Algaculture
An open pond Spirulina farm
Algaculture is a form of aquaculture involving the farming of species of algae. The majority of algae that are intentionally cultivated fall into the category of microalgae, also referred to as phytoplankton, microphytes, or planktonic algae.
Fish farming
Fish farming is the principal form of aquaculture, while other methods may fall under mariculture. It involves raising fish commercially in tanks or enclosures, usually for food. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Fish species raised by fish farms include salmon, catfish, tilapia, cod, carp, trout and others
Freshwater prawn farming
A freshwater prawn farm is an aquaculture business designed to raise and produce freshwater prawn or shrimp for human consumption. Freshwater prawn farming shares many characteristics with, and many of the same problems as, marine shrimp farming. Unique problems are introduced by the developmental life cycle of the main species
Mariculture
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. An example of the latter is the farming of marine fish, prawns, or oysters in saltwater ponds. Non-food products produced by mariculture include: fish meal, nutrient agar, jewelries
Shrimp farming
A shrimp farm is an aquaculture business for the cultivation of marine shrimp for human consumption. Commercial shrimp farming began in the 1970s, and production grew steeply, particularly to match the market demands of the U.S., Japan and Western Europe. The total global production of farmed shrimp reached more than 1.6 million tonnes in 2003, representing a value of nearly 9,000 million U.S. dollars. About 75% of farmed shrimp is produced in Asia, in particular in China and Thailand. The other 25% is produced mainly in Latin America, where Brazil is the largest producer. The largest exporting nation is Thailand.
Sunday, March 29, 2009
enviromental impacts
The concentrated nature of aquaculture often leads to higher than normal levels of fish waste in the water. Fish waste is organic and composed of nutrients necessary in all components of aquatic food webs. In some instances such as nearshore, high-intensity operations, increased waste can adversely affect the environment by decreasing dissolved oxygen levels in the water column. Onshore recirculating aquaculture systems, facilities using polyculture techniques, and properly-sited facilities (e.g. offshore or areas with strong currents) are examples of ways to reduce or eliminate the negative environmental effects of fish waste.
Aquaculture can be more environmentally damaging than exploiting wild fisheries. Some heavily-farmed species of fish, such as salmon, are maintained in net-contained environments. Unused feed and waste products can contaminate the sea floor and cultured fish can escape from these pens. Escapees can out compete wild fish for food and spread disease, as well as dilute wild genetic stocks through interbreeding. Farming carnivorous fish like salmon may actually increase the pressure on wild fish, as for farming one kilo of farmed fish up to six kilo of wild fish are used for feeding.[ However considerable research and commercial feed improvements during the 1990s & 2000s has lessened many of these environmental impacts
Certain forms of aquaculture such as the culture of seaweeds and filter feeding bivalve mollusks such as oysters, clams, mussels and scallops are relatively benign environmentally.
Aquaculture can be more environmentally damaging than exploiting wild fisheries. Some heavily-farmed species of fish, such as salmon, are maintained in net-contained environments. Unused feed and waste products can contaminate the sea floor and cultured fish can escape from these pens. Escapees can out compete wild fish for food and spread disease, as well as dilute wild genetic stocks through interbreeding. Farming carnivorous fish like salmon may actually increase the pressure on wild fish, as for farming one kilo of farmed fish up to six kilo of wild fish are used for feeding.[ However considerable research and commercial feed improvements during the 1990s & 2000s has lessened many of these environmental impacts
Certain forms of aquaculture such as the culture of seaweeds and filter feeding bivalve mollusks such as oysters, clams, mussels and scallops are relatively benign environmentally.
world production
In 2004, the total world production of fisheries was 140.5 million tonnes of which aquaculture contributed 45.5 million tonnes or about 32% of the total world production. The growth rate of worldwide aquaculture has been sustained and rapid, averaging about 8 percent per annum for over thirty years, while the contribution to the total from wild fisheries has been essentially flat for the last decade.
the history
history :
Workers harvest catfish from the Delta Pride Catfish farms in Mississippi
Aquaculture has been used in China since circa 2500 BC. When the waters lowered after river floods, some fishes, mainly carp, were held in artificial lakes. Their brood were later fed using nymphs and silkworm feces, while the fish themselves were eaten as a source of protein.
The Hawaiian people practiced aquaculture by constructing fish ponds A remarkable example from ancient Hawaii is the construction of a fish pond, dating from at least 1,000 years ago, at Alekoko. According to legend, it was constructed by the mythical Menehune. The Japanese practiced cultivation of seaweed by providing bamboo poles and, later, nets and oyster shells to serve as anchoring surfaces for spores. The Romans often bred fish in ponds.
The practice of aquaculture gained prevalence in Europe during the Middle Ages, since away from the seacoasts and the big rivers, fish were scarce and thus expensive. However, improvements in transportation during the 19th century made fish easily available and inexpensive, even in inland areas, causing a decline in the practice. When the first North American fish hatchery was constructed on Dildo Island, Newfoundland Canada in 1889, it was the largest and most advanced in the world.
Americans were rarely involved in aquaculture until the late 20th century, but California residents harvested wild kelp and made legal efforts to manage the supply starting circa 1900, later even producing it as a wartime resource.[2]
Workers harvest catfish from the Delta Pride Catfish farms in Mississippi
Aquaculture has been used in China since circa 2500 BC. When the waters lowered after river floods, some fishes, mainly carp, were held in artificial lakes. Their brood were later fed using nymphs and silkworm feces, while the fish themselves were eaten as a source of protein.
The Hawaiian people practiced aquaculture by constructing fish ponds A remarkable example from ancient Hawaii is the construction of a fish pond, dating from at least 1,000 years ago, at Alekoko. According to legend, it was constructed by the mythical Menehune. The Japanese practiced cultivation of seaweed by providing bamboo poles and, later, nets and oyster shells to serve as anchoring surfaces for spores. The Romans often bred fish in ponds.
The practice of aquaculture gained prevalence in Europe during the Middle Ages, since away from the seacoasts and the big rivers, fish were scarce and thus expensive. However, improvements in transportation during the 19th century made fish easily available and inexpensive, even in inland areas, causing a decline in the practice. When the first North American fish hatchery was constructed on Dildo Island, Newfoundland Canada in 1889, it was the largest and most advanced in the world.
Americans were rarely involved in aquaculture until the late 20th century, but California residents harvested wild kelp and made legal efforts to manage the supply starting circa 1900, later even producing it as a wartime resource.[2]
Sunday, March 22, 2009
First Post
This is the first post for the geography project.It is about aquaculture.
About Aquaculture:
Aquaculture is the farming of freshwater and saltwater organisms.Unlike fishing,aquaculture implies the cultivation of aquatic populations under controlled conditions.
About Aquaculture:
Aquaculture is the farming of freshwater and saltwater organisms.Unlike fishing,aquaculture implies the cultivation of aquatic populations under controlled conditions.
Subscribe to:
Comments (Atom)
