top of page

Build It —And They Will Come

Written by Josiah Clark, this long-form article details the decline of San Francisco  wetlands and the small glimmer of hope to be found in the restoration of Crissy Fields.

Sometimes, while you are following something overhead — a falcon, perhaps — you notice things in the background. Specks, way up there: raptors, ducks, passerines, shorebirds — aerial plankton eluding our detection most of the time. As a fledgling birder in San Francisco, I caught glimpses of shorebirds in migration wheeling high over the avenues. I yearned to search out curlews and sort through peeps, but the fertile habitats that once dominated the site of San Francisco had disappeared long before I was born.


Historical accounts of San Francisco’s biodiversity pique the interest of any ardent naturalist. Extensive swaths of riparian habitat bordered salmon-laden streams. Eagles and condors fought atop the carcasses of whales while grizzlies fed below. Estuaries on the coast and in headland valleys harbored swarms of waterfowl. In what is now known as San Francisco’s Marina district and Crissy Field, Spanish missionaries once wrote of robust dunes and waterfowl flocks that darkened the sky.


But scenes like these began disappearing from California over 200 years ago. With a loss of over ninety-five percent of the area’s original wetlands, much of San Francisco Bay’s flora and fauna have experienced disastrous declines. Shorebirds and waterfowl using the Pacific Flyway once touched down in a mosaic of fresh and saltwater wetlands where there is now only brick and asphalt. In 1911, in the wake of the 1906 earthquake and facing the impending visit of the Pan American Exposition, the last section of this marsh was filled in. For almost ninety years, the sights and sounds of wetlands vanished from the region.


When the Presidio, a former military base, was handed over to the National Park Service in 1994, habitat restoration began breathing life back into rare, native San Franciscan habitats long neglected. Riparian, dune, Serpentine scrub and grassland habitats were nurtured and expanded. Funds for habitat restoration were scant at first, but plant lists decades old were resurrected, rare and relict plant populations were pinpointed beneath the plethora of exotic grasses, and local seeds with their local genes were collected. A few encroaching eucalyptus trees, originally planted to serve as an Army wood source, finally met their long-awaited fate when their trunks yielded the structural supports for green shade-houses, where hundreds of native plants were propagated and cared for. A few park staff, local experts, college graduates, and volunteers organized to create a field office and nursery in an abandoned Army building. Regular volunteer programs brought neighbors, schools, plant buffs, and who-ever would contribute their hands to help with field restoration. The Presidio Park Stewards was born: a community commitment to care for dozens of extant jewels, native habitats and organisms persisting in an urban setting.


The visionary recreation of a small piece of wetland adjacent to the Presidio’s historic Criss Airfield began in 1997, emerging from plants for the environmental remediation of toxic materials (from lead, cadmium, and copper to polycyclic, aromatic hydrocarbons) that lay beneath asphalt and landfill, scar tissue from an era of ignorance. While the U.S. Army footed the bill for the toxic remediation, another thirty-two million dollars had to be raised for excavation, grading, and completion of the marsh that was to take place over the next two and a half years. The money came from many places and was managed by the Golden Gate National Parks Association, the park’s official non-profit partner. Three and a half million dollars came from the San Francisco Airport as mitigation for wetlands destruction there. The lion’s share of the funds came from private donors and corporate groups.


By the time I was invited to work on the project under the unglamourous but descriptive title of “seasonal weeder” in August 1999, toxins had been removed and twenty acres of pavement had been peeled back to make way for the marsh. Rainwater and bay backwash from a ruptured gutter pipe settled as temporary ponds and puddles. Bulldozers left acres of bare dirt and sand where exotic weed species indulged in their own version of primary succession in an urban setting. I did not know it at the time, but the palate was empty as it would ever be: the stage was set for an array of species to return. Plant compositions were painstakingly researched. Seeds were collected from the most similar ecosystems to retain the genetic integrity of rare species. A restoration team was formed to remind the land of the marsh it once knew well.


The multitudes of dormant exotic weeds that sprouted yielded ethnobotanical clues to cultural invasions of yesteryear and today. But a few dormant native plants appeared as well, bringing to light genes hidden from the world for centuries. Among the natives in the seed bank was a lone Beach Morning Glory, considered extinct in San Francisco since the disappearance of the area’s tidal marshes. A thick husk of ignorance and cement had glazed over the wetland while the marsh’s productive character remained dormant; just so, the relict morning glory seed lay buried and contain in its thick shell, ready to burst when the light and warmth shone down.


Some high-flying shorebirds may hardly detest Crissy Field, a mere twenty acres of wetland among oceans of development. But if Crissy Field is a speck, it is a speck of hope. For the bird that does not have enough energy to outrun a dog on the beach or extend its flight across the Golden Gate, Crissy is a crucial link on the Pacific Flyway.


Crissy Field now commonly attracts birds that were formerly rare or unheard of in the area. In a little over a year, 128 species have been seen at Crissy Field, and for San Francisco’s bustling birding community, Crissy Field has produced many attractions. While Oldsquaw, Arctic and Common Terns, or Baird’s and Semipalmated Sandpipers are enough to get even the most ardent San Francisco birders on the scene, more common species were enjoyed by all. In its first winter, Crissy attracted many duck species, with over 300 Greater Scaup being present on some days. The sounds of Killdeer have become commonplace, and many folks await their anticipated nesting. The Great Egret, long ago chosen as Crissy’s logo bird, arrived on cue: egrets breeding in nearby rookeries, including one on Alcatraz Island, are now a common spectacle for Park visitors.


The entirety of the Crissy March is visible to the public, although the wetland and dune areas have been fenced for their preservation. The adjacent bay is always worth checking, and nearly half a mile of beach is open for walking. While bird aggregations inevitably fluctuate, there are always birds to look at in the vicinity. As with most marshes in the region, the best times to visit are fall, winter, and early spring.


While the views of the Golden Gate, Alcatraz, and the sailboats may be the initial attraction for many of Crissy Field’s visitors, most people are finding other things worth looking at. Whether it is the gentle curves of the dunes, the uplands painted with wildflower, or a Great Blue Heron appearing to stalk its own shadow, the resurrection of this system provides a crucial link for humans, as well as for birds. For the hundreds of thousands of urbanites who walk the Crissy promenade each year, the restoration site is not only beautiful — it raises awareness of our shared ecological heritage and the the diverse organisms that depend on it.

bottom of page