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Rice fields 'grow' salmon

July/August 2015 California Bountiful magazine

Nigiri Project shows successful pairing



Rice farmer John Brennan explores Knaggs Ranch with his children, Sam, Sophie and Max. The Yolo County ranch not only produces food, but also provides habitat for salmon, migrating waterfowl and a variety of native species.

Rice farmer John Brennan walks the dusty roads on Knaggs Ranch in Yolo County, surveying fields where blades of grassy rice sway in gentle summer breezes. Sometimes he brings his kids along in the early evening for a stroll in the rice fields. They carry nets and buckets to hunt for critters.

The small salmon living in this field a few months before, however, are long gone. Fattened and healthy, the fish had been released back into the Sacramento River, their father explains, to follow their natural migration paths. Pacific salmon have instincts honed during millions of years, migrating along the Sacramento River in search of places to pause and feed—to put on weight and build strength—before their run to the ocean.

Although salmon have not changed their habits in millennia, the Sacramento River today is considerably different than in centuries past. Brennan notes, for example, that levees and channels have been built to control the threat of floods. These days, there aren't as many marshy places along the river for salmon to eat and rest during their long swim to the sea.

It's a problem that farmers and scientists have been working on for several years, and they've discovered a possible fix—one that uses rice fields to support the fish from winter to early spring. Then, about April, the same land is planted for rice to grow until harvest in fall.

The yearly cycle continues, moving in harmony with nature's timing, Brennan said, and providing both wildlife habitat and food using the same farmland.

Nigiri Project researchers contain juvenile salmon in a flooded rice field to determine health and growth characteristics. The farmland is used after harvest as a place for migrating salmon to put on weight and build strength before their run to the ocean.

Field for plenty

The approach is aptly called the Nigiri Project—named for the classic sushi made of raw fish served on a wedge of rice. Already in winter, rice fields offer an inviting spot to rest and grab a bite to eat for migrating waterfowl—colorful ducks, snowy swans and honking geese.

"Using the same concept for successfully creating habitat for migrating birds, we're now using it to provide habitat for salmon," Brennan said.

He refers to large maps in his Davis office and traces with his finger the rice fields throughout the Sacramento Valley that serve as annual wetlands for birds traveling the Pacific Flyway—about 200,000 acres in all. He also points to areas being used by Nigiri Project researchers to grow juvenile salmon.

"The critical role California rice fields play in providing wildlife habitat is well recognized," said California Rice Commission Environmental Affairs Manager Paul Buttner. "We appreciate efforts like the Nigiri Project. We welcome ways to expand the role rice fields play for all wildlife, including fish species."

After four years, the Nigiri Project is still considered to be in the experimental stage, but researchers, environmental groups and farmers say they are encouraged by the results.

"We're making progress," Brennan said. "It's a project that makes a lot of sense."

Within six weeks, the fish grow about five times their original weight.

Project success

Initially, there were some doubts that what works for fowl could also work for fish, Brennan said. Many wondered if the murky field water would be right for salmon; others worried there might not be enough food for the fish or about the logistics and timing of releasing the fish back into the Yolo Bypass flood channel beside the river.

The Nigiri Project was launched to answer such questions. Researchers began with about 50,000 hatchery salmon placed in 20 acres of watered rice fields on the 1,700-acre Knaggs Ranch, which Brennan manages.

The results have been nothing short of astonishing, researchers said. The fish don't just survive, they thrive. After six weeks in the watered fields, the juvenile fish grow five times their original weight and 1.5 times their length. Researchers have also found the salmon comfortably coexist with the migratory birds.

Fisheries expert Jacob Katz calls juvenile salmon growth rates in flooded rice fields "astonishing."

'Floodplain fatties'

"This is very exciting for those of us working to restore self-sustaining salmon populations," said University of California, Davis, fisheries researcher Carson Jeffres. "The system works and the fish get so fat before release; we call them our 'floodplain fatties.'"

Salmon recovery in the Central Valley relies on finding solutions that provide continued use of farmland as habitat for a variety of species and flood protection, explained California Trout program manager Jacob Katz, who works with Brennan on the research effort: "That's a tall order, but the Nigiri Project is an important step down that road."

Project researchers continue to report encouraging results from year to year and have expanded to fields in other areas of the Sacramento Valley. Katz said the Nigiri Project shows promise as a way to help build healthier salmon runs, while also demonstrating an advantageous and harmonious relationship between farming and wildlife.

"Studies like this show that agriculture and habitat restoration can go hand in hand, and that farmland can be used to help wildlife while also producing crops," said Jack Rice, an associate counsel for the California Farm Bureau Federation. "Through cooperation between farmers and researchers, more people are seeing the results and recognizing that farming can provide significant environmental benefits."

As sunlight slips into dusk at Knaggs Ranch, John Brennan starts heading his children for home. Everyone's hungry so they hurry, but halt to catch a glimpse when a rustle in the grass tells them a critter is scurrying away.

"I'm always looking for ways to make a difference," Brennan said. "Everybody's good at thinking globally, but what we need is more people thinking locally. To protect and improve the environment, we have to concentrate together—one yard, one fish at a time."

Kate Campbell
kcampbell@californiabountiful.com

 

Farmers and ranchers helping wildlife

There are hundreds of restoration and conservation projects being conducted on farm and ranch land throughout the state to benefit wildlife and, at the same time, support food production. Here are some examples from the U.S. Department of Agriculture Natural Resources Conservation Service:

Sage grouse
Working with neighbors and government agencies, California ranchers have restored habitat and helped bolster sage grouse populations along the California-Nevada border. The same conservation practices that promote healthy grazing lands also benefit sage grouse and other wildlife.

Tricolored blackbirds
This eye-catching species was once abundant in California and historically nested in wetlands, but now often uses cropland. Now, when farmers in the Central Valley find a nesting colony, they turn to conservation agencies for guidance and will delay harvesting crops until the young birds take flight.

'Livestock Pond Initiative'
Ranchers in Alameda and Contra Costa counties are restoring hundreds of livestock ponds to provide habitat for amphibians such as the protected California tiger salamander and red-legged frog, turtles and migratory birds, particularly during the drought. 

Southwestern willow flycatcher
Southern California is home to this endangered songbird's largest breeding population. Programs assist landowners, including farmers and ranchers, in helping them manage or remove invasive plants and restore native vegetation to improve potential breeding habitat.

Photos courtesy of USDA Natural Resources Conservation Service and U.S. Fish and Wildlife Service


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