Tom Philp: Nature designed California salmon to never go extinct. Why are they too close?

Tom Philp, The Sacramento Bee on

Published in Outdoors

SACRAMENTO, Calif. — Nature designed California’s Chinook salmon to be our forever fish. Why else would each spawning pair of adults produce about 5,000 fertilized eggs? If 99.96% of these eggs fail to produce adults that return from the ocean to spawn, that’s good news. That means all those eggs did their job, resulting in two adult salmon that returned to repeat the cycle.

California and the life cycle of salmon have been linked for centuries, beginning when only indigenous people lived in the state. California’s rivers and streams benefit from the nutrients salmon bring with them from the ocean. Salmon create jobs. Salmon are our shared living heritage.

Despite biological math so overwhelmingly favoring survival, our salmon are in trouble. A red flag of a species under stress: There are not enough salmon alive to allow fishing off the California coast or in its northern rivers this year for the second consecutive year.

It is nothing short of a state tragedy that California has managed to push its most iconic and resilient fish to the brink of extinction. Now, any management mistake risks unimaginable consequences. The salmon’s plight is fueled by the toxic politics of California water, with one stakeholder blaming another. It takes so many human mistakes to kill off this species. And we’re so darn close.

“We have slowly winnowed down that resiliency,” said Carson Jeffres, a salmon researcher at UC Davis whose professional life is dedicated to saving the species. “The things that keep me awake at night are that fear that we have gotten so close to the edge of the cliff that we’re starting to step off of it.”

California once had millions more salmon than people. Now it’s the other way around, and that’s no coincidence. The species has suffered from untold numbers of human-caused setbacks. Salmon are also lousy lobbyists in the halls of power in Sacramento. Humans would have to elevate them in California’s climate change agenda as a financial priority to give the fish a fighting chance.

The uphill battle

Salmon face an uphill battle because some major threats aren’t going anywhere. Consider, as examples, some key infrastructure that run Northern California: The dams that provide our water have blocked more than 90% of salmon’s original spawning grounds, particularly the coldest river stretches upstream. The river levees that protect our homes erased 95% of the original floodplains, where young salmon would feast before heading to sea. Downstream in the Sacramento-San Joaquin Delta, 1,100 miles of levees eliminated 95% of the original wetlands where salmon could eat and hide.

So right off the bat, today’s salmon have only 5% of their original freshwater neighborhood needed to survive and about half of their original water (the other half diverted for human uses in the Sacramento River watershed).

As the fertilized eggs grow into baby fry and then fingerlings, salmon have a deadly first year trying to make their way downriver to San Francisco Bay.

“You lose the vast majority of the fish as juveniles,” Jeffres said.

In the Delta, nature intended young salmon to be eaten by a single hungry adversary, the pikeminnow. Now, salmon face six predators: the same native fish plus three introduced species of bass and two strains of catfish.

Then there are the two large water projects in the southern Delta: the Central Valley Project and the State Water Project. Federal pumping regulations permit the “taking” of 1.2% of the most endangered salmon of all, those juveniles in the Delta hope to return as adults in the winter. That’s another percent of death nature didn’t originally account for.

Once in the ocean, where salmon spread from the Central Coast to Oregon, management is largely beyond regulation. It’s hard to tell a killer whale what to eat.

The only thing regulators can annually adjust is the amount of commercial and recreational fishing. To do that, government biologists must first estimate how many adults are swimming in the deep, a census effort that pushes human extrapolation to its limit.

This forecasting, known as the Sacramento Index, “is the hardest thing that we do in terms of managing these stocks,” said Michael O’Farrell, leader of the Fisheries Assessment Modeling Team for the National Oceanographic and Atmospheric Administration. The math has to be right for regulators to agree on the number of California’s Chinook salmon to be “harvested” by fishermen so that enough survive to make it back upstream to spawn.


Salmon’s recent setbacks

If everything goes right, salmon populations will vary more than the stock market, thriving in wet cycles and surviving droughts. The unprecedented closure of the salmon fishing season for two consecutive years is a reflection that in recent years, too many things have gone wrong.

Some examples:

In the cool waters of Butte Creek, a tributary of the Sacramento River that is the primary spawning ground of the spring Chinook, a 2021 canal failure (the culprit — our Pacific Gas & Electric) spiked temperatures and sediment in the creek, killing more than 90% of adults before they could spawn.

In the drought years of 2014 and 2015, an estimated 95% of winter-run Chinook died in the Sacramento River before spawning due to high river temperatures, some cold water delivered to human needs instead.

In 2022, that ocean salmon census ended up over-estimating the adult population. Fishermen ended up catching 75% of them as opposed to the target of 50%. The number of fall-run Chinook that made it upstream to spawn was 69% below the original forecast.

The lingering impact “is sort of a bad sign for abundance in 2025,” said William Sattherthwaite, a research ecologist with the National Oceanic and Atmospheric Administration. He is part of a scientific team with impressive brainpower to ensure that carefully managed fishing and salmon can coexist. Even Jeffres eats California salmon. “My dream is that we still have a great fishery,” he said.

Not all the news is bad. In some recent sleuthing by salmon scientists, more than 3.4 California hatchery salmon of all runs were marked beginning last spring by coded wire tags to follow their whereabouts. Nearly 2 million died (of those, about 400 directly at the water project facilities). But more than 1.5 million reached San Francisco Bay. That is a huge pulse of youngsters heading to ocean life. There is reason to hope.

How do we improve the odds for salmon quickly? In the rivers and Delta, where most die, Jeffres would like reservoir operations to better mimic nature’s pattern and increase flows every January and February. Higher flows expand available habitat to help fatten the young fish and move them toward San Francisco Bay before Delta water temperatures rise and make those six predators more hungry. In dry years with low flows and higher Delta water temperatures, “it’s a massacre,” Jeffres said.

Since the 2015 drought, regulators have increased how much water Shasta Dam must carry over from year to year in hopes there will always be enough cold water behind the dam to release for spawning in the fall — a four-fold increase since the 1970s. That’s a start.

Laws have not saved the salmon

But it is also telling that salmon are on the brink despite California having some of the strictest environmental laws on the planet. The government’s ability to regulate this species to safety is dubious at best. Consider that the state’s primary plan to protect the Delta by balancing the uses of water has not been updated by the State Water Resources Control Board since Bill Clinton was in office. It’s a telling example of water’s political and regulatory paralysis.

There is no shared sense of responsibility to save the salmon because we have devised such self-centered regulatory systems. We have, for example, a seniority-based water rights system that has left everyone out for themselves. So we point fingers rather than join hands.

We are blessed to have some really smart people dedicated to saving this fish. They have all kinds of ideas to improve the math of salmon’s survival, particularly better habitat conditions throughout the freshwater life stages and getting some adults above some big dams to reach that precious cold water. But salmon would truly have to be a state financial priority, high on California’s climate change agenda. Salmon are not.

It would not be the proverbial last straw that would kill California’s salmon. That’s not how the math of killing our forever fish would actually work. Extinction would be the result of decades of wrongs we have done and never having the foresight to make things right.

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