Coastal Dune Restoration Project FAQs

Native dune habitat.
Healthy sand dunes covered by native plants.

The National Park Service (we) want to restore 600 acres of coastal sand dunes. These dunes are critical to the survival of endangered and threatened plants and animals. We plan to remove non-native iceplant and beachgrass with a combination of mechanical removal, manual removal, and spot spraying of herbicides. After 15 years of experience and intensive study, we decided to use herbicides as a last resort.

We hope this FAQ (frequently asked questions) will answer some of your questions in plain language. For detailed, authoritative information, check our Finding of No Significant Impact (FONSI) (530 KB PDF) and the Environmental Assessment.

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Why are you restoring coastal sand dunes?
Point Reyes National Seashore preserves some of the last remaining high quality coastal dune habitat in the United States.

We want to restore coastal sand dunes by removing hundreds of acres of non-native plants. This should bring back habitat for birds, butterflies, and flowers threatened with extinction.

Many decades ago, iceplant and European beachgrass began invading and stabilizing coastal sand dunes. By 2009, these plants carpeted more than 1,400 acres of the seashore. Populations plummeted for western snowy plovers, Tidestrom's lupine, and other threatened or endangered species living in the dunes.

After we cleared 80 acres of dunes near Abbotts Lagoon, more than 15,000 Tidestrom's lupine plants sprouted. Snowy plovers moved in to nest and raise young. And the dunes started moving more naturally.

For more information, visit our Why is Dune Restoration Important?


How are you restoring coastal sand dunes?
We plan to eliminate carpets of iceplant and beachgrass with a combination of mechanical removal, manual removal, and spot spraying of herbicides. This combination should restore more dune area with less damage than the other options we studied.

Mechanical removal means digging up plants with excavators and burying plants with bulldozers. Manual removal means pulling or digging up plants by hand. We plan to spot spray herbicides with a backpack sprayer and calibrated nozzle on dry, calm days. We might also use mowing and controlled burns for pre-treatment.

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Where are you restoring coastal sand dunes?
For this project, we plan to restore coastal sand dunes at selected spots on Point Reyes Beach (also called the Great Beach) and along Limantour spit.

Map of the Coastal Dune Restoration Project Areas.
Map of the project areas.

When will the project start?
In the fall of 2015, we plan to start mechanical removal and manual removal of iceplant and beachgrass, followed by spot spraying herbicides in the fall of 2016.


How do you know this project will work?
We have restored 400 acres of dunes over 15 years with many different methods. We've found that the combination of mechanical removal, manual removal, and spot spraying herbicides removes invasive plants effectively, with the lowest environmental impact.

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How will you protect the environment?
We plan to:

  • use buffer zones and spray shields to protect rare plants, wildlife, wetlands, and organic ranchlands.
  • look for sensitive birds, frogs, flowers, wetlands, and cultural resources before work begins.
  • work during seasons, days, and times that won't harm sensitive plants, wildlife, and visitors.
  • reduce contractor vehicle speed limits to protect butterflies.
  • spot spray herbicides with calibrated nozzles from backpacks on dry, calm days.
  • stop spot spraying herbicides for 24 hours before and after rainfall or until plants are dry.
  • close areas to visitors for 24 hours after spot spraying herbicides.

Which endangered or threatened plants and animals will this project help?

A fuzzy speckled plover chick stands behind a buff-colored plover that is sitting on the sand.
A male western snowy plover with a newly hatched chick.

NPS / Matt Lau

Western snowy plover
These small birds nest in open sand, not in carpets of iceplant or beachgrass. Snowy plovers have lost two-thirds of their major nesting areas in Washington, Oregon, and California. In 2014, we found 20 snowy plover nests in recently restored dunes. Visit our Snowy Plovers at Point Reyes for more information.

An orange-colored butterfly with numerous black and silver spots on a yellow flower.
A Myrtle's silverspot on a gumplant flower.

© Geoff Smick.

Myrtle's silverspot butterfly
This two-inch-wide butterfly feeds on the nectar of native plants that grow in coastal sand dunes. Once found from San Mateo County to Sonoma County, it was listed as a federally endangered species in 1992. Now the butterfly lives in only a few locations in Sonoma County and Point Reyes National Seashore. You can learn more about Myrtle's silverspot butterfly from San Francisco Bay Area National Parks Science and Learning's 2011 "Myrtle's Silverspot Butterfly" video.

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Tidestrom's Lupine. © Doreen Smith.

Tidestrom's lupine
Deer mice that hide in beachgrass devour the seeds of this low-growing wildflower. And the lupine's seeds germinate much better in active sand dunes. It grows in a handful of locations from Monterey to the Russian River, including Point Reyes National Seashore. After we cleared 80 acres of dunes near Abbotts Lagoon, more than 15,000 Tidestrom's lupine plants sprouted.

Beach layia (Layia carnosa). © Doreen Smith.

Beach layia
Once found from southern Oregon to southern California, this daisy now grows in just a few spots in northern California. The plant's population at the seashore dropped by almost half since 2014. We expect their numbers to grow in restored dune areas.

Restoring coastal sand dunes should help many other native plants and animals thrive.


What's the difference between natural dunes and stabilized dunes?
Natural coastal dune fields usually have two or three sets of parallel dunes, with the oldest dunes farthest inland. Blowouts, or gaps where sand blows through, break up the dune fields. Individual dunes and the entire dune field move in response to high winds.

Dunes stabilized by invasive plants look very different. The dunes closest to the ocean are steep, continuous ridges without blowouts. Farther from the ocean, dunes starved of new sand are slowly overgrown by bushes.

One of the biggest differences is sand movement. Two years after we restored dunes near Abbotts Lagoon, sand had buried 10 acres of grassland, scrub, and wetland.

Natural dunes also clean up groundwater better than stabilized dunes.

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How will climate change affect coastal sand dunes?
Rising sea levels and stronger, more frequent storms could flood low-lying coastal areas. Sand dunes protect the coast from storm surges and giant waves.

Natural dunes can move in response to a changing climate. As they migrate, they will continue protecting the coast while providing homes for rare plants and animals.

Dunes stabilized by invasive plants may erode into the ocean and gradually shrink. Eventually, storm surges and giant waves will wash over them, flooding inland areas, and destroying endangered species habitats.

Restoring coastal sand dunes should make Point Reyes National Seashore more resilient to climate change and sea level rise.


What are the most common concerns about this project?
The most common concerns are about the use of glyphosate herbicide and the project's effects on nearby ranches.


Why don't you use…?
Over the years, we've tried many methods for eliminating iceplant and beachgrass. We tried digging them up, but European beachgrass roots can reach 12 feet deep, and re-sprout from a 2-inch chunk.

We tried burrowing deeper with an excavator, but digging up large areas can harm nearby ranches, dunes, wetlands, and threatened and endangered species.

Some of the other techniques we've tried or studied include:

  • Hand pulling plants
  • Mechanically mowing plants
  • Burying plants with a bulldozer
  • Grazing
  • Using saltwater or vinegar as an herbicide
  • Applying thick layers of wood chips or black plastic tarps as mulch

For this project, we plan to use a combination of mechanical removal, manual removal, and spot spraying herbicides. The National Park Service uses herbicides as a last resort, when we can't effectively control invasive plants using other methods.

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What is glyphosate?
Glyphosate is an Environmental Protection Agency-approved herbicide, widely used to kill plants around homes and on farms. Roundup® is the best-known brand of glyphosate herbicide.


Will you use Roundup®?
We won't use the regular Roundup formula. We plan to use Roundup Custom®, formerly known as AquaMaster®. Regular Roundup includes a surfactant that helps the glyphosate penetrate leaves. However, the Environmental Protection Agency (EPA) prohibits using that formula near wetlands because the surfactant can harm aquatic life.

Roundup Custom does not contain a surfactant. We plan to add a different surfactant (Competitor®), which contains ingredients commonly found in food. The EPA has approved Competitor for use near wetlands.


Why are you using glyphosate?
We use herbicides only as a last resort. For 15 years, we've tried different methods to remove iceplant and beachgrass. We've been most successful using a combination of mechanical removal, manual removal, and spot spraying herbicides containing glyphosate. Our Finding of No Significant Impact (530 KB PDF) and Environmental Assessment also found that this approach should have the lowest environmental impact.


Does glyphosate interfere with hormones?
The EPA recently reviewed glyphosate for endocrine disruption – interfering with hormones in humans and other animals. The EPA found "no convincing evidence of potential interaction with the estrogen, androgen or thyroid pathways in mammals or wildlife" for glyphosate.

Environmental Protection Agency Memorandum. EDSP Weight of Evidence Conclusions on the Tier 1 Screening Assays for the List 1 Chemicals, June 29, 2015. Available at (accessed 30 March 2020). (1,043 KB PDF)

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Does glyphosate cause cancer?
In 2013, the EPA reviewed available research and concluded:

"…glyphosate does not pose a cancer risk to humans."

We rely on EPA guidance for the proper use of all herbicides and pesticides.

The EPA plans to complete a comprehensive review of glyphosate soon. If they revise glyphosate's risk assessment, we will reconsider our herbicide choice.

The European Union and the UN Food and Agriculture Organization also concluded that glyphosate does not cause cancer.

Environmental Protection Agency. Final rule. "Glyphosate; Pesticide Tolerances," Federal Register 78, no. 84 (May 1, 2013): 25396. Available at (accessed 08 October 2015). (240 KB PDF)


Why did I read recently that glyphosate does cause cancer?
In March 2015, the UN International Agency for Research on Cancer classified glyphosate as a "probable carcinogen." Other IARC probable carcinogens include wood smoke, employment as a barber or hairdresser, and working night shifts.

However, in June 2015 the IARC also said:

  • Their research evaluates cancer hazards but not the risks associated with exposure.
  • Their research does not measure the likelihood that cancer will occur because of exposure.
  • The risk associated with two agents classified the same may be very different.

The EPA and other agencies use the IARC information to conduct further research and determine the balance of risks and benefits of herbicides like glyphosate. We rely on EPA guidance for the proper use of all herbicides and pesticides.

International Agency for Research on Cancer. 2015. IARC Monographs Volume 112: Evaluation of Five Organophosphate Insecticides And Herbicides. (accessed 08 October 2015). (47 KB PDF)

International Agency for Research on Cancer. 2015. IARC Monographs Questions and Answers. (accessed 08 October 2015). (133 KB PDF)

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Does glyphosate kill butterflies, bees, birds, and other animals?
Glyphosate affects a chemical pathway in plants that animals don't have. However, using glyphosate can affect animals indirectly. For example, many farmers and homeowners use glyphosate to kill the milkweed eaten by monarch butterfly caterpillars.

The regular formula of Roundup® includes a surfactant that can harm aquatic life. We are using a different formula, EPA-approved for use near wetlands, which does not include that surfactant.


Why don't you wait for the full EPA review of glyphosate?
If we delay removal of iceplant and beachgrass, they will cover more of the dunes.

For this project, we plan to spot spray herbicides containing glyphosate starting in the fall of 2016. If the EPA completes their glyphosate review before we start, we plan to reconsider our herbicide choice. If the EPA changes the herbicide label directions, we will follow the new label.


Will glyphosate from this project hurt nearby organic ranches?
We plan to spot spray herbicides on dry, calm days, and keep at least 25 feet away from organic pastures. Based on our experience, we don't expect the herbicides to impact nearby ranches.


What is National Park Service guidance on glyphosate?

  • The NPS defers to the EPA on matters of pesticide classification and registration.
  • The NPS and other Federal land management agencies are waiting for guidance from EPA before making any changes to the use of products containing glyphosate on Federal lands.
  • Those using pesticide products are required to read the label and adhere to label directions.

Will clearing the dunes dump sand into nearby ranches?
We plan to avoid that problem several ways:

  • Work closely with the ranchers
  • Start work on the ocean side of the dunes, farthest from the ranches
  • Gently slope the back sides of the dunes when we use bulldozers
  • If needed, plant native plants on the back sides of the dunes to minimize sand movement

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Last updated: July 12, 2024

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