The role of water quality in sustainable aquaculture production
Julia Mas Munoz
Global Aqua Nutrition & Product manager
Summary
In sustainable aquaculture, prioritizing optimal nutrition, health management, and water quality is essential for robust fish growth. Understanding and maintaining appropriate water parameters, along with effective pond bottom and soil management, are crucial for success in aquaculture operations.
Healthy, robust fish are a prerequisite for an efficient, sustainable aquaculture operation. As a farmer looking to get the most out of your production system, it pays to prioritise three key factors that go firmly hand in hand: optimal nutrition and effective health and management strategies. A key focus in health management is water quality. To maximise performance, it is important to understand the water quality requirements of the cultured species and follow proper water management procedures.
Water quality in aquaculture
Water is the culture environment of all aquaculture species. It is where they carry out vital functions such as feeding, swimming, breeding, digestion and excretion. Maintaining good water quality is therefore of prime importance. In aquaculture, animals are raised under high stocking densities. This generally makes them more prone to diseases, which can be difficult to control and is often associated with the indiscriminate use of antibiotics. The equilibrium of nutrition, environment and health is highly important, and sudden changes in water quality often lead to “environmental stress” and vulnerability to many opportunistic pathogens – factors linked to poor growth and survival.
Water management: optimal water-quality parameters
Each cultured species has its own range of water-quality parameters within which they can survive, grow and reproduce. Within these tolerance limits, a species will also have an optimal range within which it performs best and outside of which performance will decline. For optimal water management, it is important to regularly monitor the physical (temperature), chemical (pH, DO, ammonia, nitrates, conductivity) and biological (bacteria, plankton and parasites) parameters that determine water quality. The importance of each factor, the determination method and the monitoring frequency all depend on the type of production system that is in use and its intensity.
We advise using the following water parameters to evaluate your aquaculture production system and maintain conditions within the optimal range:
|
Parameter |
Unit |
Optimal range |
|
Temperature |
ºC |
Species dependent |
|
Dissolved oxygen (DO) |
ppm |
>3 and 5, for most warm and cold-water species respectively |
|
Turbidity (transparency) |
cm |
Species dependent, typically between 30-60 |
|
Total suspended solids |
mg/L |
<20 |
|
Ammonia (NH3) |
mg/L |
<0.02-0.05 |
|
Ammonium (NH4) |
mg/L |
<0.4 |
|
Nitrite (NO2) |
mg/L |
<1-2 |
|
Nitrate (NO3) |
mg/L |
<300 |
|
pH |
|
6.5-8.5 |
|
Alkalinity |
mg/L CaCO3 |
50-300 |
|
Hardness |
mg/L CaCO3 |
>40, but preferably > 100 |
|
Carbon dioxide |
mg/L |
<10 |
|
Salinity |
ppt |
Species dependent, typically <0.5-1 for freshwater species |
|
Chlorine |
mg/L |
<0.02 |
|
Hydrogen sulphide |
mg/L |
No detectable level |
Pond bottom and soil management: key to good water quality
The bottom of the pond is its “chemical laboratory”, and it plays an important role in the overall water quality of a pond system. However, soil quality problems are common in aquaculture, which is why it is important to apply certain management methods or techniques during both pond preparation and the culture period. These include improving the soil’s texture, acidity, and oxidation, as well as pond drying, nutrient removal via flushing or using probiotics, plankton removal, chlorination and liming.
Supporting you on the farm
De Heus has developed the Natural Power programme to help you optimise your nutrition, management and health strategies. Our hands-on programme gives you the tools needed to develop healthy animals, improving your productivity and profitability while using antibiotics prudently.
Our management strategy also includes standardised water quality protocols, and we can advise you on the tolerance range of aquaculture species. We help you establish the critical levels and assess the key water-quality parameters on a routine basis to prevent issues from occurring, and to quickly resolve them when they do.
Learn more about the Natural Power programmeAbout the author
Julia Mas Munoz
Global Aqua Nutrition & Product manager
