Aquaculture, probably the fastest growing proteinaceous food producing sector, now accounts for nearly half of the World’s food fish production. Though, Inland Aquaculture is relatively recent, World production of farmed fish food is soaring through effective utilization of resources. Inland aquaculture also includes Inland saline aquaculture which is the farming or culture of aquatic animals & plants in inland resources of saline groundwater. Earthen ponds remain the most commonly used type of facility for Inland Aquaculture production.

Farmers gradually preferring advanced aquaculture systems like biofloc powered raceway tanks, aquaponics, and floating cages. Now a day’s cage farming is encountering most of the researchers and farmers keen attention. Demand will be very high for the fish consumption, declining stocks of many native species and poor economy has drastically increased the fish production in floating cage culture. Inland farmers are also searching for the best alternative to the agricultural crops.

Contribution of Inland Aquaculture:

 In 2016, Inland Aquaculture was the source of 51.4 million tons of fish food, or 64.2% of the World’s farmed food fish production. Finfish farming dominates in Inland Aquaculture, accounting for 92.5% (47.5 million tons) of total Inland Aquaculture production. Inland Aquaculture production also includes some Marine shrimp species, such as white-leg shrimp, that can grow in freshwater or inland saline-alkaline water after acclimatization. Inland Aquaculture is usually practiced worldwide for,

• Food fisheries based on wild stocks
• Sustainable food fish production
• Enhancement of food fisheries in smaller water bodies, reservoirs and lakes
• Recreational fishing

Global Aquaculture Production:

Aquaculture is playing a key role in many emerging economies, by virtue of its potential to contribute to increased food production while helping reduce pressure on other fishing activities. This indicator is measured in tons and USD (United States Dollar). Globally, Africa has a production of 19.5 lakh tons which includes only finfishes. America has a production of 11.4 lakh tons including 10.7 lakh tons of finfishes, 68 thousand tons of crustaceans and 1000 tons of other aquatic animals. Asia is the globally leading continent with a production of 477.65 lakh tons that includes 439.83 lakh tons of finfishes, 29.65 lakh tons of crustaceans, 2.86 lakh tons of Mollusc and 5.31 lakh tons of other aquatic animals. Europe has a production of 5.02 lakh tons of finfishes only. Oceanica has a total production of only 5000 tons of finfishes. Globally, 513.6 lakh tons is the production, including 475.1 lakh tons of finfishes, 30.33 lakh tons of crustaceans, 2.86 lakh tons of mollusc and 5.31 lakh tons of other aquatic animals. The continent wise production of main food fish groups through aquaculture is given in table 1.

Table 1: Aquaculture Production of Main Groups of Food Fish Species by Continent,  

              2016 (thousand tonnes, live weight)

      Source: FAO, 2018

Species Wise Production:

         Major group of species considered for Inland Aquaculture constitutes Finfishes such as Carp, Tilapia, Salmon, Sea Bass, Sea Bream and Trout. It also includes Shellfishes such as marine shrimp, freshwater crayfish, Molluscans such as Clams, Mussels, Oyster and Seaweeds.

FINFISHES:

         Among Finfishes, Grass carp, Ctenopharyn godonidellus is the dominant species having a production of 50.18 lakh tons in 2012, 55.39 tons in 2014 and 60.68 lakh tons in 2016. Grass carp contributed 11% of total finfish production in 2016. Followed by Silver carp, Hypophthalmichthys molitrix which is produced at a rate of 41.93 lakh tons in 2012, 49.68 lakh tons in 2014 and 53.01tons in 2016, contributing 10% of total finfish production. Later, is the Common carp, Cyprinus carpio having a production of 37.53 lakh tons in 2012, 41.61 lakh tons in 2014 and 45.57 lakh tons in 2016 making 8% of total finfish production. Next ranks the Nile tilapia, Oreochromis niloticus contributing 8% in total finfish production, with a production of 32.60 lakh tons in 2012, 36.77 lakh tons in 2014 and 42 lakh tons in 2016. Bighead carp, Hypophthalmichthys nobilis is being produced in a rate of 29.01 lakh tons at 2012, 32.55 lakh tons in 2014 and 35.27 lakh tons in 2016 contributing 7% in total finfish production followed by Carassius spp. contributing 6% in total finfish production with a production of 24.51 lakh tons in 2012, 27.69 lakh tons in 2014 and 30.06 lakh tons in 2016. Later comes the Catla, Catla catla, cultured at a rate of 27.61 lakh tons in 2012, 27.70 lakh tons in 2014 and 29.16 lakh tons in 2016 contributing 6% in total finfish production. The total amount of finfish species produced in 2012 is 444.53 lakh tons, in 2014 is 496.8 lakh tons and 2016 is 541 lakh tons.

CRUSTACEANS:

                The world aquaculture production of crustaceans cultured in inland water bodies contributes 29.4%. Several freshwater crustacean species have already been introduced into Africa, often without the knowledge and permission of the authorities. Giant freshwater prawn (Macrobrachium rosenbergii), a low saline water crustacean whose production in South East Asia is non-negligible. All farmed freshwater prawns today belongs to the genus Macrobrachium. Till 2000, the only species farmed was the giant river prawn (Macrobrachium rosenbergii). Since then, China has begun farming the Oriental river prawn (M. nipponense) in large quantities, and India farms a small amount of monsoon river prawn (M. malcolmsonii).

MOLLUSCS:

            Freshwater mollusc contributes only 1.2% in total aquaculture production. Mariculture is a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, an enclosed section of the ocean, or in tanks, ponds or raceways which are filled with seawater. Molluscan culture is a branch of Mariculture, practised in Saltwater. It is rarely practised in Inland water bodies. Hence it’s production is in negligeble amount.

AQUATIC PLANTS AND AQUATIC WEEDS:

         Global production of Aquatic plants, overwhelmingly dominated by seaweeds had an output volume of 30 million tons in 2016. The seaweed industry in India is mainlya cottage industry and is based only on the natural stock of agar-yielding redseaweeds such as Gelidiella acerosa and Gracilaria edulis, and aligns yielding brown seaweeds species such as Sargassum and Tubineria. The dominant species is Tropical seaweed species of Kappaphycus alvarezii and Eucheuma spp (commonly used in Indonesia for Carrageenan extraction). China is the leading producer producing 14387 thousand tons (live weight) contributing about 47.9% of total seaweed production.

INTEGRATED FISH FARMING:

Inland finfish farming is dominated by developing countries. In many countries, aquaculture operations, together with animal husbandry & agriculture, are approved or prohibited based on environmental assessment under a new zoning exercise. In Hubei, for example, the largest inland aquaculture producer in the country, all fish pens and cages were removed from several major lakes where fish farming was previously allowed. As a consequence, Hubei fisheries officials envisaged a plunge in fish production of close to 7 percent in 2017. On the other hand, fisheries authorities have intensively promoted a series of new aquaculture technologies and high-yielding farming systems since 2016, coupled with large-scale expansion of crop–fish integration, including rice–fish culture.

CONCLUSION:

        To ensure sustainable fishery wealth of our inland water bodies, we need to take up cage farming in freshwater and seaweed culture in brackish water. The strong demand for fish products from developing countries is expected to continue growing, yet the ecological constraints of ecosystems means that the traditional capture fisheries sector will not be able to increase its supply beyond historical levels. Therefore, to meet this demand, the aquaculture sector will need to sustainably intensify its production. Additional improvements in feed and disease management will have to materialize for this to happen. Successful demonstration of filed level viable advanced aquaculture technologies and continuous adoption of variety of best practices in the farmers production operations will further ensure the food security especially nutritional security of the world through sustainable blue revolution.

Note: This article is written on the basis of facts and statistics given in the State of World Fisheries and Aquaculture (SOFIA-2018) published by FAO.