Technical Points of Cage Fish Farming and an Introduction to Suitable Species

Cage fish farming is a production method in which cages are placed in lakes, reservoirs, ponds or nearshore waters and fish are confined within the cage enclosure for rearing. Because water inside and outside the cage can exchange freely, the fish can obtain ample dissolved oxygen through the natural current, and leftover feed and feces can also be flushed out of the cage with the water flow, so the rearing environment is relatively close to the natural state. This method offers flexible investment, concentrated management and easy harvesting, and it is widely used in freshwater aquaculture.

Compared with traditional pond fish farming, cage fish farming has several obvious features. First, water use efficiency is high, and multiple cages can be installed in the same body of water for simultaneous production; second, water quality is easy to maintain, the fish's activity and feeding can be readily observed, and when disease occurs it is easier to detect and isolate in time; third, when harvesting, the cage only needs to be gathered up, saving the trouble of draining the pond to catch fish. However, this model depends to some extent on water conditions, and reinforcement and protection must be prepared in advance when strong winds, floods and other weather events occur.

There are many species suitable for cage farming. Common ones include conventional fish such as grass carp, common carp, crucian carp and tilapia, and special aquatic products such as swamp eel and loach can also be farmed, while shrimps such as freshwater shrimp and crayfish can likewise use the cage model. When choosing species, local water temperature, feed sources and market demand should be considered comprehensively. The cage specifications and mesh size should be determined according to the target species, ensuring both smooth water exchange and prevention of fish and shrimp escaping through the mesh.

In daily management, feeding should be done at fixed times and in fixed amounts, with the quantity flexibly adjusted according to water temperature and feeding conditions. The cages should be checked frequently for damage, and algae and debris attached to the netting should be removed promptly to keep the water flowing freely. In hot seasons, especially, attention should be paid to changes in water quality and the activity of the fish, and any abnormality should be dealt with as soon as possible. Only by doing a good job of preventing escape, disease and pests at ordinary times can farming proceed smoothly and yield relatively good returns.