Fish farming or pisciculture involves raising fish commercially in tanks or enclosures such as fish ponds, usually for food. It is the principal form of aquaculture, while other methods may fall under mariculture.
Major species
Species | Environment | Tonnage (millions) | Value (US$ billions) |
---|---|---|---|
Grass carp | Freshwater | 5.23 | 6.69 |
Silver carp | Freshwater | 4.59 | 6.13 |
Common carp | Freshwater | 3.76 | 5.19 |
Nile tilapia | Freshwater | 3.26 | 5.39 |
Bighead carp | Freshwater | 2.90 | 3.72 |
Catla (Indian carp) | Freshwater | 2.76 | 5.49 |
Crucian carp | Freshwater | 2.45 | 2.67 |
Atlantic salmon | Marine | 2.07 | 10.10 |
Roho labeo | Freshwater | 1.57 | 2.54 |
Milkfish | Marine | 0.94 | 1.71 |
Rainbow trout | Freshwater Brackish Marine | 0.88 | 3.80 |
Wuchang bream | Freshwater | 0.71 | 1.16 |
Black carp | Freshwater | 0.50 | 1.15 |
Northern snakehead | Freshwater | 0.48 | 0.59 |
Amur catfish | Freshwater | 0.41 | 0.55 |
Categories
Growth is limited by available food, commonly Zooplankton feeding on pelagic algae or benthic animals, such as crustaceans and mollusks. Tilapia filter feed directly on phytoplankton, which makes higher production possible. Photosynthetic production can be increased by fertilizing pond water with artificial fertilizer mixtures, such as potash, phosphorus, nitrogen, and microelements.
Another issue is the risk of algal blooms. When temperatures, nutrient supply, and available sunlight are optimal for algal growth, algae multiply at an exponential rate, eventually exhausting nutrients and causing a subsequent die-off in fish. The decaying algal biomass depletes the oxygen in the pond water because it blocks out the sun and pollutes it with organic and inorganic solutes (such as ammonium ions), which can (and frequently do) lead to massive loss of fish.