The scientists studied sediment samples from Qinghai Lake to understand the distribution of nutrients like phosphorus and nitrogen. They found that the levels of these nutrients varied across different spots in the lake. The study showed that the amount of nutrients in the lake is influenced by factors like water depth and human activities like tourism and pollution. The researchers also discovered strong relationships between nitrogen, phosphorus, and organic carbon in the lake sediments. Overall, the study highlights the importance of managing nutrient inputs to protect the water quality of Qinghai Lake.