This document discusses pisciculture (fish farming). It begins with an introduction describing fish farming and hatcheries. It then describes the major categories of fish aquaculture as extensive and intensive. Specific types of fish farms are outlined, including cage systems, irrigation ditch/pond systems, composite culture, integrated recycling systems, and classic fry farming. The conclusion restates that fish farming involves raising fish commercially and that it provides an alternative to overfishing of wild fisheries due to increasing market demand.

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THEORETICAL BASES OF NATURAL SCIENCE
EDUCATION - II
ONLINE
ASSIGNMEMNT
TOPIC: PISCICULTURE
Submitted to
NasiyaM,
Sabarigiri College of
Teachers Education,
Anchal
Submitted By
Ajeesh Kumar. N
Natural Science
Reg No: 13379001
Submitted on : 29/08/2014

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CONTENT
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INTRODUCTION
MAJOR CATEGORIES
TYPES OF FISH FARMS
CONCLUSION
REFERENCE
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3-4
4-6
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7

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INTRODUCTION
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 hatchery. Worldwide, the most important fish species used in fish farming
are carp, salmon, tilapia and catfish.
There is an increasing demand for fish and fish protein, which has resulted in
widespread overfishing in wild fisheries. Fish farming offers fish marketers another
source. However, farming carnivorous fish, such as salmon, does not always reduce
pressure on wild fisheries, since carnivorous farmed fish are usually fed fishmeal and
fish oil extracted from wild forage fish. The global returns for fish farming recorded
by the FAO in 2008 totalled 33.8 million tonnes worth about $US 60 billion.
Majorcategories of fish aquaculture
There are two kinds of aquaculture: extensive aquaculture based on local
photosyntheticalproduction and intensive aquaculture, in which the fish are fed
with external food supply.
Extensive aquaculture
Limiting for growth here is the available food supply by natural sources,
commonly zooplankton feeding on pelagic algae or benthic animals, such as
crustaceans and mollusks. Tilapia species filter feed directly on phytoplankton,
which makes higher production possible. The photosynthetic production can be

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increased by fertilizing the pond water with artificial fertilizer mixtures, such as
potash, phosphorus, nitrogen and micro-elements. Because most fish are
carnivorous, they occupy a higher place in the trophic chain and therefore only a
tiny fraction of primary photosynthetic production (typically 1%) will be
converted into harvest-able fish.
Intensive aquaculture
In these kinds of systems fish production per unit of surface can be
increased at will, as long as sufficient oxygen, fresh water and food are
provided. Because of the requirement of sufficient fresh water, a massive water
purification system must be integrated in the fish farm.
SPECIFIC TYPES OF FISH FARMS
Within intensive and extensive aquaculture methods, there are numerous
specific types of fish farms; each has benefits and applications unique to its
design.
Cage system
Fish cages are placed in lakes, bayous, ponds, rivers or oceans to contain
and protect fish until they can be harvested. The method is also called "off-shore
cultivation"when the cages are placed in the sea. They can be constructed

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of a wide variety of components. Fish are stocked in cages, artificially fed, and
harvested when they reach market size.
Irrigation ditch or pond systems
These use irrigation ditches or farm ponds to raise fish. The basic
requirement is to have a ditch or pond that retains water, possibly with an
above-ground irrigation system. Using this method, one can store one's water
allotment in ponds or ditches, usually lined with bentonite clay
Composite fish culture
The Composite fish culture system is a technology developed in India by
the Indian Council of Agricultural Research in the 1970s. In this system both
local and imported fish species, a combination of five or six fish species is used
in a single fish pond. These species are selected so that they do not compete for
food among them having different types of food habitats.
Integrated recycling systems
One of the largest problems with freshwater pisciculture is that it can use
a million gallons of water per acre (about 1 m³ of water per m²) each year.
Extended water purification systems allow for the reuse (recycling) of local
water.

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Classic fry farming
This is also called a "Flow through system" Trout and other sport fish are
often raised from eggs to fry or fingerlings and then trucked to streams and
released. Normally, the fry are raised in long, shallow concrete tanks, fed with
fresh stream water. The fry receive commercial fish food in pellets. efficient as
the New Alchemists' method, it is also far simpler, and has been used for many
years to stock streams with sport fish.
CONCLUSION
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 young (juvenile)
fish into the wild for recreational fishing or to supplement a species' natural
numbers is generally referred to as a fish hatchery. The most common fish
species raised by fish farms are salmon, carp, tilapia, European seabass, catfish
and cod.
Increasing demands on wild fisheries by commercial fishing has caused
widespread overfishing. Fish farming offers an alternative solution to the
increasing market demand for fish and fish protein.

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REFERENCE
1. Based on data sourced from the FishStat database
2. < http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-
62252011000400024>
3. Fishery and Aquaculture Statistics: Aquaculture Production 2008 FAO Yearbook,
Rome.
4. FAO FishStat Plus (2012)
5. Stress and Physiology By Dr. BiIlKrise at Bozeman Technology Center, and Dr.
Gary Wedemeyer at Western Fisheries Research Center. January 2002
6. Weaver, D E (2006) Design and operations of fine media fluidized bed biofilters for
meeting oligotrophic water requirements Aquacultural Engineering 34(3): 303-310.
7. Avnimelech Y, M Kochva, et al. (1994) Development of controlled intensive
aquaculture systems with a limited water exchange and adjusted carbon to nitrogen
ratio. Israeli Journal of Aquaculture Bamidgeh 46(3): 119-131.
8. < http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-
62252011000400024>
9. Off-shore fish farming term
10. < http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-
62252011000400024>
11. < http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-
62252011000400024>
12. Strategy for transfer of composite fish culture technology
13. Pond fish farming
14. Berggren, Alexandra (2007) Aquaculture in Sweden towards a sustainable future?"
Master's Thesis, Stockholm University.
15. McLarney, William Freshwater Aquaculture: A Handbook for Small Scale Fish
Culture in North America
16. Flow-trough system term
17. "Fuss Over Farming Fish", Alaska Science Forum, June 27, 1990
18. Journal of Fish Biology 68 (2): 332-372 February 2006
19. Sea Lice and Salmon: Elevating the dialogue on the farmed-wild salmon
storyWatershed Watch Salmon Society, 2004.
20. Bravo, S. (2003). "Sea lice in Chilean salmon farms". Bull. Eur. Assoc. Fish Pathol.
23, 197–200.