Importance of Cage Culture in Aquaculture

Context: Recently, Ministry of Fisheries, Animal Husbandry and Dairying organised a webinar on “Cage aquaculture in Reservoir: Sleeping Giants” as a part of “Azadi Ka Amrit Mahotsav”.

• Department of Fisheries, GOI earmarked the investment targets for promoting cage aquaculture under flagship scheme Pradhan Mantri Matsya Sampada Yojana (PMMSY).

Key Points

• Cage aquaculture involves the growing of fishes 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 (with rope, buoy, anchor etc.) with a round or square shaped floating net to hold and culture large numbers of fishes and can be installed in reservoir, river, lake or sea.
• Cage farms are positioned in such a way to utilize natural currents, which provide the fish with oxygen and other appropriate natural conditions.

Factors Causing Cage Culture

• Factors such as increasing consumption of fish, declining stocks of wild fishes and poor farm economy have increased interest in fish production in cages.
• Many small or limited resource farmers are looking for alternatives to traditional agricultural crops.
• In view of the high production attainable in the cage culture system, it can play a significant role in increasing the overall fish production in India.

Significance

• Removes Constraints of fish farming on land: 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.
• Least Carbon Emission: Cage culture is a low impact farming practice with high returns and least carbon emission activity.
• Expanding Opportunities: Aquaculture appears to be a rapidly expanding industry and it offers opportunities even on a small scale.
• Better Utilization of India’s long Coastline: Suitable locations in India's long coastline, vast brackish water areas available in coastal states and other underutilized water bodies can be better utilized by adopting cage culture.

Disadvantages

Cage culture also has some distinct disadvantages. These include:

• Feed must be nutritionally complete and kept fresh.
• Low Dissolved Oxygen Syndrome (LODOS) is an ever present problem and may require mechanical aeration.
• Fouling of net cage and Escapement.
• The incidence of disease can be high and diseases may spread rapidly.
• Vandalism or poaching is a potential problem and Navigation issues.
• Accumulation of unused feed and excreta will lead to water pollution as well as eutrophication.
• Change in water quality parameters.
• Conflicts within the local community.
• Predation by aquatic mammals and birds.
• Overcrowding of aquatic organisms in cages.

Road Ahead

• Cage culture is the most efficient way of raising fish. Cage can erected in various suitable water bodies in various sizes and shapes. Stocking density of fishes in cage depends on the species cultured and growth rate of fishes.
• A production of 20-40kg/m3 can achieved in normal conditions from cages. Identification of ideal site for vital for cage farming. Proper feeding with quality feeds in of paramount importance for a successful cage farming Regular monitoring of net cages and fishes ensures a good harvest from cages.