Technology We Use Pond Fish Farming Integrated Fish Farming Fish Seed Production Fresh Water Prawn Culture Pond Fish Farming Fish Farming is an age old activity and in practice from ancient times. The concept of composite fish culture was developed by ICAR in late seventies under a coordinated composite fish culture project. This comprises the culture of 3 indigenous species of fish viz. rohu, catla and mrigal and 3 exotic fish i.e silver carp, grass carp and common carp, keeping in view their different food habit and habitat. This practice has been very well accepted by the farmers of Haryana as its cultural practices are analogous to agriculture. The successful fish culture requires ploughing of pond, addition of manure, stocking of fish seed; eradication of unwanted aquatic plants and animals, watering the pond; harvesting the crop and marketing of the produce. The fish culture technologies and economics are simple and understandable to the fish farmers. To produce one kilogram fish, the requirements are:- - one cubic meter water - three number fish seed - one kilogram manure and 100 gm inorganic fertilizer - one kilogram supplementary feed - and one year time Cost of production of fish is Rs. 15/kg and the sale price on an average is Rs.30/- per kg. A net profit of Rs.61,000 per hectare
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Technology We Use
Pond Fish Farming Integrated Fish Farming Fish Seed Production Fresh Water Prawn Culture
Pond Fish Farming
Fish Farming is an age old activity and in practice from ancient times. The concept of composite fish culture was developed by ICAR in late seventies under a coordinated composite fish culture project. This comprises the culture of 3 indigenous species of fish viz. rohu, catla and mrigal and 3 exotic fish i.e silver carp, grass carp and common carp, keeping in view their different food habit and habitat. This practice has been very well accepted by the farmers of Haryana as its cultural practices are analogous to agriculture.
The successful fish culture requires ploughing of pond, addition of manure, stocking of fish seed; eradication of unwanted aquatic plants and animals, watering the pond; harvesting the crop and marketing of the produce. The fish culture technologies and economics are simple and understandable to the fish farmers. To produce one kilogram fish, the requirements are:-
- one cubic meter water- three number fish seed- one kilogram manure and 100 gm inorganic fertilizer- one kilogram supplementary feed- and one year time
Cost of production of fish is Rs. 15/kg and the sale price on an average is Rs.30/- per kg. A net profit of Rs.61,000 per hectare per year is obtained, The pond fish culture practice is being adopted by farmers in all the districts of the state. There are 8,065 fish culture units having an area of more than 12,883 hectares in the state. The ownership of these ponds vested with the panchayats. Panchayat leases out their ponds to the farmer's for fish farming. These village ponds are generally visited by cattle for drinking water. The cattle refuse dung and urine in the pond. The organic waste released by the cattle are recycled into manure and help in the production of plankton which is basic food for fish. Thus all the village fish culture ponds in Haryana are the good example of fish cum cattle farming. With the passage of time, the farmers have modified the technologies as per the need. Generally Rohu,catla, mrigal and common carp are used for culture. The stocking density is kept at 20000 fish seed per hectare. Farmers have adopted the technique of multiple harvesting. which give better returns. Govt. provides 20% subsidy to general category while 25% to scheduled caste fish farmers for excavation of new pond/ renovation of old pond and fisheries inputs.
Economics of Fish Farminga) Expenditure
Construction of Pond,Water Supply Channel, Installation of Tubewell/Renovation/Lease Amount
Electricity & Water charges Cost of 250Kg Lime 2000 Fish Seeds 100 Quntals Organic Fertilizer 250 KG Urea 500 KG Single Super Phosphate Supplimentry feed Medicine, Fishing, Watch & Ward
TOTAL EXPENDITURE
b) Income Sale of 4200 KG Fish
c) Net Income (B-A)
Note:- The Income may vary on the productivity and market price of a pond
Integrated Fish Farming
Fisheries Department provides technical and financial assistance for integrated fish farming. The Integrated fish farming practices utilize the waste from different components of thc 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. The possible'integrated farming systems are given below:
a) Fish cum Agriculture System b) Fish cum Animal System
Fish cum Paddy CultureFish cum water chestnutFish cum Pappaya
Fish Cum DairyFish cum Pig FarmingFish cum Rabbit Farming
Fish cum MulberryFish cum Mushroom
Fish cum PoultryFish cum Duck Farming
Fish cum Dairy
Fish-cum-Dairy Farming is considered as an excellent innovation for the use of organic wastes. Use of cow/buffalo manure in fish farming is a commonly prevailing practice. On an average, one cow/buffalo excretes 12000 kg of dung and 8000 litre urine per year. The cattle faeces and urine are beneficial to the filter-feeding and omnivorous fishes. On an average, 3-4 cows/buffaloes can provide sufficient manure to fertilize one hectare pond. In this system, farmer gets milk, fish and calf as well, which increases revenue and reduces input costs. The system gives a net profit of Rs.1,14,000/- per year from one hectare land.
Economics of Fish cum Dairya) Expenditure Rs.
Construction of Pond,Water Supply Channel, Installation of Tubewell/Renovation/Lease Amount
20000
Electricity & Water charges 10000 2000 Fish Seeds 1500 Construction of Shed for Animals (Rs. 80000/- for 10 years) 8000 Purchase of 5 Murrah Buffalo (Rs 20000/- for 5 years) 20000 13000 Kg Animal Feed 78000 Medicine for Animals & Fishes 2000 Labour Charges 20000
TOTAL EXPENDITURE 159500
b) Income Sale of 4200 KG Fish 126000 Sale of 10000 Ltr. Milk 140000 Sale of 5 Young ones of Buffalo 7500
c) Net Income (B-A) 114000
Note:- The Income may vary on the productivity and market price of a pond
Fish cum Piggery
The pig dung as an organic manure for fish culture has certain advantages over cattle manure. The waste produced by 20-30 pigs is equivalent to one ton of Ammonium Sulphate applied to the soil.The pigs are fed largely on kitchen waste, aquatic plants and crop byproducts. At present, fish-pig integration is practiced in all the developing countries. Several exotic breeds of pigs have been introduced in the country to augment pork production. The popular races are the white
Yorkshire,Berkshire and Landrace. The pigsties should provide adequate protection from adverse weather conditions. A run or courtyard adjacent to the pig house is essential. The size of the pig house depends on the number of pigs to be reared. Floor space is provided @3-4 m2 for every pig weighing 70-90 kg.The pigsties are built mostly at the pond sites and even over the ponds. The washings from the pigsties containing dung and urine are either channelised directly into the pond or composed before its application. The boars, sows and finishing stocks are housed separately. Maize, groundnut, wheat- bran, fishmeal, mineral mixture provide base for concentrated feed mixture. In advanced countries,garbage is widely used to economize pork production and provided after pre-cooking when pig dung is applied to a pond. It enhances the biological productivity of the pond. A portion of dung is directly consumed by some fish also. The excreta voided by 35-40 pigs is found adequate to fertilize one hectare of water. Integrated fish-pig farming is a viable and feasible scientific approach to augment fish production at low cost. The net income in this integration from one hectare of pond is Rs.l,39,000/-.
Fish-cum-Poultry
The droppings of birds in this system are utilized to fertilize the pond. Poultry litter recycled into fish pond produces 4500-5000 kg fish per hectare per year. Broiler production provides good and immediate return to the farmers. Success in production depends mainly on the efficiency of the farmer, experience, aptitude and ability, in the management of the flock. This involves procurement of better brood stock, housing, brooding equipment, feeders, water trays and management practices,which also includes prevention and control of diseases. The poultry litter is applied to the pond in daily doses at a rate of 40-50 kg per hectare. The application of litter may be deferred during the days when algal blooms appear in the ponds. One adult chicken produces about 25 kg of compost poultry manure in one year. 500-600 birds would provide sufficient manure for fertilization of one hectare of fish pond. Farmer can get a net income of Rs.l,37,157/- from one hectare of pond in one year. Govt. provides financial assistance to the farmers for promoting this system.
Economics of Fish-cum-Poultrya) Expenditure Rs.
1Construction of Pond,Water Supply Channel, Installation of Tubewell/Renovation/Lease Amount
20000
2Electricity & Water charges 100003Construction of Poultry Shed ( Rs.80000/- for 10 years) 8000
4550 Chiks 2750522500Kg Poultry Feed 900006Medicines for Fish & Poultry 50007Fishing, Sale of Poultry Birds & Labour 20000
TOTAL EXPENDITURE 157250
b) Income Sale of 4200 KG Fish 126000 Sale of 118750 Eggs 148437 Sale of 500 KG Poultry Birds 20000 Total Income 294437
c) Net Income(B-A) 137157
Note:- The Income may vary on the productivity and market price of a pond
Fish cum Duck farming
Fish cum Duck Integration is most common in the developing countries. This type of integration is not popular in northern states of India. Ducks are of several types and Khaki Campbell is recommended for fish-cum-duck integration Fishpond being a semi-closed biological system with several aquatic animals and plants provides an excellent disease-free environment for the ducks. In turn, ducks consume juvenile frogs, tadpoles and dragonfly etc. there by making a safe environment for fish. Duck droppings go directly into the pond, which in turn provide essential nutrients such as carbon, nitrogen and phosphorus that stimulate growth of natural food organisms. Ducks also help in aerating the pond water, alongwith bottom racking. About 300 ducks are enough to fertilize a pond of one hectare. The system results in a net income of Rs. 77500/- per year per hectare. However, due to difficulty in marketing of eggs and duck meat, the system is not very common in the state.
Fish cum Horticulture
Integration of fish cum flowers, fruit plants, vegetables and mushroom can be takcn up. The pond humus is used as manure for plantation. Pond water can be used for plants which is rich in nutrients, thereby decrease the cost on inorganic fertilizers. The pond dykes are used for the plantation. The culture practice can be taken up as per suitablity to the location i.e. location specific. The economics also varies and depends on the type of plantation.
Fish Seed Production
Quality fish seed is the pre-requisite for successful fish farming. Department is using the techniques
of hypophysation for the production of fish seed of culturable varieties. The breeding season of common carp fish in Haryana is February-March every year where as the breeding season of other species is monsoon season. Brood stock of required fish are maintained and sex-wise segreggate is made two month before. The pairing is made and injected with calculated dose of pituitary gland or ovaprim, ovatide or ovpal is injected to male and female fish. Within the 6-8 hours of the injection eggs from female and sperm from male are released in the water. The fertilizer is external. Normally one kg fish releases about one lakh eggs. The hatchlings are known as spawn. The spawn is reared in the nursary pond. After 15 days, the spawn attains the size of 25 mm and ready for stocking in the pond. More than 50 lakh fry can be produced per hectare fish seed farm in both the seasons in a year. The income from sale of fish seed is Rs. 3.25 lakh approx. per year @ Rs. 6500 per lakh. Fisheries department provides technical and financial assistance for setting up of ecotype hatchery and fish seed rearing units.
Economics of Fish Seed Productiona) Expenditure Rs.
Construction of Eco Hatchery, Ponds, Water Supply Channel, Installation of Tubewell ( Rs/- 8 Lakh for 10 Years)
80000
Electricity & Water charges 50000 Cost of 250 Kg Lime 750 1500 Kg Brood Stock 60000 100 Quntals Organic Fertilizer 5000 250 KG Urea 1250 500 KG Single Super Phosphate 1500 Supplimentry feed 50000 Injecting Material, Medicine, Fishing, Watch & Ward 25000
TOTAL EXPENDITURE 273500
b) Income Sale of 500 Lac. Fish Spawn 200000 Sale of 50 Lac. Fish Fry 325000 Sale of Spent Brood Stock 20000 TOTAL 545000
c) Net Income (B-A) 271500
Note:- The Income may vary on the productivity and market price of a pond
Location of Fishery Seed FarmsGovernment Farms
Sr. No. Location of the Farm Total Land Area (in hectares)
Total WaterArea (in hectares)
1 Jansui (Ambala) 1.00 0.94
2 Sidpura (Karnal 3.00 1.98
3 Jyotisar (Kurukshetra) 14.60 6.93
4 Rohat (Sonepat) 3.00 1.42
5 Damadama (Gurgaon) 6.61 1.25
6 Badkhal (Faridabad) 6.50 3.50
7 Lisana (Rewari) 4.81 1.93
8 Sampla (Rohtak) 6.44 3.24
9 Kakroi (Sonepat) 4.52 2.31
10 Jhajjar 4.00 1.42
11 Tohana (Fatehabad) 4.20 1.60
12 Hisar 21.80 7.17
13 Dadupur (YamunaNagar) 0.60 0.08
14 Mundri (Kaithal) 2.00 0.90
15 Ottu (Sirsa) 2.80 1.30
Private Farms
Sr. No. Location of the Farm Total Land Area(in hectares)
Total Water Area(in hectares)
1 Dherdu (Kaithal) 2.00 1.80
2 Bhutana ( Karnal) 10.00 8.00
3 Mandheri (Kurukshetra) 10.00 6.40
4 Laloda (Fatehabad) 3.50 1.80
5 Gochi (Jhajjar) 1.00 0.60
6 Dabra (Hisar) 4.50 3.45
7 Satrod( Hisar) 4.00 3.25
8 Julani-Khera (Kaithal) 1.50 0.80
9 Mauli (Panchkula) 1.00 0.60
10 Majra (Jhajjar) 1.00 0.60
11 Gagan Kheri (Hisar) 1.60 1.20
Fresh Water Prawn Farming
There are more than 100 species of Freshwater prawn found in the world. There are more than 25 species are found in India. Out of these 10 species are important from commercial point of view. Out of them Macrobrachium rosenbengii is the main species which is used in culture practices. This is also know as giant prawn. This can be cultured in both fresh water as well as brackish water. It is fast growing animal and farmers can culture profitably. It contains 20-22 percent animal protein and has less cholestrol. It has essential amino-acids and mineral which are very important for human beings. In culture
practices, the freshwater prawn has two stages i.e Nursery Pond and Growout Pond. Fresh water prawn is stocked in nursery pond for 45-60 days then it is shifted to grow-out ponds. The ponds are prepared by using manure and fertilizers. The stocking density in nursery pond is kept 2.00-2.50 lakh per hectare. Feed is provided 5 times @ 8-10 gm per kg body weight at initial stage. Check trays are used to regulate the feeding. Prawn crop becomes ready for sale with 7-8 months. The expenditure about Rs. 1.50 lakh per hectare and income is Rs. 2.50 lakh. Thus net income is Rs. 1.00 lakh per hectare in 8 months.
Economics of Prawn Culture (Per Hect.)a) Capital Investment Rs.
Construction of Pond,Water Supply Channel, Installation of Tubewell/Renovation/Lease Amount
200000
b) Recurring Expenditure Rs.
Electricity & Diesel 10000 Cost of 250Kg Lime 750 20 KG Urea 160 50 KG Single Super Phosphate 250 Seed Cost of 50000 Seeds 27500 Artificial Feeding , Palleted Feed 2000 kg 44000 Vitamins, minerals & medicines 1000 Expenditure on marketing, harvesting and watch & wild 10000
EXPENDITURE 93660
c) Economics Expenditure on Capital Investment @16% 320000 Deprecation on Capital Investment @10% 20000 Recurring Expenditure 93660
TOTAL EXPENDITURE 145660
d) Income Sale of 1000 kg Prawn @ Rs.250/- per kg 250000
e) Net Income ( Income - Total Expenditure) 104340 Note:- Theabpve economics may change as per productivity of pond and market prices of the
PRAWN
2ND PARTFresh Water Fish FarmingFRIDAY, 01 MAY 2009 00:00 AMBRISH JHA OPPORTUNITIES - AGRICULTURE & RURAL
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Fish culture is practiced in less than 30 percent of the total areas available. This has a potential to create huge job
opportunities, provided fish cultivation is done on a scientific basis
India is a large producer of inland fish, ranking next only to Japan.
With an abundance of freshwater resources, India has still not been able to tap even 30% of the potential area for
inland fish production. Many entrepreneurs have, however, chosen to take this occupation on commercial scale. This
is best manifested in Andhra Pradesh, which with 10,56,000 tons of inland fish production in 2007-08 ranked next
only to West Bengal, which is far more endowed with water resources. Andhra Pradesh has emerged among the
ranks encouraging farmers to form cooperatives to take up farming in ponds around Kolleru lake.
Both the central and state governments have come up with schemes to help the cause of the farmers.
Rate
Fish culture in ponds
Out of the total inland fish production of over 3.6
million metric tons, more than 60% is contributed
by fish culture in ponds and reservoirs. The
average productivity from ponds on the national
level is around 2,500 kg/ha/year, though in Andhra
Pradesh and Haryana it is more than 5,000
kg/ha/year, while in some other states like Bihar
and UP it is anywhere between 1,500 and 2,500
kg/ha/year. Fish culture is adopted by all kinds of
farmers – small and marginal ones, relatively
larger farmers and those who do it on commercial
scale. Sizes of ponds also depend on how affluent the farmers are. Ponds less than 100 square meters in area prove
unsustainable, while those above 1 hectare are expensive for small players. Many farmers in Tamil Nadu, for
instance, use ponds of sizes 30 feet by 30 feet to make their living. On the other hand, a water spread of anything
less than 10 hectares in Andhra Pradesh is treated as a pond.
Ponds can be perennial or seasonal. While
seasonal ponds can be used for short-term fish
culture, provided they retain water for at least four to
five months, perennial ponds are suited for fish
culture on a larger scale. Since water dries up in a
few months, seasonal ponds are easy to harvest
fish. Any perennial pond retaining water depth of 2
meters can be used for fish culture. Dr Gopinath
Sai, executive director (technical), National
Fisheries Development Board (NFDB), says a water
level of 3 to 4 feet is preferable, even in summer.
Fish farming can be practiced on scientific lines in
perennial ponds only, though seasonal ponds can be used to cultivate fry. Though different pond shapes are being
adopted by farmers, rectangular ponds are easier to work on, Sai points out. He says freshwater fish culture is a very
profitable business provided farmers take up this on scientific lines. Quality of soil, water, fish seed and fish food
needs to be of reasonably good quality to have better yields. The soil for ponds should be able to retain water, and
hence clayey soil is preferable. The water should not be acidic in nature, nor should it be highly alkaline. It should be
treated with appropriate quantity of lime. Provision for inlets and outlets should be made in ponds, as Sai and C
However, Ranjit, a fish farmer from Bihar, now into fish culture and retail trading in Delhi, says, “We do not know
about any inlets or outlets in our ponds but we manage a good catch despite that.”
Ponds are not the natural habitat of fish; it is rivers and canals. This makes it imperative for farmers to provide food
from outside and also create a desirable environment. Fish food is provided in the form of oil cakes and rice bran. But
to create conditions suitable for other organisms to grow inside ponds, fertilizers need to be applied. A combination of
organic and inorganic fertilizers is ideal, Ratnamachari says. Their application depends on the soil quality to a great
extent.
Economics of Fish Culture in Ponds (for 1ha, up to 1m excavation)
Items Amount (in Rs)
Fish Species Bred in Ponds
3.6 million metric tons - Annual produce of inland fish in India, 60 % - come from fish culture in ponds and reservoirs, 60 species - cultivated in different parts of India in ponds or reservoirs, 80% - contribution of carps from fish culture
Major species cultured in ponds
Indian major carps – rohu, catla and mrigalExotic carps – silver carp, grass carp, common carpCatfish – magur, ari, singhi.Tilapia – also known as kowai.Trout – golden mahseer, silver mahseer, silver grey mahseer and black mahseer.
A. Fixed costs
Excavation of one hectare land (10,000 cubic meter land to the depth of one meter @Rs 20/cubic meter
200000
Construction of inlet and outlet to ponds 40000
Equipment and gears 15000
Total fixed costs 255000
B. Recurring costs
Lime 500 kg @ Rs 7/kg 3500
Fingerlings 5,000 in number @ Rs 600 for every 1000 3000
4TH PARTFish FarmingFish farming is the principal form of aquaculture, while other methods may fall under mariculture. It involves raising fish commercially in tanks or enclosures, usually for food. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Fish species raised by fish farms include salmon, catfish, tilapia, cod, carp, trout and others.
Increasing demands on wild fisheries by commercial fishing operations have caused widespread overfishing. Fish farming offers an alternative solution to the increasing market demand for fish and fish protein.
Major categories of Fish FarmsBasically there are two kinds of aquaculture: extensive aquaculture based on local photosynthetical production and intensive aquaculture, in which the fish are fed with external food supply. The management of these two kinds of aquaculture systems are completely different.
Extensive (Pond) AquacultureLimiting for fish growth here is the available food supply by natural sources, commonly zooplankton feeding on pelagic algae or benthic animals, such as certain crustaceans and mollusks. Tilapia species filter feed directly on phytoplankton, which makes higher production possible. The photosynthetical production can be increased by fertilizing the pond water with artificial fertilizer mixtures, such as potash, phosphorus, nitrogen and microelements. 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 harvestable fish.
As a result, without additional feeding the fish harvest will not exceed 200 kilograms of fish per hectare per year, equivalent to 1% of the gross photosynthetic production.
A second point of concern is the risk of algal blooms. When temperatures, nutrient supply and available sunlight are optimal for algal growth, algae multiply their biomass at an exponential rate, eventually leading to an exhaustion of available nutrients and a
subsequent die-off. The decaying algal biomass will deplete the oxygen in the pond water and pollute it with organic and inorganic solvents (such as ammonium ions), which can (and frequently do) lead to massive loss of fish.
In order to tap all available food sources in the pond, the aquaculturist will choose fish species which occupy different places in the pond ecosystem, e.g., a filter algae feeder such as tilapia, a benthic feeder such as carp or catfish and a zooplankton feeder (various carps) or submerged weeds feeder such as grass carp.
Intensive (Closed-Circulation) AquacultureIn this kind 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. A clever way to achieve this is the combination of hydroponic horticulture and water treatment, see below. The exception to this rule are cages which are placed in a river or sea, which supplements the fish crop with sufficient fresh water. Environmentalists object to this practice.
The cost of inputs per unit of fish weight is higher than in extensive farming, especially because of the high cost of fish food, which must contain a much higher level of protein (up to 60%) than, e.g., cattle food and a balanced amino acid composition as well. This frequently is offset by the lower land costs and the higher productions which can be obtained due to the high level of input control.
Essential here is aeration of the water, as fish need a sufficient oxygen level for growth. This is achieved by bubbling, cascade flow or liquid oxygen. Catfish, Clarias ssp. can breathe atmospheric air and can tolerate much higher levels of pollutants than, e.g., trout or salmon, which makes aeration and water purification less necessary and makes Clarias species especially suited for intensive fish production. In some Clarias farms about 10% of the water volume can consist of fish biomass.
Especially when fish densities are high, the risk of infections by parasites like fish lice, fungi (Saprolegnia ssp.), intestinal worms (such as nematodes or trematodes), bacteria (e.g., Yersinia ssp, Pseudomonas ssp.), and protozoa (such as Dinoflagellates) is much higher than in animal husbandry because of the ease in which pathogens can invade the fish body (e.g. by the gills). The same holds for water pollution or depletion of oxygen in the water, which can ruin a fish crop within minutes. This means, intensive aquaculture requires tight monitoring and a high level of expertise of the fish farmer.
Intensive aquaculture was developed as a source for food fish. Raising ornamental cold water fish (goldfish or koi), although theoretically much more profitable due to the higher income per weight of fish produced, has never been successfully carried out till very recently. The increased incidences of dangerous viral diseases of koi Carp, together with the high value of the fish has led to initiatives in closed system koi breeding and growing in a number of countries. Today there are a few commercially successful intensive koi growing facilities in the UK, Germany and Israel.
Some producers have adapted their intensive systems and made them totally biosecure in an effort to provide consumers with fish that do not carry dormant forms of viruses and diseases.
Specific Types of Fish FarmsWithin intensive and extensive aquaculture methods there are numerous specific types of fish farms, each has benefits and applications unique to its design.
Integrated Recycling SystemsOne of the largest problems with freshwater aquaculture 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.
The largest-scale pure fish farms use a system derived (admittedly much refined) from the New Alchemists in the 1970s. Basically, large plastic fish tanks are placed in a greenhouse. A hydroponic bed is placed near, above or between them. When tilapia are raised in the tanks, they are able to eat algae, which naturally grows in the tanks when the tanks are properly fertilized.
The tank water is slowly circulated to the hydroponic beds where the tilapia waste feeds a commercial plant crops. Carefully cultured microorganisms in the hydroponic bed convert ammonia to nitrates, and the plants are fertilized by the nitrates and phosphates. Other wastes are strained out by the hydroponic media, which doubles as an aerated pebble-bed filter.
This system, properly tuned, produces more edible protein per unit area than any other. A wide variety of plants can grow well in the hydroponic beds. Most growers concentrate on herbs (e.g. parsley and basil), which command premium prices in small quantities all year long. The most common customers are restaurant wholesalers.Since the system lives in a greenhouse, it adapts to almost all temperate climates, and may also adapt to tropical climates.
The main environmental impact is discharge of water that must be salted to maintain the fishes' electrolyte balance. Current growers use a variety of proprietary tricks to keep fish healthy, reducing their expenses for salt and waste water discharge permits. Some veterinary authorities speculate that ultraviolet ozone disinfectant systems (widely used for ornamental fish) may play a prominent part in keeping the Tilapia healthy with recirculated water.A number of large, well-capitalized ventures in this area have failed. Managing both the biology and markets is complicated.
Irrigation Ditch or Pond SystemsThese 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 (many irrigation systems use buried pipes with headers. Using this method, one can store one's water allotment in ponds or ditches, usually lined with bentonite clay. In small systems the fish are often fed commercial fish food, and their waste products can help fertilize the fields. In larger ponds, the pond grows water plants and algae as fish food. Some of the most successful ponds grow introduced strains of plants, as well as introduced strains of fish.
Control of water quality is crucial. Fertilizing, clarifying and pH control of the water can increase yields substantially, as long as eutrophication is prevented and oxygen levels stay high.Yields can be low if the fish grow ill from electrolyte stress.
Cage SystemFish cages are synthetic fiber cages kept in existing water resources to contain and protect fish until they can be harvested. A few advantages of fish farming with cages are that many types of water can be used (rivers, lakes, filled quarries, etc.), many types of fish can be raised, and fish farming can co-exist with sport fishing and other water uses. However, fish are vulnerable to disease, poaching, and low levels of dissolved oxygen. In general, pond systems are easier to manage, and simpler to start.
In regards to genetic modification of fish, cage systems can be detrimental to the environment because the genetically modified fish can easily escape into the wild destroying
other breeds of fish and upsetting the balance of nature.
Classic Fry FarmingTrout 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. While not as efficient as the New Alchemists' method, it is also far simpler, and has been used for many years to stock streams with sport fish. European eel (Anguilla anguilla) aquaculturalists procure a limited supply of glass eels, juvenile stages of the European eel which swim north from the Sargasso Sea breeding grounds, for their farms. The European eel is threatened with extinction because of the excessive catch of glass eels by Spanish fishermen and overfishing of adult eels in, e.g., the Dutch IJsselmeer, Netherlands. As per 2005, no one has managed to breed the European eel in captivity.
CriticismsThe issue of feeds in fish farming has been a controversial one. While vegetarian fish like tilapia require no meat products in their diets, carnivorous fish like salmon depend on fish feed of which a portion is usually derived from wild caught fish. Attempts to replace fish meal and oil in fish feed with vegetable sources of protein like soybeans are underway but have yet to be successful[citation needed].
Secondly, farmed fish are kept in concentrations never seen in the wild (e.g. 50,000 fish in a two-acre area) with each fish occupying less room than the average bathtub. This can cause several forms of pollution. Packed tightly, fish rub against each other and the sides of their cages, damaging their fins and tails and becoming sickened with various diseases and infections.
However, fish tend also to be animals that aggregate into large schools at high density. Most successful aquaculture species are schooling species, which do not have social problems at high density. Aquaculturists tend to feel that operating a rearing system above its design capacity or above the social density limit of the fish will result in decreased growth rate and FCR (food conversion ratio - kg dry feed/kg of fish produced), which will result in increased cost and risk of health problems along with a decrease in profits. Stressing the animals is not desirable, but the concept of and measurement of stress must be viewed from the perspective of the animal using the scientific method.
Some species of sea lice have been noted to target farmed coho and Atlantic salmon.Such parasites may have an effect on nearby wild fish. For these reasons, some aquaculture operators frequently use strong antibiotic drugs to keep the fish alive (but many fish still die prematurely at rates of up to 30%). In some cases, these drugs have entered the environment. Additionally, the residual presence of these drugs in human food products has become controversial.
The lice and pathogen problems of the 1990's facilitated the development of current treatment methods for sea lice and pathogens. These developments reduced the stress from parasite/pathogen problems. However, being in an ocean environment, the transfer of disease organisms from the wild fish to the aquaculture fish is an ever-present risk factor.
The very large number of fish kept long-term in a single location produces a significant amount of condensed feces, often contaminated with drugs, which again affect local waterways. However, these effects are very local to the actual fish farm site and are minimal to non-measurable in high current sites.
Other potential problems faced by aquaculturists are the obtaining of various permits and water-use rights, profitability, concerns about invasive species and genetic engineering
depending on what species are involved, and interaction with the UN Law of the Sea Treaty.
Environmentally Friendly MethodsAn alternative to open ocean cage aquaculture, one in which the the risk of environmental damage is substantially eliminated is through the use of a recirculating aquaculture system (RAS). A RAS is a series of culture tanks and filters where water is continuously recycled. To prevent the deterioration of water quality, the water is treated mechanically through the removal of particulate matter and biologically through the conversion of harmful accumulated chemicals into nontoxic ones.
Other treatments such as UV sterilization, ozonation, and oxygen injection are also utilized to maintain optimal water quality. Through this system, many of the environmental drawbacks of aquaculture are minimized including escaped fish, water usage, and the introduction of harmful pollutants. The practices also increase efficiency of feed utilisation and growth by providing optimal water quality parameters (Timmons et al., 2002; Piedrahita, 2003).
One of the drawbacks to recirculating aquaculture systems is water exchange. However, the rate of water exchange can be reduced through aquaponics, such as the incorporation of hydroponically grown plants (Corpron and Armstrong, 1983) and denitrification (Klas et al., 2006). Both methods reduce the amount of nitrate in the water, and can potentially eliminate the need for water exchanges, closing the aquaculture system from the environment. The amount of interaction between the aquaculture system and the environment can be measured through the cumulative feed burden (CFB kg/M3), which measures the amount of feed that goes into the RAS relative to the amount of water and waste discharged.
Because of its high capital and operating costs, RAS has generally been restricted to practices such as broodstock maturation, larval rearing, fingerling production, research animal production, SPF (specific pathogen free) animal production, and caviar and ornamental fish production. Although the use of RAS for other species is considered by many aquaculturalists to be impractical, there has been some limited successful implementation of this with with high value product such as barramundi, sturgeon and live tilapia in the US.
5TH PART
Ornamental Fish Farming
Ornamental fish keeping and its propagation has been an interesting activity for many, which provide
not only aesthetic pleasure but also financial openings. About 600 ornamental fish species have been
reported worldwide from various aquatic environments. Indian waters possess a rich diversity of
ornamental fish, with over 100indigenous varieties, in addition to a similar number of exotic species
that are bred incaptivity
Fish species/types suitable for breeding
Some tips for the successful production of ornamental fishes
Economics of small-scale breeding and rearing unit for live-bearers
Source: Central In stitute of Freshwater Aquaculture, Bhubaneshwar, Orissa