Along a postcard stretch of Southern California, beneath the geologic grandeur of Point Dume, Sara Cuadra cradled a rake and prodded what seemed like just a patch of white sand.

To the untrained eye, this was just another pretty spot in Malibu — a popular site for film shoots and Instagrams, body surfing and long walks by the sea. But here among the bluffs of Westward Beach, where the shoreline has quietly eroded with each passing year, Cuadra has spent weeks tending, square foot by square foot, a forgotten ecosystem that has long since been destroyed.

“That should do it,” she said, patting the sand with satisfaction. “I think we can start seeding.”

In a land of beach volleyball, umbrellas and picnics on the sand, it’s easy to forget the beach itself used to be a wild place. Coastal dunes once unfurled along the shore, their crests and curves teeming with plants, birds and more bugs than you could imagine. California, in fact, once boasted some of the most biodiverse beaches in the world. But for almost a century, these sandy hills have been flattened and paved over — erased to make room for ever more people seeking to live and play by the sea.

Now, with the looming threat of sea level rise and a state desperate for solutions, conservationists and a growing movement of researchers say restoring these dunes could provide a much-needed buffer from the water. These overlooked features of the coast could help buy communities a bit more time — before the ocean pushes inland and reclaims the land.

Most of these ideas remain untested in California. Pilot projects like the one in Malibu are starting with a concept so simple it seems radical: If these degraded ecosystems were just given the space to regrow, could they come back to life?

For Cuadra, the Bay Foundation’s plant whisperer, the sand is her palette, the pristine beach her canvas for a different, more resilient landscape that beachgoers could learn to love. There’s no silver bullet for sea level rise, but here is an opportunity to try something other than a concrete seawall or some over-engineered solution that would make the coast even more unrecognizable.

Her back was sore, her hands blistered from the weeks of weeding. But with enough care, a little rain and just a bit of luck, maybe, just maybe, this beach could offer a different way forward in California’s fight against the sea.

She clutched a handful of seeds that will one day bloom into red sand verbena — a fiercely stubborn succulent that slowly builds up dunes by trapping windblown sand.

It feels like a race, she said. A race against erosion, against big waves and flooding and all the rising forces of the ocean.

“We’ll see who wins,” she said. “Hopefully the plants. Hopefully us.”

There’s a sobering number often cited among scientists, coastal planners and those in the know: About 90% of California’s wetlands have been choked, drained or filled to accommodate our engineered landscape. Less talked about, however, is that perhaps even more coastal dunes have been destroyed.

Along southern Santa Monica Bay alone, more than 23,000 acres of dunes once stretched from Palos Verdes to Los Angeles International Airport, according to historical ecology maps from the 1850s.

Paved over by roads, homes — and yes, even airports — these sandy areas tend to be easy to build on and prime for oil drilling and agriculture. Today, a few dune systems remain along the state’s northernmost coast, as well as along Monterey Bay, Santa Barbara and other pockets of the south-central coast.

As for those Southern California dunes that were spared from development, many have been mechanically flattened and “groomed” for a more pristine beach experience.

Decades of grooming have squeezed the life out of the sand. Heavy machinery, intended to clean the beach, has methodically smoothed out areas where plovers once nested and where grunions bury their eggs. Gone too are the native plants, the now-endangered butterflies and the bugs that once brought so many different birds to the shore.

As these beach tractors scrub the sand for trash each day, they also rake up all the kelp that has washed ashore — removing an important building block in the dune formation process, as well as a major nutrient source for animals.

Beaches in a more natural state

On ungroomed beaches, kelp wrack and native plants help trap windblown sand. Small mounds of sand build up into dunes, which support birds and intertidal species.

Windblown sand

Winds

Kelp wrack

Foredune

Backdune

Windblown sand

Winds

Kelp wrack

Foredune

Backdune

Windblown sand

Winds

Kelp wrack

Foredune

Backdune

It would seem absurd to rake all the leaves off the floor of a forest, ecologists say, but many Californians have stopped seeing their beaches as an interconnected part of nature.

“We have some of the richest beaches in the world; we also have some of the most impacted beaches in the world,” said Jenny Dugan, a researcher at UC Santa Barbara who has spent more than 20 years studying the biodiversity of our beaches. “The contrast is really striking between what a beach can be in California, and what a lot of beaches are in California.”

Take the invertebrates, for example. Dugan, a coastal marine ecologist, has identified at least 27 species of native intertidal beetles on a beach in Santa Barbara County that does not get groomed. (Compare this with a similar beach in Chile, for example, where only one species has been documented.) Just recently, she discovered a fly that had never been described before — another yet-to-be-named species on California’s vibrant shore.

Dugan’s voice rings with excitement whenever she talks about the “roly polies,” a sensitive isopod whose survival indicates a highly biodiverse beach, and talitrids — also known as beach hoppers — that maintain balance by munching on the kelp before it rots.

These critters also attract all the shorebirds that once frequented the coast. Birds like the western snowy plover, which relies on dunes and having enough space on the beach to nurture their young.

And California least terns, whose numbers have also plummeted as their nesting habitats continue to vanish along the shore.

To rebuild dunes, David Hubbard, a research specialist at UC Santa Barbara and co-founder of Coastal Restoration Consultants, recommends starting with the three “ecosystem engineers”: red sand verbena, beach bur and beach saltbush.

These three plants are particularly good at starting the process of trapping and forming mounds of sand, known as hummocks, that continue to accumulate until they become dunes that are three, six, sometimes more than 20 feet tall.

Once the ecosystem engineers have stabilized the dune, plants like beach evening primrose can move in and help develop the habitat further, said Hubbard, who has advised numerous restorations across California, including the one in Malibu.

These plants are a rare sighting these days. Many beaches are now matted with a stubborn carpet of ice plant, whose fleshy green leaves and aggressive roots spread so quickly that they crowd out native plants. As one park ranger put it: Ice plant may look green and familiar, but to wildlife, it may as well be concrete.

This invasive plant from South Africa was popularized decades ago as a cheap way to control erosion. Agencies such as the U.S. Army Corps of Engineers and the California Department of Transportation once planted them as a way to stabilize cliffs and highway embankments. But the ice plant quickly invaded much of the coast and got out of control.

Dunes in their natural state can also help delay or soften the onslaught of wave erosion. The trick is to see them not as static features on the beach, but as a dynamic, ever-adjusting bank of sediment that stores and supplies sand depending on the season and tide.

With the increasing pressures of sea level rise, these sandy ecosystems may be the first to vanish if the human-built world does not change course. A recent study led by the U.S. Geological Survey found that dune habitats in California may have already reached a tipping point. Experts say it’s important to identify areas along the coast that still have enough space — and time — to give dune restoration a try. These projects take not only years to grow, but also years to plan.

“Every site on the coast is different. Every project takes a really long time to get put on the ground,” said Hubbard, who noted that balancing public access, safety, towel space and other recreational uses must also be factored into these plans. “There’s the ecological side … but also implementation, coordinating with the landowners, making sure all the stakeholders get brought in. … It gets a lot more complicated when you get to the human side.”

With the Malibu project, city officials were intrigued by the Bay Foundation’s proposal to fence off 3.1 acres of sand along Point Dume and Zuma Lagoon, weed out the ice plant and replace the area with native plants. The nonprofit’s research team had already demonstrated proof-of-concept on a smaller, more controlled plot of beach in Santa Monica in 2016: Within just a few months, a snowy plover nest had appeared for the first time in seven decades. Now after more than four years of careful maintenance and monitoring, little mounds of sand have formed.

The city saw this pilot project as a way to test relatively inexpensive nature-based methods — one more tool in the solution toolkit, so to speak — as well as a compelling opportunity to talk to the community about its increasing vulnerabilities to sea level rise, said Christine Shen, who oversees Malibu’s sustainability efforts.

Studies show that, without any shoreline protection, 50% of the sandy beach at Zuma and Point Dume could vanish by 2040, and as much as 70% by 2100. Whether the dunes will build up fast enough or be sufficient protection for the existing infrastructure — two lifeguard buildings, public restrooms, the parking lot and an access road — remains unclear. But at least on these two beaches, there is still enough time to try these so-called living shorelines.

“There are all these options out there, but very few of them have been tested on the West Coast — California still needs demonstration projects,” said Evyan Sloane of the California Coastal Conservancy, which funded the Malibu restoration and has been involved in many of the pilot projects testing dunes, eelgrass other potential habitats that could double as shoreline protection.

“If we don’t want our coast to become one long stretch of seawalls and rocks — with no wetlands and no beaches to lay our towel on — we need to develop more approaches to deal with these threats.”

Back at Point Dume, Cuadra knelt down to examine the field team’s progress. The beach was now cleared of 50,000 pounds of ice plant, which they had spent weeks coaxing out of the sand. She checked the dozens of wooden garden stakes now planted in its place — positioned in strategic clusters to help accumulate more sand — and the steel posts that marked where beachgoers could walk without trampling this budding ecosystem.

She noticed a rogue stem of ice plant and threw her weight into tugging the entire root system out of the sand. Dane Lazarus, a fellow watershed program coordinator at the Bay Foundation, leaned over to give her a hand.

“These roots are so stubborn,” he said. “There were some on the other side that were 2 inches thick in diameter! We had to take a pickax to them.”

The two continued to comb the sand, finalizing the prep for millions of seeds. Every step so far has been somewhat uncharted as they test and study various methods that can be used on future projects — at Dockweiler Beach, Manhattan Beach and elsewhere along the coast.

Most responses so far to sea level rise can be placed along a “green-to-gray scale.” The $250,000 project in Malibu — designed to rely on natural processes and no imported sand — is on the greenest end of the spectrum. Compare this with something more gray: a large seawall made out of concrete — costing as much as $200,000 to defend one home — or a $90-million levee to keep a small Bay Area town above water.

At Cardiff State Beach in northern San Diego County, a recent $3-million project fits somewhere between green and gray: There was not enough willpower at the time to relocate, or “manage-retreat,” the coastal highway farther inland (the most cost-effective but logistically challenging solution), so officials agreed instead to line the coast with a wall of rocks — and then cover the wall with sand and build a dune habitat and walking trail on top.

“We were trying to buy time in a way that would benefit the environment and not preclude future nature-based adaptation,” said Sloane, a project manager at the Coastal Conservancy who specializes in sea level rise adaptation. “We can’t be setting ourselves up for failure, setting ourselves up for a seawall, setting ourselves up for a bigger rock revetment. … The way we justified all of our effort, and all of the money going into this project, was that the city and the transportation agencies needed time to get their appropriate planning done to move the highway.”

Shifting to even greener ways of buying time is often a hard sell. Engineers have been wary of the idea that plants and sand could be enough, even in the short term, to protect roads and critical infrastructure.

Mark Gold, the governor’s deputy secretary for coast and ocean policy, said that good monitoring and data are critical to understanding how to make more of these projects part of the solution.

“It’s pretty extraordinary to realize what was there before we built up all the way to the shoreline, before we started grooming our beaches every day to keep the trash out,” said Gold, who has been working with more than a dozen state agencies to prepare for at least 3.5 feet of sea level rise by 2050. “From the standpoint of looking at coastal dunes as a nature-based solution to build coastal resilience, I think there’s a great deal of unfulfilled potential in the state.”

On a slightly windy Friday, Cuadra got to work sorting tens of thousands of seeds into a broadcaster that she slung over her hip. She held out a few in her hand, noting the spiky edges on the ambrosia chamissonis (beach bur) and the abronia maritima (red sand verbena) that looked like oatmeal.

She paused to admire a gray whale and its calf breaching just past the surf. A group of pelicans stretched their outsize wings and soared along the break.

“Almost every day we’re out here we see dolphins and whales and all kinds of wildlife,” she said. “It’s beautiful.”

Cuadra, who grew up in Southeast L.A., still feels a sense of wonder whenever she’s this close to the ocean. She often thinks about the Tongva and Chumash people who understood the natural rhythms of this coast, who knew these dunes before they were destroyed.

Despite the parking lot just steps away, despite the whoosh of Pacific Coast Highway and all the homes perched today on the edge of the sea, Cuadra hoped it was still possible to recognize the past as part of the present — and show more people how to share again and begin planning for a more resilient future.

Generations of people have never experienced a beach in California brimming with its full spectrum of life. She herself has never seen a snowy plover. She can recite the scientific names of so many of her plants — but has yet to witness them in their natural state.

She scattered the first seeds like confetti and gasped with delight as they settled into the sand.