Aquaculture is the farming of freshwater and saltwater organisms such as finfish A fish is any aquatic vertebrate animal that is covered with scales, and equipped with two sets of paired fins and several unpaired fins. Most fish are "cold-blooded", or ectothermic, allowing their body temperatures to vary as ambient temperatures change. Fish are abundant in most bodies of water. They can be found in nearly all aquatic, mollusks The Mollusca, common name molluscs or mollusks,[note 1] is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. This is the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. Molluscs are highly diverse,, crustaceans Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at 0.1 mm (0.004 in), to the Japanese spider crab with a leg span of up to 14 ft (4.3 m) and a mass and aquatic plants.[1][2] Also known as aquafarming, aquaculture involves cultivating aquatic populations under controlled conditions, and can be contrasted with commercial fishing Commercial fishing is the activity of capturing fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large scale commercial fishing is also known, which is the harvesting of wild fish A fishery is an area with an associated fish or aquatic population which is harvested for its commercial value. Fisheries can be marine or freshwater. They can also be wild or farmed. This article is an overview of the habitats occupied by the worlds' wild fisheries, and the human impacts on those habitats.[3] Commercial aquaculture supplies one half of the fish and shellfish that is directly consumed by humans.[4]

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, including finfish and shellfish e.g.prawns, or refers to aquaculture practiced in marine environments. Particular kinds of aquaculture include algaculture The majority of algae that are intentionally cultivated fall into the category of microalgae . Macroalgae, commonly known as seaweed, also have many commercial and industrial uses, but due to their size and the specific requirements of the environment in which they need to grow, they do not lend themselves as readily to cultivation (the production of kelp Kelp are large seaweeds belonging to the brown algae (class Phaeophyceae) and are classified as the order Laminariales. There are about 300 different genera. Some species can be very long and form kelp forests/seaweed Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae. Seaweeds can also be classified by use and other algae Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in land plants), fish farming Fish farming is the principal form of aquaculture, while other methods may fall under mariculture. Fish farming 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, shrimp farming A shrimp farm is an aquaculture business that cultivates marine shrimp or prawns for human consumption. Commercial shrimp farming began in the 1970s, and production grew steeply, particularly to service the U.S., Japan and Western Europe. Global production of farmed shrimp reached more than 1.6 million tonnes in 2003, representing a value of, oyster farming Oyster farming is an aquaculture practice in which oysters are raised for human consumption. Oyster farming most likely developed in tandem with pearl farming, a similar practice in which oysters are farmed for the purpose of developing pearls. It was practiced by the ancient Romans as early as the 1st century BC on the Italian peninsula and later, the growing of cultured pearls A pearl is a hard object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur. The finest and the growing and selling of ornamental fish. Particular methods include aquaponics Aquatic animal effluent accumulates in water as a by-product of keeping them in a closed system or tank (for example a recirculating aquaculture system). The effluent-rich water becomes high in plant nutrients but this is correspondingly toxic to the aquatic animal, which integrates fish farming and plant farming.

Contents

History

Workers harvest catfish from the Delta Pride Catfish farms in Mississippi

The indigenous Gunditjmara people in Victoria Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales to the north, South Australia to the west, and Tasmania to the south, across the Bass Strait. Victoria is the most densely populated state, and has a highly centralised population, with over 70% of Victorians, Australia For at least 40,000 years before European settlement in the late 18th century, Australia was inhabited by indigenous Australians, who belonged to one or more of the roughly 250 language groups. After sporadic visits by fishermen from the immediate north and discovery by Dutch explorers in 1606, Australia's eastern half was claimed by the British may have raised eels as early as 6000 BC. There is evidence that they developed about 100 square kilometres (39 sq mi) of volcanic floodplains A floodplain, or flood plain, is flat or nearly flat land adjacent to a stream or river that experiences occasional or periodic flooding. It includes the floodway, which consists of the stream channel and adjacent areas that carry flood flows, and the flood fringe, which are areas covered by the flood, but which do not experience a strong current in the vicinity of Lake Condah into a complex of channels and dams A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are often used in conjunction with dams to provide clean, that they used woven traps A fish trap is a trap used for fishing. Fish traps may have the form of a fishing weir or a lobster trap. A typical trap might consist of a frame of thick steel wire in the shape of a heart, with chicken wire stretched around it. The mesh wraps around the frame and then tapers into the inside of the trap. When a fish swims inside through this to capture eels Eels are an order of fish, which consists of four suborders, 19 families, 110 genera and approximately 800 species. Most eels are predators. The term "eel" is also used for some other similarly shaped fish, such as electric eels and spiny eels, but these are not members of the Anguilliformes order, and that capturing and smoking eels supported them year round.[5][6]

Aquaculture was operating in China China is seen variously as an ancient civilization extending over a large area in East Asia, a nation and/or a multinational entity circa 2500 BC.[7] When the waters subsided after river A river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including stream, creek, brook, rivulet, and rill; there is no floods A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Flooding may result from the volume of water within a body of water,, some fishes, mainly carp The Common carp is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia. The wild populations are considered vulnerable to extinction, but the species has also been domesticated and introduced into environments worldwide, and is often considered an invasive species. It gives its name to the carp family, were trapped in lakes A lake is a terrain feature , a body of liquid on the surface of a world that is localized to the bottom of basin (another type of landform or terrain feature; that is not global). Another definition is a body of fresh or salt water of considerable size that is surrounded by land. On Earth a body of water is considered a lake when it is inland,. Early aquaculturists fed their brood using nymphs In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a pupal stage. Instead, the final moult results in an and silkworm The silkworm is the larva or caterpillar of the domesticated silkmoth, Bombyx mori . It is an important economic insect since it is the producer of silk. A silkworm's preferred food is white mulberry leaves, but it may also eat the leaves of any other mulberry tree (ie, morus rubra or morus negra) as well as the Osage Orange. It is entirely feces, and ate them. A fortunate genetic A gene is a unit of heredity in a living organism. It is normally a stretch of DNA that codes for a type of protein or for an RNA chain that has a function in the organism. All living things depend on genes, as they specify all proteins and functional RNA chains. Genes hold the information to build and maintain an organism's cells and pass genetic mutation Mutations are changes in the DNA sequence of a cell's genome and are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication. They can also be induced by the organism itself, by cellular processes such as hypermutation of carp The Common carp is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia. The wild populations are considered vulnerable to extinction, but the species has also been domesticated and introduced into environments worldwide, and is often considered an invasive species. It gives its name to the carp family led to the emergence of goldfish The goldfish is a freshwater fish in the family Cyprinidae of order Cypriniformes. It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium fish during the Tang Dynasty The Tang Dynasty (June 18, 618–June 4, 907) was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li (李) family, who seized power during the decline and collapse of the Sui Empire. The dynasty was interrupted briefly by the Second Zhou Dynasty (October 16,.

Japanese Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters that make up Japan's name mean "sun-origin", which is why Japan is cultivated seaweed Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae. Seaweeds can also be classified by use by providing bamboo Bamboo listen is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family poles and, later, nets and oyster The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified shells to serve as anchoring surfaces for spores In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoans. A chief difference between spores and seeds as dispersal units is that spores have very little stored.

Romans Ancient Rome was a civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC. Located along the Mediterranean Sea, it became one of the largest empires in the ancient world bred fish in ponds.[8]

In central Europe Europe is one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus region (Specification of borders) and the Black Sea to the southeast. Europe is bordered by the Arctic Ocean and, early Christian A Christian (pronounced /ˈkrɪstʃən/ ) is a person who adheres to Christianity, an Abrahamic, monotheistic religion based on the life and teachings of Jesus of Nazareth, who Christians believe is the Messiah (the Christ in Greek-derived terminology) prophesied in the Hebrew Bible, and the son of God. Most Christians believe in the doctrine of monasteries Monastery denotes the building, or complex of buildings, that houses a room reserved for prayer (e.g. an oratory) as well as the domestic quarters and workplace(s) of monastics, whether monks or nuns, and whether living in community or alone (hermits) adopted Roman aquacultural practices.[9] Aquaculture spread in Europe Europe is one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus region (Specification of borders) and the Black Sea to the southeast. Europe is bordered by the Arctic Ocean and during the Middle Ages The Middle Ages is a period of European history from the 5th century to the 15th century. The period followed the fall of the Western Roman Empire in 476, and preceded the Early Modern Era. It is the middle period in a three-period division of history: Classical, Medieval, and Modern. The term "Middle Ages" (medium aevum) was coined in, since away from the seacoasts and the big rivers, fish were scarce/expensive. Improvements in transportation during the 19th century made fish easily available and inexpensive, even in inland areas, making aquaculture less popular.

Hawaiians Native Hawaiians refers to the indigenous Polynesian people of the Hawaiian Islands or their descendants. Native Hawaiians trace their ancestry back to prehistoric Marquesan, Tahitian, Samoan (and potentially Tongan) settlers of Hawaii (possibly as early as AD 400), before the arrival of British explorer Captain James Cook in 1778 constructed oceanic fish ponds A fish pond is an artificial lake intended for fish breeding. In medieval times in Europe, it was typical for many monasteries and castles (small, partly self-sufficient communities) to have its fish pond (see Hawaiian aquaculture). A remarkable example is a fish pond dating from at least 1,000 years ago, at Alekoko. Legend says that it was constructed by the mythical Menehune In Hawaiian mythology, the Menehune [pronounced meh-neh-HOO-neh] are said to be a people, sometimes described as dwarfs in size, who live in the deep forests and hidden valleys of the Hawaiian Islands, far from the eyes of normal humans. Their favorite food is the maiʻa , but they also like fish dwarf people.

In 1859 Stephen Ainsworth of West Bloomfield, New York, began experiments with brook trout The brook trout, Salvelinus fontinalis, is a species of fish in the salmon family of order Salmoniformes. In many parts of its range, it is known as the speckled trout or squaretail. A potamodromous population in Lake Superior are known as coaster trout or, simply, as coasters. Though commonly called a trout, the brook trout is actually a char,. By 1864 Seth Green had established a commercial fish hatching operation at Caledonia Springs, near Rochester, New York Rochester is a city in Monroe County, New York, south of Lake Ontario in the United States. The Rochester metropolitan area is the second largest economy in New York State, behind the New York City metropolitan area. Known as The World's Image Centre, it was also once known as The Flour City, and more recently as The Flower City. It is the county. By 1866, with the involvement of Dr. W. W. Fletcher of Concord, Massachusetts Concord is a town in Middlesex County, Massachusetts, in the United States. As of the 2000 Census, the town population was about 17,000. Although a small town, Concord is noted for its leading roles in American history and literature. Concord also has two state prisons within its borders, artificial fish hatcheries were under way in both Canada and the United States.[10] When the Dildo Island fish hatchery opened in Newfoundland in 1889, it was the largest and most advanced in the world.

Californians harvested wild kelp and attempted to manage supply circa 1900, later labeling it a wartime resource.[11]

Tilapia, a commonly farmed fish due to its adaptability

In the 21st century

About 430 (97%) of the species cultured as of 2007 were domesticated during the 20th century, of which an estimated 106 came in the decade to 2007. Given the long-term importance of agriculture, it is interesting to note that to date only 0.08% of known land plant species and 0.0002% of known land animal species have been domesticated, compared with 0.17% of known marine plant species and 0.13% of known marine animal species. Domestication typically involves about a decade of scientific research.[12] Domesticating aquatic species involve fewer risks to humans than land animals, which took a large toll in human lives. Most major human diseases originated in domesticated animals.[13] through diseases such as smallpox and diphtheria, that like most infectious diseases, move to humans from animals. No human pathogens of comparable virulence have yet emerged from marine species.

Harvest stagnation in wild fisheries and overexploitation of popular marine species, combined with a growing demand for high quality protein encourages aquaculturists to domesticate other marine species.[14][15]

Production volume

In 2004, the total world production of fisheries was 140,500,000 tonnes (138,300,000 LT; 154,900,000 ST) of which aquaculture contributed 45,500,000 tonnes (44,800,000 LT; 5.02E+7 ST) or about 32%.[16] The growth rate of worldwide aquaculture has been sustained and rapid, averaging about 8 percent per annum for over thirty years, while the take from wild fisheries has been essentially flat for the last decade.

Average annual percentage growth for different species groups[16]
Time period Crustaceans Molluscs Freshwater fish Diadromous fish Marine fish Overall
1970–2004 18.9 7.7 9.3 7.3 10.5 8.8
1970–1980 23.9 5.6 6.0 6.5 14.1 6.2
1980–1990 24.1 7.0 13.1 9.4 5.3 10.8
1990–2000 9.1 11.6 10.5 6.5 12.5 10.5
2000–2004 19.2 5.3 5.2 5.8 9.6 6.3
Major species groups in 2004
Species group Million tonnes[16]
Freshwater fishes 23.87
Molluscs 13.93
Aquatic plants 13.24
Diadromous fishes 3.68
Crustaceans 2.85
Marine fishes 1.45
Other aquatic animals 0.38
Carp are the dominant fish in aquaculture
Top ten species groups in 2004
Species group Million tonnes[16]
Carps and other cyprinids 18.30
Oysters 4.60
Clams, cockles, ark shells 4.12
Miscellaneous freshwater fishes 3.74
Shrimps, prawns 2.48
Salmons, trouts, smelts 1.98
Mussels 1.86
Tilapias and other cichlids 1.82
Scallops, pectens 1.17
Miscellaneous marine molluscs 1.07

Aquaculture is an especially important economic activity in China. Between 1980 and 1997, the Chinese Bureau of Fisheries reports, aquaculture harvests grew at an annual rate of 16.7 percent, jumping from 1,900,000 tonnes (1,870,000 LT; 2,090,000 ST) to nearly 23,000,000 tonnes (23,000,000 LT; 25,000,000 ST). In 2005, China accounted for 70% of world production.[17][18] It is currently one of the fastest growing areas of food production in the U.S.[19]

Mariculture off High Island, Hong Kong
Top ten aquaculture producers in 2004
Country Million tonnes[16]
China 30.61
India 2.47
Viet Nam 1.20
Thailand 1.17
Indonesia 1.05
Bangladesh 0.91
Japan 0.78
Chile 0.67
Norway 0.64
United States 0.61
Other countries 5.35
Total 45.47

Approximately 90% of all U.S. shrimp consumption is farmed and imported.[20] In recent years salmon aquaculture has become a major export in southern Chile, especially in Puerto Montt, Chile's fastest-growing city.

Over reporting

China overwhelmingly dominates the world in reported aquaculture output. They report a total output which is double that of the rest of the world put together. However, there are issues with the accuracy of China's returns.

In 2001, the fisheries scientists Reg Watson and Daniel Pauly expressed concerns in a letter to Nature, that China was over reporting its catch from wild fisheries in the 1990s.[21][22] They said that made it appear that the global catch since 1988 was increasing annually by 300,000 tonnes, whereas it was really shrinking annually by 350,000 tonnes. Watson and Pauly suggested this may be related to China policies where state entities that monitor the economy are also tasked with increasing output. Also, until recently, the promotion of Chinese officials was based on production increases from their own areas.[23][24]

China disputes this claim. The official Xinhua News Agency quoted Yang Jian, director general of the Agriculture Ministry's Bureau of Fisheries, as saying that China's figures were "basically correct".[25] However, the FAO accepts there are issues with the reliability of China's statistical returns, and currently treats data from China, including the aquaculture data, apart from the rest of the world.[26]

Methods

Mariculture

Main article: Mariculture

Mariculture is the term used for the cultivation of marine organisms in seawater, usually in sheltered coastal waters. In particular, the farming of marine fish is an example of mariculture, and so also is the farming of marine crustaceans (such as shrimps), molluscs (such as oysters) and seaweed.

Integrated

Main article: Integrated Multi-trophic Aquaculture

Integrated Multi-Trophic Aquaculture (IMTA) is a practice in which the by-products (wastes) from one species are recycled to become inputs (fertilizers, food) for another. Fed aquaculture (e.g. fish, shrimp) is combined with inorganic extractive (e.g. seaweed) and organic extractive (e.g. shellfish) aquaculture to create balanced systems for environmental sustainability (biomitigation), economic stability (product diversification and risk reduction) and social acceptability (better management practices).[27]

"Multi-Trophic" refers to the incorporation of species from different trophic or nutritional levels in the same system.[28] This is one potential distinction from the age-old practice of aquatic polyculture, which could simply be the co-culture of different fish species from the same trophic level. In this case, these organisms may all share the same biological and chemical processes, with few synergistic benefits, which could potentially lead to significant shifts in the ecosystem. Some traditional polyculture systems may, in fact, incorporate a greater diversity of species, occupying several niches, as extensive cultures (low intensity, low management) within the same pond. The "Integrated" in IMTA refers to the more intensive cultivation of the different species in proximity of each other, connected by nutrient and energy transfer through water.

Ideally, the biological and chemical processes in an IMTA system should balance. This is achieved through the appropriate selection and proportions of different species providing different ecosystem functions. The co-cultured species are typically more than just biofilters; they are harvestable crops of commercial value.[28] A working IMTA system can result in greater total production based on mutual benefits to the co-cultured species and improved ecosystem health, even if the production of individual species is lower than in a monoculture over a short term period.[29]

Sometimes the term "Integrated Aquaculture" is used to describe the integration of monocultures through water transfer.[29] For all intents and purposes however, the terms "IMTA" and "integrated aquaculture" differ only in their degree of descriptiveness. Aquaponics, fractionated aquaculture, IAAS (integrated agriculture-aquaculture systems), IPUAS (integrated peri-urban-aquaculture systems), and IFAS (integrated fisheries-aquaculture systems) are other variations of the IMTA concept.

Species groups

Finfish

Main article: Fish farming

The farming of finfish is the most common form of aquaculture. It involves raising fish commercially in tanks, ponds, or ocean 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, bigeye tuna, carp, tilapia, catfish and cod.[30]

In the Mediterranean, young bluefin tuna are netted at sea and towed slowly towards the shore. They are then interned in offshore pens where they are further grown for the market.[31] In 2009, researchers in Australia managed for the first time to coax tuna (Southern bluefin) to breed in landlocked tanks.[32]

Shellfish

Abalone farm See also: Oyster farming

Abalone farming began in the late 1950s and early 1960s in Japan and China.[33] Since the mid-1990s, this industry has become increasingly successful.[34] Over-fishing and poaching have reduced wild populations to the extent that farmed abalone now supplies most abalone meat.

Crustaceans

See also: Shrimp farm and Freshwater prawn farm

Commercial shrimp farming began in the 1970s, and production grew steeply thereafter. Global production reached more than 1,600,000 tonnes (1,570,000 LT; 1,760,000 ST) 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. Thailand is the largest exporter.

Shrimp farming has changed from its traditional, small-scale form in Southeast Asia into a global industry. Technological advances have led to ever higher densities per unit area, and broodstock is shipped worldwide. Virtually all farmed shrimp are penaeids (i.e., shrimp of the family Penaeidae), and just two species of shrimp—the Penaeus vannamei (Pacific white shrimp) and the Penaeus monodon (giant tiger prawn) account for roughly 80% of all farmed shrimp. These industrial monocultures are very susceptible to disease, which has decimated shrimp populations across entire regions. Increasing ecological problems, repeated disease outbreaks, and pressure and criticism from both NGOs and consumer countries led to changes in the industry in the late 1990s and generally stronger regulations. In 1999, governments, industry representatives, and environmental organizations initiated a program aimed at developing and promoting more sustainable farming practices.[citation needed]

Freshwater prawn farming shares many characteristics with, including many problems with marine shrimp farming. Unique problems are introduced by the developmental life cycle of the main species (the giant river prawn, Macrobrachium rosenbergii).[35]

The global annual production of freshwater prawns (excluding crayfish and crabs) in 2003 was about 280,000 tonnes (280,000 LT; 310,000 ST) of which China produced 180,000 tonnes (180,000 LT; 200,000 ST) followed by India and Thailand with 35,000 tonnes (34,000 LT; 39,000 ST) each. Additionally, China produced about 370,000 tonnes (360,000 LT; 410,000 ST) of Chinese river crab (Eriocheir sinensis).[36]

Echinoderms

Commercially harvested echinoderms include sea cucumbers and sea urchins. In China, sea cucumbers are farmed in artificial ponds as large as 1,000 acres (400 ha).[37]

Algae

An open pond Spirulina farm Main article: Algaculture

Microalgae, also referred to as phytoplankton, microphytes, or planktonic algae constitute the majority of cultivated algae.

Macroalgae, commonly known as seaweed, also have many commercial and industrial uses, but due to their size and specific requirements, they are not easily cultivated on a large scale and are most often taken in the wild.

Issues

See also: Issues with salmon aquaculture

Aquaculture can be more environmentally damaging than exploiting wild fisheries.[38] Concerns include waste handling, side-effects of antibiotics, competition between farmed and wild animals, and using other fish to feed more marketable carnivorous fish. However, research and commercial feed improvements during the 1990s & 2000s have lessened many of these.[39]

Fish waste is organic and composed of nutrients necessary in all components of aquatic food webs. In-ocean aquaculture often produces much higher than normal fish waste concentrations. The waste collects on the ocean bottom, damaging or eliminating bottom-dwelling life. Waste can also decrease dissolved oxygen levels in the water column, putting further pressure on wild animals[citation needed].

Cultivators often supply their animals with antibiotics to prevent disease. As with livestock, this can accelerate the evolution of bacterial resistance.

Fish oils

The nutritional value of farm-raised tilapia may be compromised due to the amount of corn included in the feed. Corn contains short chain omega-6 fatty acids that contribute to the buildup of these materials in the fish. "Ratios of long-chain omega-6 to long-chain omega-3, AA to EPA respectively, in tilapia averaged about 11:1, compared to much less than 1:1 (indicating more EPA than AA) in both salmon and trout." The US produced 1,500,000 tonnes (1,480,000 LT; 1,650,000 ST) of tilapia in 2005, with 2,500,000 tonnes (2,460,000 LT; 2,760,000 ST) projected by 2010. Widespread publicity encouraging fish consumption has led to increases in tilapia consumption by those with lower incomes who are trying to eat a balanced diet. The lower amounts of omega-3 and the higher ratios of omega-6 compounds in farmed tilapia raise questions of the health benefits of consuming this fish.[40]

Adequate diets for salmon and other carnivorous fish can be formulated from protein sources such as soy, although soy-based diets may also change in the balance between omega-6 and omega-3 fatty acids.[41]

Impacts on wild fish

Salmon farming currently involves a high demand for wild forage fish for feed. As carnivores, salmon need a lot of protein, and farmed salmon eat more fish than they produce. Each pound of farmed salmon require up to 6 pounds of wild fish.[42] Seventy five percent of the worlds monitored fisheries are already near to or have exceeded their maximum sustainable yield."[43] The industrial scale extraction of wild forage fish for salmon farming also impacts the survivability of the wild predator fish who rely on them for food.

Fish can escape from coastal pens, where they can interbreed with their wild counterparts, diluting wild genetic stocks.[44] Escaped fish can become invasive, outcompeting native species.[45]

Coastal ecosystems

Aquaculture is becoming a significant threat to coastal ecosystems. About 20 percent of mangrove forests have been destroyed since 1980, partly due to shrimp farming.[46] Large scale conversions of mangroves into brackish shrimp ponds have been characterized as the marine equivalent of "slash-and-burn" farming.[47] An extended cost–benefit analysis of the total economic value of shrimp aquaculture built on mangrove ecosystems found that the external costs were much higher than the external benefits.[48] Over four decades, 269,000 hectares (660,000 acres) of Indonesian mangroves have been converted to shrimp farms. Most of these farms are abandoned within a decade because of the toxin build-up and nutrient loss.[49][50]

Salmon farms are typically sited in pristine coastal ecosystems which they then pollute. A farm with 200,000 salmon discharges more fecal waste than a city of 60,000 people. This waste is discharged directly into the surrounding aquatic environment, untreated, often containing antibiotics and pesticides."[43] There is also an accumulation of heavy metals on the benthos (seafloor) near the salmon farms, particularly copper and zinc.[51]

Genetic modification

Salmon have been genetically modified for faster growth, although they are not approved for commercial use, in the face of opposition.[52] One study, in a laboratory setting, found that modified salmon mixed with their wild relatives were aggressive in competing, but ultimately failed.[53]

Prospects

Global wild fisheries are in decline, with valuable habitat such as estuaries in critical condition.[54] The aquaculture or farming of piscivorous fish, like salmon, does not help the problem because they need to eat products from other fish, such as fish meal and fish oil. Studies have shown that salmon farming has major negative impacts on wild salmon, as well as the forage fish that need to be caught to feed them.[55][56] Fish that are higher on the food chain are less efficient sources of food energy.

Apart from fish and shrimp, some aquaculture undertakings, such as seaweed and filter-feeding bivalve mollusks like oysters, clams, mussels and scallops, are relatively benign and even environmentally restorative.[15] Filter-feeders filter pollutants as well as nutrients from the water, improving water quality.[57] Seaweeds extract nutrients such as inorganic nitrogen and phosphorus directly from the water,[27] and filter-feeding mollusks can extract nutrients as they feed on particulates, such as phytoplankton and detritus.[58]

Some profitable aquaculture cooperatives promote sustainable practices.[59] New methods lessen the risk of biological and chemical pollution through minimizing fish stress, fallowing netpens, and applying Integrated Pest Management. Vaccines are being used more and more to reduce antibiotic use for disease control.[60]

Onshore recirculating aquaculture systems, facilities using polyculture techniques, and properly sited facilities (e.g. offshore areas with strong currents) are examples of ways to manage negative environmental effects.

Recirculating aquaculture systems (RAS) recycle water by circulating it through filters to remove fish waste and food and then recirculating it back into the tanks. This saves water and the waste gathered can be used in compost or, in some cases, could even be treated and used on land. While RAS was developed with freshwater fish in mind, scientist associated with the Agricultural Research Service have found a way to rear saltwater fish using RAS in low-salinity waters.[61] Although saltwater fish are raised in off-shore cages or caught with nets in water that typically has a salinity of 35 parts per million (ppm), scientists were able to produce healthy pompano, a saltwater fish, in tanks with a salinity of only 5 ppm. Commercializing low-salinity RAS are predicted to have positive environmental and economical effects. Unwanted nutrients from the fish food would not be added to the ocean and the risk of transmitting diseases between wild and farm-raised fish would greatly be reduced. The price of expensive saltwater fish, such as the pompano and combia used in the experiments, would be reduced. However, before any of this can be done researchers must study every aspect of the fish’s lifecycle, including the amount of ammonia and nitrate the fish will tolerate in the water, what to feed the fish during each stage of its lifecycle, the stocking rate that will produce the healthiest fish, etc. [62]

See also

Sustainable development portal
Water portal
Marine life portal

Notes

  1. ^ Environmental Impact of Aquaculture
  2. ^ Aquaculture’s growth continuing: improved management techniques can reduce environmental effects of the practice.(UPDATE).” Resource: Engineering & Technology for a Sustainable World 16.5 (2009): 20-22. Gale Expanded Academic ASAP. Web. 1 October 2009. <http://find.galegroup.com/‌gtx/‌start.do?prodId=EAIM.>.
  3. ^ American Heritage Definition of Aquaculture
  4. ^ Half Of Fish Consumed Globally Is Now Raised On Farms, Study Finds Science Daily, September 8, 2009.
  5. ^ Aborigines may have farmed eels, built huts ABC Science News, 13 March 2003.
  6. ^ Lake Condah Sustainability Project Retrieved 18 February 2010.
  7. ^ "History of Aquaculture". Food and Agriculture Organization, United Nations. http://www.fao.org/docrep/field/009/ag158e/AG158E02.htm. Retrieved August 23, 2009.
  8. ^ "The Harbor and Fishery Remains at Cosa, Italy, by Anna Marguerite McCann". Journal of Field Archaeology 6(4):291-311.. http://www.jstor.org/stable/529424. Retrieved 10 September 2009.
  9. ^ Jhingran, V.G., Introduction to aquaculture. 1987, United Nations Development Programme, Food and Agriculture Organization of the United Nations, Nigerian Institute for Oceanography and Marine Research.
  10. ^ Milner, James W. (1874). "The Progress of Fish-culture in the United States". United States Commission of Fish and Fisheries Report of the Commissioner for 1872 and 1873. 535 – 544 <http://penbay.org/cof/cof_1872_1873.html>
  11. ^ Peter Neushul, Seaweed for War: California's World War I kelp industry, Technology and Culture 30 (July 1989), 561-583.
  12. ^ http://www.sciencemag.org/cgi/content/full/sci;316/5823/382
  13. ^ Guns, Germs, and Steel. New York, New York: W.W. Norton & Company, Inc.. 2005. ISBN 978-0-393-06131-4.
  14. ^ "'FAO: 'Fish farming is the way forward.'(Big Picture)(Food and Agriculture Administration's 'State of Fisheries and Aquaculture' report)." The Ecologist 39.4 (2009): 8-9. Gale Expanded Academic ASAP. Web. 1 October 2009. <http://find.galegroup.com/gtx/start.do?prodId=EAIM.>.
  15. ^ a b "The Case for Fish and Oyster Farming," Carl Marziali, University of Southern California Trojan Family Magazine, May 17, 2009.
  16. ^ a b c d e FAO (2006) The State of World Fisheries and Aquaculture (SOPHIA)
  17. ^ Wired 12.05: The Bluewater Revolution
  18. ^ washingtonpost.com: Fish Farming's Bounty Isn't Without Barbs
  19. ^ [1]
  20. ^ The State of World Fisheries and Aquaculture (SOFIA) 2004
  21. ^ Watson, Reg and Pauly, Daniel (2001) Systematic distortions in world Fisheries catch trends Letter to Nature, 414: 534.
  22. ^ Pearson, Helen (2001) China caught out as model shows net fall in fish Nature 414, 477. doi 10.1038/35107216
  23. ^ Heilprin, John (2001) Chinese Misreporting Masks Dramatic Decline In Ocean Fish Catches Associated Press, 29 November 2001.
  24. ^ Reville, William (2002) Something fishy about the figures The Irish Times, 14 March 2002
  25. ^ China disputes claim it over reports fish catch Associate Press, 17 December 2002.
  26. ^ FAO (2006) The State of World Fisheries and Aquaculture (SOPHIA), Page 5.
  27. ^ a b Chopin T, Buschmann AH, Halling C, Troell M, Kautsky N, Neori A, Kraemer GP, Zertuche-Gonzalez JA, Yarish C and Neefus C. 2001. Integrating seaweeds into marine aquaculture systems: a key toward sustainability. Journal of Phycology 37: 975-986.
  28. ^ a b Chopin T. 2006. Integrated multi-trophic aquaculture. What it is, and why you should care... and don’t confuse it with polyculture. Northern Aquaculture, Vol. 12, No. 4, July/August 2006, pg. 4.
  29. ^ a b Neori A, Chopin T, Troell M, Buschmann AH, Kraemer GP, Halling C, Shpigel M and Yarish C. 2004. Integrated aquaculture: rationale, evolution and state of the art emphasizing seaweed biofiltration in modern mariculture. Aquaculture 231: 361-391.
  30. ^ McAvoy, Audrey (October 24, 2009). "Hawaii regulators approve first US tuna farm". The Associated Press. http://abcnews.go.com/Business/wireStory?id=8905220. Retrieved April 9, 2010.
  31. ^ Volpe, J. (2005) "Dollars without sense: The bait for big-money tuna ranching around the world". BioScience, 55:301–302.
  32. ^ The Top 10 Everything of 2009: Top 10 Scientific Discoveries: 5. Breeding Tuna on Land, Time magazine, December 8, 2009
  33. ^ "Abalone Farming Information". http://www.fishtech.com/abaloneinfo.html. Retrieved 2007-11-08.
  34. ^ "Abalone Farming on a Boat". http://www.wired.com/news/technology/0,1282,49847,00.html. Retrieved 2007-01-27.
  35. ^ New, M. B.: Farming Freshwater Prawns; FAO Fisheries Technical Paper 428, 2002. ISSN 0429-9345.
  36. ^ Data extracted from the FAO Fisheries Global Aquaculture Production Database for freshwater crustaceans. The most recent data sets are for 2003 and sometimes contain estimates. Retrieved June 28, 2005.
  37. ^ Ess, Charlie. "Wild product’s versatility could push price beyond $2 for Alaska dive fleet". National Fisherman. http://www.nationalfisherman.com/2008.asp?ItemID=1800&pcid=373&cid=375&archive=yes. Retrieved 2008-08-01.
  38. ^ Diamond, Jared. Collapse: How societies choose to fail or succeed. Viking Press, 2005. pgs. 479-485
  39. ^ Costa-Pierce, B.A., Author/Editor. 2002. Ecological Aquaculture. Blackwell Science, Oxford, UK.
  40. ^ Wake Forest University Baptist Medical Center (2008, July 10). Popular Fish, Tilapia, Contains Potentially Dangerous Fatty Acid Combination. ScienceDaily. Retrieved July 11, 2008, from www.sciencedaily.com
  41. ^ Espe, M., A. Lemme, A. Petei, and A. El-Mowafi. 2006. Can Atlantic salmon (Salmo salar) grow on diets devoid of fish meal? Aquaculture 255:255-262
  42. ^ Swiss WWF Factsheet, Page 7, Heading "Fische und Meeresfrüchte aus Zuchten"
  43. ^ a b Seafood Choices Alliance (2005) It's all about salmon
  44. ^ David Suzuki Foundation: Open-net-cage fish farming
  45. ^ "'Aquaculture's growth continuing: improved management techniques can reduce environmental effects of the practice.(UPDATE)." Resource: Engineering & Technology for a Sustainable World 16.5 (2009): 20-22. Gale Expanded Academic ASAP. Web. 1 October 2009. <http://find.galegroup.com/gtx/start.do?prodId=EAIM.>.
  46. ^ Heroes of the Environment 2008: Jurgenne Primavera Time special report. September 24, 2009.
  47. ^ Nickerson DJ (1999) "Trade-offs of mangrove area development in the Philippines" Ecol. Econ. 28(2):279-298.
  48. ^ Gunawardena1 M and Rowan JS (2005) Economic Valuation of a Mangrove Ecosystem Threatened by Shrimp Aquaculture in Sri Lanka Journal of Environmental Management, 36(4)535-550.
  49. ^ Hinrichsen D (1998) Coastal Waters of the World: Trends, Threats, and Strategies Island Press. ISBN 1-55963-383-2
  50. ^ Meat and Fish AAAS Atlas of Population and Environment. Retrieved 4 January 2010.
  51. ^ FAO: Cultured Aquatic Species Information Programme: Oncorhynchus kisutch (Walbaum, 1792) Rome. Retrieved 8 May 2009.
  52. ^ Mcleod C, J Grice, H Campbell and T Herleth (2006) Super Salmon: The Industrialisation of Fish Farming and the Drive Towards GM Technologies in Salmon Production CSaFe, Discussion paper 5, University of Otago.
  53. ^ Devlin RH, D'Andrade M, Uh M and Biagi CA (2004) "Population effects of growth hormone transgenic coho salmon depend on food availability and genotype by environment interactions", Proceedings of the National Academy of Sciences, 101(25)9303-9308.
  54. ^ Tietenberg TH (2006) Environmental and Natural Resource Economics: A Contemporary Approach. Page 28. Pearson/Addison Wesley. ISBN 9780321305046
  55. ^ Knapp G, Roheim CA and Anderson JL (2007) The Great Salmon Run: Competition Between Wild And Farmed Salmon World Wildlife Fund. ISBN 0-89164-175-0
  56. ^ Washington Post. Salmon Farming May Doom Wild Populations, Study Says.
  57. ^ OSTROUMOV S. A. (2005). "Some aspects of water filtering activity of filter-feeders". Hydrobiologia 542: 400. http://cat.inist.fr/?aModele=afficheN&cpsidt=17195907. Retrieved September 26, 2009.
  58. ^ "Environmental impacts of shellfish aquaculture". 2008. http://www.nrac.umd.edu/files/Factsheets/105-Environmental%20effects.pdf. Retrieved 2009-10-08.
  59. ^ "Aquaculture: Issues and Opportunities for Sustainable Production and Trade". ITCSD. July 2006. http://ictsd.net/i/environment/11849/.
  60. ^ "Pew Oceans Commission report on Aquaculture"
  61. ^ "Growing Premium Seafood-Inland!". USDA Agricultural Research Service. February 2009. http://www.ars.usda.gov/is/AR/archive/feb09/seafood0209.htm.
  62. ^ "Growing Premium Seafood-Inland!". USDA Agricultural Research Service. February 2009. http://www.ars.usda.gov/is/AR/archive/feb09/seafood0209.htm.

References

Further reading

External links

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Q. I want to start up a aquaculture business, farming snakehead (haruan). where do I start? how much capital? please help!
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A. cuba try bank pertanian.. kalau x salah, dia org sanggup biaya modal permulaan.. untuk apa perusahaan sekalipun.. about capital, u'll need like RM5000 for one pool.. (20x20 feet).. tapi pulangan memang lumayan... all the best..
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