22.4 Aquaponics in Secondary Schools

According to the ISCED classification (UNESCO-UIS 2012), secondary education provides learning and educational activities building on primary education and preparing for both first labor market entry as well as post-secondary non-tertiary and tertiary education. Broadly speaking, secondary education aims to deliver learning at an intermediate level of complexity.

While at primary education level, students are mainly directed toward observational and descriptive exercises on organisms and processes in an aquaponics, students from secondary schools can be educated in understanding dynamic processes. Aquaponics enables this increased complexity and fosters system thinking (Junge et al. 2014).

Example 22.3 One Semester Course in a Grammar School in Switzerland

Hofstetter (Hofstetter 2008) implemented aquaponic teaching units in a Grammar School (German: Gymnasium) in Zurich and tested the hypothesis that incorporating aquaponics into teaching has a positive influence on systems thinking (Ossimitz 2000) among the students. Gymnasium students in Switzerland belong to an above-average section of the student population: they have very good grades, are used to autonomous work, and show consistent ability and general interests in different issues. Three seventh grade classes were involved, with a total of 68 students (32 female, 36 male), aged between 12 and 14 years old.

Six simple, small aquaponics were constructed according to the general description in Bamert and Albin (2005) (Fig. 22.4). The students were responsible for the construction, operation, and monitoring of the systems. They were provided with the necessary materials and built the aquaculture and hydroponic units. Tomato (Solanum lycopersicum) and basil (Ocimum basilicum) seedlings were planted in expanded clay beds. Each aquarium was stocked with two common rudd (Scardinius erythrophthalmus) caught in a nearby pond and returned there after the experiment.

Each system was monitored daily, and the following operations were carried out: measuring plant height, observing plant health, measuring fish feed and feeding the fish, monitoring fish behavior, measuring water temperature, and topping up the aquarium with water. All the measurements and observations were documented in a diary, which also served to transfer information between the three groups that worked on the same system.

The teaching sequence (Table 22.3) took place between October 2007 and January 2008. Several themes were introduced in the lessons basic system concepts (relationship between system components, concepts of feedback, and self-regulation), and basic knowledge about aquaponics. All the teaching units are described in detail in Bollmann-Zuberbuehler et al. (2010). The effect of the teaching sequence on systems thinking competences was assessed at the beginning and at the end of the sequence (See Sect. 22.8.1.4) and was described in detail in Junge et al. (2014).

Example 22.4 EXPLORLabor: Science Day at Zurich University of Applied Sciences for the Students of Secondary Schools, Switzerland

Twenty students aged 18—19 (11th school year, majoring in Biology & Chemistry) from the Cantonal School at Menzingen visit the Zurich University of Applied Sciences (ZHAW) every year for an Aquaponics Workshop. The program varies slightly from year to year, depending on the current experiments in the Aquaponics Lab.

uProgram:/u

• Greetings: Introduction to the workshop.
• E-learning video: Introduction to aquaponics.
• Tour of the aquaponic demo facility; discussion of appropriate behavior in the experimental facility.
• Learning measurement methods. Division into 4 teams.
• Tour of the Aquaponics Lab, consisting of 4 systems (three aquaponic and one hydroponic). Each team gathered data from one system.

uAssignment:/u

1. Measuring water quality in different parts of the aquaponic and hydroponic systems (fish tank, biofilter, and sump) using the handheld multielectrode meter (Hach Lange GmbH, Rheineck, CH) to measure the temperature (T), pH, oxygen content, and electric conductivity (EC).
2. Using the Dualex-Clip to measure Nitrogen Balance Index (NBI), Chlorophyll Content (CHL), Flavonoid Content (FLV), and Anthocyanin Content (ANTH) of leaves of three lettuces.
3. Filling in the data in the pre-prepared Excel spreadsheet.
4. Back to the classroom: Calculating if there are differences between thelettuce plants that grow in aquaponic and hydroponic systems, comparison of the data, and discussions.

Fig. 22.4 Simple classroom aquaponics. (Adapted after Bamert and Albin 2005). The plants grow in the containers filled with light expanded clay aggregate (LECA) that is usually used in hydrocultures

Table 22.3 Sequence of teaching units in three classes of seventh grade students during one semester course in a Grammar School in Switzerland

table thead tr class=“header” thTeaching unit/th th Number of lessons /th th Methods /th th Content /th /tr /thead tbody tr class=“odd” tdTU1/td td 1 /td td Survey of existing knowledge /td td Pre-activity Test /td /tr tr class=“even” tdTU2/td td 4 /td td Lecture by teacher, research, & presentations by students /td td System basics /td /tr tr class=“odd” tdTU3/td td 2 /td td Lecture by teacher, student assignment /td td “Connection circle” tool allows the students to draw a diagram of a system (adopted from Quaden and Ticotsky 2004) /td /tr tr class=“even” td rowspan=2 TU4/td td rowspan=2 2 /td td Discovery learning /td td rowspan=2 Planning an aquaponics: sub-units, connections /td /tr tr class=“odd” td Presentations by students /td /tr tr class=“even” tdTU5/td td 2 /td td Problem-based learning (PBL) /td td Defining the main indicators of the system: Fish and plants and their interactions /td /tr tr class=“odd” tdTU6/td td 3 /td td Discovery learning /td td Monitoring the aquaponics /td /tr tr class=“even” tdTU7/td td 3 /td td Presentations by students /td td Drawing a diagram of the interconnections in the aquaponics /td /tr tr class=“odd” tdTU8/td td 1 /td td Survey of knowledge /td td Post-activity test /td /tr tr class=“even” tdTU9/td td 2 /td td Aquaponic party /td td Harvest, preparation of salad, eating /td /tr /tbody /table

Modified after Junge et al. (2014)