The Stunning Metamorphosis of San Francisco's Salt Ponds
Through captivating photography, Barbara Boissevain captures the captivating journey of San Francisco's salt ponds as they undergo a remarkable transformation from industrial salt extraction sites to their original, breathtaking marshland state
Note from the editors: Call to Earth is a CNN editorial series dedicated to covering the environmental challenges our planet is experiencing, as well as the potential solutions. In partnership with CNN, Rolex's Perpetual Planet initiative aims to raise awareness and educate the public about important sustainability issues and motivate them to take positive action.
Barbara Boissevain's photographs have drawn comparisons to the art of American painter Mark Rothko, due to their use of deep reds, oranges, pinks, and greens. However, these colors are not created on a traditional palette; they are natural, unfiltered snapshots of the salt ponds in the San Francisco Bay area.
Over the course of more than ten years, the images chronicle the transformation of the area from a commercial salt extraction center back to its original state as a marshy, muddy, and other wetland habitats. The ongoing South Bay Salt Pond Restoration Project, launched in 2003 after acquiring land from the global food corporation Cargill, is dedicated to restoring over 15,000 acres of salt ponds - an area roughly the size of Manhattan.
The vivid, unnatural colors in Boissevain's early photos are a result of the high salinity of the water. She explains that Dunaliella salina, an alga that produces beta-carotene, a red-orange pigment found in carrots and pumpkins, thrives in salty environments. Rosy-colored halobacteria also thrive in these conditions, as do brine shrimp that eat the algae and intensify the vibrant tones.
During the restoration process, the man-made levees constructed to contain water for salt harvesting are gradually dismantled, allowing the tidal systems to once again penetrate the area. This results in a noticeable change in colors, as depicted in the photos. "The striking oranges, reds, and purples slowly transform into greens, deep blues, and brown," she shares with CNN, emphasizing that the "green ribbons of life" are making their way back into the ponds.
Gradually the tidal systems are being restored and wildlife is returning to the area.
Barbara Boissevain
The less attractive appearance of the shift is seen as a positive indication by Dave Halsing, the executive project manager of the South Bay Salt Ponds Restoration Project. "We aim to eliminate those vibrant colors, which are remnants of the hypersaline waters from the salt production era," he explains.
By achieving this goal, the expectation is that wildlife will return to the area, including endangered salt marsh harvest mice, migratory shorebirds, waterfowl, and fish such as leopard sharks and steelhead.
Salt and silicon
The history of salt making in the Bay Area can be traced back to the Ohlone, Native American people who harvested salt from natural tidal pools. With the arrival of European colonizers in the 1800s, the process became industrialized, initially with small-scale operations and later dominated by industry giants like Cargill. At its peak, the Bay was home to around 36,000 acres of salt ponds. Today, Cargill still manages 12,000 acres of salt ponds, with the capacity to produce half a million tons of sea salt annually.
As people move out, wildlife moves in: 10 abandoned locations taken over by nature
Boissevain, a lifelong resident of the area, still resides there with her two daughters. Her first encounter with the salt ponds was during a third-grade science class. It wasn't until 2010, when she was en route to another photography project in a helicopter, that she saw the ponds from above for the first time.
After witnessing its visual splendor, she committed to monitoring the bay's restoration long-term. She initially took annual aerial photographs of the salt ponds but shifted to ground-level and underwater photography during the Covid-19 pandemic. Her latest book, "Salt of the Earth: A Visual Odyssey of a Transforming Landscape," offers various perspectives, showcasing the damage and the landscape's evolution.
The contrast between the restoration of the area and the rapid development of Silicon Valley is especially striking. In Boissevain's photographs of the Ravenswood salt ponds, located on the outskirts of Menlo Park, the headquarters of Meta (the parent company of Facebook and Instagram) stand prominently in the distance. It almost appears dystopian, she remarks, highlighting the discord between humanity and the natural environment.
An image of Ravenswood Ponds from 2020 shows the Meta headquarters in the background.
Barbara Boissevain
Today, wildlife has reclaimed the space, with restored ponds and man-made nesting islands providing shallow water habitat that has attracted hundreds of foraging shorebirds and ducks. Boissevain notes that the number of birds is astonishing, stating "They're screeching and partying out there." He also chose to dedicate the book to shorebirds, emphasizing their fabulousness and apparent happiness with the restored habitat.
Revival
Located along the Pacific Flyway, the Bay Area serves as a crucial rest stop for migratory birds traveling between nesting and wintering sites, as well as a year-round home for shorebirds. Halsing points out that the Ridgway's rail, a species considered "near-threatened," has relocated to the area and is now nesting there. Additionally, populations of native estuarine fish have seen an increase, according to him.
The incredible photographs uncover the hidden world beneath the soil's surface. In addition to the resurgence of wildlife, the transformation of old salt ponds into tidal marshes will provide additional advantages, including protection against flooding as sea levels increase. "Marshes are able to absorb and distribute water and energy from high tides, storm surges, and wind waves," explains the expert. "They also soak up significant amounts of carbon dioxide and assist in lowering greenhouse gas levels in the atmosphere."
Boissevain residents also benefit from this development. "The population in the area has increased significantly since I was a child. It has become much denser," she explains. "Providing people with access to natural spaces is crucial for their mental and physical well-being."
"Salt of the Earth: A Visual Odyssey of a Transforming Landscape" was published by Kehrer Verlag in 2023.
Barbara Boissevain
The area is accessible to the public through a network of trails and viewing platforms, providing an opportunity for people to connect with nature and recognize its importance. However, Halsing reminds visitors to respect wildlife and avoid disturbing sensitive habitats for endangered species. The restoration projects website highlights concerns such as popular selfie spots encroaching on nesting areas for Western snowy plovers and the disturbance of wildlife by drones. Boissevain was inspired by the photography professor David Maisel, who aimed to raise awareness about preserving our natural spaces by using the concept of the "apocalyptic sublime" to draw people in with beauty and then confront them with the harsh reality through his photographs.
The photographer is using the striking images of the salt ponds to capture people's attention in a visually saturated world. She aims to startle and interest viewers with something important and visually noticeable.
