Using a net to collect salmon in flooded rice field

S1 E6: Helping Salmon

Rice fields in the Sacramento Valley are remarkably productive and versatile. From spring into fall, they produce virtually all of America’s sushi rice. In the fall and winter, those same fields are home to millions of birds. What’s next? A promising pilot project could help inform us as to how rice fields can help restore dwindling salmon populations.

Throughout the Sacramento Valley, researchers are studying the prospect of reconnecting the historic flood plain, through getting the ‘bug buffet’ found in shallow-flooded rice fields returned to the river to supplement the food supply for migrating salmon. 

Additionally, this is year two of an exciting project to raise salmon in rice fields. Through the Rice Commission, UC Davis and California Trout, thousands of juvenile salmon are being raised in rice fields at River Garden Farms in Knights Landing. When they’re ready, these fish will be microchipped and studied as they leave the farm en route to the ocean.

Hopefully, this research will pave the way to have rice fields provide the type of boost to salmon that they have for the Pacific Flyway.

“What’s incredible is the way the rice industry has decided to mesh with the environment, in such ways that include tracking salmon from Knights Landing all the way to the Golden Gate Bridge. How does that factor in to growing rice, but it does,” remarked Jack Armstrong of the Armstrong & Getty Radio Show, after visiting the pilot project and speaking with participants. 

With the vast majority of California’s historic wetlands gone, there’s increased reliance of rice fields as ‘surrogate wetlands,’ not only for birds but perhaps to help salmon, too.

“I think they are the difference maker,” said Andrew Rypel, Associate Professor and Peter Moyle Chair of Cold Water Fish Ecology at UC Davis.” If we don’t figure out this problem with rice fields, we’re going to be in a lot worse situation if we lose those rice fields. We really need to figure this out. All of the evidence supports the idea that these are incredible habitats for fish.”

The Rice Commission’s Pilot Salmon Project is made possible through sponsors, including the US Department of Agriculture’s Natural Resources Conservation Service, Syngenta, The Bechtel Foundation and many others. Here’s a complete list of our valued sponsors.

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Episode Transcript

Jack Armstrong: What’s incredible is the way the rice industry has decided to mesh with the environment in such ways that include tracking salmon from night’s land in California all the way to the golden gate bridge. How does that factor in with growing rice, but it does.

Jim Morris: Jack Armstrong of the Armstrong and Getty Radio Program. Innovation is a hallmark characteristic of California rice and a new chapter is underway, raising salmon and rice fields in an effort to help supplement the state’s dwindling fish population.

Jim Morris: Welcome to Ingrain, the California rice podcast. I’m your host, Jim Morris. I’ve been working with farmers and ranchers for 30 years helping tell their stories. Rice is known as the environmental crop and for good reason, millions of birds spend their fall and winter and rice fields. Nearly 230 wildlife species in all live in rice fields. In fact, you might be able to hear the blackbirds in the background here at River Garden Farms in Yolo County where a new chapter is underway. It’s a pilot effort to raise salmon in rice fields. It’s a windy day here on the farm, but that’s actually helpful for researchers in their efforts. I’m with Rachelle Tallman from UC Davis grad student and you’re playing a significant role here at the pilot salmon project, and how are things going?

Rachelle Tallman: So far, so good. The fish are growing really well out here on the rice fields, warm temperatures and for the most part, good oxygen. So they’re doing pretty good. Soon, we might have to start moving things around just because we’re starting to enter an early spring. So that’s something that we’re keeping on the radar.

Jim Morris: We’ve had two years of this. Last year’s weather was completely different than this year. So what was the challenge last year and what’s the challenge this year?

Rachelle Tallman: Yeah, I think last year with all the water we had, the challenge is actually getting to our cages and checking the fish. So it made it really difficult for data collection. This year has been a lot easier data collection wise because again, the bypass is inactive and we’re on the dry side of it. The challenging part this year though is because we’re not getting the kind of rain or precipitation, we’re dealing with warmer temperatures and that’s something to be concerned about when we have fish that need to be of a certain size for us to work with them.

Jim Morris: So years back, a few years back, did you imagine you would be working in rice fields raising salmon?

Rachelle Tallman: No, I definitely knew I was going to be doing salmon, but not in rice fields. That was probably the most unexpected part.

Jim Morris: What do you think after you’ve had a couple of years under your belt with this?

Rachelle Tallman: I have so much respect for rice farmers and what they can do because I feel like I’ve had to take a crash course in how to maintain flow levels and I give huge thanks to River Garden and Conway from last year helping me figure this out because it’s a lot more difficult than you think. On paper, it comes off as one way and then when you actually have to implement it, it’s really hard.

Jim Morris: Obviously, you need to get more information before there is a conclusion, but what are your thoughts about down the road and the role rice fields could play for salmon?

Rachelle Tallman: Yeah, I think it’s really interesting. This year, we had a new component that we didn’t have last year, which was adding habitat complexity to the plots and I’m really interested to see how that impacts survival. There’s some data that suggests that once we’re putting fish in these fields, they have really high mortality. So it’d be actually very interesting to see what the survival is while we’re just growing them and then ultimately, seeing how many can we get to the golden gate.

Jim Morris: You talk about some different avenues this year, i.e. Christmas trees in the field, et cetera. What are some of the things that you’re doing that you’re testing?

Rachelle Tallman: Yeah. So with the plots, there’s eight of them and there’s four treatments. So we have the Christmas trees, canals, Christmas trees and canals, and then we have control groups. We’re kind of looking at the growth between the different plots, like the fish growth, as well as a survival to see if there is a difference in doing these treatments or not.

Jim Morris: There is a lot of hard work going on here and no one has much downtime. So tell me about some of the activities and all of the hard work here.

Rachelle Tallman: Yeah, this project really wouldn’t have been possible without the hardworking staff of the Thingy and Rypel Lab, as well as the BioTelemetry group. Each week, we’re going out and walking these eight half acre plots, as well as seining them, PIT tagging them and then eventually, we’ll be acoustic tagging them. So it really takes an army of people to get this project off the ground.

Jim Morris: Seining in particular, looked at especially excruciating. So tell me what seining is for those who don’t know.

Rachelle Tallman: Yeah, so seining involves a pretty large net and then you have two netters that basically are controlling the ends, and they spread the net out really far and start marching forward. What happens is it kind of corrals the fish into what we call a purse, which is the back of the net. So they kind of work together to try and keep the fish there and then pulling the ends together and sealing it so that we don’t lose fish as we’re trying to pull the net out of the water. It’s physically super intensive.

Jim Morris: You also had you called, PIT tagging. So tell me about PIT tagging and what this accomplishes.

Rachelle Tallman: Yeah, so PIT tagging, I tell people, it’s kind of like when you go to the grocery store and they scan the barcode. It’s the same concept except instead of being a barcode printed on a cereal box, we’re injecting a tag into the fish and it gives them a unique ID, which is helpful for us because when we are going to figure out survival, we can actually figure out which individuals made it.

Jim Morris: This is different than the telemetry tag, if I’m saying the right term, and what is that and when does that come in the process?

Rachelle Tallman: So the telemetry tag is really great for us to assess survival to Golden Gate Bridge. The reason we don’t do PIT tagging with them is the read range is a little different and as you get closer to a saltier water, it’s more difficult to use PIT tag technology.

Jim Morris: Amazing with that telemetry information, you literally can know where they end up down the road?

Rachelle Tallman: Yeah, we can figure out using statistics like how many actually made it to Golden Gate.

Jim Morris: And like anybody, the better your diet, the healthier you’re going to be. They are a little healthier right here than compared in a natural river setting?

Rachelle Tallman: Yeah, at least compared to the Sac River. The warm temperatures in the rice fields and the high food abundance allows them to grow faster, so they’re definitely bigger upon release than a hatchery fish.

Jim Morris: To carry out this work, you need cooperative farmers and there are a lot who are interested and excited about this new way to help our environment, that includes Dominic Bruno of River Garden Farms.

Dominic Bruno: But we’re very optimistic that the efforts that we’re helping or that we’re putting forward are going to provide good science to really help move these practices and expand these projects and practices across the Valley.

Jim Morris: Another key partner is Cal Trout, program manager, Jacob Montgomery logs a lot of miles in Sacramento Valley rice country, including with this project.

Jacob Montgomery: Rice fields in the Sutter and in the Yolo Bypass are ideal for this project. All the other rice fields that are outside of the bypasses don’t actually have fish that can access them, right? All those rice fields are separated by levies, but in the Yolo and in the Sutter Bypass, as soon as the river gets high enough to inundate and flood those bypasses, it also brings on fish. So those rice fields will hold water for an extended period of time and provide great ponded flood plain fish habitat.

Jim Morris: And that is the ultimate goal is to reconnect the flood plain. Can you explain what that will entail hopefully, down the road?

Jacob Montgomery: Yeah. So reconnecting the flood plain has two phases really. We want to do this phase that we’re calling on the wet side, which is inside the Yolo and in the Sutter Bypasses that this Cal Rice Commission and UC Davis project is testing treatments for. So that part is looking at extending the duration of flooding events that naturally occur in the Yolo Bypass and in the Sutter Bypass, and that’s a really important piece. In order to recover the fish populations, we really want to provide them an extended period of flooding time where they can access that habitat and get all of the growth and survival benefits from that habitat. So that’s one piece of reconnecting the floodplain. The other piece is integrating those dry side or all of the rice fields outside of the bypass, reconnecting the floodplain resources, which would be primarily fish food.

Jacob Montgomery: Since we can’t actually get fish out there, what we want to do is flood all those fields, grow a bunch of fish food out there, basically, small water bugs and then drain that water back to the river at the exact time when juvenile salmon are in the system and migrating downstream and naturally doing their sort of growth and survival in rearing thing in the Sacramento River system and provide them an extra subsidy of food resources while they’re in the river.

Jim Morris: The subsidy of food resources, rice fields are promising on that, correct? Because they are loaded with fish food. Can you explain?

Jacob Montgomery: So what happens is when you flood a rice field after harvest, the rice farmers are really doing this for a couple of reasons. The primary one being rice double decomposition, so the water is another way to break down all the leftover rice straw after harvest. They don’t have to burn it or bail it or get rid of it in some other way. The other kind of secondary purpose for it is it provides waterfowl habitat, water bird habitat, shorebird habitat. There’s the practical aspect for the farming, and the habitat aspect for the birds mostly. And we’re adding in this fish benefit because when you flood those rice fields and all that rice straw breaks down, what it breaks down into is basically it turns into a whole bunch of bugs. There’s a aquatic food web that emerges to decompose that rice straw and the outcome of that is a hugely abundant and rich biomass of small aquatic bugs that are just the perfect item of food for a fish when it’s rearing.

Jim Morris: How does the level of those zooplankton, et cetera, in a rice field compare to that of the river and how do you get it from the rice field back to the river?

Jacob Montgomery: Yeah, it’s a great question. So relatively speaking, the river is a food scarce environment. The way we measure it in the lab is we translate everything to a dry mass and we’re talking about micrograms of carbon, that’s bugs basically, per cubic meter of water. The river has somewhere between like a hundred and on a good day, maybe 2000 micro grams of carbon per cubic meter of water. The rice fields frequently are over a hundred thousand and I’ve seen measurements up to four hundred thousand, five hundred thousand micrograms of carbon per cubic meter. So we’re talking about anywhere from 200 to 500 times the biomass of food on rice fields as compared to the river.

Jacob Montgomery: Second part of that is how do you get that food on the rice fields back to the river? That’s relatively simple. So all these rice fields are designed for both irrigation and for drainage. They’re all already set up to move water on and move water off and when they move water off, they got to get that water back to the river so they can drain it out completely. It doesn’t just form a big flood somewhere. We use all that same infrastructure that the rice farms are using in the summer to irrigate. In the wintertime, we use it to flood and to drain that floodwater, all that floodplain resource generated fish food, back to the river in the exact same way that a rice farmer drains their fields normally.

Jim Morris: Is it safe to say that the salmon protection measures of the past haven’t worked out too well and we do need to try new avenues or am I overstating that?

Jacob Montgomery: Well, I think there are some really good success stories to remember. So one is that of the Butte Creek spring run salmon, that’s a classic recovery action where the local group of water managers and farmers and everyone who uses the resource out there got together to coordinate some actions to basically stop diverting water when fish were in the system or screen their diversion so that when they did divert the water, they weren’t sucking a bunch of fish out of the system at the same time and upgrade some infrastructures so that there were no barriers to fish access in some of those places. We saw a fantastic response from that fish population after all those actions were completed. There are some stories like that and that’s probably one of the better ones, but they’re few and far between. So yes, most of the conservation actions I’d say have not been so successful. And I think it’s mostly because they’re not focusing on the habitat and the population benefit that emerges from having the right habitat at the right time of year for these fish.

Jim Morris: Thanks for mentioning Butte Creek. That is a big success story in the Sacramento Valley. So in your professional lifetime, do you feel we will see a market difference in the Valley where these rice fields are actively being utilized for salmon, not only the fish food, but also raising the fish in the winter?

Jacob Montgomery: I really hope so. I think it’s entirely possible. It’s doable right now. I think the hurdles to that are more financial and political than they are logistical as far as physically getting all that floodplain habitat and making it accessible to fish. We need to develop a way to let a farmer keep their land in production and get them credit for the conservation efforts that they make in the winter time when they’re not growing rice. If we can figure out a way to do that, then yes, we will absolutely have the Central Valley within 10 years grown tons of fish food and having a big response from our fish populations.

Jim Morris: All of this optimism does not erase the fact that there is a long way to go towards a healthy salmon population. Central to this project is Andrew Rypel, associate professor, and Peter Moyle Chair of Coldwater Fish Ecology at UC Davis. He explains the current fish situation in California.

Andrew Rypel: So the estimates are somewhere in the neighborhood of 83% of native fishes in California are in some form of decline. Some are extra pay it or completely extinct already. Many are declining and are on their way. So that’s the backdrop and challenges we face.

Jim Morris: Where do we go from here? What are some of the potential solutions?

Andrew Rypel: There’s 40 million people in California and there’s a lot of activity and those people aren’t going anywhere anytime soon. So what we need to do is figure out a smart way to use the habitats that we do have to help fish get better into the future.

Jim Morris: We’re talking, in this case, about rice fields and we’re at river garden farms. Tell me what’s happening here and what a level of optimism, perhaps you have that some way, someday down the road that this can make a difference.

Andrew Rypel: We are in a rice field and why that’s important is that the Central Valley, which is really the hub of fish diversity in California, Central Valley is where a lot of that diversity was historically. All those wetlands are mostly gone. There’s only about 5% of those wetlands left, so we really shouldn’t be that surprised there’s only 5% of the fish left. But what we do have are a lot of these rice fields, anywhere in the neighborhood of 500,000 acres. What we want to do is figure out a smart way to use those habitats for fish. They’ve been wonderful examples of using these habitats for migratory waterfowl and we’re looking at making parallel programs and partnerships to help fish conservation in the future.

Jim Morris: There’s a long way to go, but how encouraged are you? Before this, we had the New Geary project, so this has been studied for a few years at least and what are some of your initial thoughts about how things are going and if rice fields might be a difference maker?

Andrew Rypel: I think they are the difference maker and if we don’t figure out this problem with rice fields, we’re going to be in a lot worse situation if we lose those rice fields. So we really need to figure this out. All the evidence supports the idea that these are incredible habitats for fish. Whenever we put fish on these habitats, they grow really well, they do really well, but we still need to answer a few more questions that are out there. One of the questions we’re interested in is we know they grow fast, but do they actually survive better out to the ocean? Can we wild these fish to be stronger salmon than they were before? If we lose rice fields or they get turned into some other type of crop, we’re going to be a lot worse off because then we won’t have these wetland aquatic, agricultural floodplains to work with.

Jim Morris: There are a lot of positives with this project between the teamwork, expertise and the natural benefits from rice fields, including abundant fish food. This is important work and we will keep you updated on how this pilot project is going. That’ll wrap up this episode. Thank you to our interview subjects and those supporting the pilot salmon project, including Syngenta, the US Department of Agriculture’s Natural Resources Conservation Service, the Bechtle Foundation, as well as many other valued supporters. We would love to hear from you, your comments, your questions. You can go to and click on, “podcast,” to subscribe and to reach out to us. Thanks for listening.