Wading knee-deep water, he is sticking a long implement into the water, fishing net behind him
Jacob Katz uses a net to catch juvenile salmon in an experimental flood plain. (Photo/Noah Berger)

This scientist is in an upstream battle to save California’s fish

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Name: Jacob Katz
Age: 40
City: Unincorporated Sonoma County
Position: Senior scientist with California Trout

J.: You work for California Trout, a nonprofit based in San Francisco that manages 30 projects dedicated to conserving, preserving and restoring wild salmon and trout. That organization, along with the UC Davis Center for Watershed Sciences, just issued a report stating that 45 percent of the state’s native salmon, steelhead and trout will be extinct within 50 years if nothing changes. What are you doing about that?

Jacob Katz: We’re in the midst of an extinction crisis — not just in California, but globally — and nowhere is it keener than in freshwater environments. Systems are difficult to tackle and slow to change, but we are making progress. We have many partners in our reconciliation ecology work from all different sectors, including agriculture, water suppliers, fishermen and officials at all levels of government.

Waterways are included in the current administration’s infrastructure spending proposals. What’s your take on that?

I hate to agree with Trump on anything, but the water infrastructure in California is in dire need of an upgrade. Much of the work I do focuses on integrating scientific knowledge about how ecosystems work and how resources are managed into California’s outdated water infrastructure.

This is bigger than fish, isn’t it?

Fish are the best indicators of the health of rivers and streams, and sustaining a healthy population of fish ensures that California has cold, clean water. That’s important for all of us.

Climate change is a factor in the declining populations of fish, but levees and dams are part of the problem, too. You say California has only about 5 percent of the fish it used to have. What happened?

The Central Valley once was a large mosaic of wetlands. Now 95 percent of that floodplain has been cut off by levees, and that’s turned the river systems into food deserts. For the past 10 years, research out of UC Davis and other places shows that when rivers overflow their banks, water spills onto the low-lying grounds and that’s where you get an explosion of life, of food.

You’re based in the Windsor office, and you are the principal investigator for the Nigiri Project, one of California Trout’s fish restoration programs. The project proposes flooding the rice fields in the Central Valley after each harvest to create wetlands. How does that work?

After rice is harvested in fall, the rice fields can be flooded to provide habitat for ducks and geese in early winter. By midwinter and early spring, this shin-deep water creates good habitat for salmon and other native fish. When the fish move to the rivers and streams, you plant rice again. We can have both farms and fish if we understand the natural system that we’re managing and try to mimic it so that farm fields function like a natural floodplain wetland.

Is the Nigiri Project moving forward?

We are partnering with the California Rice Commission, working with their growers to make rice a fish-friendly crop. Last year’s experiment, on about 10,000 acres, went very well. We took samples of incredible amounts of bugs. These zooplankton, invertebrates that feed on detritus in the flooded fields and on each other — that’s fish food. This is part of 21st-century conservation.

What drew you to this work?

I’m a Sonoma County kid, and I grew up hearing about the incredible abundance of fish and wildlife here that since has disappeared. When I was just 3 or 4, my dad put a fly rod into my hand and we spent summers going down rivers looking for trout and salmon. That really sparked my interest in biology, and a childhood spent playing in creeks turned into a lifelong vocation.

What was your Jewish upbringing like?

I’m your average Russian-Mexican Jew. My mom’s family is an American amalgam of Mexican and European ancestry and my father is from Eastern European Jewish stock. I traveled extensively in Israel with my grandfather, who came from a long line of rabbis. Joseph Katz was an atheist, and with every fiber of his being, a Jew. He came up working the ground in the sun alongside Moshe Dayan and other founders of the State of Israel. He knew the Bible inside and out, and we often discussed the stories. Fables, he called them.

What impression did that make on you?

Talking with my grandfather was my path to Judaism, how my Jewish identity was established. The questioning, the curiosity, the need to understand for oneself — that’s at the heart of my Judaism.

Now you’re questioning how to stop potential extinction of a species. What do you like best about your job?

I like being part of an organization that is dedicated to stewardship and to integrating a working knowledge of nature into our management of it. I believe we can manage more effectively and create a world that works for people and for fish. That is a noble endeavor to pursue.

“Talking With” focuses on local Jews who are doing things we find interesting. Send suggestions to [email protected].

Patricia Corrigan

Patricia Corrigan is a longtime newspaper reporter, book author and freelance writer based in San Francisco.