) MP loads in relation to habitats, feeding habits, and trophic levels (TL). Concentrations of MP ranged from 0 to 51.30 particles/fish in gills (mean 3.71) and 0 to 52.60 in GIT (mean 3.73), with highly skewed distributions. Habitat emerged as the strongest predictor of MP accumulation, with pelagic and demersal species exhibiting significantly higher MP burdens than benthic species. Feeding habit influenced gill MPs but showed no significant effect on GIT (p > 0.05), while TL affected only gill MPs; however, species at higher TL (4–5) had elevated GIT MPs. Regression models explained limited variance (R² < 0.150), suggesting other environmental or biological factors are critical. These findings highlight habitat as a key determinant of MP exposure and call for further research on polymer types, hydrodynamics, and fish behavior.