Aquaculture is defined as the cultivation of aquatic organisms such as fish, shellfish, algae and other aquatic plants in natural or controlled marine or freshwater environments. It involves some form of intervention in the rearing process to enhance production, such as regular stocking, feeding and protection from predators. Aquaculture is commonly practiced in both freshwater and marine environments and can take place in ponds, tanks, cages or other contained structures. The history of aquaculture dates back thousands of years to ancient China where carp cultivation began, and it has since developed worldwide into a major food production industry.

1. Definition of aquaculture
 Aquaculture define as follows
 The cultivation of aquatic animals and pla
nts, especially fish, shell fish,
and seaweed, in natural or controlled mar
ine or freshwater
environments; underwater agriculture.
 The cultivation of freshwater and marine re
sources, both plant and
animal, for human consumption or use.
 The science of cultivating marine or freshwat
er food fish, such as
salmon and trout, or shellfish, such as oy
sters and clams, under
controlled conditions.

2.  Aquaculture, also known as aquafarming, is the
farming of aquatic organisms such
as fish, crustaceans, molluscs and aquatic plants.
 Aquaculture involves cultivating freshwater and
saltwater populations under controlled conditions,
and can be contrasted with commercial fishing,
which is the harvesting of wild fish.
 Broadly speaking, the relation of aquaculture to
finfish and shellfish fisheries is analogous to the
relation of agriculture to hunting and gathering.
 Mariculture refers to aquaculture practiced in
marine environments and in underwater habitats.

3.  According to the FAO, aquaculture "is understood
to mean the farming of aquatic organisms including
fish, molluscs, crustaceans and aquatic plants.
 Farming implies some form of
intervention/involvment in the rearing process to
enhance production, such as regular stocking,
feeding, protection from predators, etc.
 Aquaculture is the farming of aquatic organisms
such as fish, shellfish and even plants.
 The term aquaculture refers to the cultivation of
both marine and freshwater species and can range
from land-based to open-ocean production.

4.  Aquaculture -- also known as fish or shellfish farming --
refers to the breeding, rearing, and harvesting of plants and
animals in all types of water environments including ponds,
rivers, lakes, and the ocean.
 aquaculture producers are "farming" all kinds of freshwater
and marine species of fish, shellfish, and plants.
 Aquaculture produces food fish, sport fish, bait fish,
ornamental fish, crustaceans, molluscs, algae, sea
vegetables, and fish eggs.
 Aquaculture includes the production of seafood from
hatchery fish and shellfish which are grown to market size in
ponds, tanks, cages, or raceways.
 Aquaculture also includes the production of ornamental fish
for the aquarium trade, and growing plant species used in a
range of food, pharmaceutical, nutritional, and
biotechnology products.

5.  Aquaculture
 “the farming of aquatic organisms, fish, molluscs,
crustaceans, aquatic plants, crocodiles, alligators,
turtle and amphibians” – is known as
AQUACULTURE.
 Here the word farming implies any specific form of
intervention in the rearing process to enhance
production, such as regular stocking, feeding,
protecting from predators, etc.
 It also implies that the cultivated animals have
individual or corporate ownerships.
 They are grown in Brackish water with a content of
around 0.5% salinity in water bodies such as
estuaries, coves, bays lagoons, etc.

6.  Marine aquaculture refers to the culturing of species that
live in the ocean. Marine aquaculture primarily produces
oysters, clams, mussels, shrimp, and salmon as well as
yellowtail, barramundi, seabass, and seabream.
 Marine aquaculture can take place in the ocean (in cages)
or in on-land, manmade systems such as ponds or tanks.
 Recirculating aquaculture systems that reduce, reuse, and
recycle water and waste can support some marine species.
 Freshwater aquaculture produces species that are native
to rivers, lakes, and streams.
 freshwater aquaculture is dominated by catfish but also
produces trout, tilapia, and bass.
 Freshwater aquaculture takes place primarily in ponds and
in on-land, manmade systems such as recirculating
aquaculture systems.
 The cultivation of marine or freshwater organisms,
especially food fish or shellfish such as salmon or oysters,
under controlled conditions. Also called aquafarming.

7.  Aquaculture or farming in water is the aquatic equivalent of
agriculture or farming on land.
 Defined broadly, agriculture includes farming both animals
(animal husbandry) and plants (agronomy, horticulture and
forestry in part). Similarly, aquaculture covers the farming of
both animals (including crustaceans, finfish and molluscs)
and plants (including seaweeds and freshwater
macrophytes).
 While agriculture is predominantly based on use of
freshwater, aquaculture occurs in both inland (freshwater)
and coastal (brackishwater, seawater) areas.
 FAO (1988) introduced a definition of aquaculture which
reduces its confusion with capture fisheries:
 Aquaculture is the farming of aquatic organisms, including
fish, molluscs, 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.

8.  Aquaculture is commonly defined as the
active cultivation (maintenance or
production) of marine and freshwater aquatic
organisms (plants and animals) under
controlled conditions.
 This definition encompasses a broad range
of operations, cultivating a wide variety of
organisms, using a wide variety of production
systems and facilities.
 Aquaculture is the culture of aquatic
oranisms and it is the farming in water. It is
an industry or occupation it is also called
culture fisheries.

9. History of aquaculture
 MILESTONES IN AQUACULTURE DEVELOPMENT
 2000–1000 B.C.
 Aquaculture to Chinese aquaculturist, considered the earliest
beginnings of aquaculture as during the period 2000–1000 B.C.
 This indicated that aquaculture has a long history dating as far as 4000
years ago.
 However, during the period, and especially before the advent of
printing, no records were available except the narratives handed down
from one generation to another especially those found in the seat of
power during those periods.
 Admittedly, China was the cradle of the beginning of aquaculture
utilizing mainly the common carp (Cyprinus carpio).
 It is said that aquaculture as a husbandry developed in China resulting
from the fact that population started to have a settled condition and has
been kept as an unbroken tradition.
 No detailed description of aquaculture practices was however available
during that early period.

10.  500 B.C. (473 B.C. or 475 B.C.)
 This year is considered of very great significance in the annals of the
history of aquaculture. Many authors round the year as 500 B.C.
although most agree that the exact year is 475 B.C. and some even use
473 B.C. as the period when Fan Lai (also spelled Li or Lee by some
authors) wrote his book, “The Classic of Fish Culture”. This book
consisted the earliest monograph of, fish culture. Although the narrative
also dealt on fantasies and metaphysical aspects, it is the first to record
and describe the structure of ponds, the method of propagation of the
common carp and the growth of fry. Excerpts of an English translation
and Chinese facsimile of this book are appended.
 500 B.C.-500 A.D.
 This period can be considered the Golden Age of common carp culture
which has continued to develop in China as well as in neighbouring
countries where the Chinese people migrated or have some form of
foreign relations. Not only is actual progress attained in the techniques
of culture but also scattered records of the culture systems were made
during this period. At about this time in the Indian sub-continent,
specifically during the period 321 to 300 B.C., the use of reservoirs to
hold fish was first described.

11.  618 to 906 A.D. (Tang Dynasty in China)
 The reign of the Tang Dynasty is particularly significant in
the history of world aquaculture. The Tang emperor in China
had the family name of Li which happened to be the
common name of the widely-cultivated common carp.
Because of this coincidence, an imperial decree/verdict was
issued prohibiting the culture as well as other activities
connected with this fish. This decree, however, instead of
putting a constraint to the development of aquaculture
turned to be a blessing in disguise. The Chinese people who
were then at the time very much engrossed in fish culture as
a source of food and livelihood, looked for other species of
fish for pond culture. This resulted in the discovery of the
silver carp, the big-head carp, the grass carp and the mud
carp, all very suitable pond culture species. It was also
found that when raised in polyculture in the same pond,
these species complement each other by eating different
types of food and staying in different environmental strata
within the pond. This led not only in the discovery of new
species for culture but also in maximizing the productivity of
freshwater pond culture,

12.  906 to 1900 A.D.
 906 to 1120 (Sung Dynasty),
 The initiative to collect fry of cultivable species seasonally along the
rivers was started during the Tang Dynasty as a result of the prohibition
decree on the common carp, Systematic fry collection and dispersal in
natural waters was highly developed during following period under the
Sung Dynasty, At about this time in India, the published work
Namasollasa presented a compilation describing the fattening of fish in
reservoirs. In China, in 1243, Chow Mit published his Kwei Sin Chek
Shik which described fry transport in bamboo baskets.
 1368 to 1644 (Ming Dynasty).
 It was during the Ming period that works describing the complete
aquaculture process were detailed. Methods for culturing fry to adult, the
structure of ponds, rearing density, polyculture, stocking/catching
rotation, application of food and fertilizer and disease control were dealt
with in aquaculture works during this period. In the year 1400
brackishwater aquaculture was recorded as having been started in
Indonesia. This was suggested in the penal laws of the country (Kutara
Menawa) which provided for the prohibition of stealing fish from ponds.
In China, in 1639, the Complete Book of Agriculture which included pond
fish culture was released.

13.  Independent developments in other areas
 French Indochina.
 In the French Indochinese countries, the waves of Chinese migration
had influenced the development of aquaculture. Due to the indigenous
species in this area which became of value to the native population,
cage culture of siluroids and related species developed independently
and became a distinct aquaculture practice in this area. This practice
has continued up to the present time (e.g. cage culture along Mekong
River in Kampuchea).
 Sub-continent of India.
 The practice of building water reservoirs of varying sizes as source of
water and for religious purposes, started at very early period in this area.
At the beginning, they were not used for fish culture. Subsequently,
however, they were initially used to hold fish and later on to culture
them.
 Indonesia.
 The early development of brackishwater aquaculture is attributed to this
country at the beginning of the 15th century. This initiative was spread to
neighboring areas including the Philippines, Malaysia, Thailand and
southern parts of China (Taiwan).

14.  Europe.
 Aquaculture in Europe also started during early period. Palaces of the early
rulers, as well as temples and monasteries of the religious, were provided with
water areas. Later on, these were used for temporary holding of fish and
subsequently, they were used as environment for the culture of fish. Common
carp and trout were recorded as the major species.
 North America.
 There were attempts to develop aquaculture during the 19th century specially
aimed at the development of sport fishing. A book, A Manual of Fish Culture, was
published by the United States Commis sion of Fish and Fisheries in 1897. This
dealt mainly on established hatcheries for the production of seeds to stock game
waters but also includes some food species of finfish, oysters, clams, etc.
 Africa.
 There were earlier attempts mainly from Europe to spread aquaculture in African
countries. Due to the nomadic nature of most African communities at the time,
the establishment of aquaculture became difficult. However, the presence of
extensive flood plains provided environment for growth and reproduction of
indigenous species during the rainy season and concentrating them in
depressions or marshes during the dry season. This stimulated the early
beginnings of aquaculture in that continent. At the present time, many initiatives
for aquaculture development are being started in several countries in Africa. The
tilapia, common carp and catfish are the selected species for culture.

15.  Elsewhere.
 a) Latin America. There is no local tradition of aquaculture in this region
but widespread development are being initiated at the present time
which are gaining interest and support,
 b) Australia and New Zealand. Aquaculture development in these
countries has been very recent and is just gaining momentum. Trout and
other cold water species and mollusc culture, mussels and oysters, are
developed.
 c) Pacific Island countries. Varied types of development, especially
seafarming activities, are just being initiated in the various Pacific Island
countries,
 d) Middle East and Israel. Although there are existing rivers which can
be focal points of development for aquaculture in this region, early
historical records did not mention any early aquaculture activities.
Religious tradition in this area, however, indicated heavy utilization of
fish for food. Present development show that much progress in
aquaculture has occurred in the area especially in Israel. Here carp and
tilapia culture have attained advanced state, and the other countries in
the region have initiated aquaculture development programs.

16.  e) Japan and Korea. There is no doubt that
aquaculture developed in these two countries
during very early period. Perhaps China had some
influences in this development such as in the use of
goldfish and carp for culture. But at same period in
their history especially in Japan, the “closed door
policy” was enforced in that country. At that time
aquaculture continued to flourish especially in the
culture of a very wide variety of species. This is
probably the reason why in that country most any
aquatic species of high economic value are
subjected to culture - finfishes, crustaceans,
molluscs, other vertabrates and many kinds of
marine invertebrates that could be the subject of
trade. Development of efficient and high culture
technology is also a characteristic of Japanese and
Korean aquaculture.

17.  1900–1700 - Expansion in operation and breakthroughs in
seed production
 This period witnessed worldwide expansion of aquaculture.
Easy means of communications and widespread exchange
of information through national and international agencies
have stimulated the acceleration of the expansion in
aquaculture.
 The urgent need for seeds to fill the expanded aquaculture
industry resulted in technology breakthroughs in inducing
the spawning of cultivable species, the seeds or fry of which
were only formerly obtained from wild waters. In this period
the cultivated Asiatic carps and the Indian major carps were
induced to spawn under controlled conditions. Likewise the
penaeid shrimp species and the giant freshwater prawns
used in culture were also hatched under control in
hatcheries.

18.  1970-near future - Continued expansion and selective
culture of high value and exportable species and
intensification
 In this period more species were brought into culture. The
industry continued to expand both in area and in quantity of
production,
 A new trend to select species that are most profitable to
culture was adopted by operators in the industry. Therefore,
high value species especially those with high export
demand were emphasized. Penaeid shrimps, high value
finfishes (seabass/groupers), seaweeds and related species
became important aquaculture items.
 As demand and high market value for selected species
persisted, high technology methods and intensification of
operations became the norm of the industry. There is
competition for major markets and maintenance of product
quality standards also became a major concern.

19.  History of Aquaculture in India
 Occurrence of fish in India dates back to three
millennium BC. Fish remains and cut marks have
been obtained from evacuations at Mohenjodero
and Harappa of Indus Valley Civilization (2500 BC
– 1500 BC) indicates utilization of fish as food. In
India Kautilya, in his “Artha Shastra” written around
300 B.C. described how fish could be poisonous in
tanks during war. King Someswara son of king
Vikramaditya VI was the first to record the common
sport fishes of India and group them into marine
and freshwater forms in his book Manasoltara
compiled in 1127 AD. During British rule in India,
they developed sport fisheries through
the introduction of trouts in the hill streams of
Nilgris, Kashmir and Kulu valley.

20.  With the formation of fisheries departments, the culture of
food fishes and sport fishes received encouragements. The
first scientifically designed fish farm was constructed by the
then Madras fisheries department at Sunkesula in Krishna
district (now Andhra Pradesh) during 1911. Fisheries
Departments were established for development of
aquaculture in West Bengal, Punjab, Uttar Pradesh, Andhra
Pradesh, and Karnataka during 1908-1947.
 In earlier days fry were collected from wild waters for
culture. The urgent need for seeds to fill the expanding
aquaculture industry resulted in technology breakthroughs in
induced spawning of cultivable species during the period
from 1700 to 1900. Indian scientists achieved the first
success in induced breeding of Indian major carp through
hypophysation in 1957 and Chinese succeeded in Chinese
carp in 1958. Likewise the penaeid shrimp species and the
giant freshwater prawns used in culture were also hatched
under control in hatcheries.

21.  The development of freshwater aquaculture in the country became
established following the establishment of the Pond Culture Division at
Cuttack in 1949 under the name of the Center of Central Inland
Fisheries Research Institute (CIFRI), West Bengal. Whereas
Brackishwater farming in India is an age-old system confined mainly to
the bheries (manmade impoundments in coastal wetlands) of West
Bengal and pokkali (salt resistant deepwater paddy) fields along the
Kerala coast, without additional input, except that of trapping the
naturally bred juvenile fish and shrimp seed. The importance of
brackishwater aquaculture was recognised only after the initiation of an
All India Coordinated Research Project, (AICRP) on 'Brackishwater Fish
Farming' by ICAR in 1973.
 The project developed several technologies pertaining to fish and shrimp
farming, however, scientific and commercial culture at present is
restricted to farming of shrimps. The earliest attempt on mariculture in
India was made at the Mandapam centre of CMFRI in 1958–1959 with
the culture of milkfish ( Chanos chanos ). CMFRI has developed various
technologies for a number of species including oysters, mussels and
clams among sedentary species, as well as for shrimp and finfish.
CMFRI initiated a pearl culture program in 1972 and successfully
developed the technology for pearl production in Indian pearl oysters.

22.  History Of Aquaculture In India.
 Aquaculture in India dates back to 500 B.C.
 The first written evidence of this was found in
Kautilya’s “Arthashastra”.
 When the inhabitants started to use paddy fields
and the low lying areas for cultivation, the trapped
water of tides and monsoons brought in natural
seeds of fin and shell fish which got trapped when
the water receded.
 After the independence in 1947, the focus of
sustainability had aquaculture as a part of it.
 The sector grew at a compound rate of about 7%
during the seventies and picked up in the eighties.

23.  Aquaculture has a place in world history.
This Japanese fish market that likely was
part of an aquaculture system.

24.  The use of integrated vegetable growing and fish
farming poly-culture systems have long been used
in Far Eastern countries such as Thailand and
China. Farm waste is commonly added as feed for
fish. Plus fish are often cultured in flooded rice
paddies.

25.  Salmon aquaculture blends the knowledge of
the past with the technology of today

27.  a traditional fishermen in India

28.  Scope of aquaculture
 Activities for the purpose of obtaining food and other
products from water bodies involve catching and
gathering as well as farming and raising aquatic
organisms (above all fish, crustaceans, molluscs and algae).
 Annual worldwide production in the fishery and aquaculture
sector amounts to around 95 million tonnes.
 The principal forms of activity are:
 - capture fisheries
- aquaculture
- stocking and ranching
 All three types of activity can be carried out in seawater,
brackish water and fresh water and in both coastal and
inland waters.
 Deep-sea operations primarily involve capture fishery,
with aquaculture playing only a very small role. Stocking and
ranching may include use of deep-sea areas in that fish
released near the coast (e.g. salmon) may spend their
growth phase in the open sea.

29.  While inland and inshore fisheries and aquaculture are
predominantly artisanal, deep-sea operations are primarily
on an industrial scale where capture fisheries are concerned
and exclusively so in the case of aquaculture.
 Capture fisheries utilise natural stocks of aquatic organisms.
Such activities influence the stocks not only
by catching them but also by means of conservation
measures (closed seasons, protected areas, catch quotas,
use of selective gear).
 In aquaculture measures are taken to directly influence at
least the growth stage and if possible also the reproductive
stage, above all by controlling water quality(through the
conditions under which the organisms are
kept), nutrition (through feeding and pond fertilising)
and health (by means of prophylactic and therapeutic
measures).
 The reproductive stage can be controlled by influencing
maturation, egg and sperm production, hatching and larva
raising. The characteristics of the organisms bred can
be genetically influenced (e.g. by means of selection,
crossing or genetic engineering).

30.  Stocking and ranching combine
aquaculture with fishery (culture-based capture
fisheries). Natural or artificial bodies of water
are stocked with young organisms which
were hatched under supervisionand spent the
particularly critical early stages of their life cycle
under controlled conditions. When
the stocks created or augmented in this way
reach the end of their growth stage, they are
fished using normal capture-fishery techniques.
 Between the "production" process - carried out
under natural conditions (fisheries) or controlled
conditions (aquaculture) - and consumption of the
products there are a number of other stages which
may likewise have environmental impacts: keeping
fresh, processing, packing,
transporting and marketing.

31.  Fisheries and aquaculture can be divided into five main areas:
 - artisanal small-scale fisheries
- small-scale aquaculture
- fisheries and aquaculture in artificial lakes
- fishery in the 200-mile exclusive economic zone
- fisheries and aquaculture in mangrove swamps
 In the first two areas, emphasis must be on supporting low-income
groups of the population and ensuring that appropriate
technologies are applied. These two aspects likewise form the focus of
attention in the use of artificial lakes for fisheries and aquaculture. By
contrast, activities involving fishery in the 200-mile exclusive
economic zone - predominantly at industrial scale - centre on
preservation of resources and on managing and monitoring their
use. Particular importance must be attached to environmental
protection and resource conservation when the intention is to utilise
mangrove swamps for fisheries and aquaculture, as measures
involving the use of this fragile ecosystem should aim from the very
outset to ensure that adverse environmental
impacts are avoided altogether or kept to an absolute minimum.

32.  Scope for aquaculture
 Production of protein rich, nutritive, palatable and
easily digestible human food benefiting the whole
society through plentiful food supplies at low or
reasonable cost.
 Providing new species and strengthening stocks of
existing fish in natural and man-made water-bodies
through artificial recruitment and transplantation.
 Production of sportfish and support to recreational
fishing.
 Production of bait-fish for commercial and sport
fishery.
 Production of ornamental fish for aesthetic appeal.
 Recycling of organic waste of human and livestock
origin.

33.  Land and aquatic resource utilization: this
constitutes the macro-economic point of view
benefiting the whole society. It involves (a)
maximum resource allocation to aquaculture and its
optimal utilization; (b) increasing standard of living
by maximising profitability; and (c) creation of
production surplus for export (earning foreign
exchange especially important to most developing
countries).
 Providing means of sustenance and earning
livelihood and monetary profit through commercial
and industrial aquaculture. This constitutes the
micro-economic point of view benefiting the
producer. In the case of small-scale producer, the
objective is to maximise income by greatest
possible difference between income and production
cost and, in the case of large scale producer, by
maximising return on investment.

34.  Production of industrial fish.
 Fish flesh, on the average, contains: moisture and
oil, 80%; protein; 15–25%; mineral matter, 1–2%;
and other constituents, 1%. Water content is known
to vary inversely with fat content.
 Need for artificial recruitment has arisen in order to
replace or augment stocks decimated by:
 decline of water quality and destructive fishing (e.g.
pollution, poisoning, dynamiting);
 barrier to migration caused by execution of river
valley projects (e.g. anadromous fish) and
overfishing.

35.  From the global view point, the fish which have
overwhelmingly dominated artificial recruitment are:
i) Oncorhynchus ii) Acipenser iii) Salmo. Artificial
recruitment of carp, tilapia and mullet are also
important mostly in tropical and subtropical
countries.
 Oncorhychus and Salmo transplants have
contributed maximum to sport and recreational
fishing.
 Production of livebait e.g. for skipjack tuna
(Katsuwonus pelamis) is an example of bait
production for commercial fishing. Some potential
live-bait species are: Tilapia mossambica,
Dorosoma petenense, Engraulis japonicus,
Sardinella malanure, several species of mullets and
cyprinids.

36.  A wide variety of ornamental fish such as sword tail
(Xiphophrus helleri); angel fish (Pterophyllum scale),
siamese fighter (Betta splendens), goldfish, and common
carp. The last mentioned supports intensive breeding of
fancy carps (live jewels) of Japan.
 There has come into being fish-cum-livestock culture, in the
form of an integrated system especially involving cattle,
pigs, ducks and poultry.
 Several by-products are obtained from fish. They include
fish meal used for animal feeding (in aquaculture an
important component of most fish feeds) and as manure;
fish flour; fish oil; leather; gelatin and glue from fish skins;
imitation pearls; isinglass; adhesives; insulin from fish
pancreas; sex hormones from gonads etc.
 Production of industrial fish includes production for purposes
of reduction to fishmeal or fertilizers. Seaweeds are cultured
for marine colloids and pearl oysters for cultured pearls.

37.  Importance of Aquaculture
 As the human population continues to grow, finding means
to feed those people is one of the most important challenges
faced around the globe. Even in troubled economic times,
men, women and children need to eat.
 And a healthy diet, high in protein is necessary to ensure
that growing population does not succumb to sickness and
disease. Fish and other aquatic organisms fit the model for
healthy sources of protein.
 Harvests of wild sources of fish, crustaceans and other
aquatic species cannot keep up with the demand presented
by the growing human population. Trying to match demand
through commercial fishing interests would eventually result
in overfishing and the loss of those species entirely.
Therefore, while aquaculture is required to meet the human
demand, it also relieves the strain on wild species to allow
them to continue to be a significant source.

38.  The role of aquaculture in ensuring a consistent
supply of aquatic species for human consumption
cannot be overstated. Medical research into the
health benefits of frequently eating fish is plentiful.
One popular buzz word within the healthy eating
movement is Omega-3 fatty acids, which are
typically found in most fish. Multiple research
studies indicate these fatty acids help reduce many
forms of cancer and promote healthy brain tissue.
Eating fish regularly has also been shown to reduce
the risk of heart disease through reducing the
probability of clot formation, lowering blood
pressure and increasing the good cholesterol levels
in the blood stream.

39.  Some studies also suggest inclusion of fish into a healthy
diet can have a positive impact on the development of
Alzheimer’s disease in elderly persons or blood sugar levels
in diabetics.
 Fish and aquatic species in general are a much healthier
source of protein compared to livestock commonly
consumed. Beef, pork and chicken all have their positive
attributes, but none stand up to the positive attributes of fish.
 Professionals in all aspects of agriculture struggle with
improving their efficiencies and outputs to meet the food
demands of the constantly increasing human population.
Aquaculture is no different, and in fact, plays a critical role in
this arena. Fish farming is typically much more efficient than
cattle or pork production and other forms of agriculture.
Land dedicated to fish ponds will produce ten times or more
consumable product than the same land used to raise cattle
or pork, while requiring significantly less input.

40.  But aquaculture does not exist without
drawbacks. Depending on their location,
whether it is a landlocked fish pond, or a
floating cage in a saltwater estuary, high
concentrations of aquatic species can alter or
destroy existing wild habitat, increase local
pollution levels or negatively impact local
species genetic makeup.

41.  Principles of site selection for aquaculture pond
 Sites should be selected for fish farms only where
water of the required volume and quality is
available at the times needed for operating the
farm.
 Preference should be given to sites where a gravity
water supply to the farm is possible.
 The quality of the water available must be such that
the desired fish can be raised, e.g. fresh, brackish
or salt water.
 Gravity drainage of the ponds should be possible.
 The fish farm should be sited primarily in areas
unsuited to other agricultural uses.
 The soil in the area selected should, if possible, be
impervious.

42.  For low construction costs, plain areas with slope less than
one percent should be selected.
 - The site should be in the vicinity of transportation routes,
or where the access road can be constructed economically.
 - In the proximity of inhabited areas, considerations of public
health and the necessity of guarding against poachers
should be kept in mind.
 - Fish farms need electrical power, so the possibility and
cost of connection should be considered.
 - Any existing electric power line must be excluded from the
area envisaged for the fish farm.
 - Skilled operators are essential for operating major fish
farms efficiently. An important consideration in site selection
is, therefore, to provide an attractive environment and
facilities for both professionals and operators.

43.  Basic Principles of Arrangement
 Fish farms consist of many ponds performing different functions in fish
production. Their relative positions, as well as their connection to the water
supply and drainage facilities, power supply and transport roads, in fact the
general arrangement of the fish farm, has a major influence on the operating
costs. In deciding on the general arrangement, the following should be
considered:
 - The farm centre, consisting of operating buildings and living quarters, should
have good road access.
 - The facilities requiring frequent attendance, such as the hatchery, rearing and
nursery ponds, holding ponds and pumping station, should be as near as
possible to the centre.
 - Separate filling and drainage possibilities should be provided, if possible, for
each pond.
 - Transport of feed from the grain storage to the ponds and of the fish harvested
to the holding ponds should involve short hauling distances.
 - The holding ponds should be close to the common external cropping pits
serving several ponds.
 The foregoing principles can be realized best by an arrangement in which the
operating buildings, the holding ponds and the water control structures are in the
vicinity of the geometrical centre of the area. Wherever the terrain conditions
permit, this type of arrangement should be adopted.
 The layout of the site is governed by the combined requirements of
operation and the particular site conditions. Prior to designing work, all
information should be collected regarding technological requirements and
the data particular to the site.

44.  Technological Requirements
 - Species of fish to be produced.
 - Sequence of operations envisaged: production
from hatching to market fish, or production of
market fish alone.
 - Method of fry production.
 - Production quantities envisaged.
 - Methods and possibilities of nutrient supply to the
ponds, such as organic manure, duck farming,
fertilizer application.
 - Feed distribution (fish feed, grain feed, etc.).
 - Transport management - method and means of
in-farm and external transportation.
 - Buildings required (operation, social-cultural
amenities, grain store, equipment shed, repair
shop, housing, etc.).

45.  General Technical Data
 - Data on existing water uses affected.
- Data affecting water supply and drainage.
- Future development plans for the area.
- Data on other facilities (roads, railways,
etc.)
- Property conditions and data.

46.  Geodetical Data
 Topographic surveys to the scale 1:500 to 1:5000 and with
contour lines of 20-25 cm (perhaps 1 ft) vertical spacing are
needed for the entire fish farm area, in order to permit
designing complete pond drainage and earthwork volume
estimates of the required accuracy.
 On any existing earth structures (embankments, canals,
etc.) cross sections should be taken at 50-100 m spacing,
with points spaced sufficiently close to each other to plot the
actual terrain with ± 20 cm accuracy on the cross sections of
1:100 scale.
 Cross sections should be plotted at the sites of major
structures (intakes, road crossings, etc.)
 Cross sections at not more than 500 m intervals and
continuous profiles are needed on the connecting stream or
canal extending for the distance affected by the fish farm
(e.g. to the backwater limit).
 The topographic survey should be connected, especially as
regards elevations, to the national survey network.

47.  Hydrological and Meteorological Data
 Where water is obtained from a natural stream, data must
be acquired on the stages and flow rates to be anticipated at
the diversion point in the periods of pond filling and for
compensation of water losses. Water supply should be
designed for a flow rate of 80 percent probability.
 In the case of ponds through which floods must be
conveyed, or the dikes which are required to retain floods on
the stream, the designer will require also data on design
flood levels and discharges. The probability of occurrence of
the design flood is normally specified by the competent
water agency. In the absence of such specification, the flood
of 1 percent probability of occurrence (once in a hundred
years) should be adopted as the design flood. In the case of
minor ponds, where a dam failure would cause no other
losses, a flood of say 3 percent probability might be adopted
as the design flood. The retention capacity of upstream
ponds is taken into account in estimating the design flood.

48.  Data on the peak values of monthly evaporation
and rainfall are needed for estimating the water
demand.
 Data on the monthly average and extreme
temperatures are needed for selecting the species
of fish for farming, for planning the necessary feed
supply rates and for designing the holding and
storage facilities of live fish.
 The annual volume of sediment entering the ponds
should be estimated.
 Data are needed on the direction and highest
speed of wind prevailing in the area in order to
design wave protection.

49.  Geotechnical Data
 The geotechnical explorations should be extended to the
entire area of the fish farm, to provide data on the soil
stratification in the pond area, under the dikes, along the
canal traces and at the sites of structures.
 The data obtained by soil explorations should be suited to
estimate:
 - seepage losses
- underseepage conditions and the hazard of piping failure
- stability of the dikes
- the required degree of compaction
- the allowable flow velocity in the supply canals, and
- the foundation of the structures.
 The methods of exploration and laboratory testing, as well
as the interpretation of the results are described in more
detail in Chapter 5 on soil characteristics for aquaculture
farms.

50.  Water Quality Data
 The water supplied to the fish ponds must not
contain pollutants and toxic substances detrimental
to fish life. The composition of the feed water
should be subject to quality analysis, including the
following:
 - oxygen content
- pH value
- total salts content
- ammonia content
- free CO2 content
- phenols, oil and tar content.
 The water quality analyses should be such as to
enable prediction of the interactions between the
soil and the feed water.

52.  Considerations in the Selection of Sites for Aquaculture
 The success of an aquaculture depends to a large extent on
the proper selection of the site to be developed into a fish farm or
hatchery.
 Factors to be considered in site selection.
 In order to select a suitable site for aquaculture, the following
factors have to be considered on the site
 Ecological factors
Biological and operational factors
Economic and social factors

53.  a) Ecological factors: the following are the ecological factors
 Water supply: An assured water supply of sufficient quantity and
adequate quality is the most important factor to be considered when
deciding on the suitability of a fish pond site.
 Therefore, the investigations for a proper water source should be
most thoroughly conducted in site selection. The source of water
may be an irrigation canal, river, creek, reservoir, lake, spring,
rainfall runoff and dug or deep wells.
 Water can be supplied via feeder channel, storage tank or pipeline
by gravity or by pumping to the ponds. The most economical method
is by gravity.

54.  If rainfall runoff is to be used, and stored in a reservoir to supply
the ponds, a ratio of 10 to 15 ha of catchment area to 1 ha of
pond is required if the catchment area is pasture; a slightly
higher ratio is needed for woodland, and less for land under
cultivation.
 The drainage possibility of the ponds should be carefully
investigated during the site selection. Gravity drainage of the
ponds is preferable. For draining a pond by gravity, its bottom
should be at a level higher than that which the maximum water
table reaches during the harvesting periods in a normal year.

55.  Water quality: Quality of water is one of the most significant
factors to be considered in site selection.
 It should be investigated by taking a number of water samples
from the proposed water source for laboratory analyses of
physical, chemical, biological and micro-biological properties,
including health hazards.
 Water test procedures should be in accordance with the relevant
Standard Classification in the country on water quality. From a
production point of view, emphasis should be placed on the
following:

56.  (i) Physical properties - temperature, colour, odour, turbidity,
transparency, suspended solids.
 (ii) Chemical properties - pH, dissolved oxygen, biochemical
oxygen demand, free carbon dioxide, alkalinity, salinity, dissolved
solids, ammonia, all as regards both useful and toxic qualifies;
also whether pollutants of agricultural or industrial origin are
present, and if so, to what extent.
 (iii) Biological properties - quality and density of plankton.
 (iv) Micro-biological properties - species and quantity of
parasites.

57. 
 An adequate amount of water is required to build the fish farm
because water depth needs to be adjusted at regular intervals. Natural
water bodies such as reservoir, river, and lakes have stable water
quality parameters (Water temperature, dissolved oxygen, pH,
alkalinity and water hardness) when compared to borewell and well
water. The site should be away from the flood area. Water should not
be acidic or alkaline and if found to be so, suitable correction is to be
done by applying lime or organic manure respectively.
 The ideal water temperature is 20 – 300C for a fish farm. Water Salinity
is the amount of salt dissolved in water. A few freshwater fishes such
as tilapia and catfishes grow even in salt water, but the carps can
withstand only in freshwater

58.  Climate: Important climatological factors to be obtained from
the meteorological station nearest to the site are as follows:
 mean monthly temperature
 mean monthly rainfall
 mean monthly evaporation
 mean monthly humidity
 mean monthly sunshine
 mean monthly wind speed and direction

59.  Obviously, the longer the period of record, the better the data will
be. Information on the pattern of precipitation (maximum in any
24 hours) and incidence of high winds, heavy storms or cyclones,
should be considered.
 The incidence and amount of damage caused by storms or
earthquakes in the project area should also be noted.

60.  Hydrological characteristics: The most important data needed
for site selection can be gathered from such sources as Irrigation
Departments or other Water Authorities.
 The following are needed: data for discharge, yield, floods and
water elevations of existing water sources (rivers, irrigation
channels, reservoirs, springs, etc.).

61.  Soil characteristics: Field investigations to determine surface
and sub-surface soil conditions at the site should be made as
early as possible.
 Often money can be saved if proper soil explorations are made
before the site is procured. They may reveal soil conditions
undesirable for pond construction, in which case another site
may have to be found.
 Investigations should be carried out in order to ascertain the
suitability of soil both for construction and operation of ponds.

62.  For engineering purposes, the techniques used for soil investigations
vary from relatively simple visual inspection to detailed sub-surface
exploration and laboratory tests.
 Visual inspection of the site is an essential preliminary step. In order to
provide data on sub-surface soils, a test pit measuring 0.80×1.50 m with
a depth of 1.50 to 2.0 m, depending on the land form and the elevation
of the water table, should be dug in each hectare of the site.
 Digging of a test pit permits visual examination of soil and also makes it
possible to obtain disturbed and undisturbed samples of soils
encountered in the different layers below ground level.

63.  Soils have characteristics that can easily be determined by sight
and feel. Visual examinations are employed in place of precise
laboratory tests to define the basic soil properties.
 A sandy clay to clayey loam is the best type of soil both for pond
construction and growing natural foods at the pond bottom.
 Areas with a layer of organic soil over 0.60 m in thickness are
unsuitable for any kind of fish pond, because it would be difficult
to maintain water levels in the ponds due to high seepage; also, it
would be necessary to transport suitable soils for dike
construction to the site, and this will be costly.

64.  Big surface stones or rock outcrops may make an area unsuitable for
anything except lined ponds or concrete raceways.
 For production purposes, a chemical analysis of the soil should be
conducted by using representative samples from the different layers
found in the test pits. In general, the pH, available nutrients such as
phosphorus, potassium, organic carbon and nitrate, etc., are determined
by chemical analysis of soil.

65.  Evaluation of soil suitability
 Soil suitability can be evaluated by three methods.
 In squeeze method, take the soil in wet hand and squeeze the soil by closing
your hand firmly. If it holds its shape even after opening the palm of your
hand, soil is suitable for pond construction.
 The ground water test is the best method to evaluate the soil suitability. Dig
a pit of one-meter depth and cover it with leaves for a night. If the pit is
filled with ground water in the next day morning then a pond could be built.
 However, in such soils, drainage may require more time due to the
availability of sufficient groundwater. If the pit is empty the next morning,
the site is suitable for pond construction, but the water permeability has to
be tested.

66.  The third method is the water permeability test. Pour the water into the pit
and cover with leaves. If no water is found in the pit on the next day morning
then there is seepage.
 To confirm this, once again pour the water into the pit and cover it with
leaves. If the water availability is high then the site is suitable for
construction.
 But if the water is drained, the site is not suitable for pond construction.
However, the site can be used through use of plastic or heavy clay to cover
pond bottom.

68.  Land: It should be confirmed that the proposed land area is
suitable. The general conformation of the land should be with slopes
not steeper than 2 percent. If wasteland, unsuitable for agriculture
or other direct use, is selected for a project, the cost of the land will
be low.
 Land elevation and flood level are important factors in determining
the suitability of the area for the construction of a fish farm or
hatchery.
 The land should be free from deep flooding; the maximum flood level
for the past 10 years should not be higher than the top of the dikes.
Observation of the marks left by flood waters on bridges or other
structures at the site, or questioning of local people, may give
information about the expected heights of floods.

69.  The shape and size of available land should be considered: land with a
regular shape and extensive enough for future expansion is ideally
suitable for a fish farm.
 It is very important to know the development plans for the area as it
would be unwise to select a site for a project in a region where future
industrial activity may cause air and water pollution. Similarly, if a site
is adjacent to a heavily populated area, the risk of pollution should be
borne in mind.
 However, some industrial and agricultural wastes may be utilized in fish
farming. In such cases, special investigations should be conducted on
their utilization or required treatment.

70.  Underground utilities crossing the site (oil pipelines, etc.) may
render otherwise good sites unsuitable for a project.
 Generally, high electric power poles, radio masts and the like are
not allowed in the pond area. The type and density of vegetation
depend partly on the land elevation.
 Vegetation is also an indicator of soil types and of the elevation of
the water table. The type and density of vegetation, its size and
the root systems of trees largely determine the method of clearing
the site and, therefore, the construction time and cost.

71.  Grassland, abandoned paddy fields, open woodland or land
covered with low shrubs and bushes allow cheaper construction
than land with very thick jungle or swampy areas with high
trees.
 However, in the cyclone belt or in areas where strong winds are
frequent, it is very important to have a wide and high windbreak
of thick vegetation against the direction of the prevailing wind.

72.  Biological and operational factors
 Before a site can be selected for a project, the following
should be ascertained:
 Species to be cultured
Resources and availability of stocking materials (spawners, fry or
fingerlings)

73.  Social and economic factors
 The ecological and biological factors are a prerequisite for good
practices in aquaculture site selection and site management. It is also
important to get to know the social and economic background of the
area and understand the culture and traditions, particularly ideas and
beliefs locally associated with aquaculture practices.
 The social fabric, market, and its structure, services directly or indirectly
linked with aquaculture sector such as transportation, storage,
wholesale market aspects etc are to be considered. The land identified
for farm should be without legal issues and fish farming should be
accepted by the local people.
 Other factors include availability of labour, electricity, medical facilities,
and transportation.

79. Different systems of aquaculture
Monoculture: Monoculture, as the name implies, in the culture of a
single species of an organism in a culture system of any intensity, be
it in any type of water, fresh, brackish or salt.
Fresh water: Common carp in Japan, Carps in India, Tilapia spp in
several countries of Africa, Rainbow trout (Salmon gairdneri) culture
in several countries.
Channel catfish (Ictalurus punctatus) in U.S.A., Catfish, Clarias
gariepinus in Africa.

80.  Brackish water: Milkfish, Chanos chanos in the Philippines, Mullet
culture in several countries. Pearl spot in India
 Seawater: Yellowtail in Japan, Kuruma shrimp, Peneaus japonicus,
Scallop (Patinopecten yessoesin) in Japan, Pacific salmon
(Oncorhynchus spp) in North America, Sea bass in India.
 Feeding with species specific feed is the main basis for monoculture in
the case of finfish.

81.  Polyculture: Polyculture, as the name implies, is the culture of several
species in the same waterbody. The culture system generally depends on
natural food of a waterbody sometime augmented artificially by
fertilization and/or by supplementary feeding. If artificial food is given it
is a common food acceptable to all or most species that are cultured.
 Fresh water: Polyculture of Clarias gariepinus and tilapias in Africa,
Polyculture of several species of Chinese carps in China, Taiwan etc.,
Polyculture of several Indian major carp species in India, Polyculture in
Indian major carps, Chinese carps and other fish in India (called
composite fish culture in India).

82.  Brackish water: Milkfish and shrimp culture in Philippines and
Indonesia, Mullet and shrimp culture in Israel.
 Milk fish and Mullet in India. In systems where production depends on
natural fish pond zonation i.e. ecological niches assume great
importance.

83.  Integrated fish farming: Integrated fish farming refers to the
simultaneous culture of fish or shell fish along with other culture
systems. It may also be defined as the sequential linkage between two or
more culture practices.
 Generally integrated farming means the production or culture of two or
more farming practices but when fish becomes its major component it is
called as integrated fish farming. Fish culture can be integrated with
several systems for efficient resource utilisation.

84.  The Integrated fish farming practices utilize the waste from different
components of the system viz. live stock, poultry, duckery, piggery and
agriculture byproducts for fish production. 40-50 kg of organic wastes
are converted into one kg of fish, while the pond silt is utilized as
fertilizers for the fodder crops, which in turn is used to raise livestock.
 The system of integrated farming is very wide.
The system provides meal, milk, eggs, fruits, vegetables, mushroom,
fodder & grains in addition to fish. It utilizes the pond dykes which
otherwise remain unutilized for the production of additional food and
income to the farmer.

85. a) Fish cum Agriculture
System
b) Fish cum Animal
System
Fish cum Paddy Culture
Fish cum water chestnut
Fish cum Pappaya
Fish cum Mulberry
Fish cum Mushroom
Fish Cum Dairy
Fish cum Pig Farming
Fish cum Rabbit
Farming
Fish cum Poultry
Fish cum Duck
Farming
:

86.  Pond culture: A fish pond is an enclosure (earthen or concrete) built to
retain water for the purpose of growing fish. Wooden troughs, fibre glass
and plastic tanks are other media of growing fish. Growing fish in ponds
from which they cannot escape allows feeding, breeding, growing and
harvesting of the fish in a well planned way.
 Pond culture, or the breeding and rearing of fish in natural or
artificial basins, is the earliest form of aquaculture with its origins
dating back to the era of the Yin Dynasty (1400-1137 B.C.). Over the
years, the practice has spread to almost all parts of the world and is
used for a wide variety of culture organisms in freshwater,
brackishwater, and marine environments. It is carried out mostly using
stagnant waters but can also be used in running waters especially in
highland sites with flowing water.

87.  Cage culture: Cage culture of fish utilizes existing water resources but
encloses the fish in a cage or basket which allows water to pass freely
between the fish and the pond. The origins of cage culture are a little
unclear. It is likely that the first cages were used by fishermen as
holding structures until fish could be accumulated for market. The first
true cages for producing fish were seemingly developed in Southeast
Asia around the end of the last century. These early cages were
constructed of wood or bamboo, and the fish were fed trash fish and
food scraps.
 It is the culture of fish or other organisms in a river, lake or bays by
holding them in cages. Cages are built of metal rods, bamboo mesh or
PVC pipes and covered by mosquito cloth or nylon net. Cage culture, in
recent years, has been considered as a highly specialized and
sophisticated modern aquaculture technique, receiving attention for
intensive exploitation of water bodies, especially larger in nature, all over

88.  Pen culture: A Pen is defined as “a fixed enclosure in which the bottom
is the bed of the water body”. Pen is to be destinguished from the Cage
which in turn is defined as “an enclosure with bottom and sides of
netting or bamboo etc., whether floating at the surface or totally
submerged.” The word ‘pen’ here is also used synonymous with
‘enclosure’ as it is used in enclosure culture.
Pens are the specially designed nylon or bamboo made enclosures
constructed in a water body into which fish are released for culture.
Such type of culture is referred to as pen culture.

89.  By the very nature of the fixed enclosure walls of pens it is obvious
that they cannot be moved about as in the case of cage. There is
economy of material in the pen for the bottom material used is saved
and therefore and for other reasons the pen can be and are much bigger.
Pen culture is possible only in the three zones, namely, intertidal,
sublittoral and seabed -all having natural bottom as the limit of the
lower side of the enclosure.
 In the case of freshwater bodies, except for the very large lakes -
evenhere tidal influence is little compared with the sea, the intertidal
zone is non-existent. Largely the enclosure of a pen is restricted to
shallow area adjacent to the shore. The pen or enclosure may be (a)
completely enclosed on all four sides in the middle of a bay, with no
foreshore or (b) a shore enclosure with a foreshore extending to deep
water surrounded by a net structure or (c) a bay or loch enclosure with
an embankment or net structure only at the entrance.

90.  Raft culture: Rafts are generally made of bamboo poles or metal rods
with buoys at the top for floating in the water.
 These are used in the culture of oysters, mussels and seaweeds in open
seas.
 Raft culture refers to the culture of shellfish, notably mussels, and
seaweeds usually conducted in open waters using rafts, long lines or
stakes.
 The stakes are impaled in the seabed in inter-tidal areas and ropes
are suspended in deeper waters from rafts or buoys.

91.  Sewage fed fish culture: Sewage is a rich nutrient resource, cheaply
available around big towns and cities. It can be well-utilized: for
fertilizing paddies, fishponds and horticulture crops.
 Waste recycling also helps in maintaining a clean environment. For fish
culture sewage water of stablizing tank as well as the water after
dilution can be utilized.
 Air breathing fishes are more suitable to be cultured in sewage
treatment ponds as they can survive in water with lesser dissolved
oxygen content.
 The fish like Clarias batrachus, Heteropneustes fossalis, Channa spp.,
Tilapia mossambicus and Ctenopharyngodon idella (grass carp) are the
species of choice to be considered for culture in sewage treated ponds.

92. The species of Tilapia have proved to be most suited for culture
in sewage irrigated ponds.
They have lesser demand of dissolved oxygen and are able to
survive at high ammonical nitrogen level of 5.43 ppm.
They grow and breed freely in sewage ponds so profusely that to
keep their population under control either monosex culture of Tilapia
or a polyculture along with Clarias have been recommended for
obtaining higher yield.

93.  Extensive fish culture: Extensive culture systems receive no intentional
nutritional inputs but depend on natural food in the culture facility,
including that brought in by water flow e.g., currents and tidal
exchange.
 Extensive fish farming is done in the ocean, natural and man-made
lakes, rivers and fiords. Limiting for growth here is the available food
supply by natural sources, dependence on natural productivity and little
control over the stocks. The fish are grown without the use of fertilizer or
farmer feeding. Fish chosen for extensive aquaculture are very hardy
and often do well in high densities. Carp, tilapia, tuna and salmon are
the most prominent forms of extensive aquaculture.

94.  In these systems little or no input is used in the production. Fish are
stocked in cages, still water earthen ponds and other water
impoundments (for example reservoirs) and left to feed for themselves.
 Low stocking densities and thus low yields characterize the systems. The
main cultured species are Tilapines (e.g. Oreochromis niloticus), catfish
e.g. Clarias gariepinus and Cyprinus carpio.
 These are low input-low-output production systems.

95.  Semi-intensive fish culture: Semi-intensive culture systems depend
largely on natural food which is increased over baseline levels by
fertilisation and/or use of supplementary feed to complement natural
food.
 In semi-intensive fish farming, the fish still obtain significant
nutrition from the food web within their pond, but they are also given
supplementary feed at least two times per week and the fertilization is
done once per week.
 This means the fish can grow faster and to a larger size or at a
greater stocking density. The feed may be of vegetable origin or may
include fish, fish oil or fishmeal.
Grass carp is the farmed fish species with the highest global production
in cages.

96.  These systems form the bulk of aquaculture production in world. In
these systems still water earthen ponds and cages are used as holding
units for fish culture. Still water pond culture uses the natural
productivity of the water to sustain the species under culture.
 However to enhance productivity, the ponds are fertilized using both
chemical and organic fertilizers at varying proportions to enhance
natural productivity.
 Exogenous feeding using cereals bran and other locally available feeds is
done to supplement pond productivity. Polyculture
of Oreochromis niloticus, Clarias gariepinus, Cyprinus carpio and other
carps is practiced with various combinations of species.

97.  Intensive fish culture: Intensive culture systems depend on
nutritionally complete diets added to the system, either fresh, wild,
marine or freshwater fish, or on formulated diets, usually in dry pelleted
form.
 In intensive farming, the fish are raised in artificial tanks at very high
densities and are subject to supplemental feeding and fertilization.
Farmers must have a thorough understanding of the targeted species so
that water quality, temperature levels, oxygen levels, stocking densities,
and feed are set at the optimal levels to promote growth, reduce stress,
control disease, and reduce mortality.
 Essential here is aeration of the water, as fish need a sufficient oxygen
level and fresh water for growth.

98.  This is achieved by bubbling, cascade flow or with a water
purification system.
 Intensive aquaculture does have to provide adequate water quality
which means, beside the optimal level of dissolved oxygen, also the level
of pH, the temperature, the concentration of ammonia and others
parameters have to be controlled to minimize stress and diseases of fish.
 The cost of maintenance of an intensive farming is higher than in
extensive farming, especially because of the high cost of fish feed.
 In these systems water flows in and out continuously (flow through).
This allows higher stocking densities. The systems require good supply
of good quality water.
 Less land is required to produce the same quantity of fish as
compared to extensive and semi intensive systems.

99.  The systems employ mainly raceways, various types of tanks and
floating cages as holding units.
 In these systems, more fish are produced per unit area by
complementing or substituting the natural productivity in the culture
units by exogenous feeding using complete feeds (the feeds are
specifically manufactured for the species under culture) and water
aeration.
 Such operations require high initial capital investment and high
operational cost.
 They are mainly suited for high value fish like the Rainbow trout.

100.  Factors for success Fish farmers ranked ten items they believed
contribute to the start-up of a successful fish farming business.
 1. Aquaculture requires hard work and commitment for success.
 2. Recognize that fish are live animals and need to be treated as
such.
 3. Human resources, management skill, and a drive to succeed are
essential.
 4. Start small to reduce risk of loss while you are learning about
aquaculture.
 5. Grow a high-value high-quality product and provide good service.

101.  6. Business experience and knowledge are needed.
 7. Marketing your fish is where the money is made.
 8. Aquaculture is a high risk business.
 9. It takes a long time to make a profit in aquaculture.
 10. Work only with a proven fish production technology.

115.  Definition of culture environments
 Freshwater CultureBy freshwater culture is understood the cultivation of aquatic organisms where the end product is raised in freshwater, such
as reservoirs, rivers, lakes, canals and groundwater, in which the salinity does not normally exceed 0.5‰. Earlier stages of the life cycle of these
aquatic organisms may be spent in brackish or marine waters.
Brackishwater CultureBy brackishwater culture is understood the cultivation of aquatic organisms where the end product is raised in
brackishwater, such as estuaries, coves, bays, lagoons and fjords, in which the salinity may lie or generally fluctuate between 0.5‰ and full
strength seawater. If these conditions do not exist or have no effect on cultural practices, production should be recorded under either "Freshwater
culture" or "Mariculture". Earlier stages of the life cycle of these aquatic organisms may be spent in fresh or marine waters.
MaricultureBy mariculture is understood that the cultivation of the end product takes place in seawater, such as fjords, inshore and open waters
and inland seas in which the salinity generally exceeds 20‰. Earlier stages in the life cycle of these aquatic organisms may be spent in
brackishwater or freshwater.
Definition of ongrowing units
 Ponds and tanksare artificial units of varying sizes constructed above or below ground level capable of holding and interchanging water. Rate of
exchange of water is usually low, i.e. not exceeding 10 changes per day.
Enclosures and pensrefer to water areas confined by net, mesh and other barriers allowing uncontrolled water interchange and distinguished by
the fact that enclosures occupy the full water column between substrate and surface; pens and enclosures will generally enclose a relatively large
volume of water.
Cagesrefer to open or covered enclosed structures constructed with net, mesh or any porous material allowing natural water interchange. These
structures may be floating, suspended, or fixed to the substrate but still permitting water interchange from below.
Raceways and silosare artificial units constructed above or below ground level capable of high rates of water interchange in excess of 20
changes per day.
Barragesare semi-permanent or seasonal enclosures formed by impervious man-made barriers and appropriate natural features.
Rice-cum-fish paddiesrefer to paddy fields used for the culture of rice and aquatic organisms; rearing them in rice paddies to any marketable
size.
Rafts, ropes, stakesrefer to the culture of shellfish, notably mussels, and seaweeds usually conducted in open waters using rafts, long lines or
stakes. The stakes are impaled in the seabed in inter-tidal areas and ropes are suspended in deeper waters from rafts or buoys.
Hatcheriesrefer to installations for housing facilities for breeding, nursing and rearing seed of fish, invertebrates or aquatic plants to fry, fingerlings
or juvenile stages.
Nurseriesrefer generally to the second phase in the rearing process of aquatic organisms and refer to small, mainly outdoor ponds and tanks.
Other Definitions
 To help classifying ambiguous practices it should be noted that:
(a) by sea-ranching is understood the harvest of enhanced capture fisheries, i.e. the raising of aquatic animals, mainly for human consumption,
under extensive production systems, in open space (oceans, lakes) where they grow using natural food supplies. These animals may be released
by national authorities and re-captured by fishermen as wild animals, either when they return to the release site e.g. salmon, or elsewhere
(seabreams, flatfishes).
(b) the production of wild-caught fish raised temporarily in holding facilities is considered as enhanced capture.