There is heightened interest in the idea of deploying aquaponics technology (the fusion of aquaculture with hydroponic vegetable production) in food deserts. At its best, aquaponics allows local people to produce their own fresh fish and produce in a sustainable manner: the wastewater from the fish is used to provide water and fertilizer to the plants. However, there are significant technological and social barriers that have hindered adoption of aquaponics by marginalized populations living in food deserts. Barriers include 1) systems that are prone to instability without advanced technical knowledge, 2) fish and produce quality that do not meet consumer quality demands (e.g. muddy fish flavor), and 3) food safety issues given that pathogens in the fish wastewater can contaminate the vegetables. Failure to address these three issues will continue to place aquaponics systems (and the corresponding nutritional and environmental benefits) out of reach of marginalized populations. The objective of this project is to improve understanding of how aquaponics design decisions affect stability, pathogen dynamics, and product quality.

The central hypothesis of this project is that algal biofloc and decoupled systems will exceed the performance metrics of bacteria-centric biofloc and coupled systems (85% of current systems) in terms of 1) system stability and ease of operation, 2) nutritional and flavor profiles, and 3) pathogen management when placed in the hands of novice users. This project will allow rigorous testing of integrating algal- biofloc and decoupled plant production into small-scale aquaponics systems, both independently and in combination. The test systems will be operated by high school students in East Alabama (after hands-on training) in a synergistic school-university partnership. The university team has extensive experience conducting research on aquaponics systems and algal-bacterial treatment of waste, and engages frequently in educational and outreach programs with novice users. The three specific research aims are to: (Aim 1) Test the integration of algae and decoupling into biofloc aquaponics to improve stability and ease of operation for novice users (high school students). The hypothesis is that integration of green algae into the biofloc and deployment into a decoupled aquaponics system will improve system stability (nitrification capacity) and reliability (plant and fish survival). (Aim 2) Determine the contribution of algal biofloc to improved nutritional quality and flavor profile of aquaponics products. The hypothesis is that integrating Chlorella algae into the biofloc will increase the omega-3 fatty acid profile of fish, antioxidant content of vegetables, and improve the fish flavor profile by displacing opportunistic bacteria and cyanobacteria species that generate muddy flavors. (Aim 3) Quantify the impacts of algal biofloc and decoupling on indicator pathogens in aquaponics. The hypothesis is that the presence of algal taxa like Chlorella in the biofloc and use of decoupled systems will reduce the presence of indicator pathogens. While students and teachers will run the different aquaponics systems, Auburn University and the Bashan Institute of Science will conduct advanced chemical, microbiological, and genomic analyses of the systems. Students, after formal parental informed consent, will evaluate system ease-of-use and flavor of products through surveys. Improved understanding of microbial dynamics in aquaponics can translate broadly to other areas of aquaculture, nutrient recovery, and waste management. Improved understanding of how design choices impact user experience may translate to research on other scalable food production technologies. The project is designed to lead to enhancement of education of high school student participants who live in low-income communities with limited food access. Approximately 225 students will engage in hands-on learning by operating the aquaponics systems, allowing them to learn and apply knowledge of agriculture, biology, chemistry, nutrition, and engineering. Potentially, these students can impact the future of sustainable food production: the skills that they learn should extend to a wide range of career and education pathways. It is expected that reaching them in their formative years will result in measurable changes in self- perceptions regarding STEM topics, which will be assessed through survey instruments.

This project is jointly funded by the CBET/ENG Environmental Sustainability program and the Established Program to Stimulate Competitive Research (EPSCoR).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.