Cage fish farming is also known as aqua farming or aquaculture. Aquaculture involves cultivating of freshwater and salty water fish under controlled conditions such as cages; and can be contrasted with commercial fishing, which is the harvesting of wild fish.
Cage aquaculture involves the rearing of fish in existing water resources while being enclosed in a net cage which allows free flow of water. It is an aquaculture production system made of a floating frame, net materials and mooring system (rope, buoy, anchor etc.) with a round or square shape floating net to hold and culture large number of fish. It can be installed in a reservoir, river, lake or sea.
There are 4 types of fish-rearing cages namely:
i) Fixed cages,
ii) Floating cages,
iii) Submerged cages
iv) Submersible cages.
Cage culture is a low impact farming practice with high returns and least carbon emission activity. Farming of fish in an existing water body removes one of the biggest constraints of fish farming on land, ie., the need for a constant flow of clean, oxygenated water. Cage farms are positioned in a such a way as to utilize natural currents, which provide the fish with oxygen and other appropriate natural conditions.
Key factors a farmer should consider in cage farming:
- Site selection is a key factor in any aquaculture operation, affecting both success and sustainability. It determines running costs, the rate of production and mortality factors.
- Stocking of right sized fingerlings. The stocking density and size of stocked fish varies with different species.
- Proper feeding of quality feeds, periodic monitoring and cleaning of cages contributes immensely to the success of cage farming.
- With proper management of cage erected at an ideal location, cage farming can yield a production of 20-40kg/m3 with various species of fish.
Advantages of cage fish farming
- Many types of water resources can be used, including lakes, reservoirs, ponds, strip pits, streams and rivers which could otherwise not be harvested.
- A relatively low initial investment is required in an existing body of water.
- Harvesting is simplified.
- Observation and sampling of fish is simplified.
- Allows the use of the pond for sport fishing or the culture of other species.
- Less manpower requirement.
- Generation of job opportunities for unemployed youth and women.
- Additional income to fishers during closed seasons.