AQUACULTURE (Fish Farming) – What is involved? Part 1

By Mwaka Keembe

AQUACULTURE is the process of rearing, breeding and harvesting of aquatic species, both animals and plants, in controlled aquatic environments such as dams, ponds, tanks etc.

Furthermore, fish farming is easier to do than other kinds of farming as fish are not care-intensive, but only requiring food and proper water conditions as well as temperatures.

The process is also less land-intensive as the size of ponds required to grow some fish species such as tilapia is much smaller than the space required to grow the same amount of protein from beef cattle.

The sector of fish farming has kept on advancing and growing rapidly. This growth has been driven in recent years by improved knowledge and technological advancements as well as an increased demand for aquatic products that cannot be met from wild stocks alone.

Aquaculture is already an important contributor to food and nutrition security, while also providing a vital livelihood for many, and an important economic activity at local, national, and global scales. The expectation is that the aquaculture sector will continue to expand and develop alongside the rapidly rising global population.

However, there are other activities, including other food production sectors, which are competing for the same space and natural resources, so it is vital that all sectors are managed and developed sustainably.

Steps For Pond Construction

Build your pond in successive steps:

1.      Clear all vegetation, rocks, etc. from the area

2.      Remove the top soil and keep it aside

3.      Mark the limits of the inside banks at ground level

4.      Mark the limits of the inside banks at bottom level

5.      Dig inside these last limits by layers of 20 cm (upper end) to 30 cm (lower end)

6.      Use this soil to build up the banks, layer by layer and tightly packed

7.      Form the inside slopes of the banks

8.      Form the outside slopes of the banks

9.      Add topsoil on top and on the outside slopes of the banks

10.  Inside the pond, dig a small draining ditch

Note: Soil with enough clay content to hold water. Clay and silty clays are excellent soils for holding water because the stop water from steeping through. Take soil samples at frequent intervals and have them analyzed to determine suitability.

Water Quality

Water quality determines not only how well fish will grow in an aquaculture operation, but whether or not they will survive. Fish influence water quality through processes like nitrogen metabolism and respiration.

Knowledge of testing procedures and interpretation of results are important to the fish farmer. Some water quality factors are more likely to be involved with fish losses such as dissolved oxygen, temperature, and ammonia. Others, such as pH, alkalinity, hardness and clarity affect fish, but usually are not directly toxic.

Each water quality factor interacts with and influences other parameters, sometimes in complex ways. What may be toxic and cause mortalities in one situation, can be harmless in another. The importance of each factor, the determination method and frequency of monitoring depends upon the type and rearing intensity of the production system used.

look out for the may edition where Mr. Keembe will look into the details of water quality management focusing on both physical factors and chemical factors.

For more or further details, you can get in touch with Mwaka Keembe on 0972134193 or better still WhatsApp him on the same line as well as send him an email mwakakeembe@gmail.com. He is a qualified Fisheries Technician from Natural Resources Development College (NRDC) here in Lusaka and based in Lusaka West along Mumbwa road.

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