The sediment in Sancha Lake, China, has changed due to human activities, leading to eutrophication. The levels of nitrogen, phosphorus, and organic carbon in the sediment match the lake's water quality. Human actions like manufacturing and farming have worsened the lake's condition. To improve water quality, we need to limit these activities. Cage culture is a major source of phosphorus in the sediment, and it takes a long time for levels to decrease after stopping this practice.