(Photo by Casey Kuhn - KJZZ)

Tark Rush holds a striped bass that's about to be shipped to Southern California.

(Photo by Casey Kuhn - KJZZ)

Workers at Desert Springs Tilapia load striped bass into the net.

(Photo by Casey Kuhn - KJZZ)

John Healy looks over one of several tanks he's constructed in his backyard that holds tilapia.

Arizona doesn’t have a lot of fish farms compared to coastal states, like California or Louisiana.

In the desert where water is scarce, some experts are pushing for a process called aquaponics, where the wastewater from the fish is used to fertilize crops. One Arizona fish farm could become a new standard in sustainable agriculture.

Two workers in galoshes waded through a shallow pond on a recent July day. Just a few hours ago, it was teeming with thousands of shiny, wriggling fish.

“This was striped bass in here, and now they’re harvesting them to take up and pack,” said Tark Rush, owner of Desert Springs Tilapia.

Rush started as a shrimp farmer in remote Dateland, Arizona. Then he switched to striped bass and tilapia 14 years ago to make more money.

“So I just kind of learned slowly and steadily and I just decided, 'hey I can make a little money doing this,'“ Rush said.

That day he’d harvested 2,000 pounds of striped bass and 6,000 pounds of tilapia. Those are packed up and trucked to Los Angeles and San Francisco, where people pay more for fresh, not frozen, fish.

Rush sees fish farming not just as a way to make money, but also to save money by reusing the fish water on the 500 acres of Bermuda grass crop he grows nearby.

“What I’m trying to do is everywhere we’re pumping water, we’re going to put fish in front of it," Rush said. "That will save on fertilizer and it will save on half of the pumping costs.”

Aquaponics, explained

The fish put waste in the water, which eventually turns into nitrates, a big ingredient in fertilizer. Rush said he saves more than $100,000 a year on fertilizer by using this nutrient-rich water.  And, he gets double the use from costs of pumping groundwater from his wells.

This sustainable practice has been championed by University of Arizona College of Agriculture and Life Sciences environmental science professor Kevin Fitzsimmons, who spoke via Skype.

"We’ve been promoting farmers to be as efficient as possible," Fitzsimmons said. "With aquaculture, they can actually get two crops out of the exact same water."

Aquaculture is the same as farming fish. And traditional crop farming in Arizona’s desert requires a lot of irrigation; the dry climate means much of the water used on crops evaporates or runs off the fields.

With record-low water levels in Lake Mead, a key source for Arizona agriculture, Fitzsimmons said public scrutiny creates a pressure to conserve.

"So the farmers in Arizona and the rest of the southwest all need to become more efficient for economic reasons, environmental reasons, social reasons," Fitzsimmons said. "So they’re under a lot of pressure from all sides."

While Rush may be one of the few farmers to use aquaponics commercially, it’s a growing hobby-business for Glendale resident John Healy, who owns Southwest Aquaponics and Fish Hatchery.

"It doesn’t necessarily fill my pockets, but it’s on the cusp," Healy said.

Healy started growing tilapia four years ago, and now his suburban backyard is taken over with large above-ground fish tanks.

Backyard aquaponic gardening growing popular

The water pumps cycle fish water through growing garden plants, without the use of soil. Healy said he wants to be an example for sustainable growing while he sells fish and equipment for home gardeners wanting to try out aquaponics.

"This is really kind of a lab activity or a lab site for people who want to get into aquaponics, vegetable gardening in their backyard," Healy said.

He said business has almost doubled every year.

"I see more and more dirt farmers moving to aquaponics," he said. "Almost, I'm like doing missionary work trying to convert these people."

With backyard aquaponics on the rise, the commercial fish farming in the Southwest may soon follow suit.

Back in Dateland, Tark Rush thinks the next decade will see more and more growth in fish farming.

"Because as we get going, we’re just getting less marine fish," Rush said. "Already at least 60 percent of the fish come from farms now. And that's jumped up over the last five years over 20 percent. So it’ll get bigger and bigger."

And in a continuing drought, getting two crops from one water source may be a future for irrigation in Arizona.