Accumulation and Occurrence of Microplastics in Different Feeding Species of Wild Fish in Baiyangdian Lake
Microplastic pollution in freshwater environments has escalated, leading to increased accumulation in wild fish. This study investigated the occurrence characteristics of microplastics (MPs) in the gills, gastrointestinal tract (GIT), and muscle of four wild fish species with different feeding habits from Baiyangdian Lake, China. MPs were detected in all tissues. The average abundance was highest in the GIT (11.63 ± 10.76 items/individual), followed by gills (7.44 ± 6.79 items/individual), and lowest in muscle (3.91 ± 3.16 items/individual). The majority of MPs were transparent and black fibers smaller than 0.5 mm. Polymer analysis identified polypropylene (PP) and polyethylene (PE) as dominant components. Significant differences in MP abundance were observed among species, with carnivorous and herbivorous fish (e.g., snakehead and grass carp) showing higher total MPs than omnivorous and planktivorous fish (e.g., mosquitofish and topmouth gudgeon). However, when normalized by body weight, smaller fish exhibited higher MP concentrations in the GIT, suggesting a greater risk per unit mass. This study provides baseline data on tissue-specific MP distribution in wild freshwater fish with varying feeding behaviors and habitats, highlighting the influence of trophic level and body size on MP accumulation.