II. research method and process

1.Collect water sample
From Huairong Reservoir floodgate to sluice gate, we collect water sample from five places in this 6.2km distance. They are: reservoir, bridge beside Shichang, Shichang section, Taixiaduan and Taishangduan.

2.Experiment
① identify the sort of algae and count the number
② observe the algae in microscope and calculate density of cellar according to the formular below.