Evaluation of ecotoxicological effects associated with coastal sediments of the Yellow Sea large marine ecosystem using the marine copepod Tigriopus japonicus

A copepod bioassay with Tigriopus japonicus was applied to evaluate the relative ecotoxicity of sediments in the Yellow and Bohai seas, and contributions of individual PAHs to copepod toxicity were evaluated. Mean toxicity was greatest in the Yellow Sea of China, followed by the Bohai Sea and Yellow Sea of Korea. Elevated concentrations of sedimentary PAHs, alkylphenols, and styrene oligomers back-supported the significant toxicities observed in bioassay. Copepod toxicity in relation to PAHs indicated the greatest contribution by indeno [1,2,3-c,d]pyrene. However, lacked contribution by PAHs, viz., 2.4 and 3.0 % for the total immobilization and mortality, respectively, indicated a large proportion of unknown toxicants being widely distributed along the Yellow Sea Large Marine Ecosystem (YSLME) coastline. Overall, the present study provides useful baseline information for evaluating the potential sedimentary toxicants, with emphasizing further investigation to identify the unknown toxicants at an LME scale, and elsewhere.

Automated summary

A copepod bioassay was used to evaluate the ecotoxicity of sediments in the Yellow and Bohai seas, and the contribution of individual PAHs to copepod toxicity was assessed. The study found that the Yellow Sea of China had the highest toxicity, followed by the Bohai Sea and Yellow Sea of Korea. Elevated concentrations of PAHs, alkylphenols, and styrene oligomers in the sediments supported the observed toxicities. It was also discovered that a large proportion of unknown toxicants were distributed along the Yellow Sea Large Marine Ecosystem coastline.