Aquaponics is the integration of aquaculture and hydroponics. There is expanding interest in aquaponics as a form of aquaculture that can be used to produce food closer to urban centers. Commercial aquaponics uses methods and equipment from both the hydroponics and aquaculture industries. There have been few studies of commercial-scale aquaponics production, and the purpose of this research was to document the production methods, crop and fish yields, and profitability of commercial aquaponics in the United States (US) and internationally. An online survey was used for data collection, and 257 respondents met the inclusion criteria for the study. Eighty-one percent of respondents lived in the US, and the remaining respondents were from 22 other countries. The median year that respondents had begun practicing aquaponics was 2010. A total of 538 fulltime workers, 242 part-time workers, and 1720 unpaid workers or volunteers were employed at surveyed organizations. The most commonly raised aquatic animals by percent were tilapia (69%), ornamental fish (43%), catfish (25%), other aquatic animals (18%), perch (16%), bluegill (15%), trout (10%), and bass (7%). Production statistics, gross sales revenue, investments, and sales outlets for operations are reported and compared to other fields of aquaculture and agriculture. A multivariable logistic regression model was used to study which factors were associated with profitability (as a binary outcome) in the past 12 months. Several factors were significantly associated with profitability: aquaponics as the respondents' primary source of income (p b 0.01; Odds Ratio: 5.79; 95% Confidence Interval: 3.8-9.0), location in US Department of Agriculture plant hardiness zones 7-13 (p b 0.01; OR: 4.17; 95% CI: 3.2-5.5), gross sales revenue ≥$5000 (p b 0.01; OR: 3.58; 95% CI: 2.2-5.8), greater aquaponics knowledge (p b 0.01; OR: 2.37; 95% CI: 2.0-2.9), and sales of non-food products (e.g., supplies, materials, consulting services, workshops, and agrotourism) (p = 0.028; OR: 2.13; 95% CI: 1.1-4.2). Our survey findings provide a better understanding of the business of aquaponics, which may enhance future commercial operations.

Aquaponics, a combination of fish farming and soilless plant farming, is growing in popularity and gaining attention as an important and potentially more sustainable method of food production. The aim of this study was to document and analyze the production methods, experiences, motivations, and demographics of aquaponics practitioners in the United States (US) and internationally. The survey was distributed online using a chain sampling method that relied on referrals from initial respondents, with 809 respondents meeting the inclusion criteria. The majority of respondents were from the US (80%), male (78%), and had at least a high school degree (91%). The mean age of respondents was 47±13 years old. Most respondents (52%) had three years or less of aquaponics experience. Respondents typically raised tilapia or ornamental fish and a variety of leafy green vegetables, herbs, and fruiting crops. Respondents were most often motivated to become involved in aquaponics to grow their own food, for environmental sustainability reasons, and for personal health reasons. Many respondents employed more than one method to raise crops, and used alternative or environmentally sustainable sources of energy, water, and fish feed. In general, our findings suggest that aquaponics is a dynamic and rapidly growing field with participants who are actively experimenting with and adopting new technologies. Additional research and outreach is needed to evaluate and communicate best practices within the field. This survey is the first large-scale effort to track aquaponics in the US and provides information that can better inform policy, research, and education efforts regarding aquaponics as it matures and possibly evolves into a mainstream form of agriculture.

a b s t r a c tAquaponics is a form of aquaculture that integrates hydroponics to raise edible plants and fish. There is growing interest in aquaponics because it can be practiced in non-traditional locations for agriculture such as inside warehouses and on marginal lands, and it can provide locally grown products without using synthetic pesticides, chemical fertilizers, or antibiotics. Yet questions remain about the ecological and economic sustainability of aquaponics. The objective of this study was to describe the operating conditions, inputs (energy, water, and fish feed) and outputs (edible crops and fish) and their relationship over two years for a small-scale raft aquaponics operation in Baltimore, Maryland, United States. The system had roughly 1% water loss per day and used an average of 35,950 L for replenishment per year. Predicted values suggest rainfall could completely replace the existing water needs. The average energy use was 19,526 kWh for propane and electricity per year at a cost of $2055 US dollars. The largest uses of electricity were in-tank water heaters. Comparing inputs to outputs, 104 L of water, 0.5 kg feed, and 56 kWh energy ($6 in energy costs) were needed to produce 1 kg of crops; and 292 L of water, 1.3 kg feed, and 159 kWh of energy ($12 in energy costs) were needed to produce a 1 kg increase in tilapia. Raising tilapia was a net loss, while raising crops was a net gain when comparing market prices to energy costs. Understanding energy, water, and feed use in aquaponic systems is essential to inform farm business plans. These data can serve as a point of comparison to other small-scale aquaponic systems, and inform future work on life cycle assessments of aquaponics.

School gardens and demonstration farms are exciting avenues for experiential learning in education. Aquaponics, the combination of aquaculture and hydroponics, is an attractive educational tool because systems are self-contained ecosystems that allow teachers and students to explore a wide range of science, technology, engineering, and mathematics (STEM) topics. The aim of this study was to characterize the use of aquaponics in education in the United States (US) using an online survey. One hundred respondents who completed the survey were engaged with aquaponics education and met the inclusion criteria for the study. Thirty-six percent of respondents worked for primary and secondary schools, 53% represented colleges or universities, and 11% worked for vocational or trade schools. Respondents reported the subjects taught, target audiences, number of participating students or visitors, and the resources and funding used by their organizations. Respondents used aquaponics to engage students in a variety of STEM subjects. In total, respondents and their institutions engaged an estimated range of 12,320 to 50,250 participants per year in aquaponics education. The typical school invested $1,000 to $4,999 US dollars (USD) in their aquaponics facility during the previous year, with a combined total of $1.4 to $6.6 million USD invested by all academic institutions. Aquaponics is an emerging educational tool, and there is a need for continued collaboration, technical support, and training for educators from universities and aquaculture education and research centers in the US and other countries.