Finfish Breeding and Hatchery Management (2+1)

Water quality:

• Water quality plays an important role in hatchery production of aquatic organisms.
• A pond with good water quality will produce faster-growing, healthier and more viable fry than a pond with poor water quality.
• Some of the most influential water quality parameters affecting fish health are – temperature, dissolved, oxygen, pH, suspended solids, alkalinity, hardness, ammonia, nitrite, hydrogen sulfide, etc.
• It is important to monitor their levels on a daily basis to avoid any adverse consequences in hatchery, nursery and brood-stock pond.

The water quality requirements for carp hatchery and nursery are as follows :

• Clean, clear and assured water supply, free from pollutants and algal blooms
• Temperature : 24-31⁰C
• Dissolved oxygen : > 5 ppm
• pH : 6.5-9.0
• Suspended solids : < 5 ppm
• Alkalinity : 20-300 ppm as CaCO₃
• Total hardness : > 20 ppm as CaCO₃
• Ammonia-N : < 0.02 ppm
• Nitrite-N : < 0.2 ppm
• Hydrogen sulfide (H₂S-) : <0.002 ppm

Measures to maintain optimum water quality parameters

1. Use fresh oxygen-rich water, free from turbidity (filtered water preferred in hatchery-proper)
2. Avoid accumulation  of organic matter in hatchery and ponds
3. Prevent algal blooms
4. Use aerators wherever necessary