Abstract
The Bohai Bay is a semi-closed bay located in the western part of the Bohai Sea in China. Due to the discharge of industrial wastewater into the Bahai Sea, which caused potential water pollution, we need to evaluate the degree of pollution. In this study, sediment samples were collected near a factory outlet around the Bohai Bay and extracted by alcohol. Zebrafish embryos were used to monitor PAHs in the sediment extract (SE). Chemical analysis was carried out by GC-MS. The results showed that mortality was significantly increased in the 5 mg/mL SE group at 24 hpf (p < 0.001), and in the 0.5 mg/mL and 1 mg/mL SE groups at 96 hpf (p < 0.01). By 72 hpf, the hatching rate of zebrafish embryos was significantly inhibited in 0.5 mg/mL, 1 mg/mL and 5 mg/mL SE groups, respectively (p < 0.05). Interestingly, SE could significantly reduce pigmentation in the eyes of zebrafish embryos (p < 0.05). SE inhibited the thyroid-related genes Tpo, Thrβ and Dio2 mRNA expression. However, SE significantly increased Dio3 mRNA expression by 1.67 to 5.09 fold (p < 0.05). Chemical analysis showed that SE mainly contained polycyclic aromatic hydrocarbons such as fluorene, phenanthrene, fluoranthene, and fluorene. Our results indicate that zebrafish embryos may be useful for biomonitoring PAHs pollution in the sediments.
