Desert fish farms, that is.

A decade ago, the idea of raising fish in the desert might have been ridiculed, but 10 years of successful aquaculture in Israel and the Southwestern United States showed the idea can work.

Shrimp raised in salty underground water by the Wood Brothers Farm in Arizona are marketed as "Desert Sweet." (www.desertsweetshrimp.com)

"People thought we were lunatics at first," Appelbaum said while on a recent tour in New York City. "But we know there is a need and this can answer that need. Much of the world has arid land that is rich in sun and cheap labor — for aquaculture you don't need much else to be successful."

Aquaculture may not need much, but water, of course, is necessary.

Raised in Ancient Water

To host fish and shrimp in the desert, farmers draw water from deep underground aquifers that exist under many arid regions of the world. The warm, ancient water is contained in prehistoric caverns 50-150 feet beneath the desert surface and is slightly brackish or salty.

In 10 years of experimentation, farmers found that some species, including shrimp, catfish, tilapia (a fish that has become more popular on U.S. dinner tables in recent years) and striped bass thrive in the warm, slightly salty water. In fact, the warm water appears to accelerate the breeding rate of many species.

To access the salty water supply, farmers drill through the desert floor using equipment similar to oil drilling machinery and collect it in above ground pools, creating comfortable living quarters for edible creatures.

Keeping fish and shrimp farms in desert communities may seem impractical, but the enclosed farms actually hold a key advantage over coastal ones — the animals remain protected from diseases that are often spread between seaside farms through ocean waters.

Appelbaum, the head of Israel's Bengis Center for Desert Aquaculture in the Negev Desert, estimates more than 30 million tons of shrimp and fish are raised from desert fish farms each year, producing an industry worth more than $40 billion. In Israel, most are raised in the Negev Desert, where temperatures average about 97.5 degrees Fahrenheit in August and annual rainfall is close to zero.

Shrimp are not in great demand in Israel since the crustacean is considered a nonkosher food, but, as Appelbaum points out, the London market is a mere 3 ½-hour plane trip away. The shrimp's quick maturation rate (about five to six months) also makes it a more desirable crop, since aqua farmers can harvest at least two crops a year.

In recent years Arizona has also made significant contributions to the annual harvest with 30 licensed fish farms or facilities producing about 1.3 million pounds of striped and large-mouth bass, catfish, tilapia and trout and more than 168,000 pounds of shrimp.

The Wood Brothers Farm an hour outside Phoenix markets its shrimp as "Desert Sweet" since the brackish water from the state's underground aquifer lend the shrimp a particularly sweet flesh.

"As water supplies get tighter, we have to be creative about how we can put water to use," explains Kevin Fitzsimmons, an aquaculture extension specialist at the University of Arizona who has been encouraging the development of aquaculture in the state.

Inland fish farms have also been installed recently in Alabama, Georgia, Florida and west Texas. U.S. researchers are now visiting regions in central China where it's believed farmers are using brackish water to raise shrimp and fish. And Appelbaum is encouraging development in Central Asian countries by recruiting students from the regions to his desert aquaculture program.

From Spa to Fish to Olives

The desert fish farms are promising since they use a water resource that is not in high demand for urban centers because of its salinity. Farmers have learned, however, how to use the salty resource for growing some crops.

For about 30 years farmers have drawn the underground water to raise tomatoes, olives, figs and other salt-tolerant crops. This produce is generally sweeter than that raised in regular water, since the salt water inhibits growth and the crops retain their juices, including sugars.

Now that fish and shrimp farms are well under way, researchers are eager to combine desert agriculture with desert aquaculture.

Sharing water between fish and agriculture works well since water once used to house fish is enriched by fish waste and makes a nourishing drink for crops. Some have considered adding a third station to the recycled water chain.

Since water from these deep underground aquifers is naturally hot, it could first be used in hot-water spas, says Appelbaum, then pooled to host fish and shrimp and finally sprayed on crops.

Right now, agriculture remains the highest water consumer in the world, using 70 percent of the world's water supply. The World Resources Institutes recently estimated that by the year 2025, 48 countries with 3 billion people could face chronic water shortages.

Although the underground brackish aquifers are not an endless water resource — Appelbaum estimates most contain about 200 years worth of water — he argues using the salty resources can help buy time until the day when scientists find a cheap way to desalinate ocean water.

As Fitzsimmons says, "In the desert, and maybe in the future, we've got to use every liter of water we've got."