Critical control points in Penaeus vannamei aquaculture: Dynamic tracking and comprehensive risk assessment of...

In this study, periodic dynamic tracking and sampling of water, organisms, feed, and feed additives were performed to investigate the contamination characteristics, bioaccumulation, and sources of antibiotics, and the ecological, health, and resistance risks were evaluated. Eleven antibiotics were detected, predominantly including florfenicol, enrofloxacin, and trimethoprim. Aqueous concentrations ranged from 0.61 to 3.9 × 10⁴ ng/L and increased over time, indicating a statistically significant increase in total antibiotic levels during the later stages (S3-S5, p < 0.05). The antibiotics originated mainly from aquaculture ponds and were not effectively removed by tailwater or purification ponds, allowing substantial loads to be discharged. The bioaccumulation factors (BAFs) indicated that the accumulation capacity of juvenile was greater than that of adult and mature stages, and sulfamethoxazole had the highest BAF. Trimethoprim and florfenicol pose medium to high ecological risks in effluents, whereas antibiotic residues detected in P. vannamei remained below the health‑ and resistance‑ risk thresholds for all age groups. These findings highlight (i) the limited efficacy of current tailwater treatment systems and (ii) the heightened vulnerability of juvenile stage, both of which represent critical control points for antibiotic management and targeted mitigation to increase aquaculture sustainability and product safety.