Surprise Bird-Rich Wetlands Emerge on Dry Lakebed of Shrinking Salton Sea

In February 2020, Andrea Jones scrambled up Obsidian Butte, a lava dome on the southeastern corner of Salton Sea. Amid the expanse of dry, exposed lakebed, the result of decades of water diversions and ongoing drought, she also saw a glimmer of green—unexpected reeds and cattails taking hold around the edge of the sea, signs of budding wetlands. Birds, including dowitchers, American Avocets, Common Yellowthroats, and Black-necked Stilts, flitted about. “It seemed like a sanctuary to me,” recalls Jones, director of bird conservation at Audubon California.

Later that day, as her team tromped through the arid San Felipe wash on the sea’s southwestern shore, they stumbled on another nascent wetland. “We walked half of a mile through bone-dry playa, and suddenly Marsh Wrens and Song Sparrows emerged from reed-filled shallow water bursting with song," Jones says. "Then Sandhill Canes flew by." It was becoming clear how, despite the Salton Sea ecosystem undergoing a massive transition, these wetlands were sustaining high numbers of shorebirds and ducks.

In early 2020, Jones and Frank Ruiz, Salton Sea program director for Audubon California, took to the skies to get a better look. Once viewed from a plane, “those wetlands stick out like a sore thumb,” Ruiz says. Green patches contrasted starkly against the sandy backdrop. Agricultural drains—dozens of ditches and pipes directing water off nearby farmland—once flowed directly into the sea. But as the sea shrinks, their outflow now trickles and meanders across exposed playa, allowing wetlands to form.

They are a happy surprise amid an otherwise desperate scene at the Salton Sea, a 343-square-mile inland saltwater lake and the largest remaining body of water in California. It sits in an ancient lakebed, which has expanded and receded over centuries, filling with water during floods and then evaporating in the desert. Its current existence dates back to 1905, when floodwaters breached a levee on the Colorado River. It's been sustained almost entirely by a dwindling supply of highly polluted agricultural runoff from the Coachella Valley on the sea’s north shore and the Imperial Valley to the south. In recent decades, however, persistent drought made worse by climate change and fights over rights to limited water reduced these inputs into the sea. In the last 10 years alone, the Salton Sea surface has dropped by 10 feet and shrunk by 38 square miles.

Bird populations have shifted significantly as the sea shrinks, responding to changes in their prey. Fish numbers plummeted by 97 percent over the past decade; only Mozambique tilapia and native desert pupfish can still survive in the saltier waters. American White Pelicans, Double-crested Cormorants, and other fish-eating birds, which once numbered in the thousands, are largely gone, says retired ornithologist Robert McKernan, who has conducted weekly bird surveys on the Salton Sea for almost a decade. Other populations are erratic. Eared Grebe numbers plunged from 3 million in the 1980s to 100,000 or 200,000 in recent years, McKernan says.

Even so, the Salton Sea remains the best habitat left in southern California for 400 species of migrating birds and 65 species of waterbirds, including the federally endangered Yuma Ridgway’s Rail. “It’s become the replacement for Tulare Lake, Owens Lake, and Mono Lake,” Jones says, referring to nearby lakes that have dried up in the last century. “The birds have no other place to go.”

The emergent wetlands are therefore a welcome accident and critical bird habitat in a state that has destroyed roughly 97 percent of its wetlands. Yet they can disappear just as swiftly as they emerged without efforts to stabilize them. “These wetlands will dry up now if not taken care of,” she says.  

So Jones decided to take care of them. Funded by a $700,000 grant from the U.S. Bureau of Reclamation, Audubon California has begun a wetland enhancement project, which aims to at least double 250 acres of burgeoning wetlands near Bombay Beach, a former beach getaway turned ghost-town art community on the south side of the Salton Sea, by further spreading water out on the dry playa. The project will also help suppress the toxic dust that has left surrounding communities with a 30 percent asthma rate when it blows off the desiccated landscape and is breathed in. Additionally, a state agency effort is underway to restore 4,100 acres of medium-salinity wetlands at the mouth of the New River, which delivers polluted and high-salinity runoff and wastewater into the sea, to create deeper pools of fish habitat. Together the projects aim to sustain the wetland refuges that will allow Salton Sea to continue to provide desperately-needed bird habitat in southern California.

The wetlands were first observed in 2016 by McKernan; he calls them "postage stamps." They were small refuges of freshwater agricultural inflow where he noticed birds congregating. To his surprise, the new habitat persisted at the drain outputs and soon were robust enough to support a prey base. “By 2019, we saw herons concentrated at these drains, foraging on smaller fish,” he says.

When Daniel Orr, director of geospatial science at Audubon California, mapped their extent, he documented a stunning 6,752 acres of vegetation on the exposed playa, of which 5,409 acres were vascular plants; the rest were algae. “Most of the habitat that is popping up in the south and the northern parts of the sea is mostly from the agricultural drainage,” Orr says. The agricultural water, however, comes from the hotly-contested Colorado River. For a century nearly every drop of Colorado River water has been claimed for farms, cities, and other uses, divvied up by water-sharing agreements among the seven U.S. states in the river basin and Mexico. Now, given increasing drought and ever-higher demand, the federal government has tasked those states to make necessary cuts. While negotiations are still underway, water cuts are expected to force some farmers to leave fields unplanted. Without water for crops, there is no water for the sea, causing it to shrink further.

The remote stretch south of Bombay Beach has a more reliable water source: artesian springs.  Jones and Ruiz were intrigued to find Northern Pintails and Northern Shovelers thriving there. “It had the feeling of a real wetland with ponds of unvegetated open water nestled in the reeds,” Jones says. Graduate student Camila Bautista has used oxygen isotopes to confirm that the water fueling the Bombay Beach wetlands comes from springs, rather than the Colorado River.

Without a steady supply of water, the survival of the rest of the wetlands forming around the agricultural drains is uncertain. The two chief Colorado River storage reservoirs, Lake Mead and Lake Powell, have dropped to their lowest levels on record. The seven Colorado River basin states have struggled over the last few months to come up with a plan to drastically cut water use. 

The Audubon team is bracing for the inevitable cuts. “It’s just a matter of how much water we will be losing,” Ruiz says. They won’t be able to save all of the emerging wetlands, dependent as they are on farmers’ excess. That will make Bombay Beach, which doesn’t rely on the Colorado River, all the more vital for birds of the Salton Sea.