Variations in the marine seawater environment and the dominant factors in the Lianyungang coastal area

Abstract

Seawater physical parameter data obtained from August 2015 to May 2016 of the Lianyungang coastal area were analyzed, and discussed the spatiotemporal variations, and compared with historical data to assess pollution trends and the current status of the seawater environment. The study found that the seawater quality in the Lianyungang coastal area was better in spring, while the degree of pollution was increasing in other seasons. DIN and DIP were the main seawater pollutants, followed by COD and Oil, while most of highly polluted areas were in the near-shore and estuary. The DIN concentration has increased significantly in recent years, while the DIP and COD were relatively stable from 1996 to 2016. This area has been become eutrophic and lightly organic polluted, while that was seriously in autumn and winter. The N/P ratio exceeded the Redfield ratio in summer and the nutritional level was “medium phosphorus limited potential eutrophication”. The correlation analysis suggested that nutrients that affected seawater mainly come from land-based sources. This study provides basic support for the proper development and utilization of marine resources and environmental protection in the Lianyungang coastal area, and a scientific basis for ecosystem management of marine resources.