Characteristics of Phytoplankton Community Structure and Eutrophication in Hasu Sea

In this paper, we first obtained the data of each water quality monitoring point in May and July Hassel Sea 2021, analyzed spatial distribution element total phosphorus (TP), nitrogen (TN), transparency (SD), high manganese index (CODmn) chlorophyll a (Chl. a) data, then used integrated trophic state method algal species quotient to evaluate lake. The results were assess lake’s status. showed that measured value was 1.15 times May, which points H1, H2, H3 moderately eutrophic, H4, H5, H6 mildly while six all indicating eutrophication summer higher than spring, there trend gradual deterioration during interannual variation, needed attention It is necessary pay strengthen management. Comparing nutrient status values parameter, a), (TP) play significant role degree Sea, accounting for 23.94%, 23.05%, 20.18%, respectively. evaluation heavily eutrophic when green algae applied, rest composite except H4 (located Xianglu area). two methods, it can be found evaluated by applying are more serious, sensitive response lake, great chance bloom disaster late stage Sea.