Stocking in fish farming

This is important for fish farmers because most farmers do not know the right density or the amount of fish to be stocked in a pond.

Many think that they can get a lot of fish by stocking heavily, not knowing that each pond has a maximum carrying capacity and once it is overstocked the fish will not die, but it will not grow and instead suffer stunting and this will automatically kill the market and the yield.

Farmers are advised to stock within 10 days after filling the pond with water.

Fingerlings weigh between 7 to 10grammes. About 2kg per square metre for catfish is recommended, while 1kg is recommended for tilapia. This means that if tilapia weighs 10 grammes, you can stock as many as 100 fingerlings in a square metre. On the other hand, if cat fish fingerlings weigh 10grammes and you need 2kg, you stock 200fingerlings per square metre.

Feeding fish

Fish is fed on prepared fish feeds. The feed should provide the nutrients required for growth and survival of the fish. The amount of feeds a fish consumes daily is determined by its body weight.

Normally, it is 5% of its body weight for newly stocked fingerlings. Feed percentages drop as the fish mature to at least 1% as they near full maturity.

If fingerlings weigh an average 45 grammes after four to five weeks in the pond, the total percentage of feed is 3.8%x45grammes=1.7g. Well-fed fish will have gained at least 122grammes by the 9th week. By this time, each should be feeding around 3% of their body weight, which is around 3.7grammes.

You then multiply feeds per fish by the number of fish in the pond to get the total amount of feeds that are dropped in the pond. Feeds must be dry and not mouldy before they are dropped into water. If well-fed, fish should be ready to harvest at eight months.

Keeping off birds

Birds are one of the leading predators of young fish. Use fish nets and put them over each of the ponds. These prevent the birds from swooping into the ponds to ‘steal' the fish. To locate the fish nets, set up strong short poles on the sides of the pond and it is on these poles that the nets are fastened, about a foot over the ponds.

Snakes are also known to feed on fish from ponds. In fact, if a farmer is not careful, snakes can easily make fish farming untenable. In order to keep off other predators like snakes, plant anti-snake herbs, like tobacco, around the fish ponds.

Compiled by Joshua Kato (editor, Harvest Money)