U.S. Fish and Wildlife Service Logo U.S. Fish and Wildlife Service

2006 "Volunteers Working With Invasives"
Grants Report Form

Display Report


Project Title: Control of the Invasive Perennial Pepperweed in Tidelands of San Pablo Bay
Region: 8
Station: San Pablo Bay NWR
Contact Person:
Name and Phone Number
Giselle Block 707-769-4200
Project Description:
(Up to 250 words)
The objectives of this project are to reduce the cover of perennial pepperweed (Lepidium latifolium) and to restore native plant assemblages while providing education in tidal marshlands of San Pablo Bay. The project includes tidal marsh that occurs from Sonoma Creek west to the mouth of the Petaluma River. The project includes three primary partners that manage land within the project area (1,460 acres): the San Pablo Bay National Wildlife Refuge, the CA Department of Fish and Game, and the Sonoma Land Trust. Initiation of pepperweed monitoring and control will reduce the continued spread within the San Pablo Bay region. These actions will benefit many estuarine-dependent species, including the endangered salt marsh harvest mouse and endangered California clapper rail, and will increase the success of tidal marsh restoration efforts already underway and others that are in the planning stages. Lastly, the project will provide a basis for long-term pepperweed control throughout San Pablo Bay and potentially the entire San Francisco Estuary.
List of Invasives Species Targeted:Common NameScientific Name
  pepperweed Lepidium latifolium
Project Status: InProgress
Project Completion Date
or Estimated Completion Date:


Volunteer Affiliation:
(Check all that apply)
VA_FriendsGrp                                 VA_Other
Volunteer Involvement:
Describe the type of work the volunteers performed. (Up to 150 words)
Inventory of Lepidium latifolium is conducted primarily by refuge volunteers using global positioning systems (GPS) and the Weed Information Management System (WIMS). Refuge volunteers and volunteers from our Friends group, Sonoma Land Trust, the Bay Institute, and Save the Bay assisted with plant propagation at the refuge native plant nursery in 2006. These volunteers will out-plant the nursery stock of natives on the refuge during fall 2006.
Total Number of Volunteers: 150
Total Number of Volunteer Hours: 1400
List both new and existing partnerships utilized in this project. (Up to 150 words).
Sonoma Land Trust, The Bay Institute, Save the Bay, CA Department of Fish and Game, Friends of San Pablo Bay NWR, Marin-Sonoma Mosquito and Vector Control District, U.C. Davis, Marin-Sonoma Weed Management Area


Project Results:
Give an overview of the results of the project. Include quantifiable measure of success, such as maps produced, efficacy of control measures, number of sites where invasions were detected early and responded to, number of community contacts, etc. (Up to 250 words).
A complete census of 1,500 acres of tidal marsh was completed in 2006. over 100 acres of tidal marsh contain Lepidium within an area stretching from the mouth of the Petaluma River to the mouth of Sonoma Creek. Accounting for the variability in cover among patches of Lepidium, 33 acres were infested with Lepidium (100% cover). These data were used to develop a Lepidium Control Plan for the refuge. The plan was developed through a partnership with researchers at U.C. Davis who specialize in Lepidium control. The plan is adaptive in that changes will be made to it on an annual basis following assessment of treatment effects and incorporation of new information as it becomes available. Beginning in January 2006, the refuge native plant nursery and associated volunteers began propagation of native tidal marsh transition zone plants from seeds collected within 15 miles of the refuge. To date, we have over 3,000 plants representing 22 species. These plants will be outplanted during fall 2006. Planting will occur in areas where Lepidium is present and will be removed in 2007. This process will be repeated in 2007 following treatment of Lepidium patches. The funds provided by the USFWS for this project were to be used for treatment of Lepidium. Treatment must occur during the bud stage of Lepidium in order to be effective. The funds were not obtained until July 2006, pushing the treatment forward to 2007. A poster of results to date will be presented at the California Invasive Plant Council Symposium during October 2006.
Number of Acres Treated: 60
Number of Acres Inventoried and/or Mapped: 2,000
Number of Acres Restored: 2,000


Budget: Account for funds in broad categories such as equipment, volunteer stipends, travel, coordinator salary/contract, etc.

Total Grant Amount:

$ 7,000

Breakdown of Expenditures:


Total $ Spent
% of Total Grant
Equipment / Supplies 5,000 0
Chemical 19,000 0
Biocontrol Agents
Volunteer Stipends
Volunteer Coordinator Salary/Contract
Restoration Materials 18,000 100
Other 7,000 7,000
TOTAL 42,000 100

Recommendations: (OPTIONAL)
How useful was this program for meeting refuge invasive species objectives and how can it be improved?
This program has allowed the refuge to continue it's program to reduce cover of invasive pepperweed on the refuge. I would suggest putting the grant funds in a seperate account, not combined with 1261 funds.


- Return to Main Menu -