The tide is high at Elkhorn Slough, as it usually is this time of year. Harbor seals and sea otters take refuge in the sheltered waters, sunning, feeding on crabs and entertaining kayakers. By now, most of the sharks have migrated back out to Monterey Bay. They’ll return again in the late spring, and through the summer they’ll breed in the slough’s shallow waters. Along the banks, pickleweed seasonal colors turn the marshes rusty red.

Birds like Western sandpipers and black-bellied plovers roost in higher grounds, taking a rest from their winter journey to warmer climates. In all, tens of thousands of birds stop at Elkhorn Slough as they travel along the Pacific Flyway, the migration route for West Coast birds. As the tide ebbs, these birds will fly down from their posts and feed along the exposed mudflats before resuming their long commutes.

“There are a couple places where you can paddle up the slough and park your kayak on an ebbing tide and be enveloped by streams of shorebirds,” says Mark Silberstein, executive director of Elkhorn Slough Foundation. “It’s kind of like you’re in a school of fish. They surround you, and the sound of the wind and the wing is just one of those things that connects you.”

A few flocks of pelicans pass through. Most already have made their migration down to Baja, where they winter and breed. Earlier, in the fall, raptors flew overhead.

“This is an incredible window on these phenomena that most people have very little idea about, or little understanding of, or little consciousness of,” Silberstein says.

But the slough is in trouble. Man has been altering Elkhorn Slough for more than 100 years, and now its tidal marshes are rapidly eroding. This threatens the plant and animal life, and it’s harmful to human interests, too, including the railroad, Highway 1 (which crosses the slough), eco-tourism and water quality. Invasive species and global warming also pose danger to the water and wetlands. And as with any waterfront property in California, there is always pressure to build big homes with amazing views. It will take a collective effort to save Elkhorn Slough.

Curious, with reason

As Silberstein and co-author Eileen Campbell write in Elkhorn Slough, published by Monterey Bay Aquarium, “Elkhorn Slough is a curious place.”

There are scientific reasons for this: Elkhorn Slough estuary contains California’s second-largest salt marsh, and it’s one of the most biologically rich areas along the coast. The slough and watershed include 45,000 acres of oak forests, maritime chaparral, mudflats, working farms, streams and wetlands, all of which provide habitat for some 102 fish species, 340 birds species and 550 marine invertebrates species. More than two dozen rare, threatened or endangered species, like the red-legged frog and the Santa Cruz long-toed salamander, make the watershed their home. While reading the numbers may make one’s eyes glaze over, actually seeing the plants and animals up close is delightful.

There’s the way the light plays on the salt marsh and sandy dunes as the plants turn colors with the changing seasons. There are the sounds of the slough: the wind and the sea, sea lions barking, harbor seals slapping, sea otters breaking open clams, birds calling and flapping their wings. As Silberstein says, it’s one of the few places in the world where you can stand in the shade of an oak and see shark fins cutting through the water.

Not just attractive to animals

The diverse plant and animal life also brings humans to the slough – to kayak alongside sea otters and harbor seals, to bird watch, to walk the trails from the hilly uplands to the mudflats at the waters’ edge, to teach students about the estuary, to conduct scientific studies and to discover new species of sea critters.

It’s a beautiful place, but the marshes are disappearing. About 50 percent of the tidal marsh has been lost in the past 70 years. This puts the entire ecosystem out of balance.

There also are the ever-present land-use tensions: More and more people want to live on the coast, and they need homes and safe roadways. Consequently, Elkhorn Slough feels developers’ pressure. Currently, a plan to expand the Pajaro Valley Golf Course – building 174 dwellings, adding nine holes to the 18-hole course, expanding the clubhouse by 6,650 square feet on 272 acres – sits in the county’s approval pipeline. The proposed development could reach to within 200 feet of the slough. An environmental impact report, nearly a decade in the making, likely will be released to the public by the end of January, according to Monterey County planners. Once they make the EIR public, county supervisors will schedule a hearing on the proposed development before voting on it.

Changes with the seasons

A narrow arm of the Monterey Bay, Elkhorn Slough reaches about seven miles from its mouth at the Moss Landing Harbor to the Carneros Creek. It extends inland and bends at its elbow before branching into five thin fingers. It’s considered a seasonal estuary – where fresh and salt water meet – because it doesn’t have a year-round freshwater flow. In the winter, the Carneros Creek runs from the upper Elkhorn Valley and flows down into the slough. But in the spring, the creek goes dry, and by late summer, when the sun evaporates the still, upper waters, the slough becomes saltier than the sea.

On a clear day in early fall, a lookout point near the visitor’s center offers breathtaking views of the slough and its surroundings. Grassy hills dotted with oak trees, manzanitas and other maritime chaparral slope down to pickleweed marshes along the slough’s main channel and freshwater wetlands. At low tide, mud flats can be seen between the water and the vegetation. Along the ocean end of the slough, small, silvery plants take root in fragile sand dunes.

Brown pelicans and seagulls fly overhead, egrets and herons hunt the marshes, and loons and diving ducks glide along the water. Beneath the water’s surface, clams, worms and ghost shrimp burrow in the mud, some bat rays and sharks feed on the burrowing invertebrates, and bright green bay pipefish hide in clumps of eelgrass.

But it isn’t a pristine landscape. The railroad runs along the slough, and the Highway 1 bridge crosses its mouth. Looking southwest, the Moss Landing Power Plant and its two 500-foot smoke stacks rise in the distance.

Trails lead down to the old Elkhorn Dairy Barn, which, at its peak between the 1920s and 1950s, supplied 75 percent of Watsonville’s retail dairy products. Now the land and the old, vacant barn are owned by the Elkhorn Slough National Estuarine Research Reserve. Other trails loop around the marshes and the slough’s five fingers.

Silberstein points out the diverse slough habitats, from the grassy uplands to the submarine canyon that dives more than a mile from Monterey Bay’s surface.

“What’s so cool about Elkhorn Slough is that you can go from these upland ridge tops to the deep sea in about five miles, from these rare maritime chaparral plants to these really diverse, bizarre sea creatures that [scientists] discover,” Silberstein says.

Founded in 1982, the Elkhorn Slough Foundation is a nonprofit dedicated to preserving and restoring the slough and its watershed. To this end, the foundation works to acquire land in the watershed, some of which comes from gifts. The foundation buys other parcels with a combination of public and private money. Then, in partnership with the research reserve, the foundation manages the properties, restoring wetlands and grasslands and working with farmers and ranchers to provide sustainable farming operations.

‘Center of the universe’

Silberstein’s standing at the lookout point, binoculars seemingly attached to his eyeballs, with reserve Manager Becky Christensen, who works for the state Department of Fish and Game. (Another slough curiosity: It’s one of those rare places where the state, federal government and a nonprofit work in harmony. The research reserve is one of 27 in the country, owned and managed by Fish and Game, and operating in partnership with the National Oceanic and Atmospheric Administration and the Elkhorn Slough Foundation.)

Silberstein suddenly points to a group of falcon-like birds, with white feathers underneath and black wingtips and shoulders. “White-tailed kites!” he shouts. “Look at them – one, two, three, four, five. These guys are breeding in the trees.”

“This is an incredibly rich, diverse, important, rare place,” Christensen says. “But,” she adds, “it is in need of care. There are habitat issues. There are water issues.

“It’s easy to drive by on Highway 1 and see the sparkling water and say, ‘Wow, this is a beautiful place.’ You can see that from just one kayak trip. But there are invasive species under the mud, under the water you’re kayaking on. The banks are eroding away because of tidal scour and unless you’re measuring that, you wouldn’t notice dramatic differences.”

In the distance, a flock of white specks fly by. “We have some white pelicans,” Silberstein says, binoculars obscuring his eyes.

Elkhorn is a hub of research, education and conservation, and yet there’s something about it that induces even hard-core scientists to talk about the place in magical terms.

“Mark calls it the cosmic center of the universe,” Christensen says.

Elkhorn Slough is also a nationally important resource. But it almost wasn’t. If developers and industrialists of the past had had their way with the estuary and wetlands, all of it might have been lost.

People’s heavy influence

People have been altering the nature of Elkhorn Slough for more than a century. Farmers diked and drained wetlands in the late 1800s to create land suitable for growing crops and grazing dairy cows. Sports enthusiasts took advantage of the estuary’s large numbers of waterfowl, ponding areas and using them for duck hunting.

Beginning in the early 1860s, sea captains and growers built a number of landings, warehouses and a wharf to allow local farmers to ship their products to San Francisco and beyond. In 1872, the Southern Pacific Railroad built tracks, and trains began moving produce beyond the Central Coast.

In 1946, the U.S. Army Corps of Engineers drastically altered the slough’s landscape, dredging a new entrance to Moss Landing Harbor. Previously, the slough wound north before flowing into the bay. The Corps cut straight through the sand dunes between the harbor and the slough, which directly opened the estuary to Monterey Bay.

“When I was growing up in the late ‘30s and ‘40s, it was still a brackish habitat,” says Supervisor Lou Calcagno, whose north Monterey County district includes Elkhorn Slough. “A lot of ducks, waterfowl galore, and salt ponds.

“That all changed when the Corps of Engineers opened the Harbor. The jetty you see now by Sea Harvest restaurant – that was man made. The harbor district – that’s all dredging. Behind the Whole Enchilada – that’s all dredging. The Captain’s Inn [Moss Landing Inn Bed and Breakfast] – all dredging, too.”

Once the Corps dredged a new entrance to Moss Landing Harbor, it increased the size and speed of tidal currents coming in from the sea. This intensified scour and erosion, and it encouraged farmers to further modify the natural environment.

“With the tidal action came more levies,” Calcagno says. “Farmers had levies out along the Elkhorn Slough to protect their farms and grazing ground. As time progressed, all the marshland was basically levied off.”

Calcagno, a dairy farmer, was born and raised on the banks of Elkhorn Slough. In 1982, he co-founded Elkhorn Slough Foundation. He remembers the nearby canneries – and their horns that would call the fish cutters, factory workers and sardine packers to work – before the sardine fishery fell into decline. He also remembers heavy industry coming to Elkhorn Slough after the United States entered World War II.

In 1942, Kaiser Refractories built a plant to extract magnesium from seawater. The magnesium was used to makes bombs, and after the war, the plant (located next to the existing Moss Landing Power Plant) was converted to produce bricks. A few years later, Pacific Gas & Electric Co. began building its steam-generated power plant that came online in 1950.

Today, other developments planned for the area in the 1960s and ’70s sound absurd. In 1965, Humble Oil (now Exxon) proposed a 50,000-barrel-a-day refinery. PG&E considered a nuclear power plant. The state Department of Transportation wanted to re-route Highway 1 across the middle of the slough. And developers envisioned hundreds of condos on the slough, complete with a marina for wealthy homeowners’ sail boats.

Some imagined it the start of a Salinas-Moss Landing Industrial Corridor. “I remember the signs on either side of Highway 1,” Calcagno says. “They said, ‘Where power, water and electricity meet.’ ’’

But then, strong community opposition, along with changes in federal and state laws, including passage of the National Environmental Policy Act, the Clean Water Act and the California Coastal Plan, killed the industrial dreams. The slough, in a sense, went to the birds. And the slugs and the salamanders and the sharks. But development plans didn’t all disappear.

In 1998, Pajaro Valley Golf Course owner Charles Leider submitted a proposal to Monterey County’s planning department to expand the golf course and build 174 townhouses and single-family homes. About that time, local artist Mari Kloeppel became a community activist.

“We saw the red flags [showing where the new building would be located] go up, and it was all along the banks of the Elkhorn Slough on the northern end,” Kloeppel says. “We were shocked. We had just assumed that property was protected.”

Kloeppel called county planners to learn the scope of the proposed development and then called a neighborhood meeting. “About 40 people showed up in our little house.” And FANS, or Friends, Artists and Neighbors of Elkhorn Slough, came to life.

The planned development likely will raise several environmental issues. Water is in short supply in north Monterey County, including Elkhorn Slough. Ground water is overdrafted – it’s being pumped out of the ground faster than nature can recharge the aquifer – and seawater intrusion and nitrate contamination threaten freshwater wells. Additionally, the planned development’s proximity to Elkhorn Slough would make it difficult to control runoff into the estuary. Plus, Salinas Road (where the golf course is located) and other country roads in the area aren’t built to accommodate heavy traffic.

“People have dreams and ideas, and they are going to try to build those dreams,” Kloeppel says. “When it comes to land use, as long as the land is in private ownership, people can ask to do whatever they want. So they’re gonna ask. And it’s up to the county and the Coastal Commission to decide whether the ideas are appropriate or not.”

So much lost, so little time

For years people didn’t value marshes. But now, the tides are turning, so to speak. For Elkhorn Slough, it’s not too late.

The numbers are staggering: 50 percent, or 1,000 acres, of Elkhorn Slough’s salt marshes have been lost over the past 50 years because of human activity. Currently, channel banks erode at the rate of one to two feet per year, and interior marsh dieback rates are at least three acres per year. This harms the estuary’s plants and animals, but it also affects water quality, public access sites and roads.

Since 2004, a group of scientists, local, state and federal officials, conservationists and community members – more than 100 collaborators in all – have been working on a project to restore the Elkhorn Slough watershed, called the Elkhorn Slough Tidal Wetland Project.

“Estuaries worldwide have been very highly altered by human activities, and Elkhorn Slough is no exception,” says Kerstin Wasson, reserve research coordinator and the project’s lead scientist. “The challenge is figuring out how we can best conserve and restore the destroyed habitats in the face of the future alterations and constraints posed by human activity.”

In other words, Elkhorn Slough is a working landscape. It’s got farms and homes, a nearby harbor, fishermen and boats, a railway running though it, and a highway crossing over its Army-Corps-of-Engineers-created mouth, which nature didn’t intend to be its mouth at all.

As detailed in the plan, the project has three main goals: “conserve existing high-quality estuarine habitats, restore and enhance degraded estuarine habitats and restore the physical processes that support and sustain estuarine habitats.”

Wasson describes the situation as a “three-ring circus,” with a ring each for government agencies, scientists and community members. They meet separately; occasionally they all convene.

Within the next year, she says, the group will make the tough decisions about how to reduce marsh dieback and estuarine habitat erosion. “And then we start the road to implementation – EIRs, permits, funding,” Wasson explains.

The Tidal Wetlands Project team doesn’t have the solutions – yet. They are considering various options, including building tidal gates, or a fill under the Highway 1 bridge to restore the original size of the Elkhorn Slough mouth, or even re-routing the mouth to its former location. “Frankly, we just don’t know what is the best alternative right now,” Wasson says. “So we’ve got hydrologists, biologists, social scientists, economists and the community weighing in. It’s not just a science question or just a harbor question. There’s not one solution that will satisfy all targets.”

For example: increased tidal flushing, which happens as a result of the deep, wide, man-made mouth of the slough, improves water quality and prevents stagnation. It also causes erosion and loss of salt marsh. “But on the other hand, it’s good for kayaking,” Wasson says. “”It’s good for boating, and eco-tourism.” Then she argues another counter point: “Restoring a more natural amount of tidal flushing is the only way to bring our salt marsh back. It would be better for some species, clams and fish species that need a shallow habitat.

“We’re dealing with shades of gray, and weighing complex ecological and human tradeoffs.”

It takes a village

Back at the reserve, Christensen and Silberstein watch as a train runs through the marsh.

“It takes a lot of different efforts to preserve a slough,” Christensen says. “Scientists who come and work here. Taking that science and getting it into the minds of children and adults through education. People think it’s only the advocates saving the slough. But you’ve got to know what to save and how to save it.”

Then Silberstein gets mystical. “There’s a spirit that has generated here that has produced collaborations that don’t often happen,” he says. “People have been able to share some common vision. There’s this common sense that here’s something we need to take care of.”

Adds Christensen: “Nobody today is saying let’s put a marina or a nuclear power plant on the slough.”

The will to preserve the slough exists. But it takes more than will. It takes a slew of people – elected officials, government agencies, nonprofits, scientists, friends, artists and neighbors – to save a slough.

CHECK OUT THE ELKHORN SLOUGH TIDAL WETLAND PROJECT ONLINE AT ELKHORNSLOUGH.ORG/TIDALWETLANDPROJECT/INDEX.HTML