By Jimmy Luyima
To embark on successful fish farming, it is crucial to bear in mind key considerations.
Dr Owori Wadunde, a retired Senior Research Officer from the National Fisheries Resources Research Institute and an experienced fish farmer says while fish farming can be profitable, it requires meticulous planning and adherence to proper procedures.
For starters, one needs to acquire sufficient knowledge, as success hinges on your understanding of fish farming intricacies.
Regardless of your existing knowledge base, certain circumstances must be taken into account for optimal results. These include:
· Availability of water and water quality
· Influence of environmental factors
· Physical properties of water
· Climatic factors
· Fishing mortality
· Temperatures
Managing water for successful fish farming
The significance of water quality in fish farming cannot be overstated, as poor-quality water adversely affects the fish’s health and growth. Farmers need to be vigilant about both the chemical and physical aspects of their water.
Temperature control
Maintaining an optimal temperature is crucial for the fish’s well-being, influencing their behaviour, feeding habits, growth, and reproduction. Different fish species thrive in specific temperature ranges, so choose fish that align with the water temperature available to you.
Suspended solids
Issues such as plankton, fish waste, uneaten feed, or suspended clay particles can disrupt water quality, especially in recirculating aquaculture systems. Fish waste, in particular, can contribute significantly to nitrogen levels, potentially irritating fish gills.
Photosynthesis
Photosynthesis, driven by phytoplankton, regulates critical water quality parameters. This process converts carbon dioxide into a food source, releasing oxygen as a by-product. It plays a pivotal role in maintaining a balanced ecosystem.
Dissolved gases
Monitoring dissolved gases—oxygen, carbon dioxide, nitrogen, and ammonia is crucial. Dissolved oxygen levels, in particular, are paramount for fish respiration. Low levels can lead to fish kills, making it a top priority in aquaculture.
Oxygen: Essential for fish respiration, its levels are critical for fish health.
Carbon dioxide: Tolerable at concentrations of 10 ppm, provided oxygen levels remain high.
Nitrogen: Excessive supersaturation levels, especially above 110%, can pose problems.
pH: The pH scale determines acidity or basicity, ranging from 1 to 14.
Alkalinity: Reflects water’s ability to neutralize acids without altering pH, measured in bases like bicarbonates and carbonates.
Success in fish farming hinges on a meticulous understanding and management of these water quality factors. By prioritising these considerations, fish farmers can enhance the health, growth, and overall success of their aquaculture ventures.
