Contamination Characteristics and Ecological Risk Assessment of Antibiotics in Typical Eriocheir sinensis Aquaculture Environments of Jiangsu Province

In order to evaluate the pollution level and ecological risk of antibiotics in the typical Eriocheir sinensis aquaculture environments of Jiangsu Province, the residues of five classes of antibiotics (macrolides, tetracyclines, beta-lactams, quinolones, sulfonamides) in surface water and sediments of four ponds in Gaochun and Jintan were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results show that there was a certain degree of antibiotic contamination in water of both Gaochun and Jintan Eriocheir sinensis ponds. The main antibiotics in Gaochun water were quinolones, tetracyclines and macrolides, while the five classes of antibiotics were evenly distributed in Jintan water. Among them, residual of antibiotics was the highest in GC2 water, including chlortetracycline hydrochloride (241.99 ng·L^-1), spiramycin (198.53 ng·L^-1), ciprofloxacin (168.81 ng·L^-1), sarafloxacin (165.40 ng·L^-1), norfloxacin (126.17 ng·L^-1), enrofloxacin (117.42 ng·L^-1) and enoxacin (103.08 ng·L^-1). The concentration of antibiotics in sediments was relatively low. Correlation analysis between antibiotic residues and corresponding water pollution indicators show that the residual concentrations of clindamycin, doxycycline, and penicillin G sodium salt were significantly correlated with COD_Mn. The risk quotients (RQ) indicate that there was a certain extent of ecological risk of antibiotics in the Eriocheir sinensis aquaculture environments of Gaochun and Jintan, especially the macrolide and quinolone antibiotics in GC2, which directly affected the growth of phytoplankton such as algae. The use of antibiotics should be controlled in the breeding process to reduce the ecological risk.