Coho salmon found in Sonoma Coast creek for first time in 60 years
The excitement started with a flash of silver followed by a hefty dose of disbelief.
A team of conservationists and biologists from The Wildlands Conservancy, the nonprofit that manages the 5,600-acre Jenner Headlands Preserve on the Sonoma Coast, couldn’t believe what they were seeing: the telltale color and shape of juvenile coho salmon, darting back and forth in the clear current of the East Branch Russian Gulch.
It had been decades since the endangered fish had made its way to that arm of the watershed.
And yet there they were, as Ryan Berger, Corby Hines and Luke Farmer of The Wildlands Conservancy looked on.
“I had never heard of coho being in the Russian Gulch in recent memory,” said Hines, a ranger with the group.
Coho salmon once thrived in the coastal watersheds of Sonoma County and the broader North Coast, where winter rain, summer fog and the protective canopy of towering redwood forest sustained young fish and spawning adults over millenia.
Decades of logging, including industrial-scale operations that picked up after World War II, decimated much of the forestland, unleashing enormous amounts of sediment into the stream channels, burying the gravel beds that salmon and steelehead trout needed for spawning.
Development, gravel mining and other human activities eliminated flood plains, channelized flows, and limited the woody debris and shade that keeps the water cool enough for young fish to survive.
By 1965, the last year Russian Gulch was surveyed for coho salmon, water temperatures were past the 70-degree threshold for salmon survivability. Coho, the rarer of two native salmon species, were gone and steelhead, an ocean-going rainbow trout, were a rarity.
That changed with the confirmation that came after the flash of silver this summer.
Hines and California Fish & Wildlife biologist Mary Alswang returned days later and documented the presence of coho during a snorkel survey.
The biologists didn’t find just one fish, but 239 young coho and 336 young steelhead or fry, the term for fish that are less than a year old.
Coho had been sighted in the main stem and West Branch Russian Gulch in 2005, but hadn’t been seen in the East Branch since 1965, Hines said.
While their return is cause for celebration, the fish documented this summer represent a small fraction of the abundant runs historically found on California streams. They were declared an endangered species two decades ago, and together with the two other imperiled species, Chinook and steelhead, tens of millions of dollars have been spent in the region trying to restore habitat, improve flows and remove barriers to boost wild fish numbers.
Overall salmon stocks, including fish bred and released from hatcheries, have continued to struggle, however, with California now in its third year without a commercial season, where Chinook are the targeted species and coho are off-limits.
“The status of salmon in California is not great,” Charlie Schneider, connectivity program manager with the group CalTrout, said during the 50th annual Zeke Grader fisheries forum on Oct. 1. “But as anglers, we’re hopeful and hope is the fuel for momentum.”
There are some reasons to be hopeful.
Along with the Jenner Headlands discovery, Chinook salmon were recently sighted in Alameda Creek in the lower Niles Canyon for the first time in 70 years. The sightings come just weeks after Pacific Gas and Electric Co. and CalTrout finished a $15 million project to remove a gas pipeline that was the last barrier impeding upstream migration.
Schneider noted that coho salmon were also found earlier this fall farther north in tributaries of the Navarro River of Mendocino County, a watershed devastated by logging in the 1960s.
“Salmon are pretty good at finding and using habitat when it is suitable to them,” Schneider said. “Coho have had some decent runs the last couple of years on the North Coast so it’s great to see them showing up in some of the smaller watersheds.”
In Sonoma County, special restoration work has gone into restoring wild coho salmon. Local runs were on the brink of extinction 20 years ago when a few hundred wild juveniles were collected from west Sonoma County’s Green Valley Creek and other small streams. That effort led to the Coho Recovery Broodstock Program in 2001 at Lake Sonoma, which hopes to rebuild a self-sustaining population.
The program releases young fish in local waters deemed to be good coho habitat, hoping they imprint on those streams and return as adults to reproduce naturally.
The “rewilding” effort, as Berger, the Wildlands Conservancy Sonoma Coast calls it, has been aided in recent years by back-to-back seasons of strong rains plus the Wildlands Conservancy’s restoration work.
The projected Jenner Headlands property provides a unique place to advance restoration efforts. The property was preserved in 2008 by a coalition of six public and private agencies for $36 million, the largest conservation acquisition in the county at the time and still the costliest.
The Wildlands Conservancy took over management of the property in 2013 and opened in to the public in 2018. A year later, the group got to work restoring stream beds, including sediment leftover from the era of heavy logging. When they were done, they’d repaired about 3.5 miles of channel for spawning.
Then they waited.
Season after season, Berger and his team continued to check the streams to see if they had returned to baseline conditions: water at 70 degrees or lower, with adequate oxygen and balanced pH levels.
“We knew the streams being degraded overtime meant it probably wasn’t in great condition,” Berger said.
Juvenile salmon need water no warmer than 70 degrees to survive. They stay in pools of fresh water for a year after emerging from their gravel beds in April before making their way to the ocean the following spring “to eat a bunch and get strong,” Berger said.
Salmon then stay in salt water for two years before returning — typically — to the same fresh water they were born to spawn. But, as Berger and his team acknowledged, sometimes salmon will venture somewhere else and find other water that is still suitable for spawning.
Last year, The Wildlands Conservancy received a report of an adult salmon sighting from a hiker, which could explain this year’s discovery of juvenile fish.
“I don’t think it was born in East Branch Russian Gulch. It likely wandered away, discovered newly open habitat and took advantage,” Berger said, adding that “it was a really good year for coho salmon across Sonoma County watersheds.”
Amie Windsor is the Community Journalism Team Lead with The Press Democrat. She can be reached at amie.windsor@pressdemocrat.com or 707-521-5218.