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Habitat work shows benefits for protected salmon

Issue Date: March 7, 2018
By Christine Souza
Roger Cornwell, general manager of River Garden Farms in Knights Landing shows the insects or aquatic food source created in a rice field through the “Fish Food on Floodplain Farm Fields” project.
Photo/River Garden Farms
Jacob Katz, senior scientist for California Trout, samples water from the rice field to determine the number of insects. He says an estimated 250 pounds of insects per 100 acre-feet of water will go to benefit salmon and other fish in the Sacramento River.
Photo/River Garden Farms
Monitoring a salmon-rearing study that involved lowering large root wads attached to boulders into the Sacramento River near Redding, River Garden Farms co-owner Less Canter, left, looks at sonar imagery of juvenile Chinook salmon with scientist Dave Vogel.
Photo/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 participants in the projects.

Farmers, researchers, agencies and organizations that have come together as partners in salmon and species 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 said, 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 said.

"But over the past few years, a new approach to helping species is emerging," Rice said. "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."

Cannon Michael, a Los Banos farmer who chairs the San Luis & Delta-Mendota Water Authority, said a previous "flow-only focus"—simply requiring more water to be devoted to fish flows—has not yielded positive results.

"Farmers are suffering and the fish continue to suffer," Michael said, noting that the authority has been a partner in several recovery projects.

"We're looking to change that trajectory and improve outcomes, not just for fish, but for farms, communities and others served by the Central Valley Project and the State Water Project," he said.

For example, in integrating salmon conservation practices with working farms on floodplains, the Nigiri Project began in 2012 by flooding rice fields in the Yolo Bypass west of Sacramento. It has shown benefits for juvenile Chinook salmon before they run to the ocean.

That proven effort was altered slightly in 2016 as the "Fish Food on Floodplain Farm Fields" project by the University of California, Davis, Center for Watershed Sciences; California Department of Water Resources; and California Trout, and funded by the San Luis & Delta-Mendota Water Authority and the Metropolitan Water District of Southern California.

Jacob Katz, senior scientist for California Trout, said the program began 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 said. "We just had to drain the food back to the river system."

Roger Cornwell, general manager of Knights Landing-based River Garden Farms, said the way that 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, Katz explained, in which rice stubble and other vegetation is broken down by microbes, and microbes are eaten by insects. 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.

"Bugs are there, but they never get back to the fish in the river, so what we've been asking farmers to do is to actively drain their decomp fields to get those bugs into the canals, and get the canal water back to the river where fish can benefit," Katz said.

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 and to the river.

"Great, robust fish populations mean more secure water delivery to our cities and to our farms," Katz said. "It's got momentum and I think we're going to see real change with how rivers are managed in the immediate future."

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 said. "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 purpose of the structures is to increase the likelihood young salmon will be able to 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 take shelter from high-velocity water moving through the river. People overseeing the project said 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, said young salmon began using the structures last spring, soon after they were installed. Although the fish did not use all 25 structures, many were used exactly how the project was intended, he said.

For the next two years, Vogel plans to continue surveying the fish to determine their presence around the structures.

"We've demonstrated they (refugia) are successful; now we would like to see the project greatly expanded," he said. "Many of the restoration efforts that had been implemented by the federal government had been relatively piecemeal, just focused on projects without a holistic approach to address each life stage of the salmon to ensure fish make it safely back out to the ocean."

(Christine Souza is an assistant editor of Ag Alert. She may be contacted at

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.

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