California salmon are at risk of extinction. A plan to save them stirs hope and controversy

Illustration of a Chinook salmon breaching with a dam in the background

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Shasta Dam stands more than 600 feet tall, the height of a 55-story building, with a colossal spillway that towers over the Sacramento River in a curved face of concrete.

Since its completion in 1945, the dam has created California’s largest reservoir, which provides water for farms and cities across the state. But it has also blocked Chinook salmon from returning upstream to the cold, spring-fed streams near Mt. Shasta where they once spawned.

Cut off from that chilly egg-laying habitat, endangered winter-run Chinook have struggled to survive. They’ve had help from an elaborate spawning operation at a government-run fish hatchery, which is intended to function like a life-support system for the salmon.

A map showing Shasta Dam is located about nine miles northwest of Redding, California, on the Sacramento River.

Mt. Shasta

Trinity

Lake

Shasta

Lake

Historical

salmon

habitat

Redding

sacramento

River

15 miles

Shasta Dam

A map showing Shasta Dam is located about nine miles northwest of Redding, California, on the Sacramento River.

Mt. Shasta

Shasta

Lake

Trinity

Lake

Historical

salmon

habitat

Redding

sacramento

River

15 miles

Shasta Dam

A map showing Shasta Dam is located about nine miles northwest of Redding, California, on the Sacramento River.

Mt. Shasta

Trinity

Lake

Shasta

Lake

Historical

salmon

habitat

Redding

sacramento

River

15 miles

Shasta Dam

A map showing Shasta Dam is located about nine miles northwest of Redding, California, on the Sacramento River.

Mt. Shasta

Shasta

Lake

Trinity

Lake

Historical

salmon

habitat

Redding

sacramento

River

15 miles

Shasta Dam

But that support system is no longer enough. As global warming fuels worsening drought conditions and extreme heat, experts say winter-run Chinook are being pushed to the brink of extinction.

Last year, the water flowing from Shasta Dam got so warm that it was lethal for winter-run salmon eggs. Most of the eggs and young fish died. State biologists estimated that only 2.56% of the eggs hatched and survived to swim downriver, one of the lowest estimates of “egg-to-fry” survival yet.

With California in a third year of drought, state and federal officials are moving ahead with plans to truck fish above Shasta Dam and reintroduce them to the McCloud River. After the fish spawn and die, their offspring would be captured and trucked back to waters below the dam to begin their journey to adulthood in the Pacific Ocean.

“The status quo hasn’t worked. And this is why we’re advocating for reintroducing them back into their historical habitat,” said Jonathan Ambrose of the National Marine Fisheries Service.

“They keep smelling their home above the dam,” Ambrose said. “We believe that if we can get them up there now, they’ll thrive.”

The reintroduction plan, however, has raised concerns among members of the Winnemem Wintu Tribe, whose ancestors were displaced by the construction of Shasta Dam, and who consider the salmon to be sacred.

Leaders of the tribe say they want to develop a route for salmon to freely swim upstream past the dam instead of being hauled in trucks. They also say that many winter-run Chinook have been so altered by hatchery life and human intervention that they are no longer fit for life in the wild.

Instead of releasing hatchery-raised fish, the tribe wants to use salmon that once lived in the Sacramento River but were transplanted to New Zealand more than a century ago.

“There is nobody else who is more supportive of bringing fish back to that river than the Winnemem are,” said Caleen Sisk, chief and spiritual leader of the Winnemem Wintu Tribe. “But if you’re going to bring hatchery fish, then we will oppose it.”

A map showing winter-run Chinook salmon's migration route in California. SacramentoRiver

McCloud River

Shasta Dam and nearby Keswick Dam block salmon from their cold-water spawning habitat in the McCloud River.

Mt. Shasta

Shasta Dam

Shasta Lake

Trinity Lake

Adopted

spawning range

In the heat of late spring and summer, winter-run Chinook lay their eggs in gravel on the bottom of the Sacramento River.

Keswick Dam

Clear Creek

Swimming downstream

After the eggs hatch, the juvenile fish head downstream. In drought years, with low reservoir levels, reduced river flows and warmer water, the survival rate of juvenile fish has plummeted.

Pacific

Ocean

Historical habitat

Most of the salmon's natural upstream habitat is blocked by dams.

Sacramento

The young fish that survive swim to the San Francisco Bay and out into the ocean. Years later, adult salmon will migrate back to the Sacramento River and its tributaries.

San Francisco

San

Francisco

Bay

30 MILES

A map showing winter-run Chinook salmon's migration route in California. SacramentoRiver

Shasta Dam and nearby Keswick Dam block salmon from their cold-water spawning habitat in the McCloud River.

McCloud River

Mt. Shasta

Shasta Dam

Shasta Lake

Trinity Lake

Keswick Dam

Adopted

spawning range

In the heat of late spring and summer, winter-run Chinook lay their eggs in gravel on the bottom of the Sacramento River.

Clear Creek

Swimming

downstream

After the eggs hatch, the juvenile fish head downstream. In drought years, with low reservoir levels, reduced river flows and warmer water, the survival rate of juvenile fish has plummeted.

The young fish that survive swim to the San Francisco Bay and out into the ocean. Years later, adult salmon will migrate back to the Sacramento River and its tributaries.

Sacramento

Historical habitat

Most of the salmon's natural upstream habitat is blocked by dams.

San Francisco

San

Francisco

Bay

Modesto

30 MILES

A map showing winter-run Chinook salmon's migration route in California. SacramentoRiver

Shasta Dam and nearby Keswick Dam block salmon from their cold-water spawning habitat in the McCloud River.

McCloud River

Mt. Shasta

Shasta Dam

Trinity

Lake

Shasta

Lake

Keswick Dam

Adopted

spawning range

In the heat of late spring and summer, winter-run Chinook lay their eggs in gravel on the bottom of the Sacramento River.

Clear Creek

Swimming

downstream

After the eggs hatch, the juvenile fish head downstream.

Historical habitat

Most of the salmon's natural upstream habitat is blocked by dams.

In drought years, with low reservoir levels, reduced river flows and warmer water, the survival rate of juvenile fish has plummeted.

Sacramento

The young fish that survive swim to the San Francisco Bay and out into the ocean. Years later, adult salmon will migrate back to the Sacramento River and its tributaries.

San Francisco

San

Francisco

Bay

Modesto

30 MILES

A map showing winter-run Chinook salmon's migration route in California. SacramentoRiver

Shasta Dam and nearby Keswick Dam block salmon from their cold-water spawning habitat in the McCloud River.

McCloud River

Shasta Dam

Mt. Shasta

Shasta

Lake

Trinity

Lake

Keswick Dam

Adopted

spawning range

In the heat of late spring and summer, winter-run Chinook lay their eggs in gravel on the bottom of the Sacramento River.

Clear Creek

Swimming

downstream

After the eggs hatch, the juvenile fish head downstream.

Historical habitat

Most of the salmon's natural upstream habitat is blocked by dams.

In drought years, with low reservoir levels, reduced river flows and warmer water, the survival rate of juvenile fish has plummeted.

Sacramento

The young fish that survive swim to the San Francisco Bay and out into the ocean. Years later, adult salmon will migrate back to the Sacramento River and its tributaries.

San Francisco

San

Francisco

Bay

Modesto

30 MILES

Upstream from Shasta Dam, the McCloud River is fed by cold water that courses through spaces in volcanic rock and pours out in springs. The winter-run salmon evolved to spawn in this cold mountain water during the summer heat. And the river once teemed with fish.

For years, the Winnemem Wintu Tribe has advocated a different approach to reintroducing salmon in these cooler waters. They have called for developing a “swimway” that would allow salmon to reach the river on their own.

Walking along the edge of a creek in the green hills near Shasta Lake, Sisk looked down into the clear, shallow water.

“My hope is that they be able to swim up this river, swim up this waterway all the way to the lake, all the way to the McCloud, and out again,” Sisk said. “There are hundreds of miles of river and water spawning grounds above these dams.”

The tribe developed a reintroduction proposal several years ago that included diagrams showing how a swimway could be designed with a holding pool, pumps and a pipe system that would allow fish to swim upstream, exiting through a floating structure in the reservoir.

How a swimway for salmon would work

A diagram of the salmon swimway

Juvenile fish from McCloud River

A pipe from McCloud River carries juvenile fish and gravity-driven water to a creek connected to the Sacramento River.

To Sacramento River

Swimway pipe

Creek

Holding pool

Pump unit

Shasta Lake

Water from McCloud River is pumped into the swimway

Flexible exit pipe floats over water

(Diagram is not to scale)

Adult salmon from Sacramento River

The scent of the McCloud River draws adult salmon from the Sacramento River to the swimway, allowing them to bypass Shasta Dam.

Potential swimway locations

2 MILES

McCloud River

Shasta Lake

West Fork Stillwater Creek

Cow Creek /

Little Cow Creek /

Dry Creek

SHASTA DAM

Churn Creek

Sacramento River

A diagram of the salmon swimway

Smolts from McCloud River

A pipe from McCloud River carries smolts andgravity-driven water to a creek connected to the Sacramento River.

To Sacramento River

Swimway pipe

Creek

Holding pool

Pump

Water from McCloud River is pumped into swimway

Flexible exit pipe floats over water

(Diagram is not to scale)

Adult salmon from Sacramento River

The scent of the McCloud River draws adult salmon from the Sacramento River to the swimway, allowing them to bypass Shasta Dam.

Potential swimway locations

2 MILES

McCloud River

5

West Fork Stillwater Creek

Shasta Lake

SHASTA DAM

Cow Creek /

Little Cow Creek /

Dry Creek

Churn Creek

Sacramento River

A diagram of the salmon swimway

Smolts from McCloud River

A pipe from McCloud River carries smolts and gravity-driven water to a creek connected to the Sacramento River.

To Sacramento River

Swimway pipe

Creek

Holding pool

Pump

Water from McCloud River is pumped into swimway

Flexible exit pipe floats over water

(Diagram is not to scale)

Adult salmon from Sacramento River

The scent of the McCloud River draws adult salmon from the Sacramento River to the swimway, allowing them to bypass Shasta Dam.

Potential swimway locations

2 MILES

McCloud River

5

West Fork Stillwater Creek

Shasta Lake

SHASTA DAM

Cow Creek /

Little Cow Creek /

Dry Creek

Churn Creek

Sacramento River

Salmon are central to the tribe’s cultural and spiritual traditions. The Winnemem Wintu call salmon Nur. In their creation story, Sisk said, salmon offered humans the gift of voice.

“We’re supposed to speak up for salmon because of that gift,” Sisk said. “Whatever happens to salmon happens to us.”

That was the case when the dam was built, Sisk said. When salmon were blocked from returning upstream to the river, tribal members were forced to leave their homes in the area.

“We were no longer on the river after that Shasta Dam went in. We lost everything,” Sisk said. “It was taken. People were run off from their homes.”

The tribe’s name means “Middle Water People.” Winnemem is their name for the McCloud River, the heart of their traditional homeland, which they lost when the reservoir was filled.

The tribe, which does not have formal recognition from the federal government, has faced obstacles in seeking a say on the salmon reintroduction plan, Sisk said. But she and other tribal members have pushed to be involved and have recently joined virtual meetings with government officials to discuss initial steps, such as testing the system for collecting juvenile salmon in Shasta Lake.

Standing by the creek, Sisk said she believes salmon could swim up this stream if it were connected to a swimway leading to Shasta Lake and the McCloud River.

“There’s enough water in here,” Sisk said. “They would be able to swim this.”

In November, she was at the creek with her 5-year-old granddaughter Maya when the girl spotted something moving. Four salmon were swimming back and forth in the creek, where they hadn’t been seen for years.

Sisk said she and her granddaughter sang a song to the fish.

When Sisk shared news of the sighting, it gave tribal members hope. She said they often pray for the salmon to return.

A side profile of Caleen Sisk framed by the McCloud River in the background
Caleen Sisk, leader of the Winnemem Wintu Tribe, wants to see salmon swim in the McCloud River once again.

The fish that the Winnemem Wintu want to bring to the river are descended from eggs that were shipped from California to New Zealand in the 1890s and early 1900s. The salmon have been thriving in mountain rivers in New Zealand for more than a century, and the Winnemem Wintu say the eggs should be brought back.

Leaders of the tribe have traveled to New Zealand to see the salmon and have commissioned DNA tests to confirm their lineage. Government scientists recently told the tribe they’ll also need to have the fish tested for pathogens.

Sisk said she wishes there were fewer hurdles and hopes it will be possible to bring the salmon soon. Once they return to the river, she said, the fish will “leave their trails” so the next generation will come back.

“If salmon get to come back, just maybe there’s a little way for the Winnemem to continue to exist, too.”

Caleen Sisk

“It’s like a doorway opening for them,” she said. “Once they establish a trail, they don’t get lost.”

She said the tribe is convinced the fish from New Zealand should be the ones released in the McCloud River because they’re adapted to swimming up cascading mountain streams.

“Those Chinook, they have to be mountain climbers,” Sisk said. “They still go up and they make those jumps. They’re still in that condition.”

Sisk said she believes hatchery-raised fish aren’t as big or as healthy, and aren’t “built for” surviving in mountain streams anymore.

“They’ve changed the fish,” Sisk said. “It’s time to step back, allow the fish to be wild. Why not let the fish be wild?”

THE BOAT GLIDED across the water as Matt Johnson steered to the middle of the Sacramento River and cut the engine.

“This is the heart of winter-run habitat,” said Johnson, a senior environmental scientist with the California Department of Fish and Wildlife. “This is their primary spawning habitat.”

A self-described “fish head,” Johnson has loved salmon since he was a kid, when he marveled at the sight of large adult fish, just arrived from the ocean, swimming in a creek.

A sun-bleached salmon spine sits on dry river rocks.
The spine of a Chinook salmon lies on the banks of the Sacramento River in Redding.

Johnson and other biologists track the populations of distinct runs of salmon in the Sacramento, each named for when the fish return from the Pacific.

There are the most numerous fall-run and late-fall-run Chinook, which support thriving commercial and recreational fisheries. There is the spring-run Chinook, which is listed as threatened under the Endangered Species Act. And there is the endangered winter-run, which like the others is called an “evolutionarily significant unit” and has genetic differences.

After the salmon spawn and die, Johnson has seen how their carcasses are devoured by animals such as vultures, bald eagles and raccoons, supporting the entire ecosystem.

The tiny offspring, each about an inch long, will wriggle out of the gravel and begin their journey downstream. Those that survive will travel more than 300 miles, through the Sacramento-San Joaquin River Delta and San Francisco Bay, until they swim beneath the Golden Gate Bridge to the ocean.

Many of the winter-run fish return after three years to the Sacramento River to spawn.

The life cycle of winter-run Chinook salmon

An illustration of salmon's life cycle

Egg incubation

Sac fry

Eggs are buried in gravel nests in shallow, fast-moving streams.

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

An illustration of salmon's life cycle

Egg incubation

Eggs are buried in gravel nests in shallow, fast-moving streams.

Sac fry

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

An illustration of salmon's life cycle

Egg incubation

Eggs are buried in gravel nests in shallow, fast-moving streams.

Sac fry

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

An illustration of salmon's life cycle

Egg incubation

Eggs are buried in gravel nests in shallow, fast-moving streams.

Sac fry

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

An illustration of salmon's life cycle

Egg incubation

Sac fry

Eggs are buried in gravel nests in shallow, fast-moving streams.

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

An illustration of salmon's life cycle

Egg incubation

Sac fry

Eggs are buried in gravel nests in shallow, fast-moving streams.

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

An illustration of salmon's life cycle

Egg incubation

Sac fry

Eggs are buried in gravel nests in shallow, fast-moving streams.

Inch-long fish, fry, emerge from their eggs with yolk sacs still attached to their abdomen. They will feed off the yolk and remain in the nest until it is absorbed.

Fry emerge from nest

The fry leave the nest and swim downstream, feeding on insects.

Smolts grow

The juvenile fish, called smolts, migrate downstream by night. They typically hide during the day to avoid predators.

Juvenile salmon transform and enter the ocean

As the fish prepare for life in the ocean, they wait in the San Francisco Bay as their gills and lungs adapt to salt water.

Adult salmon return

When the salmon return three to five years later, their stomachs bloat, making it impossible for the fish to eat. They use energy stored in fat and muscle to migrate hundreds of miles upstream.

Spawning and death

With her tail, the female digs a nest in the gravel to deposit eggs. The male fertilizes the eggs, then the female buries them. The adult salmon die and become food for wildlife.

Johnson has seen highs and lows as salmon have thrived in wet years and struggled in droughts.

The winter-run Chinook have now returned from the ocean, Johnson said, and soon it will be their turn to spawn. He said the effort to get fish above Shasta Dam holds promise to help them survive.

“The stakes are high,” he said. “To see salmon back in the McCloud River would just be amazing.”

Over the last century, dams erected on rivers throughout the Central Valley have helped irrigate vast farmlands from Redding to Bakersfield, and have supported California’s growth to a population of more than 39 million.

Many dams across the state were designed without passage routes for salmon, cutting off their upstream habitats.

Over the last century, dams were built on rivers across the Central Valley, blocking off 80% of salmon and steelhead habitat.

A map showing all historical salmon rivers in Central Valley.A map showing by 1900, at least one dam was built in Central Valley.A map showing by 1915, at least three dams were built in Central Valley.A map showing by 1930, at least three dams were built in Central Valley.A map showing by 1945, at least six dams were built in Central Valley.A map showing by 1960, at least nine dams were built in Central Valley.A map showing by 1975, at least 13 dams were built in Central Valley.A map showing by 1990, at least 14 dams were built in Central Valley.

When Shasta Dam was built, the government also established Coleman National Fish Hatchery about 30 miles away. This hatchery raises millions of fish for release each year, including large numbers of fall-run Chinook that are caught and eaten.

But that operation failed to prevent major declines in the winter-run Chinook, which were listed as threatened in 1989 and declared endangered in 1994. To try to keep the winter-run population going, the government in 1997 opened Livingston Stone National Fish Hatchery at the base of Shasta Dam, where a steady stream of cold water flowed to its tanks.

If it weren’t for this hatchery, “there would be far fewer winter Chinook salmon,” said Brett Galyean, project leader for the U.S. Fish and Wildlife Service.

The adult fish swim to the base of Keswick Dam, where they are captured in a trap, loaded onto a truck and driven to the hatchery. Each winter-run Chinook is genetically tested and given a number, and each pair of male and female fish is selected.

The spawning happens from May through the end of July. The tiny fish are raised until they’re large enough to be released in the Sacramento River.

Fewer juvenile salmon survive in drought years

A map showing Shasta Dam.

Egg-to-fry survival rate

50%

More eggs hatched

40

30

Average survival

20

In 2021, an estimated 2.6% of the eggs hatched and survived to swim downstream.

10

2014

Warmer water

2015

50°

51

52

53

54

Average water temperature at Keswick Dam

A map showing Shasta Dam.

Egg-to-fry survival rate

50%

More eggs hatched

40

30

Average

survival

In 2021, an estimated 2.6% of the eggs hatched and survived to swim downstream.

20

10

2014

Warmer water

2015

50°

51

52

53

54

Average water temperature at Keswick Dam

A map showing Shasta Dam.

Egg-to-fry survival rate

50%

More eggs

hatched

40

30

Average

survival

20

In 2021, an estimated 2.6% survived and swam downstream.

10

2014

Warmer water

2015

50°

51

52

53

54

Average water temperature at Keswick Dam

To try to keep the water below a critical threshold of 56 degrees, the federal Bureau of Reclamation uses a huge temperature-control device on Shasta Dam to draw water from deeper, cooler levels when needed. That didn’t work last year, though, because the reservoir level had dropped extremely low due to water releases during the drought.

By summer, the water flowing from the dam was too warm for salmon eggs to survive.

Warm water in the Sacramento River was lethal for salmon eggs

A map showing Shasta Dam.

Daily average water temperature

65°

Low reservoir levels warmed the water beyond 56 degrees, a critical threshold for salmon egg viability.

60

2021

55

50

10-year average

45

Jan.

April

July

Oct.

Dec.

A map showing Shasta Dam.

Daily average water temperature

65°

Low reservoir levels warmed the water beyond 56 degrees, a critical threshold for salmon egg viability.

60

2021

55

50

10-year average

45

Jan.

April

July

Oct.

Dec.

A map showing Shasta Dam.

Daily average water temperature

65°

Low reservoir levels warmed the water beyond 56 degrees, a critical threshold for salmon egg viability.

60

2021

55

50

10-year average

45

Jan.

April

July

Oct.

Dec.

Water temperature recorded at Keswick Dam

As an emergency measure, the bureau rented three 500-ton diesel-powered chillers for $1.6 million and installed two of them at the base of the dam to cool the water for the fish swimming in tanks.

Without the chillers, Galyean said, “it would have been really dire straits” for fish at the hatchery.

Federal officials said they are prepared to rent chillers again this summer, and have begun designing a permanent water-cooling plant.

Hatchery managers have also been increasing the number of winter-run fish they collect for spawning. This year, they plan to bring 120 females and 180 males to Livingston Stone hatchery.

They increased the number of juveniles released into the Sacramento River from about 303,000 last year to more than 520,000 this year.

Hundreds of translucent pink salmon eggs sit submerged in a tray
Winter-run Chinook salmon eggs incubating at Livingston Stone National Fish Hatchery. (Kaitlin Dunham / U.S. Fish and Wildlife Service)

Several hundred fish also have tiny transmitters inserted by hand. This operation was performed on a recent afternoon by Arnold Ammann, a biologist with the National Marine Fisheries Service. Wearing black gloves, he lifted a finger-sized salmon from a bucket and laid it on a padded mat. The salmon was stunned with an anesthetic and lay motionless.

Ammann cut an incision in the abdomen and inserted a pill-like transmitter, called an acoustic tag. The device emits a high-frequency signal, enabling scientists to track each salmon’s movements.

When the salmon are released between February and April, the scientists monitor their journey as the fish swim past more than 400 receivers in the Sacramento River, the Delta and San Francisco Bay.

Over the last nine years, the proportion of transmitter-tagged fish that have made it to the ocean has varied from 25% to 2%, with dry years bringing the lowest survival.

Last year, scientists released 555 winter-run salmon with the tags. Only 15 fish were detected swimming past the Golden Gate to the ocean.

This year, hundreds of the tagged fish have again been released. Scientists have been watching to see how many will make it downstream.

Conservationists point to the low survival of winter-run salmon in 2021 as an alarming signal that state and federal agencies should change how they manage water.

In recent years, federal and state officials have overpromised how much water can be safely released from dams, making excessive releases to supply farms and cities, said Doug Obegi of the Natural Resources Defense Council. Despite warnings last year that many winter-run salmon would die if releases weren’t cut, Obegi said, water deliveries continued and drained Shasta Lake to a point that the reserve of deeper, colder water was used up. When salmon most needed cooling, the dam could only release warm water.

“This was entirely foreseeable and predictable. And it makes the devastation all the more frustrating,” Obegi said. “No species could survive this level of mortality repeatedly. And it really is an indicator that we are failing to protect salmon.”

After the disastrous winter-run spawning season, the river stayed warm during September, October and November, when many of the fall-run fish were arriving to spawn, said John McManus, president of the Golden State Salmon Assn.

“The loss of California’s native salmon in 2021 was predicted and could have been largely avoided if water was managed differently,” McManus said.

Hundreds of tiny dark-colored fish swim in a sandy-bottomed tank
A large adult salmon with reddish body with whitened fins and large white spots on the head and back
Juvenile fall-run Chinook salmon feed in tanks, and a returning adult, ready to spawn, swims in a holding pond at Coleman National Fish Hatchery. Juvenile fall-run Chinook salmon feed in tanks, and a returning adult, ready to spawn, swims in a holding pond at Coleman National Fish Hatchery.

Officials with the Bureau of Reclamation defended their handling of water releases, pointing out that flows into Shasta Lake last year shrank to a record low because it was so dry and hot.

“When we don’t have the inflow into Shasta, we don’t have the cold water,” said David Mooney, area manager for the bureau’s Bay-Delta office.

Mooney said the agency will continue to manage water temperatures while working on programs to improve salmon habitat and support the hatchery operation.

The reintroduction of salmon above Shasta Dam is long overdue, said Alison Willy, a biologist and board member of the Salmonid Restoration Federation who previously worked as a U.S. Fish and Wildlife Service scientist. She pointed to a 2009 biological opinion that called for the National Marine Fisheries Service and other agencies to “undertake a program to provide fish passage” and reintroduce winter-run salmon above the dam.

“They need to get up into the McCloud River,” Willy said, “so that they can survive in the wild.”

A small salmon falls from a bucket into a tank
A biologist inspects a juvenile winter-run Chinook salmon at Livingston Stone National Fish Hatchery.

During the Obama administration, federal officials had said they planned to release salmon above Shasta Dam. But in 2019, the Trump administration put the brakes on the project. State officials were assembling a floating piece of the fish-collection system at the reservoir when the federal Forest Service ordered them to stop, saying they needed a permit.

Now the project is moving forward again. In February, state agencies announced $1.5 million will be spent to install and test the salmon-collection system in Shasta Lake starting in September.

The next step in the pilot reintroduction plan, possibly in 2023 or 2024, will be releasing non-endangered fish to see how the collection system works. Then officials plan to release hatchery-raised winter-run Chinook. And if those fish successfully spawn in the McCloud River, Ambrose said, the plan is to start trucking and releasing wild fish.

Ambrose said this “measured approach” is aimed at making sure the wild salmon population isn’t negatively affected. Another critical issue, he said, will be working with the Winnemem Wintu Tribe on their concerns about the reintroduction plan.

State officials said the project is vital to help the winter-run population withstand the effects of climate change.

“The decline of salmon in the Sacramento River is really concerning,” said Wade Crowfoot, California’s natural resources secretary. “We’ve worked to address this, but frankly, we need to do more. And we need to do it more quickly.”

While the drought continues, the salmon could have another poor spawning season. Shasta Lake, now at 38% of full capacity, holds relatively little cold water to help sustain the young fish during the critical summer months.

“We are in a real challenge of balancing our water system for human needs and water supply reliability, and for nature,” Crowfoot said. “We’re taking an intensified approach to the survival of salmon.”

Crowfoot said the state Natural Resources Agency is making efforts to “reconnect with tribes,” learn from Indigenous peoples’ traditional ecological knowledge and explore ways to co-manage resources, including salmon. His stance parallels recommendations in the most recent United Nations report on climate change, which emphasized that Indigenous peoples are among the most vulnerable to the effects of global warming and that their involvement and traditional knowledge are vital in developing climate solutions.

“We’re working to have the dialogue that we need,” Crowfoot said, and “to respect the role that that community, those peoples, have played in salmon since long before California was established.”

For millennia, the Winnemem Wintu made their homes along a river that was filled with salmon. They caught fish with spears and feasted.

“Our belief is that salmon, the Chinook, are the most giving fish,” Sisk said. “They start giving from the time they’re eggs, to the time they’re little fry, to the time they’re big.”

The salmon give in the ocean, with some becoming food for other creatures, she said, and then they swim upstream, providing food for people and other animals.

Sisk has for years been working on the plan to bring salmon from New Zealand, with help from the Ngai Tahu, the Maori people of the South Island, who have offered to send fertilized eggs.

She has also fought a proposal to raise Shasta Dam, which would flood some of the tribe’s remaining sacred sites along the McCloud River.

For the last several years, she and other tribal members have led an annual journey on foot, bicycle, horseback and boat, following the old path of the salmon from the McCloud River to the Bay-Delta estuary.

During these journeys, they have gathered on Shasta Lake in dugout canoes and kayaks, slapping the water with paddles in a ceremonial call for the salmon to return.

“Every time your paddle hits the water, it’s like a fish tail. It’s calling to them,” Sisk said.

Caleen Sisk stands at the bank of a creek, surrounded by grass and trees
Caleen Sisk visits a creek where she recently saw salmon for the first time in years. She says the creek could be made part of a “swimway” route around Shasta Dam.

The Winnemem Wintu Tribe once had an estimated population of about 14,000. But in the mid-1800s, with the arrival of white settlers and miners, the population was decimated by disease and violence during a period when state officials encouraged the widespread killing of Native people.

When Shasta Dam was constructed, those who remained along the McCloud River were forced to leave their homes and their river. Sisk said they were promised lands elsewhere, but the government broke that promise.

Today, the Winnemem Wintu Tribe has 126 members. Sisk and about 30 others live together in a collection of homes on a 42-acre property northeast of Redding.

“The dam prevented everybody, salmon and the people, from going back to the river,” Sisk said. “And so now it’s like, if salmon get to come back, just maybe there’s a little way for the Winnemem to continue to exist, too.”

Sunrise over the winding river
Dawn lights up the sky over the Sacramento River in Red Bluff.