By Hanna Tamrat, Staff Writer, Inside Bay Area
Thursday, September 29, 2005
ALAMEDA
Atractor-like vehicle with spray nozzles will crawl at 2 mph on the marshes of Island shorelines next week, spraying an herbicide expected to eradicate an invasive marsh plant called Spartina alterniflora.
Called the MarshMog, the vehicle is one of the methods the city's public works' contractor is using to spray Imazapyr, a slow-acting herbicide, on the invasive, non-native marsh plants.
"(The herbicide) gets absorbed into the plants, which brown out in the winter months,"said Jim Barse, Public Works Department program specialist.
Other methods include spraying from backpacks and through 300-foot hoses extending from pickup trucks and airboats, he said.
The city started the spraying last week after conducting three public meetings in recent months. It will resume the spraying next week, putting various sections of the shoreway off limits to the public.
Commonly known as the smooth or Atlantic cordgrass, the Spartina alterniflora plant was introduced from the East Coast to San Francisco Bay as part of a marsh restoration plan in the 1970s. It spread to Alameda in the early 1980s, choking out native plants and wildlife.
Over the years, cities and agencies around San Francisco and San Leandro bays have attempted to control the spread of the exotic cordgrass. But its seeds come in from other areas through air and on water, reinfecting treated areas, Barse said.
In the first regional effort to control the spread, Alameda collaborated with the East BayRegional Park District, and the California Coastal Conservancy established the San Francisco Estuary Invasive Spartina Project to help fund the work.
The plan is to eradicate the non-native plant and its hybrids over 89 acres stretching along the shoreline of the bays.
In Alameda , herbicides were applied and completed last week from the 2800 block of Bayview Drive to the Bay Farm Island Bridge .
Not all scheduled work was completed, however, due to weather conditions. The operation will resume Tuesday and Wednesday, working from the 2400 block of Shoreline Drive to the 2600 block of Bayview Drive .
Wind and tide conditions permitting, spraying will continue Monday through Wednesday on the stretch of marshes at Bay Farm Island Shoreline Park from Veterans Court to Shamrock Lane and the Veterans Park shoreline.
Access to pedestrian walkways and bike paths at those locations will be closed, Barse said.
While it is an effective weapon against the weeds, the herbicide's toxicity is almost nonexistent for humans and animals, said Eric Grijalva, fields operation manager of the San Francisco Estuary Invasive Spartina Project in Berkeley .
"It will be toxic the way vinegar would be if you put it in your eyes," he said.
Chemicals such as bleach and gasoline, with which people come into contact on a regular basis, have far more toxicity than Imazapyr, which is registered with the Environmental Protection Agency and the California Department of Pesticide Regulation, Grijalva said. That is because the herbicide attacks only enzymes produced by plants.
Its impact on humans or animals is limited to whether concentrated levels of Imazapyr come in contact with the skin for an extended period of time. For example, if those applying the herbicide wear contaminated gloves for more than 50 consecutive hours, they may get a skin reaction, he said.
For the Spartina eradication, the herbicide has been highly diluted, and its concentration in the water is further reduced by the daily tides, he said.
Elsie Roemer Birds Sanctuary, home to several bird species, is being treated gradually to reduce the impact on the endangered California clapper rail, which populated the non-native vegetation, said Anne Rockwell, East Bay Regional Parks District manager.
In December, the district counted six nesting pairs of clapper rails at the site, she said.
"We need to maintain habitat for the birds," Rockwell said. "We don't want anything too drastic for them."
A couple of sections have been reserved for treatment in later years to allow a transition period for the birds, she said. During that time, native plants, including Spartina foliosa, grindelia and pickleweed, will take the place of the eradicated exotic plant.
"A marsh revegetation cycle will unfold at a good pace," Barse said.
For information on the Invasive Spartina Project, visit http://www.spartina.org.