Rice + Fish = Ecological Benefits

Farmers join with environmental groups on projects that benefit salmon and keep agriculture viable.

By Christine Souza

river garden farms fish food project

Roger Cornwell, general manager of River Garden Farms in Knights Landing, shows the insects and aquatic food created in a rice field through the “Fish Food on Floodplain Farm Fields” project — image courtesy River Garden Farms

Moving discussions on water and protected species from the courtroom into the field, collaborative projects to benefit salmon are proving helpful in recovering fish, according to project participants.

Farmers, researchers, agencies and organizations that have partnered in habitat recovery programs report positive results from ecosystem improvements that address passage and habitat challenges to salmon at various life stages.

That’s encouraging in several respects, California Farm Bureau Federation Senior Counsel Jack Rice says, noting that for the past several decades, environmental groups have often “perpetuated conflict by filing lawsuits that lead to regulations that lead to more lawsuits.” None of that has much helped salmon or other species, he says.

“But over the past few years, a new approach to helping species is emerging,” Rice says. “Conservationists are now working collaboratively with farmers and ranchers to identify creative solutions that will provide real ecological benefits to species while also considering the well-being of people.”

Double-cropping rice and fish food

For example, the Nigiri Project began in 2012 by flooding rice fields in the Yolo Bypass west of Sacramento. Jacob Katz, senior scientist for California Trout, says it was as a way to involve a half-million acres of rice that don’t have a direct connection to the Sacramento River.

“Just because you can’t get fish to those fields, it doesn’t mean that those fields can’t grow food to benefit fish,” Katz says. “We just had to drain the food back to the river system.”

Roger Cornwell, general manager of Knights Landing-based River Garden Farms, says the way the rice fields are designed, “We have to pump water in and pump water out, so what I can do is grow food for the fish and take that water that’s enriched with the food and put it in the river for the fish.”

Rice fields serve as shallow floodplains in which rice stubble and other vegetation is broken down by microbes, and microbes are eaten by insects, Katz says. The insects—250 pounds per 100 acre-feet of water—are the aquatic food source needed by fish.

That food is then returned to the river.

This year, the project involves working with River Garden Farms, Montna Farms and Davis Ranches to do a series of experiments to drain fields and watch how insects move through the system to the river.

Building salmon condos

In another project, 25 salmon structures called “refugia”—made of large tree trunks and root wads bolted to 12,000-pound limestone boulders—were lowered into the Sacramento River near Redding last May. People involved in the project now say young salmon have responded well.

“We are seeing juveniles using those structures, and there’s more juveniles holding in that area than we’ve ever found before,” Cornwell says. “The structures are doing as designed, holding baby smolts in the upper reaches in the Sacramento River longer and giving them shelter from predators.”

River Garden Farms invested $500,000 in the effort, with funding from the U.S. Bureau of Reclamation.

The structures are intended to increase the likelihood young salmon will grow in size and strength to prepare for their journey to the Pacific Ocean. The shelters are expected to serve as places for juvenile salmon to hide from larger predators and as protection from high-velocity water moving through the river. People overseeing the project say the shelters will entice the fish to remain in colder water longer, increasing their odds of healthy maturation.

Scientist Dave Vogel, who is working on the pilot project for River Garden Farms, says young salmon began using the structures soon after they were installed. Although the fish did not use all 25, many were used exactly how the project was intended, he says. For the next two years, Vogel plans to continue surveying the fish to determine their presence around the structures.

The California Farm Bureau Federation contributed this article. Christine Souza is an assistant editor of Ag Alert.