At the beginning of the 20th century, Miami was the hot spot. Miles of golden sand, a warm, turquoise ocean, and a temperate climate made this Florida city an attractive place for tourists.
While on the other side of the country, in the Pacific Ocean, the beaches of Los Angeles were rocky and wild: steep cliffs plunged into the cold waves and the Southern Pacific train ran on tracks parallel to the ocean.
“The municipal authorities wanted to convert Santa Monica [una de las ciudades costeras] on the American Riviera,” explains Elsa Devienne, associate professor of History at Northumbria University in the United Kingdom, author of a book on the history of the beaches of Los Angeles.
“Santa Monica wanted to establish itself as the spa city of the rich and famous. “These beach towns had big ambitions.”
The small stretches of sand in Santa Monica and Venice were already busy with the new families who had arrived in the city during the boom demographic of the 20s.
“The beaches were so narrow,” Devienne continues, “that you could barely walk on them at high tide.” According to their research, they used to have between 22.7 and 30.3 meters wide, compared to the current 151 meters.
The municipal authorities took action on the matter. They decided build a bigger beach.
They transported dune sand that existed further south, in Playa del Rey, next to what is now the extensive Los Angeles International Airport, as well as sand from the ocean floor and a failed project to create a marina in Santa Monica. “They thought, ‘Maybe we could keep doing that and expand the beaches and that would solve our problem of crowded beaches,’” Devienne says.
Between 1939 and 1957, 13.4 million cubic meters -or more than 5,000 Olympic swimming pools- of sediment on the beach of Santa Monica.
“They played God with that landscape,” says Devienne. “Los Angeles has been very lucky because it has worked. To this day, they still have wide and beautiful beaches.”
But, as Devienne points out, the climate is changing and the Los Angeles coastline is eroding. The sand that has stood the test of time so well is now vulnerable to storm surges and coastal flooding.
In fact, Southern California could lose between one-third and two-thirds of its beaches by 2100 due to rising sea levels.
The luck of those long, wide beaches may be running out. And that’s where the sand dunes come into play, which once dotted the coastline naturally.
Nature protection
Thanks to the work of those municipal officials from a century ago – and current beach maintenance practices – these are sterile and are largely lifeless.
Those long, flat stretches of sand that you see when you visit one of the beaches in Los Angeles are that way thanks to the heavy tractors They leave at dawn to clean the beach every morning.
It has been done on the beach in Santa Monica for more than 70 years. It is used to remove trash and promote recreational activities, such as volleyball, but it also contributes to greatly reduce biodiversity: Less prey is available for shorebirds and species richness decreases.
Ending this meticulously destructive grooming was the first step for Tom Ford, president of local nonprofit The Bay Foundation, which has been fortifying the beach by restoring sand dunes.
“We were looking at what we could do to further improve the coast, and we knew we were facing increasing sea level rise, storms and flooding,” Ford explains.
The foundation knew that if they managed to stop the beach cleaning and return the native plant communities to the area, the sand dunes would reappear, which would constitute a natural buffer against erosion. (A similar project had already been successfully carried out further south).
In late 2015, the foundation cordoned off a three-acre (12,140 square meter) area and scattered native seeds in the sand. They watched and waited and, thanks to some heavy rain, the seeds took root, grew and flourished.
As they grow, the plants capture windblown sand under their branches and leaves, eventually creating natural dune barriers that protect from coastal erosion.
The project was experimental, Ford explains, and so no quantifiable criteria for success were set. But in Ford’s opinion, it has been a resounding success. The dunes have already reached between 30 to 90 cm.
“The plants have really taken off, maybe better than we could have expected,” Ford says. “The most important question was how the fauna was going to respond to that habitat and that beach, despite the dramatic human presence. Fortunately, the response came very quickly.”
surprising return
In March 2016, Ford and his team noticed that, in addition to the dunes, something else had returned: the western white plovera federally threatened species that had not been seen in the Los Angeles region for almost 70 years. The first nest in the Los Angeles region was found in 2017 inside the dunes and contained three eggs.
The plovers have since returned to the restoration area to nest. They also appeared native plant species that had not been planted by The Bay Foundation, such as pink sand verbena and dune beetleswhich serve as food for birds and which had not been observed in the reference studies prior to restoration.
“While the control areas were flattened and uniform, the restored area showed small dune mounds, an increase in berm height, and constant sand retention over seasons and years,” notes a five-year report. published by the foundation.
“It was a truly extraordinary year,” Ford says. “The plovers left us a little speechless. “They came back tremendously quickly.”
The main challenge, Ford says, was not knowing whether the public would respect the cordoned off area. “We weren’t going to build a 10-metre high fence to keep people out, and the only way to answer the question of whether visitors would respect the place was to see how the situation developed.”
Ford was “pleasantly surprised.” “Everyone has responded wonderfully. We have never had an incident of vandalism or any type. I have seen children playing with driftwood that has accumulated. We hoped it would be an added experience to the beach to see it in a more natural way. Let people imagine: ‘Wow, beaches don’t have to be like a giant sand parking lot.’”
In January 2023, the dunes were tested by a strong storm that brought waves and high tides. The meteorological phenomenon caused considerable erosion on several beaches in Los Angeles, but did not affect the restoration zone, where the waves stopped in the dunes, instead of advancing between 20 and 30 meters along the beach in the control zone.
Resilience tool
“Sand dunes play an important role in coastal erosion because they serve as barrier against the advance and overflow of waves” explains Timu Gallien, associate professor of civil and environmental engineering at the University of California, Los Angeles. “When there are large waves that coincide with high tide, in many cases they can flood the beach.”
“But when you have a dune structure, it provides additional elevation. That allows those waves to rise and infiltrate the dunes, instead of rising and passing over the sand and flooding the infrastructure, parking lots, building structures and the Pacific Coast Highway that are located in the bank”.
Although Santa Monica Beach may seem wide, there are “many ways a beach can be flooded,” explains Gallien, and the wide, flat beach is not immune, especially to heavier rainfall and rising sea levels.
Gallien joined The Bay Foundation project earlier this year to officially begin observing ecosystem changes in the new phase of the project.
“Anecdotally, we have seen that the cessation of beach cleaning is allowing the nature take its courseand with limited management we have begun to see the development of some small sand dunes and depressions in the beach, as well as the reappearance of plants and animals. So the project has evolved very well so far.”
While it’s too early for Gallien to talk about the results of the Santa Monica project, a similar restoration initiative he oversaw at Cardiff State Beach in San Diego has become the benchmark project for living shorelines. That is, coastal edges made of natural materials that protect coastal communities and provide habitat for wildlife.
The Cardiff project is a hybrid structure: a dune on top, but a large ditch below. “In 2003 there was a big swell,” Gallien recalls, “and the structure worked very well. “It served its coastal protection function, and I think it is being considered a possible solution across the state.”
“Dunes are nature’s way of protecting the coast,” explains Gallien. “But we have often paved them or built on them. I think these living shoreline projects are fantastic because you are actually building with nature and not against it. And, of course, they are visually very attractive. I think it’s him way forward for many coastal municipalities.”
A report by a group of Californian scientists who have studied the dune restoration project since its inception discovered substantial differences between the beach before and after the intervention.
Dunes had visibly formed along the fenced perimeter, and new plants that had been covered by the windblown sand were still growing above the newly deposited sand. Approximately 2,760 metric tons of sand had accumulated since December 2016.
The project has been so successful that the foundation has cordoned off another five hectares (20,200 square meters) and planted more native seeds. They are also studying expanding the project by another 40 hectares (162,000 square meters).
Other southern beach officials, who have noted Ford’s success, are eager to launch their own coastal restoration projects. “People are going to love it,” he says. “It’s going to be beautiful. And we are very happy to try again.”
This article was published on BBC Future. Click here to read the original version.
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