Context: Manipur’s state fish has been introduced in cage culture to enhance production and conservation.

• The idea is to popularise cage/pen culture for fishery in the bigger water bodies without disturbing other activities in the lake or reservoir.

Manipur’s Cage culture

• The cage culture has been introduced in some north-eastern states such as Assam Tripura, Meghalaya.
• This is the first time it being introduced in Manipur.
• Manipur’s state fish ‘Pengba’ has been introduced in cage aquaculture on a trial basis in an attempt to enhance table fish production to meet the increasing demand of fish and its conservation.
• It used to be found abundantly in Loktak Lake and Nambul River in particular.
• Manipur is home to more than 200 fish species. It has seven endemic fishes among the 15 endangered freshwater fish species.

What is Cage Culture?

• Cage culture is an aquaculture production system where fish are held in floating net pens.
• Cage culture of fish utilizes existing water resources but encloses the fish in a cage or basket which allows water to pass freely between the fish and the pond permitting water exchange and waste removal into the surrounding water.
• The first cages which were used for producing fish were developed in Southeast Asia around the end of the 19th century.
• In 1950s modern cage culture began with the initiation of production of synthetic materials for cage construction.
• Cages are used to culture several types of shell fish and finfish species in fresh, brackish and marine waters.  
• Fish production in cages became highly popular among the small or limited resource farmers who are looking for alternatives to traditional agricultural crops.

Advantages

• Easy installation.
• Flexibility of management.
• Effective use of fish feeds
• Less manpower requirement.
• Better control of fish population.
• In emergencies it can be removed from one place to another
• Treatment of disease is much simple than that of pond culture.

Disadvantages

• Feed must be nutritionally complete and kept fresh.
• Stocked fish simply affected by the external water quality problems e.g., low oxygen levels.
• Diseases are a common problem in cage culture. The crowding in cages promotes stress and allows disease organisms spread rapidly.
• Caged fish are unable to get the natural food of their choice, whereas it is readily available to the free fish.
• During feeding a significant amounts of fish feed passes out through the mesh, therefore, fish require feeding many times a day.