Key Technical Points and Daily Management Methods for Cage Fish Farming

Cage fish farming involves using synthetic fiber woven into netting, assembled into cages of a certain shape and specification, and placed in larger water bodies suitable for fish farming to raise fingerlings or adult fish.

Characteristics of Cage Fish Farming

Compared with traditional fish farming, cage fish farming has the characteristics of flowing water, dense stocking, intensive rearing, high yield, flexibility, and simplicity, and it also delivers high output and good returns. This is mainly achieved through the mesh of the cage, which continuously exchanges the water body, keeping the cage constantly supplied with sufficient oxygen and feed to provide the living conditions for highly dense rearing of fish in a small volume; at the same time, it can avoid the harm of predatory fish and prevent fish from escaping, maintaining a relatively high survival rate and thus achieving the goal of high yield. Jiuquan region introduced the “small cage fish farming” technique starting in 96, and after three years of farming trials, the farming technique has now basically matured, with high yield and good returns. Summarizing three years of farming experience, “small cage fish farming” has the following advantages:

1. It can save the land and labor needed for digging fish ponds, and returns can be seen in the same year after investment; the cage can be used continuously for 2—3 years.

2. Cage fish farming can make full use of the water body without wasting water resources, and implements mixed and dense rearing of multiple fish species in the upper, middle, and lower layers, with a high survival rate; therefore, it can achieve the goal of high yield.

3. The rearing cycle is short, management is convenient, it is flexible and mobile, and operation is simple. The location where the cage is set can be moved and shifted at any time according to changes in the water environment conditions. It ensures harvest in both drought and flood, achieving high and stable yield.

4. Harvesting is easy; when harvesting, no specially made fishing gear is needed, and the fish can be marketed all at once or harvested in stages and batches according to market demand, which facilitates live fish transport and storage.

Selection of Water Areas for Cage Installation

Cage fish farming is a high-density farming method with very strict requirements for environmental conditions. Cage fish farming mainly relies on water exchange inside and outside the cage; on the one hand, it continuously supplies the cage with abundant dissolved oxygen and feed along with the water flow, and on the other hand, it promptly discharges the large amount of fish excrement from the cage outside along with the water flow. Therefore, the light, water temperature, water flow, natural feed, and other conditions of the water area where the cage is installed are crucial and must be selected well. The specific conditions for selecting a water area for cage fish farming are:

1. Sheltered from the wind and facing the sun, with a relatively broad water surface, relatively stable water level, sufficient dissolved oxygen, and no obstruction to transportation or other water conservancy facilities.

2. There is a certain slight water flow, with a flow speed generally of 3—6 m per minute. The water depth is generally above 3 m, ensuring that the bottom of the cage is more than 0.5 m above the water bottom.

3. Good water quality, clear, and pollution-free. A reservoir bay or lake branch near a water inlet with relatively abundant feed organisms.

4. It should be selected not far from the shore, with convenient transportation and easy operation.