Right Column

Aquatic Pest Control Program
Egeria Densa

• Facts on Egeria densa
• Options for the Public in Removing Egeria densa
• DBW's Authority and Funding
• Program Restrictions

FACTS ON EGERIA DENSA

What is Egeria densa (Brazilian Elodea)
Egeria densa is a shallow-water submerged aquatic plant from Brazil.

What effects does Egeria densa have on waterways?
This aquatic invasive plant can negatively impact a waterways ecosystem. It displaces native plants, blocks light needed for photosynthesis, reduces the amount of dissolved oxygen in the water and deposits silt and organic matter several times the normal rate.

Are there any impacts to recreation and commercial activity?
The plant has a significant impact on recreation and commercial activity. Dense mats of vegetation create safety hazards for boaters, obstructing navigation channels, marinas and irrigation systems.

How does Egeria densa spread and how fast does it spread?
The plant can spread at a rate of approximately 100 acres a year depending on environmental conditions. Egeria densa spreads by fragmentation. For example, cutting the weeds back only exacerbates the problem, as shreds of the plant float away and re-propagates.

Can Egeria densa be eradicated?
There is no known eradication method in the world for Egeria densa. Therefore, DBW operates a "control" program as opposed to an "eradication" program.

How did Egeria densa enter the Delta?
Egeria densa is a popular aquarium accessory. It was introduced into the Delta roughly 40 years ago, possibly from use in home aquariums.

How much of the Delta is infested with Egeria densa?
Thousands of acres are infested by Egeria densa in the Delta.

How can someone tell if the herbicide is working properly?
A good sign that the herbicide is working effectively is that the growing tips of the plant will turn a pale pink or white.

OPTIONS FOR THE PUBLIC IN REMOVING EGERIA DENSA

What options does the public have to remove Egeria densa from the Delta?

• IMPORTANT NOTICE FOR AREAS BEING TREATED BY DBW: Removal of the plant by any means by the public is strongly discouraged during the treatment season. In order for the treatment to be effective, continuous contact of Egeria densa with the herbicide is necessary.
• DBW is the only entity authorized to treat Egeria densa with herbicides.
• The two most practical options for removal for the public are harvesters to cut the Egeria densa, or using aquatic vegetation management firms, to pull the plant out by its roots.

Who can residents contact with questions or concerns relating to Egeria densa?
Members of the public may contact DBW with questions or concerns relating to Egeria densa and the Fluridone treatment at (888) 326-2822 or e-mail the department at pubinfo@dbw.ca.gov.

FACTS ON DBW'S AUTHORITY AND FUNDING

What is DBW's authority?
Harbors and Navigation Code, Article 2, Section 64 provides that DBW is designated as the lead agency of the state for the purpose of cooperating with agencies of the United States and other public agencies in controlling water hyacinth and Egeria densa in the delta, its tributaries, and the Suisun marsh.

State funding for controlling water hyacinth and Egeria densa is appropriated in California's annual Budget Act.

When did DBW begin treating Egeria densa?
The Egeria densa program was authorized by law in 1997. Treatment for Egeria densa began in 2001.

How much money does DBW spend in treating Egeria densa?
DBW currently spends approximately $6 million per year on the Aquatic Weed Control Program, subject to annual appropriation of funds by the California Legislature. At least $4 million of this budget is used for treating Egeria densa.

Where does the funding for treatment of Egeria densa come from?
Funding for the Egeria densa treatment comes from the Harbors and Watercraft Revolving Fund, which receives revenues from boaters' registration fees and gas taxes.

PROGRAM RESTRICTIONS

For treatment, three permits are required to be obtained. These permits place restrictions on where and when DBW can treat the plants (this varies throughout the Delta), establishes the chemical concentrations allowable in treated areas and requires extensive water quality monitoring.

Two permits are required by the federal Endangered Species Act from the United States Fish and Wildlife Service and the National Marine Fisheries Service (part of the National Oceanic and Atmospheric Administration).

A third permit, a National Pollutant Discharge Elimination System permit is required by the Central Valley Regional Water Quality Control Board.