Park District Works to Control Invasive Spartina

The East Bay Regional Park District, (District), in conjunction with the Invasive Spartina Program, (ISP) of the California Coastal Conservancy is continuing a program to manage non-native Spartina, (cordgrass) in the San Francisco Bay estuary. Spartina alterniflora is an invasive plant species threatening the mudflats of San Francisco Bay.  The open mudflats are essential to the ecology of the Bay and an integral part of the feeding habitat for thousands of migratory shorebirds that utilize the Pacific flyway.

Efforts to control the spread of non-native Spartina are currently entering the sixth year.  Park crews and contractors will be treating Spartina at Hayward Regional Shoreline, Martin Luther King Shoreline, Oyster Bay, Pt. Pinole Regional Park and East Shore State Park, (Emeryville Crescent), during July, through October 2009.  District crews and consultants will be spraying a State and EPA approved herbicide, (growth inhibitor), on the Spartina plants. 

The herbicide is mixed with a surfactant and blue dye in order to improve the efficacy of the herbicide and help track areas treated.  These herbicides and their adjuvants have no adverse impacts to human health or safety.  The mixtures likewise have been tested and are non toxic to mammals, birds, fish and aquatic invertebrates.  Once sprayed into the near shore area colonized by Spartina, the herbicide that is not absorbed by the plant is quickly broken down by sunlight and diluted by the tides.

A helicopter will be used for aerial applications on July 13th .  During other treatment operations through October ground crews will spray from backpacks, trucks or boats.  As per District herbicide use regulations, adjacent trails will be closed to the public for approximately 12 hours during and after treatment.

Following treatment, the Spartina plants will start to brown as a result of treatment and normal fall die back.  The real determination of the effectiveness of the treatment will be observed next spring when the plants would normally begin to grow.  Although stands of dead plant material may persist, the spread of non-native Spartina is being halted and native marsh plants are colonizing the area.  Similar treatments in 2008 have resulted in a 40% reduction in this invasive plant.  As a result of continued efforts, the Bay Area populations of non-native Spartina have shown dramatic declines.

For more information on the Regional Spartina control program contact Pete Alexander of the East Bay Regional Park District at (510) 544-2342 or Peggy Olofson of the ISP at (510) 548-2461.  For more information of the Spartina Control efforts visit the website: www.spartina.org.