1.College of Ocean Technique and Environment, Dalian Ocean University, Dalian 116023, China; 2. Zhimao Bay Marine Environmental Monitoring Station, State Oceanic Administration, Huludao 125208, China
Abstract: Distribution characteristics of chemical oxygen demand (COD), petroleum pollutants and chlorophyll a were monitored in coastal waters of the central part (Yingkou and Panjin)of Liaodong Bay in 2016 and 2017, pollution degree of COD and petroleum pollutants was evaluated by single factor standard index method and comprehensive index evaluation method and eutrophication was assessed by eutrophication index method (EI) to understand the eutrophication status in the coastal waters in the middle of Liaodong Bay. It was found that the distribution of COD and petroleum was characterized by high levels in the estuarine and coastal areas in the monitoring area, without seasonal variation. The distribution of chlorophyll a content, however, showed obvious seasonal variation, with descending order of summer> spring > autumn, about twice in summer as much as that in autumn, without the regional variation in chlorophyll a content. Eutrophication evaluation revealed that eutrophication was observed in all monitoring stations, with predominant mild and mesotrophic state. Eutrophication area was primarily concentrated in the central and northern parts of the monitored area, the most eutrophication in a part of the station at the river mouth.
2019, Vol. 34 
