Assessment on the water quality of coastal seawater in the Aoshan bay, Qingdao in spring

Based on the investigated data in spring 2019, the water quality of the coastal seawater in the Aoshan bay was evaluated by the pollution index. Nutrient limitation factors were determined by both the relative and absolute limiting principle methods, and nutritive status was assessed with both the nutrient state quality index and eutrophication index. The correlation between chemical oxygen demand (COD) and turbidity was analyzed. The results showed that: (1) The coastal seawater of the Aoshan bay was of good quality in spring, with low pollution in COD, dissolved inorganic nitrogen and dissolved inorganic phosphorus; (2) There existed silicon and phosphorus limitations but no nitrogen limitation; (3) There was no eutrophication situation; (4) COD and turbidity presented a significant positive correlation.