Bohai Bay, located in China, is a representative semi-closed bay. Over the past few years, the land encompassing Bohai Bay has undergone rapid industrialization, making it one of China's most densely populated and industrially developed regions. The presence of various industries, including crude oil production, chemical manufacturing, rubber processing, and steel production, has contributed to the pollution levels in the surrounding environment.
Unfortunately, these pollutants have the potential to jeopardize both the marine ecosystem of Bohai Bay and the well-being of the coastal residents. Efforts need to be made to address this pressing issue and mitigate the adverse effects on both the environment and the local population.
To that end, a team of researchers in the country investigated the sludge collected from the outlet of a factory, which discharges effluent into Bohai Bay. They prepared alcohol extracts of the sludge and performed ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. Through this analysis, they identified the presence of polycyclic aromatic hydrocarbons (PAHs) such as fluorene, phenanthrene and pyrene in the sediment of the sludge.
“To assess the potential impact of the sediment on zebrafish development, we used zebrafish embryos as an animal model,” shared Wenjing Dong, lead author of the study. “Our evaluations encompassed multiple aspects, including morphological observations, behavioral assessments, histological examinations, and genetic analyses.”
These comprehensive evaluations allowed the researchers to gain insights into the effects of the sediment on various levels of zebrafish development. The results revealed that the sediment caused concentration-dependent mortality and decreased hatchability. It inhibited pigmentation, reduced swimming distance, and lowered triiodothyronine (T3) levels. Thyroid hormone-related genes were downregulated (TPO, Thrβ), while Dio2 and Dio3 were upregulated. Individual PAHs induced similar effects as sediment exposure.
The team’s findings are published in the KeAi journal Water Biology and Security.
“This study highlights the negative impact of PAHs present in sediment on zebrafish pigmentation, likely due to genetic alterations related to thyroid hormones. In addition to chemical monitoring, biomonitoring endpoints such as pigmentation, behavioral changes, and gene expression can serve as valuable indicators to predict and assess PAH pollution in Bohai Bay,” added Dong.
Contact the author: Wu Dong firstname.lastname@example.org
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 100 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Water Biology and Security
Method of Research
Subject of Research
Reduced pigmentation and thyroid hormone disruption in zebrafish embryos caused by industrial sludge near Bohai Bay, China
The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.