1. Aquaponics for Sustainability Education
Jaeson Clayborn, MSc
Miles Medina, MSc
August 7, 2014

2. Objective

3. Important global trends: People
Increasing global population – 9B by 2050; 11B by 2100.
Increasing urbanization
Currently, >50% globally and >80% in the US.
By 2050, 67% globally and 89% in the US.
Increasing per capita income in developing regions
Africa, Latin America, Asia.
Increasing demand for food, especially high-protein diets!

4. Important global trends: Resources
Over 70% of global freshwater withdrawals go to agriculture.
Land use issues
Urban sprawl encroaching into rural/natural areas.
Forested/natural areas converted to agriculture.
Energy to produce fertilizers, transport food, etc.
Increasing demand for food in the future implies increasing demand for land, energy, and water.
But these are limited resources!

5. Definitions of sustainability
“Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”
–Brundtland Commission, 1987
“Development without growth beyond environmental limits.”
–Herman Daly, 1996

6. Global fishery landings and aquacultural production, 1980-2010
Global production is divided into two sets of categories: marine vs. inland, and capture vs. aquaculture. Demand for seafood has increased with population and per capita income, especially in developing regions. Production from capture (fishing) has plateaued in recent decades, so production from aquaculture (farming) has increased dramatically to meet the growing demand.
Source: FAO Fishery and Aquaculture Statistics 2010

7. Growth of aquaculture sector
59.9 M tonnes total production, incl.
39.2 Mt of fish (2010)
…90 Mt total by 2017
…75 Mt fish by 2021
Million tonnes  
88.6 M tonnes total production, incl.
75.3 Mt of fish (2010)
Aquacultural production is growing and will soon meet capture production.
Source: FAO Fishery and Aquaculture Statistics 2010

8. Sustainability of modern aquaculture: Problems
Fishmeal as a major protein input
Fishmeal production has plateaued, and it is becoming more expensive.
Heavy water use
Discharge of effluent with excess nutrients
Pollution to downstream or host ecosystems; contamination of groundwater.

9. What does aquaculture look like?
Open systems are composed of net pens in marine or freshwater environments. Waste nutrients, antibiotics, diseases, and invasive species can easily pass into the surrounding ecosystem.

10. What does aquaculture look like?
Flow-through systems, such as raceways, are constantly fed by a river or spring. Nutrients in the fish waste end up polluting the receiving waters.

11. What does aquaculture look like?
Recirculating tank systems are relatively closed to the surrounding ecology. They use filters to remove nutrients and recycle some of the water.

12. Urban hydroponics Eliminates risk from contaminated urban soils.
Land use
Urban agriculture relieves pressure to convert far-away natural areas to agriculture.
Efficient use of space through vertical production.
Climate change: Local production reduces carbon footprint from transportation.

13. Introduction to aquaponics
Aquaponics is the integration of aquaculture and hydroponics in a recirculating system.
Fish produce waste that feeds plants; plants clean the water and allow it to be recycled.

14. Aztec chinampas Mesoamerica ~1150CE
In perhaps the earliest predecessor to modern aquaponics, Aztecs grew crops in floating rafts (called chinampas). The chinampas were composed of a thin layer of muck dredged up from the bottom of a lake, and the plants’ roots would grow down into the water where fish lived.

15. Aquaponics: Nutrient & water flows
REPLACEMENT WATER
FISH YIELD
CROP YIELD
FILTERED WATER
FISH EFFLUENT
DISSOLVED NUTRIENTS
biological
nitrification &
mineralization
AQUAFEED
An aquaponic system is similar to a fish tank you would keep at home, but with a much larger filter in which plants can grow. The plants keep the water clean for the fish by removing nutrients. The secret ingredient here is the colony of nitrifying bacteria that converts ammonia in the fish waste to nitrate that feeds the plants.
In an aquaponic system, over 95% of the water is recycled. Only the relatively small amount of water that leaves the system through evaporation and transpiration has to be replaced.
Nutrients enter the system in the form of fish feed. Some of the nutrients pass through the fish and into the water where they are available for uptake by the plants’ roots.
SOLID WASTES
AQUAFEED
FISH YIELD
CROP YIELD
FILTERED WATER
FISH
EFFLUENT
DISSOLVED NUTRIENTS
biological
nitrification &
mineralization
AQUAFEED
FISH YIELD
CROP YIELD
FILTERED WATER
FISH
EFFLUENT
DISSOLVED NUTRIENTS
biological
nitrification &
mineralization
AQUAFEED
FISH YIELD
CROP YIELD
FILTERED WATER
FISH
EFFLUENT
DISSOLVED NUTRIENTS
biological
nitrification &
mineralization

16. Biofilter & Nitrification
The biofilter converts fish waste into plant fertilizer in a two-step biological nitrification process:
Nitrosomonas bacteria convert ammonia (NH4+) to nitrite (NO2-):
NH O2 → NO2- + 2H+ + H2O kcal/mole of ammonia
Nitrobacter bacteria convert nitrite to nitrate (NO3-):
NO O2 → NO kcal/mole of nitrite
The nitrifying bacteria live on all submerged surfaces in the system, including the insides of pipes and containers. The media increases the biological surface area.

17. Aquaponic systems: Water quality parameters
Near neutral pH ( )
High dissolved oxygen (DO) (6+ ppm)
Near-zero ammonia and nitrite (0 ppm)
Temperature and salinity ranges vary with fish and crop species
-pH is crucial for nutrient uptake by plants, for fish, and for bacteria.
-Oxygen is required by fish (for respiration), by plants (for respiration and nutrient uptake), and by bacteria (for respiration and nitrification). Aeration is provided by the falling action of water.
-Ammonia and nitrite can be very toxic for fish.
-Salinity: Usually, total dissolved solids should not exceed 2,000 ppm.
-Acceptable temperature range varies with fish species. In a subtropical area like SoFla, you want to choose fish and crops that can take the heat. Be careful with colder temperatures in the winter! Constantly flowing water loses heat quickly, so water temperature can drop quickly during the winter.

18. Aquaponics in the classroom: Educational opportunities
Engineering – Designing and building system.
Physics – Tinkering with components, flow rates, etc.
Chemistry – pH, nitrogen, phosphate testing.
Biology/Agronomy – Cultivating plants and fish.
Responsibility – Caring for a living system and completing maintenance tasks in a timely manner.

19. Jaeson’s Art (Brace Yourself)
Your aquaponic system
Jaeson’s Art (Brace Yourself)

20. True Sustainable Aquaponic Systems
See Next Slide

21. Solar-Powered Garden Aquaponic System
General overview of using solar energy
Solar Power (Energy Portion)
Aquaponic System (Urban Gardening)

22. Fin Jaeson Clayborn Miles Medina
Phone: (216)
Major Advisor: Dr. Suzanne Koptur
Advisor: Dr. George O’Brien

23. Study objective
To test educators’ familiarity and confidence with relevant knowledge after participating in the aquaponics research activity.
12 participants in 3 or 4 treatment groups.
4 week trial period (CER Model).
CER Model: Claims + Evidence + Reasoning = Explanation
Pre- and post-activity surveys and interviews.

24. Research activity (What you will do)
Build and maintain the aquaponic units.
Participate in the research: What is the effect of fish feed on plant growth?