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Types of aquaculture and recent advances toward farming
Fisheries and Aquaculture knowledge.
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Types of aquaculture
systems pdf
Types of aquaculture
systems ppt
Types of aquaculture pdf
Intensive aquaculture
system
Types of fish culture
system
Methods of aquaculture
Types of ponds for fish
Aquaculture
Aquaculture refers to the cultivation/ rearing/raising
of aquatic organisms for commercial, recreational or public purpose. Due to diversification
of aquaculture operations, the description of various types of aquaculture
systems may be intricate and puzzled too.
Mostly aquaculture systems are
classification on the basis of below four criteria:
a) Types of rearing
facilities (ponds, cages, raceways, pens,
enclosure, tank)
b) Water exchange (static,
open and closed).
c) Intensity of culture
(extensive, semi-intensive, intensive).
d) Fish farming methods
(monoculture and polyculture).
A) Types of rearing
facilities
1.
Ponds
Ponds
are commonly used for fish culture. In ponds water is maintained in enclosed
area by construction of dike or bund, where aquatic organisms are stocked and
grown. Rainwater, canal water and manmade bore are mostly used to fill the
ponds. Ponds differs widely in size, shape, topography, water and soil quality.
Different types of ponds are as:
1. Spawning ponds
2. Fry nursing ponds
3. Fry holding ponds
4. Storage ponds for
marketable fish
5. Overwintering ponds
2.
Raceways
Raceway
culture is simply rearing and raising of fish in running water. Water flows at
fast rates so the residence time of water in a raceway is very short usually on
the order of a few minutes instead of hours or days in ponds. Fishes are
stocked in high density in raceways so referred as high production system.
Raceways ponds are of two types.
Linear type: Ponds are arranged in
sequence. In this system the volume of water entering the pond is large and
same water is used again and again from pond to pond. The main drawback of this
system is that if disease occurs in initial ponds that may directly affect the
connected ponds.
Lateral type: Ponds are arranged in
parallel .In this type the volume of water entering the pond is small but fresh
supply of water is always guaranteed. No transfer of disease occur from pond to
pond
3.
Concrete or fiberglass tanks
Various types of tanks are
available. Based on the shapes the tanks are circular, rectangular or oval.
That water enters through nozzles in such a way that creates a rotary
circulation within the tank and discharge occur through tank center by bottom
drain surrounded by screen. Typically circular tanks is 4 m in diameter with a
water depth of 0.75 m. the inflow of water is about 4 l/sec. Maximum stocking
rates of around 25-50 kg/m3in tanks where the water is changed every 1-2 hour.
By using aeration this could be as high as 150 kg/m3.The fish in
tank culture are fed complete feed, usually 30-35% crude protein for fish over
50 g average weight.
Floating cages and pens
Floating cages:
Cage culture is rearing
of fish from juvenile stage to commercial size in a volume of water enclosed on
all sides. Cages are floating structures with a net suspended below and are
adapted to water areas which cannot be drained. Cages may be square,
rectangular or round. Culture of fishes in cage is innovative and novel concept
to explore potential of lakes, reservoirs and riverine resource’s.
Advantages of cage culture
Ø Uses existing water
bodies.
Ø Lower capital cost
compared with land based farms.
Ø It has technical
simplicity with which farms can be established or expanded.
Ø Easier stock management
and monitoring compared with pond culture.
Disadvantages of cage culture
Ø Stock vulnerable to
external water quality problems such as low DO, Algal blooms.
Ø Stock is more vulnerable
to fish eating predators such as water rates and birds.
Ø Growth rate influenced
by ambient water temperature.
Pens
Pen culture is raising of fish in volume of
water enclosed on all sides except bottom is. Pens are consider as hybrid
between pond and cages. In pens the
bottom of the lakes/ reservoirs forms the bottom of the pens.
Advantages of pen culture
available space.
Easy to harvest.
Ø The flexibility of size
and economy.
Ø Availability of natural
food.
Disadvantages of pen culture
Ø High DO and water flow
Ø Rapid spread of disease
Ø Risk of theft
Ø Conflict with multiple
use of natural water
a) Earthen ponds
(b)Raceway
(c)Concrete tanks
(d)Fiberglass tanks
(e)Floating cages
(f) Pen culture
Type of culture structure
(B) Water exchange
According to water exchange
there are two main systems
1.
Static systems
The pond with no exchange of water during the
culture period. Static pond culture is usually extensive. The major problems is
maintaining water quality. Example of static systems are traditional pond
culture
2. Open systems
The aquatic organisms
are confined / protected within the farm in a substantial amount of water (lake
or ocean) so that the water quality is maintained by natural flows and
processing. Open system uses the environment as fish farm. There is no
artificial circulation of water through or within the system.These are
intensive systems. The example of open system is Cage system.
3. Closed or
re-circulating system
Recirculating systems is
attributed by minimal connection with the surrounding environment and the
original water source. These systems have minimal exchange of water during a
production cycle, so the name ‘closed’ systems.
Advantages of closed systems
Harvesting is easy
Complete
control over water condition
Stocking density is High
Require
minimal water
Food and
drugs can be added efficiently into the system
Disadvantages of closed systems
1. High capital coast
2. Require very careful
management
3. Rapid spread of disease.
C) Intensity of culture
1. Extensive /conventional system:
Extensive aquaculture is
least managed form of fish farming i.e. little care is taken. An extensive
aquaculture system involves large ponds measuring 1 to 5 ha in area with
stocking density limited to <5000 fishes /ha. No supplement feed is given
therefore, has limited inputs to maintain fish growth and survival. Noaeration
and fertilization. Yield is poor 500kg-2 tonn/hac. Labour and investment costs
are low and this system results in minimum income.
2. Intensive system:
High intensity
aquaculture yields 15-100ton/hac or more. The stocking rate is much higher
10-50fish/m3. It is well managed form of fish farming. Fish are fed with complete
diets (protein rich diets). BMP is
undertaken to maintain optimum water quality parameters.
Intensive systems may be
in:
• ponds {shrimp ( tropical
/subtropical regions)}
• Raceways {trout species
(temperate regions)}
(D) Fish farming methods
1. Monoculture
Monoculture is a fish
production system in which one species is reared in culture system. Monoculture
of high value and market oriented fish in intensive system is common practice. The
major fish species cultivated in monoculture are trout, tilapia, carpetc.
2.
Polyculture
Polyculture is a fish production
system in which two or more different fish species are farmed. Species
successfully stocked together are differ in their feeding habits and occupy
different trophic niches in the pond. Common fish species in India polyculture
are catla, rohu, mrigal, silver carp, grass carp and common carps and this system is
sometimes also called as composite fish culture, Polyculture of common carp with all-male
tilapia, and sometimes also with silver carp commonly practiced in Egypt.
Recirculatory aquaculture systems (RAS)
The key obstacles for further growth ofaquaculture
systems are lack of space and new sites (due to competition with other uses and
interests), restricted fresh water availability, and concerns over pollution.
The Recirculating Aquaculture Systems (RAS) has been encouraged as one of the
possible solutions and opportunities to further expansion of aquaculture. It is
environmentally friendly way of producing fish at a commercial level.
The
nutrients from the farmed fish can be used as fertilizer on agricultural
farming land or for biogas production. Recirculating Aquaculture System may
produce up to 500 MT of fish per year in same area.Recirculatory aquaculture
circumscribe the system used for the rearing of aquatic animals where 90% or
above of water is reconditioned and circulated. It is an intensive land-based
aquaculture system carried either in open air or indoors.
RAS COMPONENTS
1)
Fish Tanks
The
tanks must meet the requirements of fishboth in terms of design andenvironment.5000-10000
liters non-corrosive tank (plastic or fiberglass) are most commonly used.
2)
Mechanical filter
Mechanical
filter is used to remove the suspended solids from the system. These solids,
primarily faecal matter, need to be removed in order to maintain water quality.
Variouskinds of rotating screens such a drum filter, disc filter, rotating
belt, horizontally disc are used
Foam fractioner
Foam
fractionation is used to remove and control the build-up of fine suspended
solids and dissolved organic solids which cannot be removed by traditional
filter.
3)
Bio filter
The
bio filter is a biological process carried out by bacteria.
i) Heterotrophic bacteriathat oxidise the organic matter by consuming
oxygen andproduces CO2, ammonia, and sludge.
ii) Nitrification which is conducted by nitrifying bacteria, removing
ammonia from water byturning it into nitrite and nitrate.
Bio filters used in recirculation systems can be
designed as
i) Fixed bed filters -the plastic media is fixed and not moving while
the water flowsthrough it.
ii) Moving bed filters – the plastic media is moving around in the
water inside the bio filter by a current created by pumping in air.
4)
Degassing/aeration/stripping
Method
of removal of CO2, free Nitrogen and H2S from system water flow which are
harmful to fish. In a degasser, the water flows through a distribution plate
with holes, and is then flushed down through a fixed bed of plastic media
stacked in columns.
5)
Oxygenation
In
RAS system DO must be monitor and adjusted to saturation level. Aeration can
bring the saturation level up to above 90%.
7)
Ultraviolet light
UV
disinfection is used to destroy DNA in biological organisms. It is used to kill Bacteria,
viruses, fungi and small parasites.
8)
Ozone
Ozone
is used to destroy unwanted organisms too small to be caught by the mechanical
filters. In ozone treatment technology micro particles are broken down into
molecular structures that will bind together again and form larger particles so
the microscopic suspended solids too small to be caught can be removed from the
system. This technology is referred as water polishing.
SPECIES SUITABLE FOR RAS
Arctic char (Salvelinus alpinus), Atlantic
salmon, smolt (Salmo salar), Eel (Anguilla anguilla), Grouper (Epinephelus
spp.), Barramundi/ Asian Seabass/Bhetki (Lates calcarifer), European Seabass/
Seabream (Dicentrarchus labrax / Sparus aurata), Sturgeon (Acipenser spp.),
Turbot (Scophthalmus maximus), Whiteleg Shrimp (Penaeus vannamei), Yellowtail
Amberjack (Seriola lalandi), Cobia (Rachycentron canadum), Silver/Indian Pompano (Trichinotus Blochii/
Trichinotus mookalee), Tilapia (Oreochromis niloticus), Pearl spot/Karimeen
(Etroplus suratensis), Pangasius (Pangasianodon hypophthalmus), Rainbow Trout
(Oncorhynchus mykiss), especially in Hilly/cold water Region.
Advantages of RAS
Bio-secure:
Closed indoor facility, Very low water
requirement, Entry and exit of
Pathogensis restricted Economy:
Less cost than water exchange system Predictable/Low
risk: Constant water parameters (no water exchange), hence less stress to animals,
Protected from external entry of pathogens, Isolated from weather related water
quality fluctuations.
Antibiotic free:
Bacterial load under control due to following
factors, higher level of Biosecurity, Reduced levels of suspended solids, Low
stress condition, low Ammonia/nitrite, constant DO/Ph/Alkalinity/Temperature,
Use of Probiotics, Ozone
Eco-friendly: Zero usage of
hazardous chemicals, Very low water discharge, lower power consumption, lesser
space required due to higher densities, Release of pathogens into the
environment controlled due to better biosecurity.
Disadvantages
Ø Constant uninterrupted
power supply is required if electric power fails than backup of electricity is
required.
Ø Capital cost of starting
a recirculating aquaculture system is high as compared to ponds and raceways.
Ø Good water source is
required preferably borehole
Ø Good fish feed quality,
preferably high protein and fat extruded diets with high digestibility
Ø Technically skilled
staff able to work in a medium tech environment
Application of
aquaculture in food production
Food security is the principal path for
development of the socioeconomic status in any country in the world to overcome
malnutrition.
The present scenario suggest that under developed countries are
still facing problem of malnutrition.
The human nutrition deficiencies thus focus
on the importance of animal protein in their regular diet. Fisheries plays a significant
role in overcoming this problem. Thefishes are the highly nutritious and
cheapest protein sources, and a valuable supplement in diets by providing
essential vitamins, proteins, micronutrients, and minerals, for the
economically backward people.
Aquaculture is playing an essential role in the
developing countries for development of national economic and global food supply.
The aquaculture has the continuous potentiality for developmental goals for the
country economy and better human welfare.Fish provides about 16% of the animal
protein consumed by humans and are a valuable source of minerals and essential
fatty acids.
Fish is the primary source of omega-3 fatty acids in the human
diet.Omega-3 fatty acids are important nutrients for normal brain and eye
development of infants, and have preventative roles in a number of human
illnesses example cardiovascular disease, lupus, depression, and other mental
illnesses. Asia predominates both capture fisheries and aquaculture production,
whereas India is second largest aquaculture producer in world.
The present fish
production of India is 13.42 mmt out of which inland share is 65 %( 9.71mmt) and
marine share is 35 %( 3.71mmt).Indian aquaculture is dominated by major carps
which accounts for 80%.
Aquaculture vs Agriculture
Aquaculture is the
cultivation of aquatic products such as aquatic plants, fish and other aquatic
organisms especially for human consumption. Agriculture is the cultivation of
the Plants and their harvesting, and the rearing, management and husbandry of livestock.
Types of aquaculture systems ppt
Types of aquaculture pdf
Intensive aquaculture system
Types of fish culture system
Methods of aquaculture
Types of ponds for fish
Aatira Farooq, M.FSC first year division
aquaculture, CIFE Mumbai and Dr. Mohd Ashraf Rather, Assistant Professor, SKUAST-K