Nursery System

The UVI Tilapia Nursery is a recirculating aquaculture system capable of producing 100,000 50-gram tilapia fingerlings each year.

The tilapia nursery consists of 12 rearing tanks, filter tanks, water circulating pump and regenerative air blower.

Fry are stocked at 1,000/m², 2,000 fish/tank.  One tank is harvested and restocked each week.

Fry are stocked at 1-g and reared to 50-g in a 12 weeks. 

Solid waste is removed by a drum filter and dissolved nitrogen waste is removed in a fluidized bead media filter.

Considerations for nursery management

• Water flow/exchange rate – 1x per hour
  • A faster flow rate will remove waste faster and provide for a cleaner growing environment
    • But will require more energy to be used for swimming against the current
    • Will require higher electricity consumption to pump water faster.
• A slower flow rate will require less swimming and energy use by the fish
  • But water quality will be less than optimal for fish health and growth
  • Will lower the electrical requirements of the water pump
  • Feed ad libitum 4 X each day for 30 minutes per feeding
    • Ad libitum feeding allows for precise rationing of daily feed intake and best feed conversion
      • But requires more labor and time
• Fixed rate feeding saves time
  • But can lead to underfed fish and slow growth
  • Can lead to overfed tanks and wasted feed
  • Stock once – harvest once
    • Tanks should be stocked at recommended rate and harvested completely 12 weeks later
    • Stock splitting
      • Stresses fish during transfer
      • Fish growth slows as peak biomass is reached before splitting