The Importance of Pickleweed & The Plight of California's Coastal Salt Marsh

The evidence is there: I am a proponent of the underdog, and that sentiment extends to underappreciated habitats.  Marginalized, abused and underappreciated habitats abound in California, right alongside majestic Sierran peaks and captivating rocky Pacific shorelines.  From coastal dunes to deserts, sagebrush scrub to the grasslands and wetlands of the Great Central Valley, much of California's less glamorous habitats have been largely degraded. 

The coastal salt marsh is certainly one such habitat. 


Picklweed-dominated salt marsh, with shallow salt pan and dunes in the background, blooming gumplant in the
foreground. Salinas River NWR.

Coastal salt marshes, also called tidal marshes, occur in protected areas of bays and estuaries that are subject to tidal influence but sheltered from the strong winds and waves found elsewhere along the coast.  Salt marshes are found widely scattered along California's coast, and in an unaltered system they function in conjunction with tidal flats (mud flats), shallow naturally occurring salt pans and freshwater streams to create a diverse and highly productive habitat mosaic.

In Northern California, Humboldt Bay, Tomales Bay, San Francisco Bay, Monterey Bay and Morro Bay all support remaining patches of salt marsh habitat.  Farther south (and outside of my realm of expertise) remnants of salt marsh can be found in the Carpenteria Marsh south of Santa Barbara, Ballona wetlands in Los Angeles, Bolsa Chica near Huntington and lagoons in the San Diego area.

In the Monterey Bay region, I highly recommend a visit to Elkhorn Slough and Moss Landing harbor.  Salinas National Wildlife Refuge also provides access to salt marshes, salt pans and dune habitat.  In the San Francisco Bay area, there are a few salt marsh areas left and some are being restored.  Try visiting Don Edwards National Wildlife Refuge, China Camp State Park or the small restored marsh at Crissy Field.


Salt marsh at China Camp State Park

Around the year 1800, scientists estimate there were approximately 190,000 acres of salt marsh in the San Francisco Bay alone.  By 2009, that number had dropped to about 40,000 acres, with less than a quarter of original salt marsh remaining.  As the largest estuary on the west coast of North and South America, the tidal marshes around the San Francisco Bay provide critical - and critically endangered - habitat for an array of wildlife species in addition to providing a number of ecosystem services to surrounding areas.

Historically, tidal wetlands, like freshwater wetlands, were seen as unproductive, wasted land, and herculean efforts were made to "reclaim" this land.  (I hate that phrase, by the way; it's a total misnomer.)  Around the San Francisco Bay, dikes and levees were built to create arable land, and wetlands were backfilled for urban development.  Flood control projects were instated and extensive salt ponds were created, further reducing tidal wetland habitat.  (Ironically, the creation of artificial salt pond habitat during the late 1800's and early 1900's corresponded with the draining (e.g. destruction) of important and extensive inland wetland habitats of the Great Central Valley, such as Tulare Lake, and provided some shorebirds, like American Avocets and Black-necked Stilts, with an alternative suitable breeding ground after they were forced to abandon the Valley.)

But there is good news.  For the past decade or two, efforts have been underway to restore some of the Bay's salt marshes, as well as other California tidal wetlands.  The goal is set for San Francisco Bay: 100,000 acres of salt marsh are needed for the ecosystem to successfully sustain itself.  In the southern part of the Bay, former salt ponds are being reconfigured to a more natural state in an effort to strike a sustainable balance between salt pond management and tidal marsh habitat.  According to reports, the plan is working; salt marsh habitat is returning, and with it, endangered wildlife is also making a small comeback.

Salt marsh and mudflats provide food and shelter for an abundance of birds at Moss Landing harbor

Wetland areas such as the coastal salt marsh provide a number of services to human populations as well as to wildlife.  Wetlands provide flood control, acting as a sponge to soak up flood water and store it safely.  They also function as a filter, improving water quality, and a barrier, preventing shoreline erosion.  (Think of those long tubes of straw you see at construction sites, only much, much larger, more efficient and far more aesthetically pleasing!)  And of course, wetlands possess the intrinsic value shared by all natural, unspoiled areas.  We need beautiful places, like wetlands, in which to reconnect with nature as adults, as well as introduce children to its never-ceasing wonders.

The climate of coastal salt marsh areas is generally about the same as nearby coastal strand habitats (beaches and dunes, collectively): mild year-round temperatures, a long growing season, little available freshwater and low rainfall, thick fog, and heavy salt spray driven by harsh winds.  But despite these tough conditions and twice-daily inundations of saline sea water, a number of plant species are able to thrive - particularly, halophytes (salt tolerant plants).  One of the most important and conspicuous of these is Pickleweed (Salicornia spp.)


Pickleweed

Pickleweed, also called Glasswort and Pacific Swampfire, was indeed used for making pickles at one time by early pioneers, due to its high salt content.  Surprisingly, it was also used to make glass, as another of its names would suggest.  High sodium content in the fleshy leaves of Pickleweed was converted to soda ash when burned, which is one of the raw materials used in glass production.  (I don't know a whole lot about it, but it seems soda ash allows silica - the raw material sand - to melt at a lower temperature.  The type of glass produced by this method is called soda-lime silica glass, so named for its three essential ingredients.)  The moniker "swampfire" is descriptive of the plant's succulent leaves, the tips of which turn red and drop off as they accumulate excess salts.

Illustration of the zonation of plants in salt marshes and adjacent communities, from one of my favorite books,
A Natural History of California, by Allan A. Schoenherr

Other plants of the salt marsh vegetation types grow in accordance with their tolerance of tidal inundation.  For example, salt grass (Distichlis spicate) doesn't tolerate inundation and is therefore found only along the upper edges of the marsh.  (Salt grass is also found in inland areas of alkaline or saline soils, near wetlands as well as some upland areas in the Great Central Valley, east of the Sierra Nevada crest, and in desert regions.)  Cord grass (Spartina foliosa), on the other hand, tolerates being covered with sea water during rising tides and is found along lower margins of the marsh.


Salt marsh gumplant

Plant diversity is low in the costal salt marsh, but other species indicative of this unique habitat include arrow grass (Triglochin spp.); the succulent-leaved sea blight (Suaeda spp.); the humble yellow-flowered Marsh Jaumea (Jaumea carnosa) and showy yellow-flowered salt marsh gumplant (Grindelia stricta), both of Asteracea; alkali heath (Frankenia spp.), which is not really a heath at all; the equally misnamed marsh rosemary or sea lavender (Limonium californicum), which is neither a rosemary nor a lavender but pretty nonetheless; and the curious dodder (Cuscuta spp.), which infests salt marsh plants (as well as desert plants) with its strange, parasitic orange strands and is actually related to morning glories.  (Will the wonders of botany ever cease?) 

This mosaic of plants serves to support banks and prevent erosion, filter water by trapping sediments and taking up nutrients, and provide valuable habitat for a number of species of birds as well as mammals.  The high productivity of salt marshes produces an abundance of detritus (particles of decomposing organic matter) which feeds amphipods and other invertebrates such as worms and snails, which in turn support an abundance of avian life.  Herons and egrets patrol the edge of still water, while Long-billed Curlews probe the mud.  Black-necked Stilts forage in the shallows and American Avocets filter food from the water using their upturned bills. 

Along the water's edge, the rarely seen endangered Ridgeway's Rail (Rallus obsoletus), which was known as the California Clapper Rail (Rallus longirostris obsoletus) prior to 2014, and the California Black Rail (Laterallus jamaicensis coturniculus) make their homes in dense marsh vegetation.  The Ridgeway's Rail is almost entirely restricted to tidal marshes of the San Francisco Bay.

Belding's Savannah Sparrow

Several sparrows are also salt marsh obligates, requiring this unique habitat type for survival.  The Belding's Savannah Sparrow (Passerculus sandwichensis beldingi) lives in pickleweed, feeding on seeds and able to drink sea water. Three distinct subspecies, or geographic "races," of the Song Sparrow (Melospiza melodia) exist in salt marshes around the San Francisco Bay: Alameda (M. m. pusillula), San Pablo (M. m. samuelis), and Suisun (M. m. maxillaris).  These populations are highly sedentary, as pairs remain on their territory year round, able to raise multiple clutches of young on the abundance provided by perhaps less than one acre of salt marsh habitat.

Also endangered and endemic (restricted) to the San Francisco Bay's salt marshes is the Salt-marsh Harvest Mouse (Reithrodontomys raviventris).  This little nocturnal mammal builds its nest in the marsh vegetation, and has adapted to survive on sea water.  Due to the extensive loss of salt marsh habitat, the Salt-marsh Harvest Mouse has become restricted to a few isolated patches of habitat around the Bay.
 

A tangle of pickleweed, perhaps the most important plant of the salt marsh



Whether birding along the shore of a pickleweed marsh, hiking upland coastal trails or kayaking through Elkhorn Slough, I hope you are able to take a moment to appreciate the intricate ecosystem that is the coastal salt marsh.  Habitats like these don't often get the publicity of glamorous Coast Redwood forests, and it's likely you're far more familiar with charismatic Spotted Owls or awe-inspiring California Condors than secretive rails and mice, but these little creatures require our attention anyway - even more so due to the years of degradation their habitats have suffered.

For an uplifting read (with photos a million times better than mine), check out this National Geographic article: How the Bay Area Is Restoring Nature's Delicate Balance.