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Aquaculture: Fish farming offers possibilities

Question: I’d like to learn more about aquaculture. Can you help, please?

Over-exploitation and climate change put a strain on natural marine and freshwater fish stocks. Aquaculture can help alleviate the pressure and ensure that stock keeps up with the rising demand.

Some farmers do not consider aquaculture viable because it’s technical and capital-intensive, but it can be a successful business if farmers seek the right advice and plan carefully, says Etienne Hinrichsen, Chair of the Aquaculture Association of South Africa. “There’s room for development in this industry, but if you do it wrong you can burn your fingers,” he says.


Hinrichsen says consumer perception of farmed fish can be a constraint. “The market for fish in South Africa is still quite conservative and more work is needed to improve the acceptability of fish products,” he says.

Work is also being done to increase value-adding in the industry, which creates more opportunities for fish products.

“Worldwide, the demand for fish is higher than its availability, in terms of natural resources. Aquaculture is the only way to keep up with the demand.” Almost 50% of the world fish supply is farmed.

Growth in the sector is also hugely important, particularly with the decline of world fish stocks and the growing demand for high-quality protein. Aquaculture already makes up the difference between rising demand and stagnant supplies from capture fisheries.


“It is capital-intensive, but there’s no reason why aquaculture shouldn’t succeed,” Hinrichsen says. Setting up a fish farm requires research, dedication and technical expertise.

“To stay ahead of the game, you have to use the best genetic stock, feed and water to produce an economically competitive product. This is challenging, but not impossible,” he says.

Farming fish isn’t labour-intensive so, from a cost-saving perspective, farmers won’t have to budget a significant amount for labour. More jobs are created in value-adding and processing, though.

Fish are cold-blooded and supported in a water medium. As a result, they have a very low feed conversion ratio. This means that they are more efficient users of feed in comparison with other traditionally farmed animals.


  • It’s important to choose the right species. Consider consumer demand and the inputs required before making a decision.
  • Trout, for instance, is popular in recreational and commercial markets, but remember that the stocking density is much higher for commercial farming and the fish need optimal production conditions.
  • Catfish are suitable for farming as they’re hardy and can be farmed at high densities.
  • The common carp is an exotic fish, but it dominates world production of freshwater fish. “It is a good fish to farm because it doesn’t require specialised input,” Hinrichsen says.
  • Interestingly, crocodiles are also considered part of the aquaculture industry. The industry relies heavily on the export market and exchange rate – especially for crocodile skin.
  • The crocodile meat industry is also growing, but the income will not surpass that of the skin.


  • Hinrichsen explains that entry into the marine fish industry is more difficult because it’s capital-intensive and technologically advanced.
  • South Africa’s offshore environment isn’t really suitable, because of the rough seas. Even so, the country is a significant player in the international abalone market.
  • Rapidly increasing production in China is, however, putting pressure on this market. South Africa also has a firmly established mussel and oyster industry.


Aquaculture (fish farming) is the rearing of freshwater and salt water organisms such as fish with fins, molluscs, crustaceans and aquatic plants.

Aquaculture takes place under controlled freshwater, sea water or brack water conditions for commercial, subsistence or recreational purposes.

Commercial fishing is different, as it involves harvesting wild fish.

Also read:
Aquaculture: Put food on the table and earn a promising extra income
Kafue Fisheries showcases the real benefits of integrated aquaculture farming

  • This article was written by Wilma den Hartigh and first appeared in Farming SA.

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