imazapyr – Conservation Sense and Nonsense

Spartina eradication: Herbicides are their dirty little secret

This is a good news/bad news story about the eradication of non-native Spartina marsh grass and the impact it has had on the population of endangered California Clapper Rail:

Spartina alterniflora, Smooth Cordgrass. USDA photo

The good news: US Fish & Wildlife has temporarily halted efforts to eradicate non-native Spartina (Spartina alterniflora) in the San Francisco Bay Area because the population of endangered California Clapper Rail has declined by 50% during the period of eradication efforts from 2005 to 2011. (1) This problem was identified several years ago and was attributed to the lack of cover for the rail as a result of eradication of non-native Spartina, which grows more densely, taller, and doesn’t die back in winter as the native Spartina does. (2)
The bad news: US Fish & Wildlife attributes this negative impact on the Clapper Rail population on the slow recovery of native Spartina (Spartina foliosa).
Spartina foliosa – USFWS

They do not acknowledge that non-native Spartina provides superior cover compared to the native species. Nor do they acknowledge that non-native Spartina was killed with herbicides. Therefore, they do not consider the possibility that the slow recovery of native Spartina may be attributable to the herbicides that were used to kill the non-native plant. They also continue to claim that the recovery of the endangered California Clapper Rail depends upon the return of native Spartina, despite the overwhelming evidence to the contrary. The California Clapper Rail is a sub-species of Clapper Rail; the Clapper Rail is abundant on the East and Gulf Coasts and not endangered perhaps because of the superior cover provided by Spartina alterniflora on those coasts. (3) Based on these fictions, US Fish & Wildlife proposes a new strategy that will simultaneously eradicate non-native Spartina while intensively planting native Spartina. (1)

We have been following the Spartina eradication project since 2011. For the benefit of new readers, we will review the issues with a few excerpts from previous posts on Million Trees.

Spartina alterniflora: Treasured on the East Coast, reviled on the West Coast

Spartina alterniflora (Smooth Cordgrass) is a species of marsh grass native to the Atlantic and Gulf coasts of the United States, where it is considered a valuable plant making important contributions to the coastal ecology:

Its dense growth provides protection against storm surge and “erosion control along shorelines, canal banks, levees, and other areas of soil-water interface.” (4)
It filters nutrients, sediments and toxins from the water that flows off the land before reaching the ocean, acting as a natural water treatment facility.
It provides cover and food for birds, mammals and marine animals that live in the coastal marsh.

Where Smooth Cordgrass has died back in its native range, the dieback has been considered a serious environmental threat:

In 2001 the Governor of Louisiana declared a “state of emergency” when Smooth Cordgrass declined and the state obtained $3 million of federal funding to study and hopefully reverse the decline. This study resulted in the development of a method of aerial seeding of Smooth Cordgrass to restore declining areas of marshland. (5)
A similar, but smaller dieback of Smooth Cordgrass in Georgia led to a collaborative research and on-going monitoring effort by 6 research institutions in Georgia.
Similar dieback of Smooth Cordgrass has been reported as far north as the coast of Maine. A researcher at the Connecticut Agricultural Experiment Station is quoted in that report as saying, “In New Orleans, if their marshes were intact, the storm surge of Katrina would not have reached the levees.” (6)

The war on Smooth Cordgrass on the West Coast

Smooth Cordgrass is not native on the Pacific Coast of the United States. Therefore it is treated as an alien invader to be eradicated with herbicides:

$24 million was spent to eradicate Smooth Cordgrass in San Francisco Bay and Willapa Bay from 2000 to 2010 (7)
$16.3 million is projected to be spent on the entire West Coast from 2011 to 2020 (7)

Spartina is being eradicated with an herbicide, imazapyr. This is a new herbicide about which little is known. The analysis that was done to justify its use in the Spartina eradication project admits that no studies have been done on its effect on shorebirds, including the endangered Clapper Rail.

The Material Safety Data Sheet mandated by the Environmental Protection Agency tells us that imazapyr is “not readily biodegradable.” So, in the event that we eventually learn that this herbicide is harmful to shorebirds and/or to us, we probably should assume that it will still be in the environment in the nearly 200 sites in the San Francisco Estuary on which it has been sprayed. Imazapyr is also being sprayed–sometimes from helicopters–in hundreds of places along the West Coast, including Oregon and Washington.

Imazapyr is often mixed with glyphosate by the Spartina eradication project. Glyphosate is a non-selective herbicide. That is, it kills any plant it is sprayed on at the right stage of its growth. But imazapyr is far more insidious as a killer of plants because it is known to travel from the roots of the plant that has been sprayed to the roots of other plants. For that reason, the manufacturer cautions the user NOT to spray near the roots of any plant you don’t want to kill. For example, the manufacturer says explicitly that imazapyr should not be sprayed under trees, because that tree is likely to be killed, whether or not that was the intention.

Furthermore, no tests have been conducted on the toxicity of combining multiple pesticides in a single application. Therefore, we know nothing about the possible synergistic effects of combining imazapyr and glyphosate.

These facts about the herbicides used to eradicate non-native Spartina bear repeating. The main herbicide being used is known to be mobile in the soil and persistent in the environment. The herbicide with which it is often mixed is an indiscriminate killer of any plant on which it is sprayed. Therefore, the likelihood that these herbicides will prevent the establishment of the new plantings of native Spartina should be taken into consideration. The entire enterprise seems deeply flawed, both harmful and futile.

Bringing it home to the Bay Area

So, what does this have to do with you? If you are concerned about pesticide use, you might be interested in the fact the East Bay Regional Park District (EBRPD) used 203 gallons of imazapyr in 2009 and 121 gallons in 2010 for the sole purpose of eradicating Spartina on their properties. We don’t know how much imazapyr EBRPD used in 2011, 2012 and 2013, because they haven’t published a report of pesticide use since 2010. Since their properties are only on the east side of the San Francisco Bay, we should assume that at least that much imazapyr was used by land managers on the west side of the Bay.

Displacement of Clapper Rails in San Francisco

California Clapper Rail. British Wikipedia

In July 2011, a Clapper Rail was seen and photographed at Heron’s Head in southeastern San Francisco. There was quite a bit of excitement about this sighting because a Clapper Rail had not been seen in San Francisco for decades. That excitement dissipated when we learned more about where this bird came from, which provided a probable reason for its arrival.

The Clapper Rail was wearing a radio collar that had been put on him and 109 other rails by the USGS to track their movements. He had moved from Colma Creek, 11 km south of Heron’s Head, which is one of nearly 200 Spartina “control sites” in the San Francisco Estuary. The bird sighted at Heron’s Head is one of three Clapper Rails that have left Colma Creek since 2007, when the radio collars were placed. The Spartina control project has been going on for over 10 years, so we have no way of knowing how many Clapper Rails were displaced prior to 2007. In 2012, non-native Spartina at Heron’s Head was sprayed with herbicides. Where did the Clapper Rails go from there? Was there anywhere left for them to hide?

Pesticide Application Notice, Heron's Head, 2012 — Pesticide Application Notice, Heron’s Head, 2012

As our readers know, native plant advocates claim their “restoration” projects benefit wildlife. They can offer no evidence for this claim. But there is considerable evidence that proves them wrong. The endangered California Clapper Rail is one such case.

(1) Adam Lambert et.al., “Optimal approaches for balancing invasive species eradication and endangered species management,” Science, May 30, 2014, vol. 344 Issue 6187

(2) “West Coast Governors’ Agreement on Ocean Health, Spartina Eradication Action Coordination Team Work Plan,” Released May 2010, page 12

(3) Cornell Ornithology Lab: http://www.allaboutbirds.org/guide/clapper_rail/id

(4) “Smooth Cordgrass,” USDA/NRCS Plant Fact Sheet.

(5) Dorset Hurley, “Geogia’s Marsh Die Back and Louisiana’s Marsh Browning,” Altamaha Riverkeeper

(6) “What’s killing off our salt marshes,” Going Coastal Magazine, September 15, 2008

(7) “West Coast Governor’s Agreement on Ocean Health,” May 2010, page 5-6

When the cure is worse than the disease: Incompetent pesticide use

One of our readers sent us a link to an article about a “restoration” project gone awry in his neighborhood. Mount Baldhead is a city-owned park in Saugatuck, Michigan. US Fish & Wildlife funded a $700,000 federal grant to eradicate non-native plants on Mount Baldhead and several other municipal parks in the area. The grant was used to hire “certified applicators” to spray the non-native plants with imazapyr. Mount Baldhead was sprayed in summer 2010 and again in fall 2011. In spring 2012, the native oaks and maples, under which the non-native plants had grown and were sprayed, began to show signs of damage. Now a significant portion of the native forest is leafless and barren.

Mount Baldhead, Saugatuck, Michigan. A clearer view of the damage is available in the article to which we provide a link. We were denied permission to publish that picture. — Mount Baldhead, Saugatuck, Michigan. A clearer view of the damage is available in the article to which we provide a link above. We were denied permission to publish that picture.

The soil on Mount Baldhead is being studied to determine how far the pesticide has seeped into areas where it was not sprayed. This information may predict the extent of the eventual damage to the native forest. The ultimate fate of the trees that have been damaged is not known. There is no antidote to the pesticide. Will the trees survive? We don’t know yet.

What does it mean to be a “certified applicator” of pesticides?

This story is of interest to us because imazapyr is being widely used in the San Francisco Bay Area and its use has increased substantially in the past year.

Because imazapyr is being used heavily, we have read the manufacturer’s label for the formulated products (Habitat and Polaris) and the federally mandated Material Safety Data Sheet.

Therefore, we know that imazapyr should not be sprayed under trees you do not want to kill. This is a product that is mobile in the soil. It is capable of traveling from the roots of the plant on which it is sprayed into the roots of adjacent plants on which it has not been sprayed, killing or damaging plants that were not the intended targets of the spraying.

In December 2011, we witnessed imazapyr being used in San Francisco’s public parks for the first time. It was being sprayed on cape ivy under native willow trees. We doubt that the willows were the intended targets of the spraying since they are native. We wonder if the willows will survive in the long run.

These incidents make us ask what, if anything, it means to be a “certified applicator” of pesticides. Does the certification require the applicator to read the manufacturer’s label? If so, does the certification require the applicator to actually follow the directions on the manufacturer’s label? Clearly, this isn’t happening and there don’t seem to be any consequences for the “certified applicator” who kills plants and trees that he/she wasn’t hired to destroy. So, we conclude that such certification is meaningless.

The Million Trees mantra

Native plant advocates believe their projects benefit the environment. We do not see the benefit they claim. This is what we see:

• Increasing use of toxic pesticides is required to kill non-native vegetation. These pesticides are inherently hazardous and their incompetent use makes them even more hazardous.
• The wildlife that lives in our open spaces is being poisoned by these pesticides and they are losing their homes and their sources of food.
• The results of these projects do not justify these dangerous practices. The projects often look more dead than alive.

Ivy Eradication: A Comedy of Errors

When the concert meadow in San Francisco’s Stern Grove was renovated in 2005, at a cost of $15 million, we were surprised that ivy was planted as the ground cover because ivy grows rampant in Stern Grove, shrouding many of the trees. But, hey! Who are we to question the choices of horticultural professionals?

Now ivy is being sprayed with herbicide–presumably with the intention of killing it–by San Francisco’s Natural Areas Program in other parks in San Francisco, so one wonders if the staff who plant it are aware of the future of the ivy they plant. Seems like another case of man creating problems which he then must solve. Perhaps full employment is the objective, rather than the creation of a beautiful garden. But we digress.

Combining pesticides

Many members of the public are of the opinion that all pesticide (herbicides, insecticides, etc.) applications are inappropriate in a park that has been designated as a “natural area.” Last year, the public complained about the spraying of Garlon in the natural areas by the Natural Areas Program because it is classified by the city’s Integrated Pest Management (IPM) policy as “Most Hazardous.” Consequently, the Natural Areas Program significantly reduced its use of Garlon in 2011.

For the most part they have substituted a mixture of glyphosate and imazapyr for Garlon. Is this an improvement? Maybe not. Although glyphosate and imazapyr have a lower hazard rating of “More Hazardous,” the Natural Areas Program increased their pesticide applications in 2011 at least 20% compared to 2010. But more importantly, little is known about the toxicity of imazapyr and nothing is known about the toxicity of combining glyphosate and imazapyr.(1) Imazapyr was approved for use in California in 2005, so only the minimal tests required by law have been done on it.

The manufacturer’s labels for these herbicides suggest that combining them is not an approved use. The label for Aquamaster (glyphosate) does not include imazapyr on the list of pesticides with which it can be safely combined. And the Polaris (imazapyr) label says it should not be combined with another pesticide unless it is expressly recommended by the manufacturer of that pesticide.

The “Aquatic Pesticide Application Plan for the San Francisco Estuary Invasive Spartina Project” is cited by San Francisco’s IPM program as the evaluation upon which it based its decision to add imazapyr to the list of pesticides approved for use in San Francisco in 2010. The evaluation explained why imazapyr is being combined with glyphosate by the non-native Spartina eradication project.

Imazapyr is apparently slow acting. It can take some months before it kills the plant on which it is sprayed. Glyphosate, on the other hand, is fast acting. The plant on which it is sprayed begins to yellow and die within a few weeks. Glyphosate is therefore used by the Spartina eradication project to provide quicker feedback to those spraying the herbicide. They know within a few weeks if they have sprayed in the right place. They don’t have to wait for the next season to spray again if necessary.

Pesticide Application Notice - Glen Park - 12-11 — Pesticide Application Notice, Glen Canyon Park, December 2011

However, glyphosate should be applied to perennial broadleaf plants during their reproductive stage of growth, when they are budding in the late spring and summer, according to the manufacturer. In Glen Canyon Park, a mixture of glyphosate and imazapyr was sprayed on ivy in December 2011, clearly not the recommended time period for spraying. A month later, there is no indication that the ivy was damaged by this spraying. This suggests that there was no point in combining glyphosate and imazapyr in this application. The public was exposed to the unnecessary risk of combining these herbicides, with no potential benefit of taking that risk.

Pesticides accumulate and persist in the soil

Was it appropriate for the city’s IPM program to use the evaluation of imazapyr for the Spartina project as the basis of their decision to approve its use by the Natural Areas Program? We don’t think so. The circumstances of the Spartina project are substantially different from those of its use by the Natural Areas Program.

Imazapyr is used to eradicate non-native Spartina in a tidal estuary. For that reason the evaluation of its use assured the public that this herbicide would not accumulate in the environment because it would be flushed away from the ground by the tide twice each day.

The evaluation also said that when imazapyr was used in a pond or stable water source, it persisted in the ground for a longer period of time. In fact, that’s exactly how imazapyr is being used by the Natural Areas Program. It has been used at Lake Merced and at Pine Lake, both stable water sources. It is also being used in Glen Canyon Park, which is a watershed.

We don’t assume that imazapyr is being used safely to eradicate Spartina. However, even if it is, it does NOT follow that it is safe for use in watersheds that are not tidal, such as those being sprayed by the Natural Areas Program.

Collateral damage of pesticides

Glyphosate is a non-selective herbicide. That is, it kills any plant it is sprayed on at the right stage of its growth. But imazapyr is far more insidious as a killer of plants because it is known to travel from the roots of the plant that has been sprayed to the roots of other plants. For that reason, the manufacturer cautions the user NOT to spray near the roots of any plant you don’t want to kill. For example, the manufacturer says explicitly that imazapyr should not be sprayed under trees, because that tree is likely to be killed, whether or not that was the intention.

Glen Canyon setting of pesticide application 12-11 — Pesticide Application Notice under willow trees in Glen Canyon Park, December 2011

Much of the ivy that was sprayed by the Natural Areas Program in Glen Park in December 2011 was sprayed under willow trees. The willow trees are native, so it seems unlikely that they intended to kill them.

Resistance to pesticides

The Federal Drug Administration recently banned some use of antibiotics in domesticated animals because the bacteria antibiotics are intended to kill are developing resistance to the antibiotics. This resistance is becoming increasingly dangerous to humans who are also the victims of those bacteria. Antibiotics are being rendered useless by overuse on domesticated animals. When humans need them, they won’t work because bacteria have developed a resistance to them.

Likewise, plants and animals are also capable of developing resistance to pesticides. Glyphosate is the most heavily used herbicide in agriculture. Recent research indicates that weeds are developing resistance to glyphosate.

The manufacturer of imazapyr says explicitly that repeated use of this herbicide is likely to result in resistance to it over the long term: “When herbicides with the same mode of action are used repeatedly over several years to control the same weed species in the same application site, naturally occurring resistant weed biotypes may survive…propagate and become dominant in that site.” So, does it make sense to use imazapyr on a plant as persistent as ivy?

The GGNRA reported spending $600,000 over 3 years trying to eradicate ivy from 127 sites. They were successful in only 7 of the sites.(2) Obviously eradicating ivy is not a one-shot deal.

If ivy must be eradicated, pesticides do not have to be used to do it. The Audubon Canyon Ranch in Bolinas Lagoon reported “qualified” success using hand-pulling methods on 5 acres over 5 years “utilizing 2375 volunteer hours.” Biannual monitoring of resprouts will be required for the foreseeable future. It’s a big commitment, but at least it is safe.

All risk, no reward

Congratulations to any reader with the patience to slog through this tedious list of apparently incompetent use of pesticides by San Francisco’s misnamed Natural Areas Program. We reward your persistence with this summary:

Combining pesticides is risky business because the toxicity of such combinations has not been tested. Therefore, when there is no benefit in doing so, these combinations should be avoided.
A pesticide that is appropriate for one purpose is not necessarily appropriate for another. In this case, imazapyr may not accumulate and persist in a tidal estuary, but it is more likely to do so in a stable watershed.
The Natural Areas Program may be killing plants it does not intend to kill by using herbicides indiscriminately.
Herbicides should not be used repeatedly on the same plants in the same locations because the plants will develop resistance to those herbicides.
If the Recreation and Park Department is planting ivy in one park and destroying it another, could it be such a bad plant that it is worthwhile to expose the public to toxic pesticides? We don’t think so, but if we are wrong, then ivy should be removed by hand without using pesticides.

(1) “Aquatic Pesticide Application Plan for the San Francisco Estuary Invasive Spartina Project,” August 2010, page 32.

(2) Liston, Heather, “Reuniting old adversaries can beat back exotic invaders,” California Wild, Winter 2006

Nativism is shooting us in the foot

A few months ago, we told you about one of the many projects to eradicate a plant species that is considered non-native. In this case, smooth cordgrass (Spartina alterniflora) is native to the East and Gulf coasts of the US, but is considered non-native on the West Coast, despite the fact that it has been here for over one hundred years. About $12 million was spent in the past 10 years on this effort, and the projection is that another $16 million will be spent in the next 10 years.

California Clapper Rail. British Wikipedia

When we told you about this project, we speculated that it was having a negative effect on an endangered species, the Clapper Rail. The non-native Spartina provides cover that is superior to the native variety of Spartina. It grows more densely and it doesn’t die back during the winter months, as the native variety does. We also pointed out that the Clapper Rail is abundant on the East and Gulf coasts and is only considered endangered on the West Coast.

Since we told you about this eradication project, we’ve learned a few things about the Clapper Rail that we hope will interest you, as it does us.

This seems to be another case in which native plant advocates are looking for a scapegoat, when they should be looking at themselves. Native plant advocates would like you to believe that the Clapper Rail is endangered on the West Coast because of the introduction of non-native red fox. The red fox is yet another creature that nativists wish to eradicate in the Bay Area. Apparently it has not occurred to them that the red fox is native to the East Coast, where the Clapper Rail is thriving. Hmmm, that seems like a bit of contradiction, No?
We have learned of the displacement of Clapper Rails from marshes in which the non-native Spartina in being eradicated.
The Point Reyes Bird Observatory, a nationally recognized institution that conducts research on birds, has concluded that the Spartina eradication project is having a negative effect on the Clapper Rail.

Evidence that eradication of Spartina alterniflora is harmful to Clapper Rails

In July, a Clapper Rail was seen and photographed at Heron’s Head in southeastern San Francisco. There was quite a bit of excitement about this sighting because a Clapper Rail had not been seen in San Francisco for decades. That excitement dissipated when we learned more about where this bird came from, which provided a probable reason for the move.

The Clapper Rail was wearing a radio collar that had been put on him and 109 other rails by the USGS to track their movements. He had moved from Colma Creek, 11 km south of Heron’s Head, which is one of nearly 200 Spartina “control sites” in the San Francisco Estuary. The bird sighted at Heron’s Head is one of three Clapper Rails that have left Colma Creek since 2007, when the radio collars were placed. The Spartina control project has been going on for nearly 10 years, so we have no way of knowing how many Clapper Rails were displaced prior to 2007.

In October 2011, the Point Reyes Bird Observatory issued the first-ever “State of the Birds Report for San Francisco Bay:” “Based on decades of monitoring, 29 partners detail the actions needed to keep birds and their habitats thriving as sea levels rise and extreme storm events increase due to global climate change.” This report acknowledges the role that the Spartina eradication project plays in the continuing decline of the population of Clapper Rails in the Bay Area:

“The Clapper Rail’s rebound during the 1990’s was possibly due to fox control but also coincided with the rapid invasion of a tall non-native plant (invasive Spartina). This invader benefited rails because it provided nesting habitat and protection from predators and high tides. Beginning in the mid-2000s, the rail population declined sharply, due in part to the removal of invasive Spartina, which threatens tidal flat and marsh ecosystems as a whole. This recent decline may be leveling off, but the future of Clapper Rails in San Francisco Bay remains tenuous.”

This is another example of the harmful obsession with non-native plants, which seems to trump other considerations, such as the welfare of the animals that benefit from the plants. As is often the case with such eradication projects, Spartina is being eradicated with an herbicide, imazapyr. This is a new herbicide about which little is known. The analysis which was done to justify its use in the Spartina eradication project admits that no studies have been done on its effect on shorebirds, including the endangered Clapper Rail. The Material Safety Data Sheet mandated by the Environmental Protection Agency tells us that imazapyr is “not readily biodegradable.” So, in the event that we eventually learn that this herbicide is harmful to shorebirds and/or to us, we can be assured that it will still be in the environment, in the nearly 200 sites in the San Francisco Estuary on which it is currently being sprayed. Imazapyr is also being sprayed–sometimes from helicopters–in hundreds of places along the West Coast, including in other states. (A new post on Save Sutro reports more alarming information about imazapyr.)

The cost of nativism

This is an example of the harmful effects of attempting to eradicate non-native species. It reminds us of a recent editorial in the New York Times about the new law in Alabama which is considered the most extreme anti-immigration law in the country. The opponents of immigration are delighted with the new law. The farmers of Alabama are warning us that they cannot replace the immigrants who are fleeing the state. Most of the work in the country’s agriculatural fields and orchards is being done by immigrants. These are jobs that Americans are no longer willing to do. This is just one of many unintended consequences of such xenophobic extremism. We consider the Spartina eradication project another example of nativism run amok.

Spartina alterniflora: Treasured on the East Coast, reviled on the West Coast

Its dense growth provides protection against storm surge and “erosion control along shorelines, canal banks, levees, and other areas of soil-water interface.”(1)
It filters nutrients, sediments and toxins from the water that flows off the land before reaching the ocean, acting as a natural water treatment facility.
It provides cover and food for birds, mammals and marine animals that live in the coastal marsh. Many other marsh plants occupy the same marshlands.
Spartina alterniflora, Smooth Cordgrass. USDA photo

Where Smooth Cordgrass has died back in its native range, the dieback has been considered a serious environmental threat:

In 2001 the Governor of Louisiana declared a “state of emergency” when Smooth Cordgrass declined and the state obtained $3 million of federal funding to study and hopefully reverse the decline. This study resulted in the development of a method of aerial seeding of Smooth Cordgrass to restore declining areas of marshland.(2)
A similar, but smaller dieback of Smooth Cordgrass in Georgia led to a collaborative research and on-going monitoring effort by 6 research institutions in Georgia.(3)
Similar dieback of Smooth Cordgrass has been reported as far north as the coast of Maine. A researcher at the Connecticut Agricultural Experiment Station is quoted in that report as saying, “In New Orleans, if their marshes were intact, the storm surge of Katrina would not have reached the levees.”(4)

The war on Smooth Cordgrass in the West Coast

Smooth Cordgrass is not native on the Pacific Coast of the United States. Therefore it is treated as an alien invader to be eradicated with herbicides:

$24 million was spent to eradicate Smooth Cordgrass in San Francisco and Willapa Bay from 2000 to 2010 (5)
$16.3 million is projected to be spent on eradication efforts on the entire West Coast from 2011 to 2020 (6)

In 2006, 2,000 acres were treated with herbicides to eradicate Smooth Cordgrass in the San Francisco Estuary. Most were retreated 3 to 5 times after initial treatment. In 2010, twenty five sites were slated for retreatment, usually with herbicides. The San Francisco Estuary Invasive Spartina Project (ISP) “defines a need for a zero tolerance threshold on invasive Spartina in the San Francisco Bay.”(7)

The ISP reports that imazapyr (Habitat) will be used in most sites, although it will sometimes be mixed with glyphosate (Roundup). (See SaveSutro for more information about imazapyr and its use in San Francisco.) The ISP acknowledges that:

“little is known about the interactive effects” of combining these herbicides or any of the surfactants used with these herbicides.
These herbicides will be applied using a variety of methods, including aerial spraying by helicopter.
Although the ISP considers imazapyr a relatively non-toxic herbicide, it also acknowledges that imazapyr has only been used since 2005. Therefore, “Only few toxicity studies exist for birds…no data exist for the potential toxicity of imazapyr to shorebirds.”(8) Given that one of the stated purposes of eradicating Smooth Cordgrass is to benefit the endangered Clapper Rail, it seems surprising that nothing is known about the effects of imazapyr on any shorebird, including the Clapper Rail.

Why is Smooth Cordgrass treasured on the East Coast and reviled on the West Coast? That question was asked and answered by Professor James Morris at an Environmental Law Conference in Eugene, Oregon on March 5, 2011. Professor Morris studies Smooth Cordgrass at the Baruch Institute for Marine & Coastal Sciences at the University of South Carolina. We urge our readers to watch a video of his presentation to the conference in Oregon. We will draw upon that video in addressing the claims (9) made by those who are attempting to eradicate Smooth Cordgrass on the West Coast:

Indictment: Smooth Cordgrass will invade mud flats, eliminating valuable habitat for plants and animals that inhabit that segment of marshland.

Defense: According to Professor Morris, Smooth Cordgrass was introduced to the West Coast in shipments of Eastern oysters over 100 years ago without eliminating mudflats. Europe has had similar experience with Smooth Cordgrass which was introduced there to reduce sediment in harbors. Professor Morris showed pictures of Danish and Dutch estuaries in which Smooth Cordgrass has existed since the 1930s without radically altering the composition of the marshland.

Indictment: Smooth Cordgrass will invade waterways, making them impassable.

Defense: Again, since this has not happened in 100 years, there is no reason to assume it will happen in the future. Furthermore, the USDA describes the narrow range of Smooth Cordgrass: “the width and thickness of vegetative colonies are controlled by a number of site specific conditions such as elevation, shoreline slope, and frequency, depth and duration of flooding” as well as salinity and acidity. In other words, the range of Smooth Cordgrass is limited.

Indictment: Smooth Cordgrass does not provide habitat value equal to the native species of cordgrass with which Smooth Cordgrass competes, particularly for the endangered Clapper Rail.

Defense: Mike Casazza at the Dixon Field Station of the USGS is presently studying the effect of eradicating Smooth Cordgrass on the reproductive success of the Clapper Rail: “Removal of invasive Spartina accomplishes the goal of Spartina eradication, but if rails fail to survive and reproduce, then the goal of species protection is unfulfilled…the potential for impact from invasive Spartina removal and the potential for mitigation by rail ecology and behavior remain poorly understood.”(10) Clapper Rails live in Smooth Cordgrass on the East Coast: “numerous” Clapper Rail families were observed nesting in Smooth Cordgrass on Dewees Island, South Carolina.(11)

Indictment: Smooth Cordgrass is outcompeting the native Pacific Cordgrass (Spartina foliosa) by displacement and hybridization.

Defense: This is probably true because of the characteristics of the Pacific Cordgrass: “S. foliosa occupies a very limited range in the intertidal zone, and the leaves and stems wither in fall and shed in the winter, leaving sparse standing matter that is ineffective at trapping sediment. Seedlings of S. foliosa are seldom found in established marshes and appear only intermittently in sheltered upper mudflats.”(12) In other words, the range of the native cordgrass is narrower, it does not grow as densely, and it is not foliated year around, thereby creating opportunities for the non-native cordgrass to occupy bare ground. Since marsh grasses are beneficial to the environment and its inhabitants, the ability of Smooth Cordgrass to occupy this vacuum seems a benefit, particularly since native cordgrass is less capable of removing sediments from water, reducing its effectiveness as a filter of pollutants from water flowing into the bay.(13)

Smooth Cordgrass is treasured on the East and Gulf Coasts because it performs valuable ecology services. Although it performs the same ecological functions on the West Coast, it is being eradicated. The evidence available to us suggests that we are spending a lot of money and effort, as well as using a lot of herbicides, to eradicate Smooth Cordgrass only because it is not native to the West Coast.

Smooth Cordgrass provides superior storm surge protection particularly during winter months when native cordgrass is dormant.
Smooth Cordgrass is more capable of filtering pollutants from water flowing into the bay.
Smooth Cordgrass provides at least equal habitat quality to the endangered Clapper Rail and probably other marsh plants and animals as well.
Smooth Cordgrass has not blocked waterways or eliminated mud flats in comparable situations over long periods of time

We invite our readers to supply us with evidence that there are legitimate reasons for the campaign against Smooth Cordgrass.

(1) “Smooth Cordgrass,” USDA/NRCS Plant Fact Sheet.

(2) Dorset Hurley, “Geogia’s Marsh Die Back and Louisiana’s Marsh Browning,” Altamaha Riverkeeper

(3) Ibid.

(4) “What’s killing off our salt marshes,” Going Coastal Magazine, September 15, 2008

(5) “West Coast Governor’s Agreement on Ocean Health,” May 2010, page 5

(6) Ibid., page 6

(7) “San Francisco Estuary Invasive Spartina Project, 2010 Pesticide Application Plan,” page 15.

(8) Ibid. page 31

(9) “West Coast Governor’s Agreement on Ocean Health,” May 2010

(10) “Ecology of California Clapper Rail in the San Francisco Bay/Delta Region,” USGS Western Ecological Research Center

(11) Judy Drew Fairchild, “Watch for Clapper Rails and chicks,” Dewees Island, SC

(12)“West Coast Governors’ Agreement on Ocean Health,” May 2010, page 12

(13) “San Francisco Estuary Invasive Spartina Project, 2010 Pesticide Application Plan,” page 10