Fish Selection for Aquaponics

38 Pages·2013·1.89 MB·English

by  Information Technology

Fish Selection for Aquaponics
Chris Hartleb
Northern Aquaculture Demonstration Facility
Department of Biology
University of Wisconsin-Stevens Point
Status of Global Aquaculture: Farmed and Wild
Selection Criteria
• Compatibility – fish, plants, bacteria
• Availability – source of fish & regulations
• Quantity – how many do you need?
• Marketing – will you sell them? To whom?
Compatibility with Plants & Bacteria
• Requirements for germination & growth
• Simultaneous fish & plant selection
Plant Requirements
(lettuce as an example)
Parameter Range
Temperature 60-80oF / 15-26oC
pH Preferred: 5.8 - 6.2
Maximum: 7.0 - 7.5
Bacteria Requirements
Plants
Bacteria
Parameter Range
Parameter Optimum Range
Temperature 60-80oF / 15-26oC
Temperature:
pH Preferred: 5.8 - 6.2
Nitrosomonas 68 – 86oF / 20 – 30oC
Maximum: 7.0 - 7.5
Nitrobacter 82 – 100oF / 28 – 38oC
pH:
Nitrosomonas 7.8 – 8.0
Fish
Nitrobacter 7.3 – 7.5
Parameter Range
Temperature 60-80oF / 15-26oC
Compromise:
pH 7.0 – 8.0
Temperature: 70-80oF / 21 - 26oC
pH = 7.0
Recirculating Aquaculture System (RAS)
Fish Tanks
Raft Tank
Water Pump
Clarifier
Degassing Tank
Mineralization tanks
Air pump
Why control using RAS?
• Physical control
– Temperature
– Light intensity, daylength, spectrum
– Dissolved gases (oxygen, carbon dioxide)
• Chemical control
– Water quality
– Feeding
– Wastewater
• Biological control
– Viruses, bacteria, fungi, parasites (pathogens)
– Fish
• Low stress = high or optimal survival & growth
Water Quality
• Temperature: poikilotherms
• Dissolved oxygen: limited in water
• pH: indicator
• Ammonia & Nitrite: fish waste products
– pH and temperature determine the proportion
– Alkaline pH more NH (toxic)
3
– Acidic pH more NH (less toxic)
4
– Bacterial nitrification converts ammonia to nitrite
• Fish are sensitive at levels >0.6 mg/L
• Hardness
– Influences fish osmoregulation
• CO : product of fish respiration
2
– Regulated by aeration
Production Water Quality Parameters for Cool-water Fish
Parameter Range
Temperature 72 - 76oF / 22 - 24oC
Dissolved oxygen 7.0 - 8.3 mg/L
Oxygen saturation 85 – 100%
pH 7.0 – 8.0
Unionized ammonia-N <0.01 mg/L
Total ammonia-N <1.0 mg/L
Nitrite-N <0.5 mg/L
Nitrate-N <250 mg/L
Carbon dioxide <10 mg/L
Total alkalinity 50-700 mg/L