Islands of lush, green cordgrass wave in the wind
and carpet the shore as lapping waves and foraging
birds dance around their stems. It could be a page
out of an Audubon calendar. But where the untrained
eye sees verdant local marsh life, local biologists
see wave upon wave of an invasive, life-choking mutant
known as Spartina alterniflora, or East Coast cordgrass.
From Elsie Roemer Bird Sanctuary to San Leandro
Bay to the fringes of Bay Farm Island, biologists
say the invasive cordgrass has turned some stretches
of shoreline into ecological deserts.
The city’s Public Works Department teamed
with the California State Coastal Conservancy and
the East Bay Regional Parks District to hold a
public information meeting on the ongoing Spartina
eradication project Wednesday evening at City Hall.
The second phase of the three-year project gets
underway this September.
Although the offending invader has spread throughout
the Bay’s marshlands, it was first introduced
in the 1970s when the Army Corps of Engineers imported
it to shore up Bay Farm Island levees. The East
Coast transplant flourished, growing taller, denser
and faster than the native cordgrass.
Then, sometime in the 1990s, biologists discovered
that nonnative Spartina had hybridized with the
native Pacific Coast species, a fairly rare event,
biologists say. The new mutant strain has since
colonized marsh shorelines around the Bay, flooding
native stands of cordgrass with hybrid pollen.
“We’ve seen an exponential spread
of cordgrass in the marshes,” said Erik Grijalva,
field operations manager for the San Francisco
Estuary Invasive Spartina Project, in an interview
The hybrid occupies about 20 acres of shoreline
in Alameda, and about 1500 acres of marshland Bay-wide,
according to Coastal Conservancy numbers. Alameda
is home to some of the most densely infested sites,
said Grijalva, an Alameda resident.
The hybrid’s mixed genetics allow it to
dominate a wide spectrum of ecological niches in
the marsh, driving out other plants and animals,
like the endangered California clapper rail and
the salt marsh harvest mouse, that depend on a
variety of micro-habitats. “It creates a
dense, monocultural marsh,” Grijalva said.
And Alameda’s Spartina infestation can
have Bay-wide effects, since the many clusters
around the Island act as a seed-source for the
plant’s continuing spread.
But biologists and environmentalists are hoping
to halt its onward march. This September, members
of the Spartina Project, founded in 2000 by the
California State Coastal Conservancy, will refine
their eradication strategy in an attempt to nudge
area marshes back to their native state.
But that won’t be easy. With roots that
delve up to 2 feet into the marsh bottom, manually
removing the invasive cordgrass is not only arduous
work, but all those boots trudging through the
marsh can further damage the habitat. New technologies
for applying a Spartina-killing herbicide might
help, including the use of a Marsh Mog, an amphibious,
GPS-guided vehicle that leaves behind a light footprint.
In addition, the project’s herbicide of
choice, a newer chemical called imazapyr, will
be applied differently this year in attempt to
more effectively target the Spartina hybrid.
But at least one local environmental group has
balked at the idea of adding another chemical to
“We are concerned that not enough studies
have been done on the chemical,” said Sejal
Choksi, program director of Baykeeper, a San Franicsco-based
environmental watchdog group. “What is the
accumulated impact on aquatic species?”
Others offer qualified support for the chemical’s
“We don’t support herbicide use normally,
but in this case it’s a necessary evil,” said
Marilyn Latta, habitat restoration director for
the Save the Bay organization, adding that, in
the case of Spartina, hand-removal just isn’t
Grijalva is confident the herbicide is safe. “It’s
one of the least toxic herbicides on the market,” he
said, adding that the chemical specifically targets
plants’ amino acids, and in such low concentrations,
doesn’t pose a threat to humans or pets.
Even with the project’s increasingly fine-tuned
plan of attack, Grijalva says it’s likely
some of the infestations will return, which can
then be targeted with periodic spot-treatments.
His agency is hoping to eradicate Spartina to the
point where volunteers and land managers can monitor
flare-ups after the program’s state and federal
funding expires in 2007.
Although other Bay habitats present a veritable
soup of invasive species — often hitching
rides into the Bay in the ballast water of container
ships — Grijalva says that with the exception
of Spartina, tidal marshlands are relatively invasive-free,
giving this project a rare chance to fully restore
large sections of shoreline.
“The opportunity we have is to control the
plant and restore the marsh to its native conditions,” Grijalva
said. “We can look forward to a day in the
not-too-distant future when the native marsh is