Instead of squiggling away like the others, one greenish-gray salmon that Gabriela Dunn released into Marin County’s Redwood Creek on Friday turned around and swam back, almost as if to give the Golden Gate National Recreation Area intern a last heartfelt goodbye.

“She doesn’t want to go,” said Dunn, 26, who held out her hand for the fish, which was on the last leg of a harrowing journey that would soon end in its death and, against all odds, breathe new life into a beleaguered waterway.

The California Department of Fish and Wildlife and the National Park Service released 188 coho salmon Friday into the creek that flows down from Mount Tamalpais, through Muir Woods, across Muir Beach into the ocean.

It is a desperate attempt to save a cherished run of fish that for thousands of years migrated yearly through this redwood-lined coastal watershed and then nearly vanished. The 3-year-old salmon were among the last survivors when they were plucked from the creek in 2015 and raised at the Warm Springs Fish Hatchery in the Sonoma County community of Geyserville.

Their relocation to a hatchery saved the coho from making the perilous journey to the ocean, where 98 percent of migrating salmon are typically killed by predators, pollutants or sickness, according to Manfred Kittel, a coho salmon recovery coordinator for the California Department of Fish and Wildlife.

“These fish are going back into the creek as adults now, and we are hoping that they will be able to swim upstream in the creek, spawn naturally and the progeny will then have an opportunity to grow up in the stream and imprint on the stream,” Kittel said. It “is really a collaborative effort to prevent the extinction of these coho salmon in Redwood Creek.”

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Redwood Creek is the historic home of the southernmost continually returning natural population of coho salmon in the western United States. Coho, which are also known as silver salmon, were once so plentiful that Miwok Indians used the area as a seasonal fishing village, competing with grizzly bears for the bounty. The fish thrived in a network of wetlands, dunes and a 13-acre freshwater lagoon.

Coho typically return from the ocean at age 3 during the first rains of the year and swim up the streams where they were born to spawn and die. The three-year coho life cycle means there are three separate generations of spawning fish.

Over the past century, the creek was forced into a narrow channel as road construction, agriculture and recreation eliminated the natural floodplain. Pollution and drought made the situation worse.

Although coho have been disappearing throughout their range, the decline in Redwood Creek has been precipitous. Fewer than 10 fish returned to spawn in five of the seven years before 2014, when the once abundant species stopped spawning in the midst of California’s five-year drought. That’s when the National Marine Fisheries Service, the U.S. Army Corps of Engineers, National Park Service and California State Parks decided to rescue all the baby fish in the creek.

Problem was, no salmon eggs, called redds, were spotted in the shade of the world-famous redwood grove, and not a single baby coho could be found that summer. Instead, fisheries biologists removed 1- to 1½-year-old fish that had been unable to migrate out to the ocean because the water level was so low. Biologists collected 200 fish in each of the next two years in an effort to make sure each year-class was safe.

Kittel believes the 2013 generation of coho went extinct. The 106 fish collected in 2014 were released a year ago in an attempt to replenish the extirpated population. The release Friday is part of the effort by fisheries biologists to play coho cupid.

A crowd of beachgoers, biologists and locals gathered Friday as the coho were brought over in a tanker truck, plopped two at a time into ice chests, wheeled over to the creek, and let go.

“By cutting out the portion in the ocean where a lot of them get eaten, we now have a lot of big, healthy fish,” Naomi LeBeau, a restoration specialist with the Golden Gate National Parks Conservancy, said as she netted the writhing fish and placed them in ice chests. “I think the future is bright. I have hope.”

The calamity in Redwood Creek is all the more troubling to conservationists in light of the recent restoration of the historic marshlands and tidal lagoon at Muir Beach, which was supposed to be a bonanza for coho. The $15 million project by the National Park Service and the parks conservancy included the rerouting into the ocean of the creek, which flows past the cozy Pelican Inn on scenic Highway 1.

Kittel said the restoration work could help as the planted fish and their offspring struggle to survive. He is waiting for lab results of tissue samples taken from juvenile fish captured in the creek last summer to determine whether they are the offspring of the fish released a year ago.

Although coho spawning has so far been pretty dismal all up and down the coast, the rains this week appear to have prompted a surge of activity.

On the other side of Mount Tamalpais, coho are just now beginning to swim up Lagunitas Creek, a waterway that has long been considered the bellwether of wild salmon health in Central California.

“The coho have arrived,” said Eric Ettlinger, an aquatic ecologist for the Marin Municipal Water District, which oversees the creek. “It’s likely that when all streams have been surveyed our count will exceed 100 coho redds, which would still be below average but no longer disastrous.”

Dunn, the intern who spent her day releasing salmon into Redwood Creek, said she is “honored” to do her part.

“I picked this job so I could contribute to preserving the Earth,” she said as she stood thigh deep in the water with her net, “so this is a great moment for me.”

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com Twitter: @pfimrite

Smattering of salmon facts

Range: Coho salmon are found on both sides of the North Pacific Ocean from Hokkaido, Japan, and eastern Russia, around the Bering Sea to mainland Alaska, and south all the way to Monterey Bay.

Description: Adults typically weigh 8 to 12 pounds and are 18 to 30 inches long, though individual fish weighing 31 pounds have been caught.

Life cycle: Anadromous, meaning adults re-enter natal freshwater streams to spawn after spending half of their three-year life cycle in the salty Pacific Ocean. Adults die within two weeks of spawning. Fry grow to 4 to 5 inches long before heading to the Pacific.