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Faculty Profiles

Research Showcase - Greg Cronin, Integrative Biology

Biologist Greg Cronin works to advance sustainable agriculture called aquaponics

The new agricultural system has high production and produces no pollution

Written by D.J. Martin, media relations intern and undergraduate student majoring in English writing and communication in the College of Liberal Arts and Sciences

University of Colorado Denver biologist Greg Cronin is working to popularize aquaponics, a breakthrough, sustainable agricultural system that produces food in small areas without soil, pesticides or pollution.

During a recent field trip of middle school students to CU Denver, Cronin said, "Air is free and readily available, water is cheap and readily available, but food is expensive." He believes aquaponics, which grows crops with water from fish tanks, can provide a more sustainable food source than what is typically available.

In 2009, Cronin attended a workshop at the Urban Farm in Stapleton, Colo. by aquaponics creator Will Allen, whose work landed him among Time magazine's 100 most influential people in the world in 2010. Cronin witnessed how aquaponics takes nutrient-rich water from fish tanks and pumps it through hydroponic systems to grow vegetables. As a result, healthy plants grow above and the fish below can be eaten.

While training as an aquatic ecologist, Cronin learned that most water pollution comes from agricultural runoff. So he was intrigued by Allen's workshop which offered a unique way to grow crops without damaging ecosystems.

After exploring the possibilities of aquaponics, Cronin travelled to the University of the Virgin Islands in St. Croix for further study.

"I was surprised at what large amounts of food can be grown in a small amount of space," Cronin said. "The lab grew 50,000 pounds of fish and a quarter million pounds of vegetables per acre, per year."

Aquaponics requires a water supply, piping, fish food, and a pump with an energy source. In other words, it can be built with local supplies and assembled within a small space. Urban farming can greatly improve from it and people can build private systems on their property.

"I've heard of people using old hot tubs," said Cronin.

Traditional agricultural practices require much more space—leading to the destruction of more wildlife—and are not sustainable. They can degrade into desertification and the runoff often carries pesticides into aquatic ecosystems.

According to Cronin, aquaponics is sustainable, more efficient and doesn't even require soil for crops.

"It's a win, win environmentally," he said. "It doesn't release any pollution into the environment."

In addition, a wide range of food can be grown in an aquaponics system including basil, beans, tomatoes, and greens to name a few.

"Any food you can grow hydroponically, you can grow aquaponically," said Cronin.

Cronin has been trying to raise funds to bring aquaponics to developing nations where he believes it can have a tremendous impact. He acknowledged that it can be expensive but the economic effects could easily off-set the cost. At the same time, he believes it could create jobs.

While food is an expensive commodity usually bought from suppliers that people know little about, aquaponics offers another option.

"Aquaponics is a way for people to grow food locally," he said, "A way for them to become more food-independent."