Fish in the Classroom: A Survey of the Use of Aquaponics in Education

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.


INTRODUCTION
teacher Erik Johansen reported on his personal experience using an aquaponics system to successfully integrate biotechnology components into his curriculum. The aquaponics system allowed his students to work on creative engineering projects, such as creating an automated fish feeder using legos, or modifying a toilet-bowl fill valve to regulate water flow (Johanson, 2009). In another example, Wardlow, Johnson, Mueller, and Hilgenberg (2002) documented the "Aquaponics in the Classroom" program, run by the University of Arkansas, in which teachers were loaned prefabricated aquaponics systems for their classrooms for use as a teaching aid in STEM education. Aquaponics systems have also been used in higher education. A team of students and professors in the Department of Environmental Science at Allegheny College developed an aquaponics system as a platform for community engagement and student research projects (Eatmon, Szymecki, & Varrato, 2012).
While examples of aquaponics in education are easy to find, the scope and extent of aquaponics in education has not been well-documented. The aim of this study was to characterize the use of aquaponics in schools in the United States, and the findings could be applicable to other countries. Specifically, we report: the demographic profile of survey respondents practicing aquaponics-based education; the characteristics of classroom systems, the target audiences of those education activities; the education subjects taught using aquaponics; the number of participants; the knowledge of system operators, and the resources and funding used by organizations. We hope that these findings can help create a foundation for future research on aquaponics education and inform educators interested in integrating aquaponics systems into their curriculums. As the aquaponics industry gains momentum, interest in aquaponics in education is likely to increase. Understanding the extent of the practice currently is an important first step in understanding the overall effectiveness of this new education technology.

Survey
An online survey questionnaire was developed and implemented as described by Love (2014). Survey questions were drafted and pretested with a group of 10 aquaponics practitioners. The final survey was distributed using Qualtrics (Provo, Utah), a web-based survey platform. Because the target population has not been previously well-defined, the survey was distributed using a chain sampling method (i.e. referral or snowball sampling) with the help of eighteen partner organizations who distributed the survey to their subscribers and members through email lists, direct email, social media posts, and online newsletters. The survey was also emailed to 365 potential respondents whose contact information was obtained at one of two aquaponics conferences in 2013 (The Aquaponics Association Conference in Tuscon, AZ and the International Aquaponics Conference in Stevens Point, WI). The survey codebook, which contains a complete list of survey questions, is provided in the supplement to Love (2014). The methodology was reviewed by the Johns Hopkins University Insititional Review Board (IRB No: 00005088).
The survey was open between June 25, 2013 and October 1, 2013, and 1084 complete responses were collected during this period. The inclusion criteria for the present analysis was as follows: any respondent who was 18 years of age or over, can read English, had operated and maintained an aquaponics system within the previous 12 month period, had taught aquaponics (e.g., host tours, classes, courses, lectures, or workshops) within the previous 12 months, and represented an educational institution (primary or secondary school, colleges, universities, or vocational schools). Respondents were asked to submit a maximum of one response per organization. One hundred respondents met the inclusion criteria.

Demographics
Just over half of all respondents (53%) represented colleges or universities (Table 1). Thirty-six percent worked for primary or secondary schools and 11% worked for vocational or technical schools. Among respondents, 77% were male, 20% were female, and 3% did not specify a gender. The mean age of respondents was 46 years old. Forty six percent of respondents had a graduate degree, and 45% had a college degree or had taken some college classes. Most respondents (54%) had less than 3 years prior experience practicing aquaponics, with only 6% of respondents having greater than 5 years prior experience. Ninety two percent of all respondents lived in the United States representing 35 different states; one respondent each lived in Australia, Malaysia, and Canada. Three respondents did not report a location.

Target audiences
Respondents were asked which groups they targeted with educational activities. While respondents primarily educated their students, many educators also targeted secondary audiences. Respondents from K-12 schools delivered educational and outreach activities to students in the following percentages by grade level: 11 th -12 th grades (56%); 9-10 th grades (47%); 6-8 th grades (36%); 5 th grade and younger (36%). In addition, over a quarter (28%) of K-12 respondents targeted all ages, including both working-age adults and retirees, with their education and outreach activities. Respondents from colleges and universities primarily targeted undergraduate and graduate students, but nearly half (47%) of all college and university respondents also targeted working-age adults in addition to students, and 20% targeted K-12 students. Respondents from vocational and technical schools primarily targeted students at these schools, but 27% also targeted working-age adults.

Subjects taught using aquaponics
Respondents were asked to select from a list of 16 subjects, including the subject of aquaponics, which they taught using aquaponics in the past 12 months. Figure 1 presents the 10 subjects taught most frequently by school type. At K-12 schools, respondents used aquaponics to teach a wide range of subjects: aquaculture, agriculture, biology, chemistry, environmental sciences, earth sciences, and food systems. In colleges or universities, aquaponics was the main subject taught, but other science, engineering, and agriculture subjects were also included. Vocational or trade schools taught a narrower range of subjects, with aquaponics being the primary subject taught. Aquaponics was also used for self-guided research projects at (80%) of all institutions surveyed, with K-12 schools and colleges and universities using aquaponics systems more frequently for self-guided projects than vocational schools.  (14) 3 (27) 3-4 4 (11) 5 (10) 2 (18) 4-5 3 (8) 6 (12) ->5 2 (6) 3 (6) 1 (9)

Educational system and leadership
The majority of respondents felt that aquaponics was integrated into their curriculum, with the highest proportion of vocational/trade school respondents (78%) reporting curriculum integration and the lowest proportion of colleges and university respondents reporting curriculum integration (60%). Seventy one percent of K-12 respondents felt that aquaponics was integrated into their curriculum. Respondents reported a high degree of support from their institution leadership (89% for K-12 school respondents, 86% for college and university respondents, 100% for vocational and technical school respondents).

Participants in tours, classes, courses and workshops
The survey collected data on the number of participants in aquaponics-related lessons, tours, workshops or courses per institution per year as a categorical variable (e.g., 1-24, 25-49, 50-99, etc. participants/year). The range of total participants per year was estimated by summing the upper and lower bounds for each response. We estimate that a total of 12,320 to 50,250 participants/year were involved in lessons, tours, or workshops using the schools' aquaponics systems. More accurate values for participants could be achieved by asking respondents to report continuous data on numbers of participants instead of categorical data. Colleges and universities saw the most participants/year, with a median number of participants ranging from 100-499; K-12 and Vocational/Trade schools both saw a median number of participants ranging from 50-99 (Table 2).

Technical knowledge of respondents
Respondents were asked to rate their knowledge of various aspects of maintaining an aquaponics system on a Likert scale of 1-5, with 5 representing "strongly agree" and 1 representing "strongly disagree." Across all school types, respondents "strongly agreed" that they knew how to modify the pH in the system and make repairs to plumbing. Respondents also "agreed" that they knew how to track fish growth rates, manage plant pests, and diagnose plant nutrient deficiencies. Respondents were less confident in their knowledge of regulations surrounding processing or selling fish.

Resources for technical assistance
Respondents were asked what resources they use to troubleshoot and solve problems related to their aquaponics operation (Table 3). Respondents used the Internet (i.e., websites, community forums, and YouTube) more frequently than any other means to troubleshoot and solve problems. Respondents contacted other practitioners more often than government agencies, university staff or agriculture extension offices that work on aquaculture or aquaponics. Over half of respondents also attended aquaponics seminars or workshops.

Size of system and location
Aquaponics systems at K-12 schools were smaller than those at college, university, and vocational schools. The median size of K-12 school systems held 1,500 L of water and occupied 19 m 2 as compared to 2,200 L gallons (32 m 2 ) at colleges and universities and 1,900 L gallons (70 m 2 ) at vocational and technical schools. K-12 systems ranged from tabletop-scale systems at 75 L, to mid-sized systems with 7,900 L, while college, university, and vocational systems had a much greater size range with the largest college system containing 150,000 L. Across all school types, just over half (55%) of all respondents sited at least part of their system in a greenhouse, while 40% sited at least part of their system indoors. Only 31% had outdoor components to their system.

Investments in aquaponics
Schools made a wide range of investments in their aquaponics facilities, from none to over $500,000 US dollars. The median amount of money invested by a K-12 school, college or university, and vocational or technical school in their aquaponics facility was $1,000 to $4,999 US dollars/year. Overall, we estimate a total of $1.4 to $4.3 million was invested in aquaponics by all schools in the study during the previous 12 months, which was calculated by multiplying the minimum and maximum value in each category by the number of responses. Collectively, by type of school, colleges and universities in the study spent $1.1 to $3.2 million on their systems in the previous year, vocational and trade schools spent $0.13 to $1.1 million, and K-12 schools spent a total of $0.13 to $0.41 million (Figure 2).

Funding sources
In the previous 12 months, respondents at K-12 schools financed their operations with government funding or grants (42%), non-governmental (NGO) funding sources including grants and gifts (22%), and income from the sale of aquaponics products, materials, workshops and consulting (14%). Among respondents at colleges and universities, 51% financed their operations with governmental funding, 25% received NGO funding, and 26% used income from the sale of aquaponics products, materials, workshops and consulting. A larger proportion of vocational and technical school systems were supported by income from the sale of aquaponics products, materials, workshops and consulting (used by 36% of respondents) compared to other academic institutions, and they had lower rates of governmental funding (27%).

DISCUSSION
Aquaponics in education exists at a frequency and scale much greater than the few documented examples might suggest. Schools across the United States, and likely other countries, are using aquaponics as a tool to reach tens of thousands of students and working-age adults in a way that can complement the growth of school gardens. In general, subjects taught using aquaponics systems focused more exclusively on STEM topics and targeted older age groups than many soil-based school gardens. Aquaponics education was popular at both the college level and among K-12 schools, indicating that it is a technology that can be used to reach a wide age range. Surprisingly, many schools, particularly colleges and universities, were using their aquaponics systems to reach populations outside of their student body, indicating that aquaponics could provide a vehicle for community outreach for academic institutions.

K-12 schools
Aquaponics education in K-12 schools is science-focused, project oriented, and geared primarily towards older students, setting it apart from the typical soil-based school garden. Aquaponics education in K-12 schools primarily targets high school students, predominately in 11 th and 12 th grade, and educators use the systems to teach a broad range of science subjects such as biology, chemistry, or agriculture. By contrast, the literature on soil-based school gardens reveals a focus on grades 8 and younger, and in addition to science courses, the gardens are also used to teach nutrition or humanities such as language arts (Williams & Dixon, 2013;Graham, Beall, Lussier McLaughlin, & Zidenberg-Cherr, 2005). Most K-12 aquaponics educators also used the aquaponics system as a venue for student research projects. Aquaponics education offers K-12 educators a technology-centric alternative to soilbased school gardens, and provides science-focused experiential learning opportunities for older students. In US states that adopt the Next Generation Science Standards, schools can also use aquaponics education as a tool to meet the new standards by providing a platform for project based learning opportunities that can help integrate cross cutting concepts with scientific and engineering practices. Aquaponics systems at K-12 schools were generally smaller than systems at colleges and universities or vocational schools. The cost of entry for aquaponics in the classroom was typically less than $5,000 US dollars, and the average system size was 1,500 L, larger than a countertop system, but still small enough to fit in a classroom. Unlike soil-based gardens, aquaponics systems can be sited indoors, in greenhouses and in small spaces, offering year round access to the system and versatility for schools that may not have suitable outdoor spaces. These advantages must be weighed against the greater need for technical knowledge for some educators.

Colleges and universities
Respondents from colleges and universities used aquaponics to teach a widerange of science subjects and for self-guided research projects. Interest in aquaponics among colleges and universities parallels renewed interest in agriculture programs and teaching farms at institutions of higher learning. While many land-grant colleges are working to shift their focus back to teaching agriculture through demonstration, campus farms and sustainable food initiatives are also developing at private institutions throughout the country (Mazurkewicz, Harder, & Roberts, 2012;Barlett, 2011). In general, college and university aquaponics systems were larger and less integrated into the curriculum. Interdisciplinary subjects such as food systems and environmental science were taught using the aquaponics system more frequently at colleges and universities than they were at other school types, where the focus was more often on single discipline subjects such as chemistry or biology. Colleges and universities attracted more participants than any other facility type, including working-age adults and K-12 students, who do not attend the institution. This indicates that these programs can be used as vehicles for education and outreach to the broader community.

Vocational and technical schools
Interestingly, while aquaculture has traditionally been taught at agriculture or vocational schools, only 11% of survey respondents represented vocational or tech schools. This low number may be due to the fewer number of vocational and technical schools overall compared to colleges and K-12 schools or our recruitment methods (see below). These institutions had notable differences compared to other schools. Vocational and technical schools invested more funds in their aquaponics systems and generated a greater proportion of their funding through sale of products produced in the aquaponics system. In general, the vocational school aquaponic systems were larger than those at K-12 schools, and displayed a very different pattern of subjects taught. Few vocational and technical schools used aquaponics systems to teach subjects other than aquaponics, indicating that for these educators aquaponics is a stand-alone subject and not a vehicle to address other STEM or food system topics. However, vocational and technical school respondents had a similar level of prior experience with aquaponics to the overall study population, indicating that aquaponics in the classroom is still relatively new for these institutions.

Respondents' knowledge
Implementing aquaponics in classrooms is not without challenges; Hart, Webb, and Danylchuk (2013) report that technical difficulties, lack of experience and knowledge, and maintenance over holidays and vacations can pose significant barriers to teachers using aquaponics in education. The lack of knowledge and experience is also reflected in the common challenges to soil-based school gardens. In a survey of California principals in schools with a garden, Graham et al (2005) report that lack of a teacher's interest, knowledge, experience, and training were a barrier to successfully using the garden for academic instruction for 70% of respondents. The technical and interdisciplinary nature of aquaponics would increase the importance of knowledge and experience for educators practicing aquaponics. Most respondents to our survey were new to practicing aquaponics; the median respondent had less than or equal to three years experience. While we did not specifically ask about major challenges faced by respondents, when asked about their knowledge of six common aspects of operating a successful aquaponics system, most respondents across all school types felt confident in their abilities, despite limited experience. However, our survey only targeted educators who have operated aquaponics systems and not those who may have felt intimated by various barriers.
The availability of trainings, resources, and mentors could help offset potential knowledge barriers. Hart, Webb, and Danylchuk (2013) reported that educators were in need of community connections and support in regards to aquaponics systems. We found that educators most often turned towards the Internet, other growers, and print resources for technical assistance with aquaponics, indicating that these methods were the most effective for obtaining information.

Limitations
The data for this analysis were taken from a larger survey of aquaponic growers, including those not involved in education, such as hobbyist and commercial farmers. As a result, our recruitment was focused on aquaponics organizations rather than schools, potentially leading to us missing some educators. Because of this recruitment method, we captured educators who were already engaged in an aquaponics network, perhaps leading to respondents having more confidence in their knowledge than educators who are not engaged with similar networks. Despite this limitation, we have captured a broad range of respondents representing a variety of academic institutions and geographic locations.
The impact of aquaponics on academic outcomes was beyond the scope of this research; however, there is a need for future work that examines how aquaponics in education affects academic outcomes, and in particular, how those outcomes compare to those of soil-based school gardens. As school gardens continue to spread, this technical alternative offers teachers a way to reach older student age groups and incorporate additional topics, including STEM subjects and student led research.

CONCLUSION
This study is the first survey to present the demographics, target audiences, educational focus, experience, and funding sources of aquaponics educators in the US. These results are informative and can serve as a baseline for comparing future research and applied in other countries besides the US. Aquaponics is an emerging educational technology, and many participating educators are new to aquaponics, indicating a potential need for more training and technical support among educators. Aquaponics education is active in a variety of settings, with a range of investments and facility sizes. Continued collaboration and knowledge transfer among aquaponics educators and supporting organizations could enable the diffusion of best practices in education.