Joint Probabilistic Risk of Organic Micropollutants in the Aquaculture Seawater Around Liaodong Peninsula

The limited number of organic micropollutants (OMPs) investigated in aquaculture seawater may underestimate the risk to marine organisms. It is critical to comprehensively investigate the occurrence of diverse OMPs in mariculture area and assess their joint risks to coastal marine organisms. Herein, the joint risks caused by multiple substances were assessed based on the screened results of approximately 1300 non-polar to polar OMPs in the seawater of mariculture ponds and raft culture areas around Liaodong Peninsula. In this study, 48 out of 886 non-polar to low-polar OMPs were detected at least once in 36 seawater samples, including 16 alkanes, 6 phthalate esters, 6 pesticides, 5 polycyclic aromatic hydrocarbons, etc. For 99 detected OMPs from both this study and our previously reported study, their aquatic toxicity data were comprehensively collected to assess the probabilistic risk. For 14 OMPs with sufficient toxicity data, their species sensitivity distribution curves were established. The results show that only three pollutants – ametryn, atrazine and diuron - alone adversely affect more than 5% of coastal marine organisms. However, for the joint risk, up to 15.2% of coastal marine organisms were affected by 14 OMPs under long-term exposure, suggesting that the OMP mixtures could enhance adverse effects. Although the ecological risks for most of compounds were acceptable, the joint risks of co-pollution by various OMPs cannot be ignored. The findings could support risk management of pollutants in aquaculture seawater, thereby contributing to the conservation of coastal marine biodiversity.