Research in the Joesting Lab at the Sustainable Aquaponics Research Center (SARC)
Aquaponics is a sustainable food production system that combines fish production (aquaculture) with plant production in a soilless environment and root growth directly in water (hydroponics). In these systems, fish waste is converted into fertilizer by nitrifying bacteria, essentially cleaning the water and allowing to be recycled back into fish production. Although these systems have the potential to provide fresh protein and vegetables in regions unsuitable for traditional aquaculture and/or agriculture, there remain economic challenges, particularly with regards to maintenance costs and food procurement, to the development of a sustainable and profitable aquaponics industry. The mission of SARC is to conduct cutting-edge research on technologies and strategies to enhance the sustainability of aquaponics. In the Joesting Lab, we focus on the plant remediation loop to investigate ways to (1) reduce maintenance cost (e.g., electricity) and (2) increase plant production.
Past Research Projects
Comparing Basil Productivity Between Aquaponics Systems with Different Output Designs to Hydroponic Grow Beds
Efficient circulation of nutrients is critical to maximize plant growth in the hydroponic plant grow beds of an aquaponics system utilizing Deep Raft Culture for plant production. The aim of this study was to compare basil productivity between aquaponics systems with different effluent output designs to plant grow beds. Specifically, plant growth and biomass was compared between a system that had a single effluent output at the beginning of the grow bed and a system that had multiple effluent outputs equally spaced along the grow bed. The results of this research was presented at the Georgia Southern University Virtual COUR Symposium in Spring 2020.
Comparison of Water Quality Between Aquaponics Systems with Different Biofilter Media and Solid Removal Method
There are myriad designs for aquaponics systems, including various methods of biofiltration and solid removal. However, to maximize fish and vegetable production, the most efficient system design needs to be determined. The goal of this research was to compare water quality between two aquaponics systems that differed in the media used in the biofilter and the method solid removal. Water quality variables (i.e., ammonium, nitrate, potassium, pH, dissolved oxygen, and conductivity) were measured weekly and compared between an aquaponics system using Kaldnes media in the biofilter and sock filters for solid removal (System 1) and a system using biobeads in the biofilter and a backwash settling chamber for solid removal (System 2). The results of this study were presented at the Georgia Southern University Virtual Honors Symposium and Virtual COUR Symposium in Spring 2020.
Potential Use of Removed Solids from an Aquaponics System as a Fertilizer for Soil-Based Growth of Basil
The solids removed from an aquaponics system are potentially high in nutrients, including nitrogen, and may have the potential to serve as an organic fertilizer source for soil-based plant growth. The purpose of this research was to compare the growth of basil between plants fertilized with Osmocote, a commercial fertilizer soil amendment, and dried fish solids removed from an aquaponics system. The results of this study are currently being analyzed.
The Effect of Air Circulation on Plant Growth and Productivity
Aquaponics systems often include aeration in plant grow beds, with the assumption that aeration will increase the efficiency of nutrient circulation, reduce solid settlement near roots that may inhibit nutrient circulation, and/or increase oxygen availability at the plant roots to assist in nutrient uptake. However, the continuous supply of air to grow beds represents a major electricity cost. The aim of this research was to determine if air circulation in grow beds functions to increase plant growth and biomass. Basil plants were placed at three locations the grow beds of four aquaponics systems, with air circulation in two beds and no air circulation in two beds, and plant growth, biomass, and tissue nitrogen content were measured in Spring/Summer 2017. The results of this research were presented at the 79th Annual Associations of Southeastern Biologists Meeting and the 2018 Armstrong Student Scholar Symposium, and manuscript is currently in preparation. This experiment was repeated with arugula and Bibb lettuce in Spring 2018, and these results were presented at the 80th Annual Association of Southeastern Biologists Meeting and the 2019 Georgia Southern University COUR Symposium.
Seasonal Patterns in Water Quality
Analysis of water quality is critical in the maintenance of an aquaponics system to ensure that the system is functioning properly and conditions remain at a healthy level for both fish and plants. However, water quality parameters can be influenced by climatic variables that may result in seasonal patterns in water quality. Furthermore, water quality parameters may also change as an aquaponics system matures. The purpose of this research was to determine if there are seasonal and/or annual patterns in water quality parameters for the four aquaponics systems at SARC. Ammonium, nitrate, potassium, pH, dissolved oxygen, and conductivity were measured weekly at various locations in each of the systems since their initiation in 2017, and water quality was analyzed to determine patterns among systems. The results of this research was presented at the 80th Annual Association of Southeastern Biologists Meeting and the 2019 Georgia Southern University COUR Symposium.
Development of a Grow Out Aquaponics System for Tilapia
Tilapia have been found to be prolific breeders in aquaculture systems, and the tilapia at SARC have been actively breeding each season since 2017. In May 2017, several tilapia broods were extracted from the systems and were transferred to the lab for rearing. These "fry" have now matured into juvenile tilapia and are ready to be transferred to larger systems. To this end, two smaller aquaponics systems were currently being constructed at the facility to serve as a grow out system for these juvenile tilapia.
Comparing Basil Productivity Between Aquaponics Systems with Different Output Designs to Hydroponic Grow Beds
Efficient circulation of nutrients is critical to maximize plant growth in the hydroponic plant grow beds of an aquaponics system utilizing Deep Raft Culture for plant production. The aim of this study was to compare basil productivity between aquaponics systems with different effluent output designs to plant grow beds. Specifically, plant growth and biomass was compared between a system that had a single effluent output at the beginning of the grow bed and a system that had multiple effluent outputs equally spaced along the grow bed. The results of this research was presented at the Georgia Southern University Virtual COUR Symposium in Spring 2020.
Comparison of Water Quality Between Aquaponics Systems with Different Biofilter Media and Solid Removal Method
There are myriad designs for aquaponics systems, including various methods of biofiltration and solid removal. However, to maximize fish and vegetable production, the most efficient system design needs to be determined. The goal of this research was to compare water quality between two aquaponics systems that differed in the media used in the biofilter and the method solid removal. Water quality variables (i.e., ammonium, nitrate, potassium, pH, dissolved oxygen, and conductivity) were measured weekly and compared between an aquaponics system using Kaldnes media in the biofilter and sock filters for solid removal (System 1) and a system using biobeads in the biofilter and a backwash settling chamber for solid removal (System 2). The results of this study were presented at the Georgia Southern University Virtual Honors Symposium and Virtual COUR Symposium in Spring 2020.
Potential Use of Removed Solids from an Aquaponics System as a Fertilizer for Soil-Based Growth of Basil
The solids removed from an aquaponics system are potentially high in nutrients, including nitrogen, and may have the potential to serve as an organic fertilizer source for soil-based plant growth. The purpose of this research was to compare the growth of basil between plants fertilized with Osmocote, a commercial fertilizer soil amendment, and dried fish solids removed from an aquaponics system. The results of this study are currently being analyzed.
The Effect of Air Circulation on Plant Growth and Productivity
Aquaponics systems often include aeration in plant grow beds, with the assumption that aeration will increase the efficiency of nutrient circulation, reduce solid settlement near roots that may inhibit nutrient circulation, and/or increase oxygen availability at the plant roots to assist in nutrient uptake. However, the continuous supply of air to grow beds represents a major electricity cost. The aim of this research was to determine if air circulation in grow beds functions to increase plant growth and biomass. Basil plants were placed at three locations the grow beds of four aquaponics systems, with air circulation in two beds and no air circulation in two beds, and plant growth, biomass, and tissue nitrogen content were measured in Spring/Summer 2017. The results of this research were presented at the 79th Annual Associations of Southeastern Biologists Meeting and the 2018 Armstrong Student Scholar Symposium, and manuscript is currently in preparation. This experiment was repeated with arugula and Bibb lettuce in Spring 2018, and these results were presented at the 80th Annual Association of Southeastern Biologists Meeting and the 2019 Georgia Southern University COUR Symposium.
Seasonal Patterns in Water Quality
Analysis of water quality is critical in the maintenance of an aquaponics system to ensure that the system is functioning properly and conditions remain at a healthy level for both fish and plants. However, water quality parameters can be influenced by climatic variables that may result in seasonal patterns in water quality. Furthermore, water quality parameters may also change as an aquaponics system matures. The purpose of this research was to determine if there are seasonal and/or annual patterns in water quality parameters for the four aquaponics systems at SARC. Ammonium, nitrate, potassium, pH, dissolved oxygen, and conductivity were measured weekly at various locations in each of the systems since their initiation in 2017, and water quality was analyzed to determine patterns among systems. The results of this research was presented at the 80th Annual Association of Southeastern Biologists Meeting and the 2019 Georgia Southern University COUR Symposium.
Development of a Grow Out Aquaponics System for Tilapia
Tilapia have been found to be prolific breeders in aquaculture systems, and the tilapia at SARC have been actively breeding each season since 2017. In May 2017, several tilapia broods were extracted from the systems and were transferred to the lab for rearing. These "fry" have now matured into juvenile tilapia and are ready to be transferred to larger systems. To this end, two smaller aquaponics systems were currently being constructed at the facility to serve as a grow out system for these juvenile tilapia.