UT Aquaponics: Using Fish for the Future
Aquaponics fuses two innovative sustainability practices: hydroponics and aquaculture. The system combines everything we love about sustainability within the community, and UT Aquaponics is putting this into practice right here at the University of Texas at Austin.
UT Aquaponics is a student-run project through Engineers for a Sustainable World, a student organization focused on sustainable engineering. The growing team of about 15 students work to maintain their greenhouses, create blueprints for their aquaponic systems, construct filters and more.
“Our goal is to teach what aquaponics is,” Sophia Doss, the project lead, said. “We give students the space to explore sustainable farming and get hands-on experience.”
An efficient, integrated system
Hydroponics is the act of growing plants using only water. Aquaculture is a form of agriculture focusing on the cultivation of fish, rather than crops or cows. With aquaponics, these methods are used in tandem. Nutrients from fish waste enter the aquaculture water and fertilize the hydroponically grown plants.
Since the aquaculture nutrients replace the need for soil, aquaponics requires minimal resources. Doss explains this, especially, is sustainable and efficient.
Traditional farming techniques lose water to irrigation, runoff and evaporation. However, by circulating and recycling it, aquaponic systems save 90% of the water wasted by conventional agriculture.
Aquaponics is currently practiced most heavily in North America, where it is experimented with at numerous universities and farms. From research and practice at schools including Texas State University and the University of Houston, to successful farms in Canada and Mexico, the system is being invested in near and far.
Technologies specifically catered to food production in the urban environment can help us address issues like food accessibility. For example, closed-loop gardening is an integrative approach that aims to maximize resource efficiency and produce no waste. Aquaponics is a prime example of a closed-loop garden system.
“When we say closed-loop gardening, we mean that all the nutrients that go in are used up,” Dr. Kanagasabapath Sathasivan, biology professor and sponsor of UT Aquaponics, said. “Even the leaves, stem and roots, you can decompose. From the compost, you can get more plants. You don’t waste any of that—you either consume or recycle.”
In prior years, the organization had fully functioning aquaponics systems in the Painter Greenhouses. However, severe ice storm damage and lack of maintenance during the height of COVID-19 made them unusable.
Promising current and future projects
Grants from the Green Fund have allowed the greenhouses to be rebuilt this year, and UT Aquaponics is working on recrafting their aquaponics systems from the ground up. Creating these prototypes and reestablishing the systems calls for plenty of hands-on work and construction. Designing filtration systems requires a great deal of trial and error, and their method is more than what meets the eye.
“The [system] we’re currently building will have different kinds of bacteria in it,” Lan Nguyen, UT Aquaponics secretary, said. “This will convert the ammonium from the fish waste into nitrite and nitrate, which acts as fertilizer for the plants.”
Precise, effective filters are essential when it comes to maintaining nutrients and mitigating possibly harmful bacteria. After plenty of behind-the-scenes work on blueprints and mock-ups, the team plans to complete three permanent systems within the greenhouses by the end of the spring semester. They hope these systems will eventually be used to produce food and flowers for UT Aquaponics to use.
This organization has been much more than a project: students can find community and learn together in a low-stress, hands-on environment. Events like their greenhouse workdays, potlucks and movie nights provide a space to make new friends and bond with like-minded peers.
“Creating a community is the best impact I've seen from this organization,” Doss said. “Just seeing people come back week after week, have a good time and make friends—that’s been my biggest accomplishment.”
As the sponsor of the club, Sathasivan acknowledges how students sacrifice their free time to invest in such extracurricular research, he stresses the invaluable hands-on experience and leadership skills they gain.
“Developing something novel, something useful — it gives you creativity and you're solving a problem,” Sathasivan said. “I encourage more students to join not only this research but any research they can get their hands on.”
Aquaponics system lead Lillian Kalmbach says she was drawn to the club by the passion of other members.
“No one’s like, ‘you're doing it wrong,’” Kalmbach said. “We're all learning together, all figuring it out together, which is fun.”
Sathasivan said aquaponics is part of a larger goal in which sustainability will benefit future generations.
“You're going to inherit the Earth and be the guardians of the Earth,” Sathasivan said. “So, you have to take care of it.”
Photo courtesy of Sophia Doss