In Minnesota, an emerging industry is starting to capture the attention of crop growers, fish processors, distributors, restaurants and many others. Aquaponics — a year-round way to grow aquatic animals and plants in the same system — lets growers produce food locally and sustainably, and it’s on the rise. There are now more than 40 aquaponics producers in the state, up from only three in 2010.
There’s just one problem with growing aquaponically: Even the growers themselves aren’t sure how best to do it.
In response to the need for more knowledge in aquaponics, a team of University of Minnesota faculty developed a new undergraduate course called “Aquaponics: Integrated fish and plant food systems,” which set students to work discovering industry challenges and researching solutions. The course debuted in spring semester this year as part of a larger collaborative effort, which includes research projects and continuing education opportunities, to position Minnesota as a national leader in the field of aquaponics. Backed by funds from the U’s College of Food, Agricultural and Natural Resource Sciences and MnDRIVE (Minnesota’s Discovery, Research and InnoVation Economy), the effort brought together experts from fisheries and wildlife, veterinary medicine and aquaculture, horticulture and plant sciences to form a team of experts to help inform and guide an emerging industry.
“We realized there were lots of research questions to be asked that none of the existing industry players had answers to,” said Neil Anderson, Ph.D., professor of horticulture science in CFANS and one of the course’s instructors. “There was a huge deficit of information.”
Aquaponics systems, which are often set up in warehouses or greenhouses, work by using the waste left behind by fish to naturally provide nutrients to nearby water-grown plants, a process similar to the way wild fish supply nutrients to plants in an ecosystem. For example, an aquaponic setup may include tilapia or shrimp grown in one tank that then transfers its water and nutrients to a nearby biofilter to change the fish waste (ammonium and urea) into nitrate nitrogen, which is then transferred to a tank full of lettuce.
Compared to traditional forms of aquaculture and soil-grown crops, aquaponics offers a few benefits. Producers grow plants and fish in a closed system, meaning the water cycles through the system and very little of it is lost. No chemical fertilizers end up working their way into nearby streams and watersheds in the form of run-off. Aquaponics opens up access to locally grown, natural produce that leaves Minnesota’s natural ecosystems unaffected.
Student interest in aquaponics gave faculty even more reason to form the new course. Laura Hayes, a senior double-majoring in horticultural science and nutrition, jumped at the chance to register because she was interested in aquaponics and wanted the opportunity to bridge her two majors with a single line of study. Hayes had watched aquaponics spring up in businesses around the Twin Cities and was eager to learn more about it while doing her own research.
“It was very hands-on and practical,” Hayes said of the course. “And I loved that it was taught by a multidisciplinary team of professors.”
Students taking the course quickly learned how the individual supply chains worked for hydroponic plants and for fish grown in aquaculture, and then set to work combining the two into a single system.
To shed some light on challenges in the field, faculty gathered an industry panel of representatives from state agencies, producers, restaurants and other organizations involved in the food supply. The panel introduced students to some of the problems they had found while exploring the use of aquaponics for their individual company’s needs. Which cultivars of crops work best in an aquaponics? How do aquaponically raised fish get to the market? Where would restaurants process the fish raised in aquaponic settings?
The students then split up into six teams to decide on and pursue research projects for the remainder of the semester. Hayes’ group, for example, researched how the potential for foodborne illnesses to spread among smooth-textured leafy greens (like lettuce) in aquaponics settings compared to illness spread in standard soil-based growing methods. The group found that aquaponically grown leafy greens had the same potential for these illnesses as their traditionally grown counterparts.
“Many industry leaders in the Twin Cities were interested in our findings,” Hayes said. “We hope our research, once published, will continue to educate the industry regarding food safety. The aquaponics sector is so small that if a single outbreak occurs, it could be very detrimental to the industry as a whole.”
Real-world challenges in food production
During their research, students grappled with the challenges that aquaponic growers face. One of the largest hurdles came when students found obtaining yellow perch for the aquaponics system proved more difficult than expected — the supply they originally ordered in September didn’t actually arrive until February.
“Our class was a microcosm of the challenges an aquaponics producer might have,” Anderson said. “This is what industry people face all the time. The students had to be problem solvers.”
The students’ research culminated in presentations at the first annual Minnesota Aquaponics Symposium, which brought students, faculty and industry together to discuss research in food safety and best practices for aquaponics systems. Each student research group presented their findings, fielding questions from aquaponics experts. Industry members at the symposium also suggested ideas for future research projects that could help guide next year’s aquaponics class.
As for Hayes, she’s staying involved in aquaponics even after completing the course. Thanks to her research accomplishments and the industry contacts she made along the way, she will intern this summer at an aquaponics organization, while also working on a scientific paper she intends to submit for publication.
“The aquaponics course taught me how to come up with an original research topic, write a research paper, collaborate with a multidisciplinary team and develop my strength,” she said. “It will hopefully give me a window into the aquaponics field as I prepare for my career and graduation.”