Eradication of marsh grass on East and West Coasts doesn’t make sense

New York State agencies have been trying to destroy the Piermont Marsh since 2013, because most of the marsh grass is not native. Piermont Marsh is adjacent to the small village of Piermont on the west side of the Hudson River, less than 30 miles north of New York City.

The community of Piermont organized to prevent the destruction of their marsh for two reasons:

  • They believed that the marsh had protected them from the devastating storm surge caused by Hurricane Sandy in 2011. The village sustained damages of $11.8 million in that storm, but villagers believed it would have been much worse without the protection of the marsh.
  • The initial plan to eradicate 200 acres of non-native phragmites proposed the use of herbicides to kill the marsh grass. The villagers were concerned about large quantities of herbicides being sprayed into their waterways.
The Piermont Marsh is also very beautiful.

I have followed the attempt to save the Piermont Marsh because it is nearly identical to our West Coast version of the same issue.  Non-native spartina grass has been nearly eradicated on the entire West Coast using herbicides over the past 15 years.  After witnessing the unintended consequences of the eradication of spartina, I was sympathetic to the community of Piermont and hopeful that their organized resistance might be successful.

Opposition to the proposed project to destroy the Piermont Marsh has accomplished a great deal.  The first round of public comment and negotiation resulted in a reduction in the size of the project from 200 acres to 40 acres.  The Piermont community was also given a commitment to conduct an analysis of the damage done to the village by the destructive storm surge in the 2011 hurricane Sandy to determine the role the marsh played in protecting the village from even greater damage.

The scientist who conducted that study reported the results of the study in July 2020.  He concluded that “the presence of the Marsh is estimated to have avoided $902,000 worth of property damage and loss.” (1) He made other significant observations:

  • The native marsh grass that the project wishes to restore does not provide as much storm protection in the spring: “Typha [the native species of marsh grass] shows far more seasonal variation than phragmites.  Unlike phragmites, which maintains its height and density year-round, Typha is shorter and sparser in the spring.” (1)
  • The scientist predicted that by 2100 the Piermont Marsh will likely be overwhelmed by sea level rise. Whatever vegetation is at the Piermont Marsh, it will be gone within 80 years.

For the moment, the Piermont Marsh project is on hold:  “[The plan] will be redrafted and the new draft should be presented to the public in 2021.” (1) Meanwhile, herbicides will not be used in the marsh and experiments will be conducted to kill marsh grass by covering it with a geotextile that deprives the vegetation of light.  However, project managers have not made a commitment to avoid herbicides in the future.

Based on my experience with opposition to such destructive projects,  delays are often ultimately victories.  Funding priorities often change and more scientific information becomes available to inform a better decision.  For example, the current draft plan contains outdated information about glyphosate.  It claims that “Glyphosate is a non-selective, systemic herbicide that controls weeds by inhibiting a specific pathway for amino acid synthesis that is unique to plants and not present in animals.”

We now know that the claim about a “unique pathway” for glyphosate existing only in plants is not true.  In 2020, plaintiffs in a class-action suit against Monsanto alleging that it falsely advertised that the active ingredient in Roundup only affects plants were awarded $39.5 million.  The settlement also requires that the inaccurate claim be removed from the labels of all glyphosate products: “…[plaintiff] says Monsanto falsely claimed through its labeling that glyphosate, the active ingredient in Roundup, targets an enzyme that is only found in plants and would therefore not affect people or pets. According to the suit, that enzyme is in fact found in people and pets and is critical to maintaining the immune system, digestion and brain function.”

In defense of phragmites

According to a study conducted in 2017, phragmites is playing the same ecological roles as their native predecessors:

“An invasive species of marsh grass that spreads, kudzu-like, throughout North American wetlands, may provide similar benefits to protected wetlands as native marsh grasses. According to new research from North Carolina State University, the invasive marsh grass’s effects on carbon storage, erosion prevention and plant diversity in protected wetlands are neutral… studies have shown that Phragmites may help reduce shoreline erosion in marshlands and store carbon at faster rates than native grasses…The team found no significant differences between ecosystem services of the marshes they studied, indicating that Phragmites’ effect was largely neutral.” 

Land managers and contractors have been trying to eradicate phragmites in the Delaware River and its estuary for nearly 40 years.  Although the contractors are still committed to that project, critics are getting louder and scientists are finding more evidence of the benefits of phragmites.  It is no longer clear that eradicating phragmites is possible, nor is it clear that it would be beneficial.

Rising sea levels as ice melts in warmer temperatures are bringing the benefits of phragmites into focus:  “Some scientists have been arguing that phragmites…could be a key line of defense against rising sea level, particularly in areas like the Mid-Atlantic where land is sinking while water continues to rise… Research from 20 years ago found that phragmites help marshes elevate faster than some other plants…”

The herbicides used to kill phragmites are aerial sprayed from helicopters, killing both native and non-native plants, resulting in barren mudflats that are more vulnerable to erosion:  “The herbicide treatment of phragmites can also mean other native plants become casualties in the process, leaving an unvegetated landscape behind. With no plants to hold sediment in place, an open mudflat can be extremely vulnerable to flooding in the face of storms or unsuccessful regrowth… ‘You know, the Phrag marsh is certainly a whole lot better than no marsh,’ [a Rutgers scientist] said.”

Trying to eradicate phragmites no longer makes sense.  So why is it continuing to happen?  A Rutgers marine biologist explains:   “Well, might I say…there’s a whole army of environmental consultants that get paid to remove phragmites and don’t get paid to leave it alone.”  That is really the heart of the matter.  The projects are designed to create jobs and apply for government funds, not to protect the environment.

The West Coast version of marsh grass eradication

If the word “spartina” is substituted for the word “phragmites” the Piermont Marsh project and the questions it raises apply to similar projects on the West Coast.  For over 15 years, non-native spartina marsh grass has been eradicated using herbicides along the entire West Coast.  The result of spartina eradication projects on the West Coast is also barren mud shoreline that is poisoned with herbicide and miles of coastline that is vulnerable to rising sea levels and erosion.

The Ridgway Rail was collateral damage of the spartina eradication project. The population of this endangered bird plummeted because its nesting habitat was destroyed.

There is another similarity between the East Coast and West Coast versions of eradicating marsh grass.  Like the native typho (cattail) that is the goal of the East Coast project, native spartina that was the goal of the West Coast project is inferior protection of the coastline against storm surges.  The native species of spartina on the West Coast that was the theoretical goal of the eradication project is shorter and less dense than the non-native species.  It also dies back in the winter, unlike the non-native species that persists throughout the year.  In other words, the native species does not provide the same protection for the shoreline that is provided by the non-native species.  In any case, plantings of the native species failed in the poisoned ground, so its benefits claimed by the project are entirely irrelevant.

These eradication projects don’t make any more sense on the West Coast than their mirror image on the East Coast. 

  1. The Piermont Marsh Alliance Report on July 16 Webinar regarding Piermont Marsh

“San Francisco’s Natural History”: A mixed bag of fact and fiction

Million Trees breaks its self-imposed silence to bring you this book review of San Francisco’s Natural History:  Sand Dunes to Streetcars, by Harry G Fuller.  It was frustrating to read this book because I had high expectations that I would like it and learn from it.  And to some extent, I did.  However, the book also repeats old myths about eucalyptus that have long ago been debunked and fabricates a new myth.  It also supports deadly and dangerous “restoration” projects in the Bay Area without acknowledging the loss of wildlife they cause. On the other hand, historical records of San Francisco’s natural history seem to be accurately reported by Fuller and he paints the picture of pre-settlement San Francisco as drifting sand dunes and treeless grass and chaparral. 

Persistent myths about eucalyptus

Fuller says, “There is evidence…that eucalyptus trees may be deadly to both wintering birds and monarch butterflies…At the same time the trees provide necessary shelter, their chemical make-up and their sticky leaves may prove deadly.”

Hummingbird in eucalyptus flower. Courtesy Melanie Hoffman

Fuller does not provide the “evidence” for this statement, so we must speculate about what he means.  It seems likely that he is repeating the 23-year old claim that eucalyptus kills birds by suffocating them with their sticky nectar when eucalyptus blooms in winter months. (Neither the nectar, nor the leaves of eucalyptus is sticky.)  A local birder reported seeing two dead birds in eucalyptus forest over the course of his long career as a serious birder and parlayed those isolated observations into the generalization that birds are killed by eucalyptus trees.  Decades of research was required to put that accusation to rest. (1, 2) Officially, the myth died when the California Invasive Plant Council updated the classification of eucalyptus in 2015.  The claim that eucalyptus kills birds was deleted from Cal-IPC’s revised classification. It was aggravating to see this claim repeated by Mr. Fuller in his book, which was published in 2017.

Fuller’s claim that eucalyptus is also deadly to monarch butterflies is unprecedented.  I have heard innumerable stories about the bad habits of eucalyptus, but I have never heard that eucalyptus kills monarch butterflies.  You won’t find that accusation anywhere on the internet and you won’t find it anywhere in the scientific literature.  I confirmed with Art Shapiro, Distinguished Professor of Ecology and Evolution at UC Davis and author of Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions, that he had never heard that claim either. 

In fact, available empirical evidence contradicts that claim. Eucalypts are the preferred trees for over-wintering monarchs in California:  “Three types of trees were used most frequently by roosting monarchs:  eucalyptus (75% of the habitats primarily Eucalyptus globulus), pine (20% of the habitats primarily Pinus radiata), and cypress (16% of the habitats Cupressus macrocarpa).  Twelve other tree species were identified…with a combined prevalence of only 10%.” (3)  Monarchs migrate down the coast of California during the winter months, when eucalyptus is flowering at a time when there is little else blooming in California.  They are an essential source of nectar during the monarch migration. 

Fuller says, “The eucalyptus’s natural herbicides prevent many other plants from growing beneath their canopy.”   

This is another accusation that has been repeatedly disproven by empirical research.  The eucalyptus forest is as biodiverse as native oak woodland (4).  The 2015 revision of the California Invasive Plant Council assessment of eucalyptus deleted previous mention of the allelopathic (the scientific term for “natural herbicide”) properties of eucalyptus.  A rigorous study at Cal Poly concluded, “In these experiments, we found that germination and seedling growth of the species tested were not inhibited by chemical extracts of blue gum foliage, either at naturally-occurring or artificially concentrated levels.” (5)  This study was presented by its author at the most recent conference of the California Native Plant Society, which should establish its credibility with native plant advocates.

Presentation at conference of California Native Plant Society

Fuller says in support of his “natural herbicide” theory, “You never see moss or lichen on a healthy eucalyptus trees.”

We don’t see moss or lichen on eucalyptus tree trunks because the thin, papery bark on the trunk sloughs off annually, leaving the trunk bare.  Moss and lichen grow slowly on tree trunks in the bark that remains on the tree throughout the tree’s life.

Spartina (aka cordgrass) eradication

Ironically, Mr. Fuller prefaces his strong support for cordgrass eradication with this admonition:  “Do not forgive ignorance, please.”  Then, he displays profound ignorance of the consequences of cordgrass eradication in the San Francisco Bay Area.  Fuller is a professional birder, yet he is seemingly unaware of the fact that the eradication of cordgrass has nearly wiped out the population of endangered Ridgway Rail (formerly Clapper Rail) in the Bay Area.  He is also unaware of the huge quantities of herbicide that have been used to eradicate cordgrass.  Elsewhere in his book, he expresses concern about pesticides and other forms of pollution, yet in the case of cordgrass eradication he turns a blind eye.  (6)

Pesticide Application Notice, Heron’s Head, 2012

Eradication of mice on Farallon Islands

Mr. Fuller also supports plans to eradicate mice on the Farallon Islands:  “The latest effort to return the Farallones to a more natural preserve is an attempt to remove all the house mice.”  He is either unaware of plans to aerial bomb rodenticides on the Farallons to kill the mice or he chooses to use the euphemism “remove” to avoid the issue.  Elsewhere in the book, he mentions that rodenticides used in Golden Gate Park to kill rats also killed Great Horned Owls that ate the dead or dying rats.  He seems to understand that non-target birds are killed by rodenticides, yet he apparently supports the use of rodenticides on the Farallons, a national marine sanctuary.  (7)

Farallon Islands, NOAA

A Cautionary Tale

Mr. Fuller displays a sincere concern for the wildlife of San Francisco throughout his book.  He also acknowledges the very real threats of climate change and pollution for the future of the environment in the Bay Area.  I do not doubt his sincerity and I believe he has written a valuable book that is unfortunately damaged by his uncritical acceptance of inaccurate versions of several important environmental issues in the Bay Area.  I believe Mr. Fuller has been a victim of “incestuous amplification” in his acceptance of these myths.  Let that be a lesson to all of us to look deeply at every issue and to verify any tale you are told by an amateur or someone with a vested interest in those issues, such as employment. 

I cannot recommend this book to anyone who is not prepared to read it critically.  If you don’t already have a basic knowledge of the natural history of San Francisco you could easily be led astray by baseless rumors. 

  1. https://milliontrees.me/2013/11/05/eucalyptus-trees-do-not-kill-birds/
  2. https://milliontrees.me/2014/07/26/birds-and-butterflies-in-the-eucalyptus-forest/
  3. Dennis Frey and Andrew Schaffner, “Spatial and Temporal Pattern of Monarch Overwintering Abundance in Western North America,” in The Monarch Butterfly Biology and Conservation, Cornell University Press, 2004.
  4. https://milliontrees.me/2011/02/04/biodiversity-another-myth-busted-2/
  5. https://milliontrees.me/2018/02/06/highs-and-lows-of-the-2018-conference-of-the-california-native-plant-society/
  6. https://milliontrees.me/2014/06/02/spartina-eradication-herbicides-are-their-dirty-little-secret/
  7. https://milliontrees.me/2014/01/10/the-mouse-eradication-project-on-the-farallon-islands-the-con-in-conservation/