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Bay Researchers Fight Uphill Battle with Invasive Cordgrass

by on November 21, 2013

An ISP staff member sprays invasive Spartina with herbicide along Alviso Slough, Santa Clara County. Photo: Drew Kerr.
An ISP staff member sprays invasive Spartina with herbicide along Alviso Slough, Santa Clara County. Photo: Drew Kerr.

Three years ago, managers at the Invasive Spartina Project thought they’d be almost out of a job by now. Their remarkable success up to that point in treating one of the most ominous invasive species in the Bay Area had left the once widespread invader, Spartina alterniflora, clinging to just a few dozen acres of scattered marsh. But the ruthlessly fast-spreading cordgrass has never made things easy. It hasn’t spread anymore, but it hasn’t been eradicated either, and after hopeful projections of near complete elimination by 2013, project managers now say it’ll be at least another three years. Despite their achievements, that last push has been the hardest of all.

“The last couple percent of hybrids are really the most difficult to get,” says Invasive Spartina Project treatment manager Drew Kerr. “They are the needle in the haystack.”

Spartina alterniflora, or Atlantic cordgrass, is a Bay invader with an unusual past. While most invasive species arrive in the Bay accidentally, hitchhikers in the ballast waters of ships from all over the world, Atlantic cordgrass was brought here intentionally.

In the 1970s the Army Corps of Engineers planted Spartina alternifolia, a resident of the Atlantic and Gulf Coasts, in an effort to stabilize levees around the South Bay salt ponds. It worked for that purpose – but then the Atlantic cordgrass cross-pollinated with our native species of California cordgrass, Spartina foliosa, creating a race of super-hybrids that were much more gregarious than their predecessors, a common phenomenon known as “hybrid vigor.”

Not only did the hybrids produce more pollen, they had the ability to self-pollinate, hybridizing among themselves and California cordgrass to create a highly fertile “hybrid swarm.”

By the 1980s, the hybrid swarm had suffocated tidal marshes and displaced California cordgrass throughout the Central and South Bay. The unintended consequences of that original planting have bedeviled efforts at Bay restoration since.

“Hindsight is 20-20,” says Marilyn Latta, who manages the Invasive Spartina Project through the California State Coastal Conservancy. “Not only were the hybrids more fertile, they grew taller, and were able to grow both lower in the tidal frame and higher up in the marsh.”

The hybrids, in other words, grew where the natives could not. And once they got cozy, they started making changes. Hybrid spartina plants are “ecological engineers” says Kerr, in that they “profoundly alter the habitat in which they live.”

ISP revegetation work is in full bloom at Cogswell Marsh. A 2011-201212 winter-planted marsh gumplant seedling thrives along the confluence of tidal channels where clapper rails hide, forage, and nest. (Photo by: Marilyn Latta)

ISP revegetation work is in full bloom at Cogswell Marsh. A 2011-201212 winter-planted marsh gumplant seedling thrives along the confluence of tidal channels where clapper rails hide, forage, and nest. (Photo by: Marilyn Latta)

Close to the tide-line, the hybrid swarm clogs channels and makes meadows out of mudflats, eliminating critical habitat for shorebirds and marsh birds, like the endangered California clapper rail, that forage in the mud at low tide. Higher up in the marsh the swarm out-competes native pickleweed, a plant that the endangered salt marsh harvest mouse requires for shelter and salty sustenance. Native California cordgrass was also threatened with local extinction as a result of cross-pollination with the hybrid swarm.

So in 2000, the California Coastal Conservancy partnered with the Don Edwards San Francisco Bay Wildlife Refuge to create the ISP. By the time the new partners had conducted four years of research about how best to counter the hybrid, the invasive cordgrass had spread into 800 net acres and spread widely over most of the Bay’s wetlands, with highest concentrations near the original introduction sites in Alameda and San Mateo counties.

Beginning in 2005, ISP staffers counterattacked with Imazapyr, an herbicide that works by disrupting synthesis of the proteins the plants require for growth. And by 2010, the hybrid swarm had been reduced by 90 percent to less than 100 net acres. That’s when ISP managers projected that, with continued control, up to 90 percent of the remaining 175 sites would have no detectable hybrids by 2013.

But success came with a caveat as biologists in and outside the project worried about the California clapper rail, which had switched from nesting in scarce native grasses to sleeping with the enemy, nesting among the hybrid cordgrass. It became the ultimate damned-if-you-do damned-if-you-don’t problem: the rails were relying on an invasive cordgrass that for now provided excellent habitat but in the long term would choke off the marshes and drive the birds out. So: treat the marsh, kill the Spartina, and leave the rails without cover? Or back off and wait for potential long-term calamity?

“This presented quite a management conflict,” Latta says.

ISP biologist Jeff Lewis, standing next to thriving California cordgrass plantings at the Alameda County Flood Control Channel. 35 seedlings were originally planted in this plot, which have since expanded greatly. Photo by: Marilyn Latta

ISP biologist Jeff Lewis, standing next to thriving California cordgrass plantings at the Alameda County Flood Control Channel. 35 seedlings were originally planted in this plot, which have since expanded greatly. Photo by: Marilyn Latta

In 2011, the U.S. Fish and Wildlife Service (USFWS) began regulating areas that could be treated with herbicide, restricting ISP access to 26 sites around the Bay. By 2012, this was reduced to 11 sites containing the last remaining 20 acres of hybrids. But with the future treatment authorizations unknown, the project timeline for total eradication has been extended by at least three years.

The ISP, in turn, has come up with a potential solution. For the first decade, the project relied mainly on passive dispersal of native seeds on the winds and tides to re-vegetate treated marshland. But to increase clapper rail habitat quickly, the ISP has begun planting native species. They chose 35 sites, mostly in the South Bay, where California cordgrass was at the lowest risk for cross-pollination, areas where the hybrid cordgrass was only found in tiny amounts.

In the last two winters they have planted more than 165,000 California cordgrass and gumplant seedlings.

Kerr and Latta say they hope the restoration efforts will boost clapper rail populations and encourage the USFWS to open up the remaining 20 acres of hybrid-infested land to treatment.

So while it might be frustrating to be so close and – still – so far away, most still consider the project with satisfaction. There have even been some unanticipated bonuses, like observing that native pickleweed happens to be highly resistant to the herbicide. Not just resistant, project managers say, but flourishing in the aftermath: in marshes left to their own devices following treatment, native plants have crept back and reclaimed their lost turf.

“It has been an incredible success story,” Latta says.

Perhaps the best measure of success is that in those limited areas the project has been able to restore native cordgrass to areas where it had been all but wiped out.

“It has come full circle,” Kerr says. “We are back to planting native California cordgrass in sites where original introduction of Atlantic cordgrass took place, which is very gratifying.”

Rachel Diaz-Bastin is a Bay Nature editorial intern.

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Bev Von Dohre on November 23rd, 2013 at 1:26 pm

There is no excuse EVER to use herbicides/pesticides. It’s all about the money. Every poison now banned was once deemed to be safe.

It’s bad enough that they are continuing to poison land and water, including in endangered Clapper Rail habitat, but then for esteemed, important Bay Nature magazine to promote it? Why? They admit the Clapper Rail is using the introduced Spartina. Leave it and them alone.

I’ve seen too much environmental destruction in the name of “environmentalism” already, like what was done to the Burrowing Owl habitat at Cesar Chavez Park in Berkeley.

(The crazed use of unnecessary herbicides in parkland does not inspire confidence. For those who care about the Clapper Rail, please help stop the herbiciding in their tiny habitat at the East Bay Regional Park Martin Luther King Jr. Regional Shoreline, Oakland. This is also an important flyway are. There is not even a pretense of an excuse for this destruction. Every spring you can see they have herbicided a wide swath of land on both sides of the walkway, right up to the bay for no reason whatsoever. This isn’t an area remotely at risk for fire danger. The poison contaminates the water and land, endangering animals and is even killing the few native plants that have been put there. Just west, across the water, at Bay Farm Island, Alameda, an even larger area leading to the bay is sprayed, brown, and dead.

Why are the bay, the land, and those who dare to walk there being subjected to this unnecessary danger? But again, it’s important to know that this is the what is already happening. People are getting money and that is what counts. So how is further poisoning of the bay and land justified? Fish, birds, and other animals will die. The water and land will be permanently poisoned. (The bay is already heavily polluted.) And more people will get cancer and chronic illness. Why?

Attempting to eliminate invasive species does not work. But this species does not seem to be the problem it’s presented as, and if it helps the Clapper Rail, just leave the Spartina and them alone.

Bay Nature Magazine is so important for the Bay Area and usually has such wonderful and helpful information about our environment. PLEASE do not join with those who are making money off adding poison and pollution to what is already damaged. Instead, help our environment recover.

From this site:

Do not apply to ditches used to transport irrigation water. Do not apply where runoff water may flow onto agricultural land, as injury to crops may result. Keep from contact with fertilizers, insecticides, fungicides, and seeds. Do not apply or drain or flush equipment on or near desirable trees or other plants, or on areas where their roots may extend, or in locations where the chemical may be washed or moved into contact with their roots. Do not use on lawns, walks, driveways, tennis courts, or similar areas. Prevent drift of spray to desirable plants. Do not use in California.


Bev Von Dohre on November 23rd, 2013 at 2:01 pm

This article is missing some critical FACTS that would help Bay Nature readers evaluate this destructive project.

Spartina alterniflora has been in the San Francisco bay much longer than Bay Nature reports. It was first introduced with shipments of eastern oysters early in the 20th century. S. alterniflora was also introduced to several harbors in Europe over one hundred years ago without spreading as Bay Nature predicts. Dire predictions of harmful spread of this species are not consistent with the facts.

Hybridization is a natural phenomenon that accelerates when there are radical changes in the climate. It is one of the basic tools of natural selection and evolution. Scientific studies report that hybridization results in greater biodiversity by facilitating speciation. The resulting species are better adapted to changes in the environment.

S. alterniflora provides greater protection against the storm surges associated with climate change because it grows taller, more densely, and it does not die back in winter as native spartina does. It therefore represents a beneficial adaptation to changes in the environment.

The clapper rail is an endangered species which has benefited from superior cover provided by non-native spartina. Planting more native spartina will not provide the same cover for this legally protected bird.

Hundreds of gallons of imazapyr are being used by this destructive project. East Bay Regional Park District reports using 203 gallons of imazapyr in 2009 and 121 gallons in 2010 for the purpose of eradicating spartina. (They haven’t published pesticide use reports since 2010). EBRPD is only one of the many owners of public land in the Bay Area that are engaged in this project. Imazapyr is both mobile in the soil and persistent. For that reason it has been banned by the State of New York because of concern about poisoning their water table.

Bay Nature would be wise to interview people who are not employed by these destructive projects before publishing such articles. Bay Nature is not providing the public with a balanced view that reflects both scientific facts and public opinion. The fact is, most “invasions” are temporary. They are usually quickly resolved by entering the food web or other natural adaptations. The scare tactics used to justify these destructive projects are not supported by the facts.

Linda Giannoni on November 24th, 2013 at 1:03 pm

I agree that applying poison is always a mistake. We are living in denial if we believe the reassurances of studies saying that any pesticide is safe or not so bad. These conclusions typically are published by the manufacturers or other self-interested parties who have themselves funded and controlled the research.

Drew Kerr is quoted as saying that hybrid Spartina plants “…profoundly alter the habitat in which they live.” It’s humans who are most profoundly altering, actually destroying, the habitat in which we and all others live. And the Spartina planting and attempted eradication is a good example. First a mistake is made while artificially manipulating the natural environment for human use, and then later a far worse mistake is made by poisoning a huge area for years. Let nature balance itself out over time.

Even the U.S. Fish and Wildlife Services has restricted ISP’s pesticide applications, and yet ISP wants to reverse that decision!

Some questions that need to be answered about any project like the ISP:
1. How much does the project cost, and who profits along with the manufacturer of the pesticide?
2. How much do the decision makers and administrators make as compared to the employees who apply the poison and bear the risk of health damage?
3. How could the funding be redirected to support healthful projects that truly protect the environment, training existing employees to work in those projects?
4. How many animals in the sprayed areas have suffered and/or died from poisoning? (Including aquatic creatures, birds and mammals.) How many other plants have been killed, including native plants? How many humans, including children, have been harmed? Again, I don’t trust reassurances from manufacturers and authorities. Poison is used because it’s toxic, harms and kills. There is no OK poison.
5. Is it a coincidence, or not, that pesticide companies began to fund and promote the native plant movement and the language of “invasive” species as public demand increased for organic food, organic farming and organic gardening?

Bay Nature usually does a beautiful job of promoting love for nature. This article supporting ISP pesticiding contradicts this value. We don’t poison those we love, not for expediency, not for money, not for the anesthesia of denial.

Thank you for the opportunity to comment.

fritzi cohen on November 25th, 2013 at 2:58 pm

Well, If I were a clapper rail i probably would prefer to “sleep with the enemy”. I fought the use of pesticides in Willapa Bay for over 20 years. Despite what you all may think, since spartina alterniflora hugs the shoreline, has to be above water half the time its growth was limited. Now that it is almost gone the aquaculture industry is going to use the space for non-native clams. The comment that follows is a sad deja vue for me. i.e.”But the ruthlessly fast-spreading cordgrass has never made things easy. It hasn’t spread anymore, but it hasn’t been eradicated either, and after hopeful projections of near complete elimination by 2013, project managers now say it’ll be at least another three years. Despite their achievements, that last push has been the hardest of all.”
In Willapa Bay getting rid of it with pesticides was supposed to take a few years, after more than 20 and combining imazapyr with glyphosate they have now appointed deputies to check the bay routinely for sprigs. I myself have been reported by neighbors for having some sprouts that I believe actually came from grass went to seed before it was sprayed. We have been very successful in mowing spartina, and preventing it from seeding.
What intrigues me is that California followed suit with Willapa Bay. I’ve always said that bad science travels like a virus and this was a very good example of that. But FYI, the industry that went after spartina has been going after the native ghost shrimp for over 60 years by spraying carbaryl. They are resisting the court order to stop using carbaryl and are trying to get imadicloprid registered. For those of you who haven’t heard about this pesticide, its been banned in many European countries because its been implicated in bee collapse. Moreover these same aquaculture people are now going after Japanese eelgrass which californians may not like as well. They got it delisted as a protected species and are now trying to get a pesticide called imazamox registered.
I think the clapper rail used good sense, but I guess that the people who hate spartina alterniflora decided that nature does not know best.

Richard Drechsler on December 8th, 2013 at 11:15 am

It appears to me (and others who commented) that the purpose of this article is to aggrandize Imazypyr and other chemicals as a means of controlling/killing wildlife.

Several publications, including one published by Point Reyes Bird Observatory, say that Spartina eradication efforts have cost the Clapper Rail their habitat in parts of SF Bay. “Hoping” (as you say) that the Rails return to an improved habitat created by the ISP is optimism, not an indicator of project success.

In July, 2010 I spotted a (radio-tagged) Clapper Rail in Heron’s Head Park that is located on the southeast waterfront of San Francisco. This is already an environmentally troubled area. The park is encircled by a Navy superfund toxic cleanup site; a PG&E toxic cleanup site and at least two debris/waste recycling facilities.

A Clapper Rail had not been seen in SF for 30 years. I investigated the bird’s origin and learned through the U.S Geological Survey that it had been tagged at the Colma Creek Marsh. Along with three other Clapper Rails, it fled from Colma Creek at the time of a Spartina eradication project.

It is likely that not one, but two of these Clapper Rails landed at Heron’s Head Park that spring, because in the summer of 2011 two juvenile birds along with their parents were reported. SF birders had high hopes that Heron Head Park could now support a new population of this endangered species.

But in the Fall of 2012 a small stand of Spartina was discovered at Heron’s Head Park. Instead of removing it manually, the method used by land stewards in the past, The Port of San Francisco approved the use Imazypyr by the ISP. The reason given was that using Imazypyr was more cost effective than removing it by hand.

It has now (12/4/13) been more than 14 weeks since the last sight or sound of a Clapper Rail has been reported at Heron’s Head Park.

The case of the Clapper Rail in SF Bay makes me wonder how the Endangered Species Act is enforced and how many organizations have been given the right to violate it.

I find it troubling that this article tries to position Imazypyr as a fertilizer for Pickleweed (and presumably other related plants). The article doesn’t tell the reader how many gallons of this poison have been dumped into our environment; how incomplete the testing has been on its effects on high order life forms; and how catastrophic its effects may be on life forms that have yet to be classified.

Finally, the article does not tell us why the Army Corp of Engineers (in the 1970’s) chose to use Spartina Alterniflora and not Spartina Foliosa (Pacific Spartina). Was flooding and storm surge a greater threat back then than it is now?

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