Aquaculture Systems – land and water-based

aquaculture systems

This article will discuss different aquaculture systems (land and water-based), feed applications under different culture systems, culture procedures, and features of different types of ponds, etc. Let’s go for details.

Any human means to improve fish production than that of the production naturally found. Man’s attempt through inputs of labor and energy to improve the yield of useful aquatic organisms by deliberate manipulation of their rates of growth, mortality, and reproduction.

Aquaculture is the farming of aquatic organisms including fish, mollusks, crustaceans, and aquatic plants. Farming implies some form of intervention in the rearing process to enhance production such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the being cultivated (FAO,1988).

Aquaculture is the water farming activity where some sorts of controls (mostly based on environmental principles) are exercised over the organisms and environment to earn profit. (Grover et al. 2000)

Related article: What is aquaculture? principles, systems, and management

Compare the different cultural systems

Culture SystemPond PreparationStocking densityFertilizer applicationFeed applicationWater/oxygen supplyFish harvesting
Extensive systemWeed fish and aquatic weeds are not removed UncontrolledNo fertilizer is applied No fish feed is applied from external resourcesNo oxygen is supplied Irregular harvest 
Improved extensive systemWeed fish and aquatic weeds are removed Semi controlled Fertilizers are applied irregularlyFish feed is applied irregularlyNo oxygen is supplied Fish harvest several times a year
Semi-intensive systemWeed fish and aquatic weeds are removed Controlled Fertilizers are applied regularlyFish feed is applied regularlyOxygen is supplied if necessaryFish are partially harvested with irregular restocking several times a year
Intensive systemComplete removal of weed fish and aquatic weeds Controlled with high stocking densityNo fertilizer is applied Balanced diet feed is applied Full-time arrangement for oxygen supplyFish are partially harvested with regular restocking several times a year

Feed application under different culture systems:

Fish culture management systemRequirement of natural food (%)Requirement of supplementary/balanced food (%)
Extensive system1000
Improved  extensive system7030
Semi-intensive system 5050
Intensive system0100

Culturable fish species and culture procedures:

SpeciesThe main field of cultivationThe main intensity of cultivation
Katla (Catla catla)PondSemi-intensive
Mrigal carp (Cirrhinus mrigala)PondSemi-intensive
Rohu (Labeo rohita)PondSemi-intensive
Walking catfish (Clarias batrachus)PondSemi-intensive and intensive
Orangefin labeo (Labeo calbasu)PondSemi-intensive
Stinging catfish (Heteropneustes fossilis)PondSemi-intensive
Bighead carp (Aristichthys nobilis)PondSemi-intensive
Grass carp (Ctenopharyngodon idella)Pond Semi-intensive
Common carp (Cyprinus carpio var. communis)PondSemi-intensive
Silver carp (Hypophthalmichthys molitrix)PondSemi-intensive
Black carp (Mylopharyngodon piceus)PondSemi-intensive
Mirror carp (Cyprinus carpio var. specularis)Pond/ Paddy fieldSemi-intensive
Pangas catfish (Pangasius pangasius)PondSemi-intensive and intensive
Pabda catfish (Ompok pabda)PondSemi-intensive
Java barb (Barbodes gonionotus)Pond/ Paddy fieldSemi-intensive
Nile tilapia (Oreochromis niloticus)Pond/ Paddy field, cultivation in a cageSemi-intensive and intensive
Giant freshwater prawn  (Macrobrachium rosenbergii)Pond/ Paddy fieldDeveloped extensive and semi-intensive

Land and water-based aquaculture systems

Land and water based systems are used to culture aquatic plant and animal organisms commercially which are briefly discussed below.

Land based aquaculture systems

Land based aquaculture systems
Image source: https://www.allianzgi.com/en/insights/outlook-and-commentary/land-based-aquaculture

Lagoons: are natural coastal features in which populations of fish and shellfish are traditionally found, water volume ranging from less than a hectare to several thousand hectares, and fish yield are generally low and can be increased with specific management.

Salines/salt-pans/Salinas: Traditional shallow coastal areas for concentrating and collecting salt offer an interesting resource for aquatic production yields are more typical of conventional ponds due to the adoption of certain types of aquaculture.

Reservoirs: are widely used throughout the world,  and represent potential resources for fishery production through enhancement or conventional aquaculture normally sited in inland areas, particularly on river systems, size can vary from a few thousand in m3 to millions of m3 in volume.

Tanks and raceways: are mainly used in intensive operations. Tanks can be of any shape. Although round tanks may be more expensive, they are superior in terms of water flow, Waste removal, and water quality.

Larger tanks are less expensive but tank greater than 10 m in diameter are difficult to design, install and manage. In general, a diameter: depth ratio of 5 to 10:1 is desirable to ensure good cleaning. Raceways are large elongated tanks, that normally have an inflow at one end and outflow at the opposite end. Length width: depth ratio should be 30:3:1 

Rice fields: are important sources of aquatic animals over large areas of Asia, the introduction of hatchery fish to rice fields appears to still be relatively localized but management and capture of wild stocks are widely practiced. The Rice field is modified in rice-fish culture to encourage fish. Usually, a trench or ditch is dug around the field as a refuge or place of safety for fish.

Ponds: are normally supplied with gravity or tidal flow water supplies. Generally, ponds are cheap and technologically simple and are still the widest structure for commercial aquaculture. Major pond site requirements are given below.

  • Sight level- high enough for drainage and low enough for economical water supply;
  • Exposure- well exposed to sunlight, sufficient for good local water mixing;
  • Soil condition- suitable for pond construction, good fertility, avoiding acidic conditions;
  • Water quality- Suitable for rearing, good growth, reduced risk;
  • Land cost- low purchase or lease price;
  • Access- reasonable access to road and/or water for construction and operation; and
  • Services- reasonable access to power supply, phone, labor freshwater, or alternatives available. Pond uses are found to be varied with deaths.

Pond depth (m):

  • 0.2 to 0.5: “Warming ponds” for spawning fish early or fry rearing ponds
  • 0.3 to 0.7: “kitchen ponds” for high productivity algal production
  • 0.8 to 1.2: typical production pond depths
  • 1.0 to 1.8: deeper ponds for overwintering
  • 1.5 to 3.0: typical reservoir ponds are also used for aquaculture

Major features of different types of ponds

features of different types of ponds
TypeMajor featuresApplications/limitations
Barragebuilt across suitably shaped Valleys; shape and size depend on topographywater storage, extensive stocking aquaculture, cage culture in deep ponds, and generally poorer stock/management and poorer yield.
Diversionbuilt-in suitable locations with well-controlled water supply, normally rectangular shape, size typically 100  to 5000 m2, depth 1 to 2 m. most forms of freshwater aquaculture can be operated and managed efficiently for good yields further increased with aeration, water flow, etc.
SunkenSize typically 100 t0 50,000 m2 depth 1 to 5 m, may need a pump for drainagenot widely use for managed systems but may have some cost advantages where sites are suitable
TidalBuilt-in lagoon and coastal plain areas with good tidal range, acceptable water quality, size typically 100 to 20000 m2 depth 1 to 1.5 m with a separate supply and drain canalsMainly for shrimp and marine fish increasingly using pump-assisted water to maintain water quality and productivity
PumpedUsually above ground, regular shape, size typically 100 to 5000 m2Normally for the more intensive system where the value and importance of environmental control justify the use of pumps
Mixed designed for a high degree of environmental control size typically  1000 to 2000 m2, depth 1 to 3 m, with a Central drainfor experimental high value, high-intensity production only

Water based aquaculture systems

water based aquaculture systems

Cages: are the most versatile and cost-effective units used for aquaculture operations. Both floating and fixed cages are used. In general, fishes are stocked at high density for farming in cages. Sufficient water flow is one of the important considerations for the cage system to remove waste from the cage area.

Some advantages of cases are relatively low cost, simple and fast to assemble, not too dependent on land availability, easy to move and relocate if needed not require water supply installation, and relatively easy to service.

Enclosures/pens: are aquaculture systems in which a section of coastal or open water is separated by a solid or open screen wall or fence to create a partially controlled internal volume suitable for holding and rearing stock. Unlike cases, they do not have a separate floor that holds the stock above and is separate from the Sea, lake, or reservoir bed. The basic criteria in selecting a site for enclosures are that sufficient water exchange is available.

Potentials of aquaculture

  • Food security (Important food item rice and fish as a culture, cheap source of animal protein-60%; hidden hunger >55% of the total fish production annual per capita fish intake of 21.90 kg against the requirement of 23 kg)
  • Nutrition security (Source of multi nutrients, macro and micronutrients protein to a building block, minerals and vitamins to disease prevention, omega 3 fatty acid to keep the health/heart good condition, malnutrition; under nutrition; child, lactating women and poor/extreme poor people)
  • Employment generation/livelihood development (involvement of >12% people; producers, hatchery/nursery operators, fishers, GO-NGO officers/staff; public-private sectors)
  • Enterprise development (series of actors, input traders-seed, feed, fertilizer, chemical, medicine, producers, processors, market players)
  • The utilization of resources (pond, ditches, tanks, canals, rivers, floodplain, rice land, etc.)
  • National income (GDP- 3.50%; one-fourth of agricultural GDP, comparable Aquaculture GDP with other countries)
  • Export earnings (fish, prawn, crab, frozen/processed food;  1.23 % of the total export earning)
  • Scope water resources (ponds, ditches, tanks, canals, floodplain, rice fields, river, lakes, back swamp, sea); farmers/fisheries; unemployed youth

Problems of aquaculture

  • Lack of quality seed (inbreeding)
  • Lack of low-cost quality feed (40-70% of the total cost inappropriate protein level)
  • Lack of inducing agents (PG, HCG, RHA, LH)
  • Water quality going bad (low water depth, pH in fluctuation, insufficient DO, high turbidity, harmful gas production)
  • Lack of region-specific aquaculture (variation in soil-water quality in different agroecological zones recommendation of the same package)
  •  Social problem (multiple ownership; short-term/poor owner-operator agreement for multiple/leased waterbody; poaching poisoning; no easy access by the poor/extreme poor to waterbody especially to the public ponds/canals)
  • Economic problem (credit/capital)

Risks of aquaculture

  • Unavailability of inputs 
  • Unavailability of labor
  • Price fall of harvested fishes 
  • Natural calamities (drought, flood)
  • Occurrence of disease/parasites)

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