Investigation of the impact caused by different sizes of polyethylene plastics (nano, micro, and macro) in common carp juveniles, Cyprinus carpio L., using multi-biomarkers

Plastic pollution poses a global threat to aquatic organisms, yet its effect on many species remains poorly documented and understood. This study addresses the impact caused by different sizes of polyethylene (PE) plastics on the common carp and evaluates their multi-biomarkers response. We investigated the histological structure and measurement of biochemical alterations, antioxidant enzymes, immunological responses, and fluctuations in blood profiles of the organisms after 15 days of exposure to a concentration of 100 mg/L of nano- (NPs), micro- (MPs) and macroplastics (MaPs). The fish health status was altered in the sole presence of PE particles. All biomarkers changed after exposure compared to the control group, with larger changes being observed with the decreasing size of particles (NPs > MPs > MaPs) compared to their absence. A synergistic effect resulting from the individual impact of plastics penetration in the circulatory system, bursting biochemical responses, and lesions in tissues, might explain the more considerable impact of NPs compared to MPs and/or MaPs. • The common carp response to size-dependent PE particles was investigated using multi-biomarkers. • The highest change in all biomarkers occurred in the presence of nanoplastics. • Damage in fish tissue increased with decreasing size of PE particles.