It seems a natural fit: a sustainable system that produces fresh vegetables and fish located in the food deserts of marginalized populations.
And while interest around such arrangements is exploding, there are significant technical and social barriers to their adoption.
Overcoming these barriers is the goal of a research project being conducted at Auburn University, led by Brendan Higgins, Assistant Professor of Biosystems Engineering, Faculty of Agriculture.
“Aquaponics at its best allows local people to grow their own fresh fish and produce it sustainably. The wastewater from the fish provides water and fertilizer for the plants. “But the development of this fusion of aquaculture and hydroponic vegetable production in food deserts is not without barriers.”
These barriers include: 1) Systems that are prone to instability without advanced technical knowledge. 2) fish or produce quality that does not meet consumer quality requirements (e.g. cloudy fish flavor); 3) Food safety issues given that pathogens in fish wastewater can contaminate vegetables.
“If these three issues are not addressed, aquaponics systems and their corresponding nutritional and environmental benefits will continue to be out of reach for marginalized populations,” Higgins said. says.
The purpose of this research project, which is funded by a $575,730 grant from the National Science Foundation, is to explore how aquaponics design decisions (e.g., integrating algae into bioflocs, coupling and separation systems) can improve microbial stability. sex, pathogen dynamics and product quality.
“Our central hypothesis is that algal bioflocs and segregation systems are better than bacteria-centric bioflocs and binding systems in terms of system stability and ease of operation, nutritional and flavor profiles, and pathogen management. (85% of current systems) performance metrics, leaving it in the hands of novice users,” Higgins said.
This project will enable researchers to rigorously test the integration of algal bioflocs and isolated plant production into small-scale aquaponics systems, either independently or in combination.
Higgins says algae biofloc is a mixture of algae and bacteria that convert nutrients into forms that are less toxic to both fish and plants. Bacterial biofloc does the same thing, but researchers have found that a mixture of algae and bacteria is more effective, at least in the lab.
“I would like to know if this applies to real aquaponics systems,” he said.
Tethered aquaponics means that water recirculates between the aquarium and the plant bed (and back again). Decoupling means that water flows in one direction.
“Our project explores these design choices in isolation and in combination,” says Higgins.
The test system will be operated by high school students in eastern Alabama after hands-on training through a synergistic school-college partnership.
“Our team has extensive experience in researching aquaponics systems and algae-bacterial treatment of waste, and frequently engages in educational and outreach programs for novice users.” He said.
Collaborators on this project include David Cline from the Department of Fisheries and Aquatic Sciences. Sheena Stewart, Education Foundation, Leadership, and Technology Division of the School of Education. Luz de Bashan and Paola Magalon of the Bashan Institute of Science.
Three specific objectives of this research project are:
We test algal integration and decoupling to biofloc aquaponics to improve stability and maneuverability for novice users (high school students). Researchers hypothesize that integrating green algae into bioflocs and deploying them in isolated aquaponics systems will improve system stability (nitrification capacity) and reliability (plant and fish survival).
Determine the contribution of algal biofloc to improving the nutritional quality and flavor profile of aquaponics products. Integrating chlorella algae into biofloc increases fish’s omega-3 fatty acid profile, vegetable antioxidant content, and improves fish’s flavor profile by replacing opportunistic and cyanobacterial species that produce cloudy flavors. .
Quantify the impact of algal biofloc and decoupling on indicator pathogens in aquaponics. The presence of algal taxa such as Chlorella in bioflocs and the use of segregation systems hypothetically reduce the presence of indicator pathogens. While students and teachers operate various aquaponics systems, Auburn University and the Bashan Institute of Science conduct advanced chemical, microbiological, and genomic analyzes of the systems. Evaluate the ease of use of the system and the taste of the product through a questionnaire.
According to Higgins, the research project is important because it hopes to solve persistent challenges that have hindered the adoption of aquaponics so far.
“For example, the integration of algae into isolated biofloc production has great potential to address microbial stability and pathogen concerns,” he said. “Furthermore, our improved understanding of these microbial dynamics in aquaponics can be broadly applied to other areas of aquaculture, nutrient recovery, and waste management. A better understanding of how it affects food production could lead to research into other scalable food production techniques.”
The project will have measurable benefits by enhancing the education of high school participants living in low-income communities with limited access to food.
“Approximately 225 students will operate an aquaponics system and engage in hands-on learning to learn and apply knowledge in agriculture, biology, chemistry, nutrition and engineering,” said Higgins. .
“This is important because these students are the future of sustainable food production. The skills they learn span a wide range of careers and educational pathways. We expect to see measurable changes in self-perception, which will be assessed through survey instruments.”