Flow-dependent modulation of microplastic toxicity in grass carp: Insights from multi-level biological endpoints and machine learning

Microplastics (MPs) are emerging contaminants in freshwater systems, yet how hydrodynamic conditions modulate their biological effects remains unclear. This study investigated the accumulation, histopathology, immune response, and gut microbiota disruption in Ctenopharyngodon idella exposed to 5 µm polystyrene MPs (1000 µg/L; ~ 1.46 × 10 7 particles/L) under static conditions and water velocities of 1, 3, and 5 Body Lengths per second (BL/s), representing low, medium, and high flow. Water velocity alone caused notable tissue damage, including gill lesions and intestinal alterations, and significantly upregulated immune response genes, with the strongest responses observed at high flow. MPs accumulated in both…

• NN
  National Natural Science Foundation of China

  Award: W2433148
• CT
  China Three Gorges University