California State Parks’ Division of Boating and Waterways (DBW) announced today its 2025 control efforts for invasive aquatic plants in the Sacramento-San Joaquin Delta and its southern tributaries (Delta). Starting March 20, DBW will begin herbicide treatments on water hyacinth, South American spongeplant, Uruguay water primrose, alligator weed, Brazilian waterweed, curlyleaf pondweed, Eurasian watermilfoil, coontail, fanwort, and ribbon weed in the Delta. The treatment start date may change depending on weather conditions and plant growth/movement. … These aquatic invasive plants have no known natural controls in the Delta, the West Coast’s largest estuary. They negatively affect the Delta’s ecosystem as they displace native plants that are essential to the area’s biodiversity while negatively impacting the economy, environment and public health.