The Current Magazine Winter 2019 | Page 20

PARTNER PROFILE

Why We’re Using Rice Fields to Grow Food for

Endangered Salmon

By Roger Cornwell, River Garden Farms

By Allison Sherlock, Watershed Coordinator, Fall River Conservancy

The winter-run chinook salmon population continues to hover around historic lows in the Sacramento River, but there may be hope just beyond the river bank.

River Garden Farms in Yolo County is one member of a coalition of farms that is working with Cal Trout and the UC Davis Center for Watershed Sciences to grow bugs on their rice fields.

Why you ask?

The bugs produced on the rice fields during the winter months are expected to help feed undernourished salmon that no longer have access to natural food sources found on California’s historic floodplains.

The project, known as Fish Food on Floodplain Farm Fields, is in the third year of a pilot program that hopes to prove Sacramento Valley rice farms can mimic historical floodplains and produce large body cladocerans, a salmon’s primary food supply.

“We like to think of these tiny bugs in the water as floating fillet for the salmon,” said Cal Trout Senior Scientist Jacob Katz. “The larger the fish grow from the bugs produced on the rice fields, the better chance they have to survive the treacherous journey to the ocean. And, that we hope, will result in more fish returning to spawn when they mature.”

Early surveys are proving that the project holds great promise in producing the amount of bugs needed to make a significant impact on fish populations.

“The amount of zooplankton and invertebrate (fish food) thriving on the rice fields have far exceeded our expectations,” said Carson Jeffres, Scientist with the UC Davis Center for Watershed Sciences. “We have great hope that this project will serve as model that can be implemented on a global level.”

This is the latest effort tied to the Sacramento Valley Salmon Recovery Program, which aims to reverse the population decline of the winter run chinook salmon.

Recent surveys reveal less than 2,000 fish are making the journey each winter from the San Francisco Bay to the upper channels of the Sacramento River. In the mid-1970s, those numbers totaled more than 25,000 each season.

Today, government agencies, conservationists and farms are searching for answers. One of the solutions can be found by looking back to what worked for another species.

An Answer May Lie Up Above

In the 1990s, River Garden Farms and others first began using water during the winter months to decompose of the rice straw after harvest. This was a solution to eliminate the smoke-filled skies that came as a result of burning the remaining straw. The response up and down the Sacramento Valley was that of legend.

In short time, millions of shore birds and various waterfowl returned to California that few generations had witnessed before.

Now, that same water on the rice fields is being used for more than just birds.

Located along the Sacramento River in Knights Landing, River Garden Farms, has the unique opportunity to borrow water, spread it out on the fields, let the sunlight and water break down the rice straw and watch as the carbon and algae by-products help produce billions of bugs at a time when the fields are not used for growing rice.

“By borrowing water from the river for a few weeks, and then returning it full of fish food, we believe we can have a dramatic impact on the salmon populations,” said Roger Cornwell, General Manager of River Garden Farms. “We are getting more pop for each drop and using it for multiple benefits.”

River Garden Farms is discovering that its fields can be used to grow crops for people in the spring and summer, while serving as habitat for birds in the fall and now as a place to help create food for endangered fish in the winter.

“We believe when we do it this way, we give the salmon a chance to live out a success story like we’ve seen with the ducks, geese and shorebirds,” said Cornwell.

This project is crucial because the river is too swift and too deep to create the type of food energy source that the salmon need for their arduous journey to the Pacific Ocean.

“Farmers are essentially reconnecting this historic floodplain that provides a great deal of energy to the river system. It’s a system that has been cut off for a century,” Katz said. “Without these collaborative efforts, the fish remain in danger and have little hope. This project creates a win-win for everyone. It means a healthy ecosystem for fish, birds and people.”