The researchers studied the water quality of Poyang Lake in China from 2009 to 2014. They looked at 11 different water quality parameters, like nitrogen and phosphorus levels, at 15 different sites. They found that water quality was worse in the river phase than in the lake phase, especially for chlorophyll-a. Eutrophication and organic pollution were the main factors affecting water quality. By controlling pollutant effluents in tributaries and managing water levels, the water quality in Poyang Lake could be improved.