How Much Longer Will Wild Coho Hang on in the Golden State?

As wild salmon teeter closer to extirpation in central California, conservationists work to rewild the floodplain and reshape our relationship with it.

RIBBONS HANG FROM redwood boughs above Lagunitas Creek in Marin County, California. They’re there to demarcate redds, saucer-shaped depressions in the gravel bed below, where coho salmon spawn and where inch-long fry later emerge to begin their tumultuous three-year life cycle between river and sea.

creekside restoraton in Tocaloma
On average Lagunitas creek and its tributaries host about 250 redds annually, but that number has been steadily decreasing. This year, there were less than 50 redds. The salmon conservation group SPAWN, along with the National Park Service and local agencies, is working to restore the floodplain as a nursery for juvenile salmon. Photo by Austin Price

“Usually between here and the road there’s a half dozen redds or more,” says Todd Steiner, pointing 100 feet or so downstream to where Sir Francis Drake Boulevard passes over the confluence of Lagunitas Creek and San Geronimo Creek, near the town of Lagunitas. But only two ribbons hang from the trees. That’s been the typical story for this year’s coho salmon run throughout the Lagunitas Creek Watershed. Even for a wild salmon population that’s been listed as endangered since 1996, this year’s spawning survey came up with significantly low numbers.

“This current year is one of the lowest numbers we’ve seen,” says Steiner, who is the executive director of the conservation group Turtle Island Restoration Network, based in nearby Olema.

Historically, anywhere from 5,000 to 10,000 adult coho created more than 2,600 redds in this watershed each year. According to NOAA’s recovery plan for the federally endangered Central California Coast population of coho salmon, Lagunitas Creek and its tributaries now have the capacity to hold 1,300 redds. This takes into account that half of the salmon habitat in this river system has been blocked or submerged by reservoirs that hold the water supply for the quarter-million people who live in Marin.

On average, Steiner and his team count 250 redds annually, but that number has been steadily decreasing. This year, there were less than 50 redds.

“You expect there to be good and bad years in the ocean, and good and bad years in freshwater,” Steiner says. “But when it gets down to the tens of surviving nests, the population might not have the resilience to survive those bad years.”

In the late 1990s, Steiner started a program called the Salmon Protection and Watershed Network, or SPAWN, after he noticed endangered coho thrashing and struggling on the fish ladder at Roy’s Dam in the town of San Geronimo. For nearly 25 years, SPAWN has fought to restore coho salmon runs in Lagunitas Creek, doing everything from suing private developers for illegal creekside development to rewilding private and public land to restore salmon habitat. SPAWN also works with the National Park Service and the Marin Municipal Water District to conduct an annual spawning survey.

For millions of years, populations of Pacific salmon have evolved to match the conditions of their home rivers. Coho salmon, smaller than Chinook, found an ecological niche in the quiet tributaries and slow-moving side channels in the rivers of central California’s coastal redwood forests and floodplains. Starting in late November, winter rains give adult coho the hydrological boost into the freshwater system to dig their redds and lay thousands of eggs. As those eggs hatch in the spring, the inch-long fry find shelter in creeks stabilized and shaded by redwoods and Douglas firs. Rotting logs and the riparian ecosystem attract the aquatic insects that coho eat, while logjams and willows allow the river to scour out pools and side channels where juvenile coho can take shelter during storms before they don their silvery scales and head for the open ocean through Tomales Bay.

Even today, the coho of the Lagunitas Creek Watershed is one of the healthiest populations of wild salmon in California. It represents up to 20 percent of the Central California Coast evolutionary significant unit of coho, a population that covers 4,000 square miles from southern Humboldt County to Santa Cruz and includes the much larger Russian River. In fact, some say that the Lagunitas Creek contains the only viable wild population left in Central California.

But for Steiner and his staff at SPAWN, this relatively healthy population is teetering dangerously close to extinction, cut down to just 5 percent of its historic population.

As David Montgomery, a University of Washington geomorphologist, wrote in his 2003 King of Fish: The Thousand-Year Run of Salmon, “Under human influences the landscape gradually evolved right out from under salmon.” In other words, wild salmon have historically maintained populations to withstand rough conditions like droughts and storms, but in just a century, human impact has done what millions of years of these conditions couldn’t do.

IN THE TOWN OF San Geronimo, Steiner unlocks the gate to a four-acre, fenced-in property alongside San Geronimo Creek. A paved driveway wraps around an old house to a three-car garage extending into the riparian zone where a small backwater spills into the rushing tributary.

“So much of the floodplain has been developed that what’s left is a kind of bowling alley,” says Preston Brown, a watershed biologist for SPAWN, as he points out the wall of quarried rock and decades-old retaining walls on either side of the creek. He notes that this spot, the confluence of two streams, is a common area to spot spawning salmon. “Here’s an opportunity to widen the corridor, slow the water down, increase the riparian buffer, put in some wood, and let this creek be more dynamic,” he says.

Woodacre Creek
Woodacre Creek, a tributary of San Geronimo Creek and historical spawning site for many of the watershed’s coho, flows through its fixed channel between houses and development. Much of the riparian area along this creek has been developed in this way. “At the same time we’re repairing the land-use mistakes of the past, we’re repeating them,” says SPAWN’s Todd Steiner. Photo by Austin Price.

Last year, SPAWN purchased this property for close to a million dollars with the intention of rewilding the floodplain and then reselling the house as affordable housing. The team plans to emulate work they’ve already done downstream, at the site of the ghost towns of Tocaloma and Jewell.

For the past few years, SPAWN has worked closely with the National Park Service to rewild these two communities on federal land. In what was once Tocaloma, where SPAWN has made its headquarters, Brown points out where creekside retaining walls and structures have been replaced by restored floodplain. With help from volunteers, SPAWN placed fallen logs in the creek and built overhanging banks with straw logs to encourage logjams and side channels with slower water. Native grasses and willows from an onsite plant nursery have taken root in the riparian area, their shoots poking through a biodegradable erosion control fabric.

“It’s like a beaver pond,” Brown says. “It’s backwater habitat that’s quiet, complex, and deep.”

Of course, emulating beavers on just a few sections of the watershed goes only so far and, as Steiner says, won’t be enough to restore endangered salmon to NOAA’s goal of 1,300 redds. “At the same time that we’re repairing the land-use mistakes of the past, we’re repeating them,” he says.

Further upstream, roads and concrete abutments hold San Geronimo Creek to its current pathway as it winds through homes in the towns of Woodacre, San Geronimo, and Lagunitas. Houses sit close to the creek — in some instances close enough that the corners of their foundations poke through the ferns and mud of the eroded riverbank.

In the middle of this residential zone, the creek runs through the San Geronimo Golf Course, the latest site of land-use contention in the area. In 2017, the Trust for Public Land purchased and closed the 157-acre golf course with the intention to sell the land to the county to be restored as a park and wetland habitat. But that move has been met with resistance from local residents attached to the golf course, resulting in a measure on this upcoming March ballot that puts the land’s function into a political quagmire between golf and ecological services.

“The problems are obvious,” Steiner says, summing up what he sees happening in this watershed. “The current major impact is continued development.”

Through litigation, Steiner has urged the county to enforce a streamside ordinance that prevents further development in the natural floodplain. People and fish can coexist, Steiner explains. That’s his goal in Marin County, but he believes we still have a long way to go to ensure the coho’s survival, even in this quiet, forested corner of the Bay Area.

Beyond restoration and county ordinances, that coexistence might require reshaping how we look at the places we occupy. As Montgomery wrote in King of Fish: “Saving salmon…will not succeed as a surgical effort orchestrated by fishery technocrats…[but] will require reshaping our relationship to the landscape, guided by the humility to admit that we do not know how to manufacture, let alone manage, a natural ecosystem.”

There are a lot of factors impacting California’s salmon, from changing conditions in the ocean to the question of water rights in our freshwater systems. But in our streamside development, the question is: How much time do we have to gain that humility?

Back at the banks of Lagunitas Creek, Steiner and Brown scan the water for any sign of a spawning fish. Nearby, San Geronimo Creek roars over a series of shoals known as the Inkwells before its confluence with Lagunitas Creek, but the chainsaws of a construction crew across the stream roar even louder as they cut through a small strand of oaks adjacent to the road.

Now late January, Steiner doesn’t expect to see any more adult coho this winter, but he takes another look, perhaps hopefully, into the gravel-bed stream. “No fish,” he says. “I’d say the run is over.”

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