Water quality in the Pearl River Estuary has improved significantly from 2008 to 2017 due to pollution control measures. Fecal coliform, biochemical oxygen demand, chemical oxygen demand, petroleum, and ammonia nitrogen levels have decreased, leading to better water quality. However, total nitrogen and total phosphorus levels have remained stable. The improvement is likely due to industrial upgrades, sewage treatment system enhancements, and pollutant reduction efforts. Efforts to reduce nitrogen pollution further are needed in the future.