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Aquaponics: Comparing Walleye & Production

Chris Hartleb Department of Biology Northern Demonstration Facility Aquaponics Innovation Center Aquaponics

• Aquaponics is an integrated, soilless system for raising and . • Benefits: • Sustainable and natural • Free of , and chemical • Highly efficient • Conservative uses of resources, , space and labor • Produces both a protein and a vegetable from one integrated system • Continuous production of food 365 days per year Aquaponics Future

“There is a lack of scientific literature when it comes to aquaponic experiments on large-scale and during long-time sequences. Moreover, many experimental setups published are small-scale without replicates. Experiments covering bigger production systems exist, but they are performed by private research centers or companies, whereby confidential findings are not always made accessible to third parties.” Economic Considerations

• Tilapia fillet: $2 - $4 per pound (retail) • Walleye fillet: $9 - $16 per pound (retail) Aquaponics Innovation Center Montello, WI

Nelson and Pade, Inc.® Demonstration

UWSP-Aquaponics Innovation Center Aquaponic Systems

Fish tanks Raft tank Water pump

Clarifier (solids filter) Degassing tank Mineralization tanks

Air pump Overview of Systems Fish Culture Clarifier, Mineralization, Bioreactor & Degassing Culture Tilapia Culture factor Range

Temperature 64 - 90oF (17 - 32oC)

Dissolved oxygen 3 – 10 mg/L

pH 7 – 8

Ammonia-N 0 – 0.04 mg/L

Nitrite-N 0 – 0.8 mg/L

Hardness 50 - 350 mg/L

CO2 0 – 30 mg/L Walleye Culture factor Range

Temperature 68 - 75oF (20 - 24oC)

Dissolved oxygen 5 – 6 mg/L

pH 6 – 9

Ammonia-N 0 – 0.02 mg/L

Nitrite-N 0 – 0.2 mg/L

Hardness 50 - 350 mg/L

CO2 0 – 10 mg/L Why it Works

Fish Plants • Optimal ratio between fish and plants – Balance between fish production and plant uptake Phosphorus Phosphorus – Feeding rate ratio Manganese Manganese • 60-100 g/day/m2 for leafy greens grown on rafts Copper Copper • Right balance is needed based on: Iron

– Type of fish Potassium Potassium – Plant growth platform Calcium Calcium – Type of plant (leafy vs fruiting) Magnesium Magnesium – Chemical composition of water Zinc Zinc • Controlled environment = year-round production Cobalt Boron*

Selenium Molybdenum*

Iodine Sulfur*

Protein Nitrogen Tilapia Growth

Market size Walleye Growth Variability in Growth Market Considerations

• Tilapia, 1½ pounds = 680 grams – Projected fry to market = 297 days (10 months) • Walleye, 1 pound = 454 grams – Projected fry to market = 1 year 10 months

Tilapia Walleye Stocked 164/system 166/system (Harvest goal) (0.5 lb/gallon, Total 492) (0.42 lb/gallon, Total 498) Survival 99% 81% % Fillet size 41% 14% 1½ pounds ½ pound Pounds of fillet 80 20 Price/pound of fillet $4/lb $9/lb Actual value $320 $180 Estimated value 193 lb of fillet = $773 116 lb of fillet = $1,044 Plant Production (Yield)

Kale 1600 3000.00 1400 2500.00 1200 2000.00 1000 800 1500.00 600 1000.00 Total yield (g) 400 Total yield (g) 500.00 200 0 0.00

Tilapia Walleye Tilapia Walleye

Romaine Pac Choi 8000.00 7000.00 7000.00 6000.00

6000.00 5000.00 5000.00 4000.00 4000.00 3000.00 3000.00 2000.00 Total Yield (g) 2000.00 Total yield (g) 1000.00 1000.00 0.00 0.00 Average Plant Biomass

25 50 Kale 45 Broccoli Tilapia 20 40 Walleye 35 15 30 25 10 20 15 5 10 5

Average plant biomass (g) biomass plant Average 0 0 (g) biomass plant Average

140

90 120 Romaine lettuce 80 Pac Choi 100 70 60 80 50 60 40

40 30 20 20 10 0 0 Average plant biomass (g) biomass plant Average Average plant biomass (g) biomass plant Average -10 -20 Root:Shoot Ratio

Kale Broccoli 0.4 0.25 0.35 0.2 0.3

0.25 0.15 0.2 0.15 0.1

Ratio Root:Shoot 0.1 Ratio Root:Shoot 0.05 0.05 0 0 8/1/2015 9/1/2015 10/1/2015 11/1/2015 12/1/2015 1/1/2016 2/1/2016 8/1/2015 9/1/2015 10/1/2015 11/1/2015 12/1/2015 1/1/2016 2/1/2016

Tilapia Walleye Tilapia Walleye

Romaine lettuce Pac Choi 0.25 0.14

0.12 0.2 0.1

0.15 0.08

0.1 0.06 0.04 Ratio Root:Shoot 0.05 Ratio Root:Shoot 0.02

0 0 8/1/2015 9/1/2015 10/1/2015 11/1/2015 12/1/2015 1/1/2016 2/1/2016 8/1/2015 9/1/2015 10/1/2015 11/1/2015 12/1/2015 1/1/2016 2/1/2016 Plant Harvest

• Plant yield did not significantly differ between tilapia and walleye systems • Nor did it differ for plant biomass and root:shoot ratio Nutrient Differences No differences 60

• Micronutrients P 3

- 50 4 – Iron 40 – Molybdenum 30 – Copper 20 – Nickel 10

Phosphorus (mg/L PO (mg/L Phosphorus • Macronutrients

0 – Calcium – Sulfur – Magnesium 160 Phosphorus (T) Phosphorus (W) 140

Water quality + 120 • Alkalinity 100 80 – Similar: 188 – 184 mg/L 60 • Hardness 40 Potassium K (mg/L – Similar: 260 – 244 mg/L 20 • pH 0 – Similar: 7.6 – 7.8 • Temperature – Similar: 23 – 21oC (73 – 70oF) Potassium (T) Potassium (W) Nutrient Differences

0.8 0.7 0.7 0.6

0.6 0.5 0.5 0.4 0.4 N (mg/L) N (mg/L) - - 0.3 2 3 0.3 NH 0.2 NO 0.2 0.1 0.1 0 0

Ammonia (T) Ammonia (W) Nitrite (T) Nitrite (W)

30

25

20

15 N (mg/L) - 3 10 NO 5

0

Nitrate (T) (W) Summary • Differences in in tilapia and walleye aquaponic systems related to composition of feed and fish absorption efficiency. – Levels within acceptable limits for both. • Plant production did not differ between systems. • Tilapia production to market-size accomplished in 10-12 months. • Walleye production to market-size accomplished in >1 year 10 months. Hybrid Walleye

Harvest in 307 days (10 months)

Harvest in 392 days (1 year 1 month)

Harvest in 462 days (1 year 3 months) Aquaponics as a Commercial Industry

Status - Industry Needs - • Small but rapidly growing industry – • Aquaponic education experiencing exponential growth. • Enthusiasm > Knowledge • Driven by: • Employment opportunities • Food security & Food quality • Currently have: • Locavore movement • Limited fresh water and land • Large commercial ventures • Students pursuing careers in aquaponics • Research in , system efficiency & economics

Aquaponics survey respondents by zip code (Love et al. 2014. PLoS ONE 9(7).) Education/Outreach Summary / Contacts

• UW-Stevens Point Aquaponics Innovation Center – Professional aquaponics certificate – Three college courses (semester long) – Internship opportunities – Collaborative research – http://www.uwsp.edu/aquaponics