“Managing the plant will be challenging,” said DBW Acting Director Sylvia Ortega Hunter. “Due to the characteristics of the invasive plant, lack of a heavy frost, continued warm temperatures and a late treatment start, last year’s water hyacinth infestation level was unusual. Since the 2013 control program has been adjusted to accommodate these issues, DBW hopes to realize better results this year.”
In order to protect listed salmon species and Delta smelt, treatment in some Delta sites will begin later in the year after peak spawning and migration times, when the fish in question are less likely to be present.
Sites will be treated using two herbicides: glyphosate or 2,4-D. Both have been approved by the U.S. Fish and Wildlife Service, the National Marine Fisheries Service and the Central Valley Regional Water Quality Control Board.
Initial symptoms of glyphosate treatment on water hyacinth do not appear for two weeks or more. Visible symptoms are the gradual wilting and yellowing of the plant, advancing to browning of vegetation and eventual decay. It can take two months for herbicide effectiveness to be clearly visible.
The program DBW conducts is considered a control – not an eradication – program. There is no known eradication method for water hyacinth once it has been established. DBW’s program seeks to minimize negative impacts of the invasive plant on navigation, public safety, recreation, agricultural activities and ecosystem services in Delta waterways.
Funding for water hyacinth treatment comes from the Harbors and Watercraft Revolving Fund, which receives revenues from boaters’ registration fees and gasoline taxes.
To report sightings or for more information regarding the control program, visit www.dbw.ca.gov or call 888-326-2822.