The Accidental and Imperiled Salton Sea

Like most folks, our travel plans for this summer have been scrapped.  As we try to come up with alternative plans compliant with social distancing regulations and such, I've been looking back at some of the magnificent places we have been fortunate enough to visit in the past several years.

Two years ago, during our semi-annual desert pilgrimage, Eric and I spent a couple of days around the Salton Sea, California's largest and most imperiled lake.

The tale of the Salton Sea stretches far back into geologic time to the Pleistocene (between about 2.5 million and 11,000 years ago), when the meandering course of the Colorado River shifted north as it crossed its broad delta at the northern edge of the ancestral Gulf of California.  This type of shift happened more than once, causing the Salton Basin (or Salton Sink) to alternately fill with water, then evaporate, then fill again.  The cycle was repeated several times, as evidenced by the presence of wave-cut shorelines and different elevations in the basin.

The most recent of the Pleistocene lakes was Lake Cahuilla, a large freshwater lake which filled the Salton Basin to a depth of 300 feet.  Lake Cahuilla spanned 35 miles across and stretched nearly 100 miles long, reaching from the Colorado River Delta north to present-day Indio.

Maximum extent of Lake Cahuilla approximately 500 years ago, filling the Salton Basin of Southern California.
Image source:

Radiocarbon dating of fish bones and other pieces of evidence suggests that by the year 1100, Cahuilla Indians were making their home along the shores of the ancient lake.  But by the time Spanish explorers visited the region in the 1500's, the massive lake had vanished.  Local legends tell of a large lake, teeming with fish, that disappeared little by little, presumably evaporating after the fickle Colorado River changed its course once again, effectively cutting off the flow of freshwater into the basin.

Recreated Cahuilla Indian settlement at the Salton Sea State Recreation Area visitor center.

For several hundred years, the Salton Basin existed as a dry lake bed, a smooth playa of dried mud and sediment that would fill to a shallow depth after significant rainfall.  These silt deposits, high in nutrients deposited by the Colorado River, have since become the fertile and productive fields of the Imperial and Coachella Valleys.

Our tale of the modern Salton Sea picks up again at the beginning of the 20th century, as farmers began cultivating - and irrigating - the fertile alluvial soils of the sunny Imperial Valley.  To bring water to their crops, irrigation canals were dug and water was diverted from the Colorado River.  In 1905, floodwaters from the Colorado River burst over the inadequate levees.  For 18 months, water from the Colorado River flowed into the Salton Basin, which lies over 200 feet below sea level, bringing the dry lake back to life.  By the time engineers were finally able to stem the tide in 1907, the Salton Sea had been born, at 45 miles long, 20 miles wide, and just 50 feet deep.  By area, it is the largest extant lake in California.  Only Tulare Lake in the southern San Joaquin Valley was larger, but this lake went extinct in the 1930's at the hands of farmers and their thirsty crops.

It might be said that this accidental sea arrived on the scene at just the right time, providing alternative habitat for scores of waterfowl displaced by the receding waters of Tulare Lake and the rest of the 95% of California's freshwater wetlands that have been destroyed.  The Salton Sea, situated as it is along the Pacific Flyway, provides critical habitat and food for over 2.5 million birds, and serves as a link to the Colorado River Delta and Gulf of California.  In 1930, the Salton Sea National Wildlife Refuge was established at the southern end of the lake.  (The refuge has since been renamed the Sonny Bono Salton Sea National Wildlife Refuge in honor of that famous individual who happened to be a proponent of saving the Sea.)

A Snowy Plover along the Salton Sea shore.

Beginning in the 1950's, the Salton Sea experienced a tourism boom.  Its proximity to the already-popular Palm Springs area made it an attractive prospect, and resorts began springing up around the lake as land owners sought to cash in on the burgeoning tourism industry.  During its peak years, the Sea saw 1.5 million visitors annually, more than visited Yosemite National Park!  Tourists, weekenders, and folks on holiday from nearby Los Angeles lined up for miles to spend their recreation dollars along the sunny shores of this inland sea.

Boating, swimming and sun bathing all appealed to these holiday-goers, but the Sea's excellent fishing was the real draw.  Several species of fish were stocked in the Salton Sea, some with greater success than others, which created unsurpassed recreational fishing opportunities.  By the late 1950's, the Salton Sea was the most productive fishery in all of California, and its lakeside communities were a mecca for anglers.

The white beaches of the Salton Sea are comprised entirely of barnacles.

During World War II, seaplanes practicing their military maneuvers inadvertently introduced barnacles to the Salton Sea.  Hitchhiking barnacles that became detached from the planes in the Sea found a lack of predators and a surprisingly hospitable environment in which they thrived.  I imagine that a decade later, when the Salton Sea was a thriving tourist destination, the barnacles weren't so numerous; there were probably actually sandy beaches around the lake.  But over the decades, the numbers of barnacles multiplied until they reached astronomical proportions.  Today, the white beaches of the Salton Sea are comprised not of sand, but of billions upon billions of dried barnacle shells.


As a terminal lake with no outlet, the Salton Sea is, perhaps ironically, subject to flooding.  In the 1970's, a series of particularly heavy tropical storms caused lake levels to rise to the point that resort towns along the shore were badly flooded.  The initial damage was done to the inundated resorts, and tourism steadily decreased as the Salton Sea fell out of favor with vacationers.  By the 1990's, lake levels began to drop considerably as changing policy diverted water to cities, leaving formerly bustling docks, boat ramps and swimming areas high and dry.  Most of the remaining businesses withered away.

Today, resort towns like Salton City on the Sea's west shore, and Bombay Beach on the east shore are ghost towns, desiccated husks of their former glory.  Yet they hold a sort of appeal for certain types: for photographers, hipsters, Instagrammers and those who enjoy steeping themselves in the things of yesteryear, I wouldn't entirely discount a visit.  Think abandoned buildings, derelict boats, rusted-out cars, eerie metal sculptures, lots of graffiti, and an annual Burningman-esque festival.  Not my cup of tea, but that doesn't mean it can't be yours!

Most of the fish species that were introduced to the Salton Sea have also died out, due to increased salinity and other environmental factors.  But tilapia, a freshwater fish native to the warm, shallow waters of Africa, which was introduced to the Sea unintentionally, has thrived and proliferated in the absence of predators.  Though considered a freshwater species, tilapia show a degree of tolerance to saltwater conditions and have been able to persist in the increasingly saline environment.  Even today, fishing is, supposedly, good around the lake, with no catch limits on tilapia.

But all is not well with the ichthyofauna of the Salton Sea.

In the mid-1990's, tilapia began dying off en masse.  The cause of these mass fish die-offs has been attributed to algal blooms triggered by agricultural runoff, but certainly poor water quality and high salinity are culprits as well.  When excessive nitrogen from surrounding fertilized fields finds its way into a body of water, the pulse of nutrients cause huge blooms of algae.  When these masses of algae die and begin to decompose, available oxygen in the water is readily consumed in the decomposition process, resulting in deadly eutrophic conditions in which fish, starved of oxygen, simply drown.  The decomposition of the fish carcasses only exacerbates the problem by consuming additional oxygen.

Not surprisingly, these mass fish die-offs are troubling and produce their own set of negative ramifications, not least of which being their contribution to the general odor of decaying matter that pervades along the lake shore.  (When we visited, I don't remember being bothered by any smells; then again, I'm rather fond of the smell of low tide along the coast.)  Occasionally, though, the sea "burps up" hydrogen sulfide from the lake bottom, a gas created by the decomposition of organic matter.  On days of "odor advisories," the lake's fragrance wafts as far as Los Angeles, 150 miles away.

The second potentially offensive thing, of course, is the presence of decomposing and desiccated fish carcasses lining the beaches and shoreline.  With a beach composed entirely of barnacles and fish bones, I wouldn't recommend going barefoot!

Desiccated tilapia on a salt-encrusted barnacle beach 

Perhaps more significant than aesthetics to the concerned naturalist and biologist are the harmful effects fish die-offs have on resident and migratory bird populations.

Over 400 species of birds rely on the Salton Sea for either breeding, overwintering, or stopover habitat during their migration along the Pacific Flyway, and the sea has become one of North America's premier birding destinations.  (Guess why we visited!)  Ducks, geese, grebes, and other migratory birds use the Salton Sea as wintering habitat, and resident breeding birds include the rare Yuma Clapper Rail, the formerly endangered Brown Pelican, and California's largest population of Burrowing Owls.

A whiteboard, updated with bird sightings, at the Salton Sea State Recreation Area's newly updated visitor center.

But even the creation of a national wildlife refuge, while undoubtedly an invaluable move, has been unable to offer adequate protection for many birds.

From the late 1980's through the 2000's, a wave of mass bird die-offs sparked major concern.  Causes for these deaths included avian cholera and botulism, and waterfowl affected included grebes, pelicans, cormorants, ducks, and geese, among others.  When combined with an abundance of dead and decaying fish, the warm conditions of the shallow Salton Sea are ideal for spreading botulism, particularly during periods of warm weather.  (And the Sea is in a low desert, so...)  When fish carrying the bacterium for botulism die and are consumed by piscivorous, or fish-eating, birds, botulism spreads through the avian population, causing a second wave of mass die-offs.  In 1996 alone, an estimated 8,500 American White Pelicans, accounting for up to 20% of the species' Western population, died at the Sea, along with 1,600 Brown Pelicans, which was an enormous blow to an already endangered species.  Newcastle disease, a virus familiar to and dreaded among those who raise poultry, cropped up in 1997 for the first time west of the Rocky Mountains, nearly wiping out a breeding colony of Double-crested Cormorants.

The situation was critical and overwhelming to authorities ill-equipped to deal with the scale of disaster faced by the avifauna of the Salton Sea.  Yet even so, heroic efforts were made by the Salton Sea Authority and the U.S. Fish and Wildlife Service to collect infected bird carcasses and rehabilitate sick birds.

Black-bellied Plover along the shore of the Sea.

Yet another concern for the birds of the Salton Sea is the threat of selenium poisoning through bioaccumulation.  Though selenium is a necessary mineral, high concentrations cause grotesque birth defects and death in birds that have consumed large quantities of the element.  Selenium from agricultural runoff concentrates in sediments, where invertebrates dwell.  When invertebrates are consumed by fish and birds themselves, the toxins they have ingested move up the food chain, concentrating at the top in predatory birds.  Species with the highest risk are those at the end of the longest chains, birds like pelicans, herons, and cormorants, which frequently consume the largest fish.

The modern day Salton Sea is sustained largely by agricultural runoff from surrounding fields, though today, even that flow has been dramatically reduced.  Water issues are complex, and agricultural runoff is notorious for carrying high loads of pesticides, fertilizers, and salts, furthering the sea's already significant salinity issue.

But to stop the agricultural runoff is to cut off the sea's main source of freshwater.  In a desert basin that routinely reaches summertime highs of 110 degree Fahrenheit, evaporation is high.  California's trend of drought doesn't help.  And the sea's shallow nature is perhaps worst of all: a small drop in lake level, say only one vertical foot or so, exposes thousands of horizontal feet of dry lake bed.

The shoreline of a shrinking sea.

As the sea shrinks and more and more dry playa is exposed, desert winds kick up impressive dust storms.  But this is no ordinary dust: this is toxic alkali dust, the result of a century of deposition of chemicals and heavy metals into the lake.  As a result, the county that holds the dubious honor of being home to the Salton Sea, Imperial County, has the highest rate of asthma-related hospitalizations in California.

While the economic implications of the loss of the Salton Sea as a recreation area are obvious in the dilapidated communities surrounding the lake, and the environmental implications of the loss of vital habitat are evident in the decreased numbers of birds, the most significant danger the shrinking sea poses is the negative effects its windblown hazardous dust has on human health and agriculture. 

The future of the Salton Sea remains uncertain.  While there are plenty of folks who would love to see the Salton Sea restored to its former mid-century glory, prohibitive costs and, frankly, a lack of available water in the West make that scheme unrealistic.  But the dust must be controlled, and habitat needs to be preserved.  A recent proposal, dubbed The Salton Sea Restoration and Renewable Energy Initiative, aims to maintain a much smaller lake at the north end of the present-day Salton Sea, and create a series of shallow ponds and wetlands in the southern end of the basin which would serve to both suppress dust and create wildlife habitat.  There is also significant potential for the development of geothermal energy in the area, as the Salton Sea itself sits on a fault running parallel to the San Andreas Fault, which begins along the Sea's eastern shore.

Sunset at Mecca Beach

So, let's review:

The Salton Sea sits in the middle of a vast desert along a major fault line, and is filled with water that is inhospitable to life.  Its beaches are composed entirely of fish bones and barnacles, it often reeks of decomposition and sulfurous gasses, and is susceptible to wind storms that kick up clouds of toxic dust laden with salts, chemicals, and heavy metals.  The water supports very little life, massive fish die-offs are commonplace, and bird population numbers are dwindling.

Who wouldn't want to visit this charming place?

That being said, Eric and I were pleasantly surprised by our visit to the Salton Sea.

Naively anticipating spring break crowds, I eagerly made reservations at Mecca Beach campground, carefully selecting a prime lakeshore campsite ahead of time by pouring over one of my favorite resources,  But I needn't have worried.  There are, after all, 1,400 campsites to choose from.  As Eric and I cruised into the desolate campground on the Monday evening following Easter, we were met with... silence.  Utter stillness and quiet.  One lone RV, a small van, and a tent down at the far end of the campground.  The rest of the sites were empty, with nary a soul in sight.  (A vastly different experience from a previous spring break trip to Joshua Tree, which involved circling the campgrounds until we found a family packing up to leave, at which time we pounced greedily on their site before it was even vacated!)

Camping at the Salton Sea's Mecca Beach campground

We had a delightfully peaceful experience along the eastern shore of the Salton Sea, watching the sun sink over the mountains as the breeze played through the tamarisk and a Cactus Wren called from atop a telephone pole.  The bathrooms were spotless, the showers had hot water, and the visitor center was newly refurbished, with an informative video, gift shop, and eager park rangers happy to chat.  The Salton Sea State Recreation Area, at least, is prepared for a brighter future ahead.

Salton Sea State Recreation Area Visitor Center
Photo from because I didn't think to snap one while we were there!


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