Fishing agriculture which is also known as fish farming is a commercial activity. In this activity, fishes are raised in tanks and other enclosures. Fish hatchery technique is used for raising immature fish into mature fish in a natural way. The most common species of fish which are raised for fish farming are carp, cod, catfish and salmon. This business is expanding with a wide pace to meet the increasing demand. Fish are in demand for different cuisines and fish protein. Fish agriculture is of two types – intensive agriculture and extensive agriculture.

Intensive Agriculture
A massive production can be done through this technique as it needs oxygen, food and fresh water. A massive water filtration system is also needed to purify the fresh water so hat there may be no risk of algae or other bacteria in the tank. A combination of water treatment and hydroponic system is the best way to keep the fresh water clean and bacteria free. The expenditure of this kind of fish farming is higher to the extensive fish farming because of high protein fish food. This king of fish farming has a risk of infection from parasites such as fungi, intestinal worms, bacteria, fish lice and protozoa. This type of fish agriculture needs adequate quantity of oxygen, nitrite and oxygen to minimize the risk of encountering with any problems. This type of agriculture needs high level of expertise.

Extensive Agriculture
In this technique, the fish are kept and fed in natural ways. They are provided the natural environment to grow. These fish are offered appropriate temperature, sunlight and food supply which help in optimum growth. With these facilities, the fish expand their growth. Although, this is a natural and safe way of fish farming but there is a high risk of algal bloom. This occurs when algae grow and multiply their biomass at an intensive rate. This exhausts the nutrients and oxygen in the water and releases organic and inorganic solutes like ammonium ions which lead to substantial fish loss. To prevent this situation, the aqua culturists suggest various pond ecosystems such as filter algae feeder, benthic feeder and weed feeders. This is a very limited of farming fish in natural or semi-natural ponds.

Another good way of fish agriculture is composite fish culture system. Four or five species of fish is raised in a single pond so that they may not compete with each other for necessities as they belong to different habitats. This way they all grow in a healthy way. Calta, silver carp, mrigal, rohu and common carp are some of the species of fish which are appropriate for this kind of fish agriculture system. Special monitoring equipments are used to keep a track over these fish so that they may grow in a better way.

Raising cold water fish such as koi and goldfish are a very profitable business but it has not shown any significant results in commercial production. Some countries such as Israel, Germany and Britain are researching on the practical methods of cold water fish farming.