sentences:  After death, it will rot and sink to the bottom of the water, causing secondary pollution to the water body, destroying the natural water quality, and may even affect the quality of residents' drinking water in severe cases.Third, due to the dense growth of water hyacinth blue, it brings great difficulties to fishermen and often destroys fishing gear, resulting in a large increase in fishing costs.The surface of the water body where water hyacinth grows heavily is often a breeding place for mosquitoes and harmful pathogens, posing a potential threat to the health of local residents.