Like ducks and geese, salmon may be next to benefit from California rice fields.
⋅ By Jim Morris ⋅
California Rice Commission
A generation ago, it may have seemed far-fetched that Sacramento Valley rice fields could play a vital role for millions of birds. However, changes in rice growing methods in the early 1990s — a shift from burning fields after harvest to adding a few inches of water to break down leftover rice straw — led to such an occurrence. Area rice fields are now home to nearly 230 wildlife species, including 7 to 10 million ducks and geese every fall and winter. The “surrogate wetlands” are now crucial to the massive Pacific Flyway wildlife migration.
California’s struggling salmon may be next to benefit from those same rice fields.
This is year three of pilot salmon research by the California Rice Commission, UC Davis, California Trout and other partners. This project will test and refine rice farming practices designed to provide habitat and food for fish. If successful, baby salmon will rear in flood bypass rice fields in the winter, when no rice is grown, then head off to the ocean.
Every step of the process is being monitored to understand the best practices moving forward. If all goes well, this project will move from pilot to voluntary adoption on suitable Sacramento Valley rice farms.
This work is supported by a grant from the Natural Resources Conservation Service, major sponsors including Syngenta, State Water Contractors and a long list of contributors. Additionally, there are major modifications to existing water infrastructure planned that will allow juvenile salmon on their way to sea better access to food-rich floodplain habitats.
This nutrient-rich food web develops naturally in winter flooded rice fields, due to organic matter and sunlight.
Finally, the Fish Food program is working with rice farmers and wetland managers on the protected or “dry side” of levees. While these fields and wetlands are not directly connected to the river and cannot host salmon, they can still support salmon populations by creating fish food. A dense invertebrate food web rapidly grows in nutrient-rich, sun-soaked shallow waters of flooded rice fields. Several weeks after being inundated, this veritable bug buffet can be strategically drained into the river to provide much-needed nutrition for small, juvenile salmon migrating downstream to the ocean.
A rewilding effort
Jacob Katz, senior scientist with CalTrout is a passionate advocate for salmon. He said he is very hopeful that the collaborative work being done in the Sacramento Valley will ultimately help fish, as well as birds, people and farms.
“There are two big reasons for my optimism,” Katz remarked. “The first is the science. It’s really clear that, if we meet every link in the chain, every type of habitat that these critters need, including salmon, we can expect a really dramatic response — an increase in abundance. The second is collaboration. Everywhere I turn, I see farmers dedicated to more ducks, more geese, more salmon — and opening their farms to a rewilding; a way of thinking about welcoming the wild back onto the farm.
“We’re not talking about going back. We are still going to be one of the most productive farming areas on Earth. But, in the non-growing season, floodplain farms can be managed as fantastic habitat for multiple species.”
Q&A with Jacob Katz
Jim Morris: Water is hardly ever an easy subject in our state. Finding enough for the environment, cities and farms is frequently contentious. One creative plan involves what at first may seem like an unlikely pairing — rice fields and salmon.
The salmon project involves many partners — the Rice Commission, UC Davis, landowners, water districts and California Trout. Jacob Katz has a PhD in ecology and is senior scientist with CalTrout. Jacob, there are several things that are going on to help salmon. Can you tell us about what’s happening to try to improve that population?
Jacob Katz: All three of the efforts underway involve floodplains or the marshlands that run adjacent to our rivers and tributaries here in the Sacramento Valley. The first we call fish food, and that’s understanding that bugs that fish eat, which make fish populations, really aren’t grown in the rivers themselves, but in the adjacent marshlands. And most of those marshlands are no longer attached to the river. So maybe 95% of the marshes that were once flooded by the Sacramento River and its tributaries are now behind levees.
And the fish food program works with farmers that now — for the most part — farm those lands to mimic those flood patterns out on their fields to spread and slow water mid-winter when they’re not farming to allow bugs to grow in those fields. And then they actively drain that floodplain-rich water, that natural wealth, back to the river where the fish are.
The second thing is actively managing fields within our bypasses, within the floodways that are the parts of the former floodplain, which are still hydrologically connected to the river. And then the third is actually changing, upgrading often obsolete infrastructure so that it allows the river and fish to connect to those floodplain bypasses more frequently and for a longer duration.
Jim Morris: Let’s start with the fish food. It’s amazing at first glance that there’s not enough food in the river, but that’s certainly true. Correct? How much of a difference can the food that’s being raised in rice fields be for the salmon?
Jacob Katz: Well, over the last 10 years or so, we’ve been running around the Sacramento Valley, throwing our plankton nets, looking for bugs in every kind of aquatic habitat. And what we found is that the rivers themselves are essentially food deserts. There’s very little food for small fish to eat there.
Whereas the adjacent marshlands, whether that’s a flooded field or a marsh habitat managed for waterfowl or a natural marsh, all of those are teaming with invertebrate life. With what I call floating filet — the exact right kind of food if you’re a young salmon, trying to get strong and fit on your journey to sea.
Jim Morris: When we look at the pilot program of raising salmon in rice fields, it works out perfectly because there’s nothing grown in the fields during the winter. How optimistic are you with what you’ve seen so far with that project?
Jacob Katz: Well, what we see is that when fish are exposed to the kind of conditions, the physical, or I call them biophysical conditions, because the depth and duration of flooding that you would’ve seen before, you allow a fish to recognize the river system that it evolved in, that it’s adapted to.
When you put a salmon into a puddle, what you find is that there is ample food there and these little guys are swimming around with their eyes closed and their mouth open, getting big, getting fat. And that’s really critical because it increases their chances, not just of making it out of the river system, but critically it increases their survival in the ocean so that they have a much better chance of returning as an adult. And that is one of the most important things we can do to bring back these salmon populations in the Central Valley.
Jim Morris: So the fish that are grown in the rice fields, how is their survivability relating to the wild population?
Jacob Katz: It looks like fish that find something to eat, and that’s what the rice fields really provide is access to the kind of habitats that fish would’ve been rearing or feeding in previously. And when they do that, when they get food, they get strong and they have a better chance making it out of the river system.
The Rice Commission and UC Davis have done some great studies showing that their survival improves on the way out to the Golden Gate, but what’s even more important is that ocean survival. That leaving fresh water well, their survival’s increased, but it’s coming back where you get the really big payoff. That’s what we’re all after is making sure that more of those juvenile fish return as adults and a bigger fish that hits the Marine environment, that hits the salt, that’s a fish that’s more likely to return as an adult.
Jim Morris: Looking at another big aspect of this is making sure the infrastructure is correct, not only to help cities and farms, but also make sure that fish are healthy. What can be done there?
Jacob Katz: Several things can be done. One thing is to increase the habitat benefit to the fish that actually get onto our floodplain bypasses. These are the flood protection areas in the Sacramento Valley, in the Sutter and Yolo Bypasses. And the Rice Commission is piloting a study now that helps manage rice fields in those bypasses so that they better serve the salmon when the salmon get out in there.
The other is increasing the frequency in which fish can actually get out of that food desert of a river and on to that food buffet that is the bypass, or is the floodplain. That’s done by putting gates or lower areas within these levees and weirs that allow the river to spill out of its heavily channelized leveed bank more often to access, to hydrologically connect from the river onto the floodplain, and allow those small fish to get out to where the food is.
Jim Morris: So this new type of thinking, actually I guess it’s a nod toward the old way things happened in historic California. How optimistic are you that this is going to work?
Jacob Katz: I’m incredibly optimistic. When you allow a salmon to recognize the river system that it’s adapted to, that it evolved in, that when we manage our rivers and our farmlands in such a way that we mimic those natural patterns — the slowing and spreading of flood water out over the shallow marshlands, that once really dominated and characterized the Sacramento and San Joaquin Valleys. What we get is an explosion, a natural explosion of biomass, of abundance.
We’ve seen that this works with the fantastic efforts from the rice industry and regulators and others that revolve around making farm fields better for waterfowl and for shorebirds. And now in Butte Creek, we see that when we do the same thing, when we focus on creating the kind of habitat that salmon need at each part of their life history, making sure that the small fish on their way to the ocean have something to eat, making sure that the big fish on their way back have unfettered access to their spawning streams and have adequate cold water for holding in before they spawn.
If you hit every link in that chain, we see that the fish populations respond and respond dramatically. We can get very rapid increases in population similar to what we’ve seen with ducks and geese in the Sacramento Valley. I believe that we can have the same thing for salmon, and it really takes this landscape-scale approach where we’re not doing this on hundreds of acres or even thousands of acres, but tens of thousands and hundreds of thousands of acres. And it takes the collaboration of farmers, regulators and environmentalists all working together to create an ecologically functioning valley.
And when we do that, we can create a valley that once again can create salmon abundance, and in so doing can create a system where water can much more easily be moved from where it’s more abundant to where it’s utilized by both agriculture and our cities.
Jim Morris: I’m reminded of what grower Fritz Durst has said many times focusing on the fix, not the fight, which is a great way to go if you can do it. It seems to be happening in the Sacramento Valley. So when we look ahead, Jacob, in our lifetimes, do you foresee a water situation that has improved to a point that is best serving the cities, the environment and farms?
Jacob Katz: Well, absolutely, and that’s because we need to get the most pop per drop, right? And there’s two real big reasons for my optimism. The first is the science. It’s really clear that if we meet every link in the chain, every type of habitat that these critters need — including salmon — we can expect a real dramatic response, an increase in abundance.
And the second is collaboration. I see wherever I turn farmers dedicated to more ducks, to more geese, to more salmon and really opening their farms to a rewilding, a way of thinking about welcoming the wild back onto the farm. We’re not talking about going back. We are still going to be one of the most productive agricultural regions on earth, but in the non-growing season, floodplain farms can be managed as just fantastic habitat for multiple species and can be done in such a way where they spread in slow waters so that that water sinks back into our aquifers to the bank of our most precious resource, water.
So when we have functioning river ecosystems, when we have a functioning Sacramento Valley, what we really have is a system that works for fins, for feathers, for farms and for people, and is better able to meet the challenges of a changing climate with resilience and ultimately with this recovery of natural abundance.
Jim Morris: As the salmon work ramps up, we will have much more in the coming weeks. For now, I appreciate spending time with Jacob Katz on this important subject. You can find out much more at podcast.calrice.org. Please subscribe and tell your friends.
Jim Morris is communications manager for the California Rice Commission. He may be reached at email@example.com.
Generous support and contributions
Pilot salmon research is supported by a grant from the Natural Resources Conservation Service. Major sponsors are Syngenta and State Water Contractors.
Other contributors include:
• American Commodity
• California Almonds – Almond Board of California.
• California Family Foods.
• California Ricelands.
• California Rice Research Board.
• Conaway Preservation Group.
• Corteva Agriscience.
• Grow West.
• Lundberg Family Farms.
• NCWA – Northern California Water Association.
• NovaSource Tessenderlo Group.
• River Garden Farms.
• S.D. Bechtel, Jr. Foundation.
• The Nigiri Project.