special training programme
TRANSCRIPT
Director Ambekar E. Eknath, Ph. D
Head, APED J.K. Jena, Ph. D
Course Coordinators B. C. Mohapatra, D. k. Balaram Behara, Ph. D.
Social Coordinators Dr Bikash Sarkar, Ph. D.
Mrs. Sukanti Behara
Special Training Programme on
Portable Carp Hatchery: Its Installation and Operation
1 1 - 13 March, 2009
Director Arnbekar E. Eknath, Ph. D
Head, APED J.K. Jena, Ph. D
Course Coordinators B. C. Mohapatra, D. Sc. Balaram Behara, Ph. D.
Social Coordinators Dr Bikash Sarkar, Ph. D.
Mrs. Sukanti Behara
FOREWORD
Freshwater aquaculture in India has witnessed s~gnificant development with an
annual growth rate of over 6% during the last decade, and at present the
production from freshwater aquaculture has reached 3.02 million tonnes. Based
on the current population growth, the demand for fish exceeds the production. In
order to meet the future demand of fish, the country has to sustain a similar
growth rate in future too. The most basic and important component of
aquaculture is quality fish seed. To accomplish this, hatcheries have undergone
a number of modifications for production of better seed. AlCRP on APA centre at
ClFA has developed Fiberglass Reinforced Plastic (FRP) carp hatchery, which
can be transported from one place to another for easy accessibility and timely
production of quality fish seed. This FRP hatchely technology has been released
as a technology package by ClFA in 2006 and suitable for producing 1.0-1.2
million carp spawn in one successful operation. This hatchery has got wide
adoption among the users and several hatchery units are being installed at
different parts of the country. At Present technology is being managed through
CIFA, and sometimes scientist and engineer from this Institute need to go to
install and operate it on site. Being the demand is increasing day by day, it
becomes very difficult to go every place for the purpose. To help the farmers and
users to install and operate hatchery themselves, a special training programme
on "Portable Carp Hatchery: Its Installation and operation" IS organized for SMS
(Fisheries) of KVKs, Zone-VIIII during 11-13 March, 2009. This training manual is
self-explanatory and highlights the hatchery operation procedures including
related aspects and seed rearing.
I am thankful to the authors for bringing out this training manual.
Kaysalyagang 1 lth arch, 2009
Contents
Title I page I -. - - - - -. - . -- Portable FRP Carp Hatchery Technology: A New --0T Milestone for Viable Fish Seed Production in India B.C. Mohapatra, Bikash Sarkarand Dukhia Majhi 1 I Familiarization of Fibre Reinforced Plastic Processing Techniques and Their Maintenance Bikash Sarkar, Dukhia Majh~ and B.C Mohapafra
Carp Seed Raising: An Economically Viable Enterprise J K. Jena and P C. Das
10
Site Selection for Installation of FRP Carp Hatchery and Design of Seed Rearing Ponds K. K. S h a n a
18
I
I Role of KVKs for Dissemination of Proven 38
Water Quality Management in Carp Brood Ponds, Rearing Facility and Hatchery S. Adhikan and K. C. Pani
Aquaculture Technologies to the End Users Balaram Behera, Suresh Chandra and Sukacn Benera
31
Portable FRP Carp Hatchery Technology: A New Milestone for Viable Fish Seed Production in lndia
B.C. Mohapatra, Bikash Sarkar and Dukhia Majhi
Central Institute of Freshwater Aquaculture (Indian Council of Agricunural Research)
Kausalyaganga, Bhubaneswar- 751 002, Orissa, lndia
Introduction
Induced breeding and hatching of carp fishes are undertaken traditionally using bundhs, hapa and recently by cement circular hatcheries having their own merits and demerits. Once installed, the cement hatcheries can not be shifted from place to place. The innovation of portable FRP carp hatchery system is adding a feather to the blue revolution in the country by producing fish seed at the farmer's field. Thus, the transportation of stocking material from different far off places to the aqua-farm sites involving substantial cost is getting reduced by introduction of this hatchery. It is designed and developed by ICAR-AICRP on Application of Plastics in Agriculture, ClFA Centre, Bhubaneswar for small fish farmers keeping in view its easy transport to different farm sites, easy installation and operation, low water consumption during fish breeding and spawn (fish seed) production, easy to repair, less space requirement for installation, less weight and durability of the product for 10-15 years.
Development of Technology
The concept was conceived under ICAR-AICRP project, and since 2001, various designs were made for the development of the system, FRP carp hatcheries with different modifications were fabricated at ClFA workshop, Bhubaneswar for testing and data validation. Finally, a well tested unit of capacity one million carp seed (spawn) production per cycle got developed and installed for seed production in 2003. The complete unit of the hatchery consists of (i) Breeding1 spawning pool, (ii) Hatching1 incubation pool, (iii) Egg/ spawn collection chamber, and (iv) Overhead storage tank/ water supply system.
System Description
The Breeding pool is of 2.15 m diameter, 0.9 rn height, 1:22 bottom slope and 3,409 1 water holding capacity (operation capacity: 2,950 I). To provide water circulation inside the breeding pool, 5 numbers of 15 mm diameter rigid PVC elbows, carrying nipples ftted in the same direction. A single point water inlet of 25 mm diameter is also ftted at the sidewall of the bottom. All
the water inlet pipes are interconnected and fitted with lndlvidual full way valves to regulate the flow of water. One or two showers are provided at the top for better aeration. The flow rate during egg collection IS maintained 1-1.5 llsec The pool IS suitable for breeding of 10-12 kg of carps in slngle operation.
The Hatching or incubatton pool is of 1.4 m diameter, 0.98 m height, 1,400 1 total volume and 1,200 1 net egg incubation volume with a FRP inner chamber (0.4 m diameter and 90 cm height covered with nylon bolting cloth of 0.25 mm mesh) to filter the excess water to the drain and water supply system through six numbers of 15 mm diameter duck-mouths fitted at the bottom of the hatchery at 45' angle. It has drainage outlets fitted at the center (inside the inner chamber) and at the bottom sidewall of outer chamber of the pool. It has the capacity of hatching 1.0-1.2 million eggs per operation. The flow rate in the pool during operation is maintained at 0.3-0.4 Ilsec.
The Eggs1 spawn collection chamber is rectangular in size with dimension of 1.0 x 0.5 x 0.5 rn and water holding capacity of 250 1. The water level in the tank is maintained at 0.45 m height (net water volume 225 1) by fixing the drainpipe of 63 mm diameter at a distance of 38.7 cm from the bottom Cotton inner hapa of the tank size is fixed ins~de it to collect eggs1 spawn from breeding1 incubation pools, respectively.
The Water storage tank of minimum capacity 2000 1 is required to operate the hatchery unit. The breeding pool and hatching pool are connected to the water storage tank separately or together in the same water line.
Carp Species Suitable for Breeding and Seed Production
The system has been designed for breeding of carps. So far all the Indian Major Carps viz., Rohu (Labeo rohita), Catla (Catla catla). Mrigal (Cirrhinus mrigala), Kalbasu (Labeo calbasu); and three Chinese carps viz., Silver carp (Hypothalmichthys molitrix), Grass carp (Ctenopharyngdon idella), Common carp (Cyprinus carpio) have been bred in many centers, where the hatcheries have been installed. The medium carps like Puntius sp. and Labeo bata also have been found suitable for breeding in the system.
Steps of Hatchery Operation
Clean the breeding and hatching pools by potassium permanganate (KMn0.t) solution and then by water before the hatchery operation.
.1 Close the outlet valve of breeding pool and then fill a with water. Fix a clean
cotton hapa inside it for fish conditioning. .1
Collect fish breeders male to female ratio in 1.1, transport them to breeding pool, place them in hapa and run the shower(s) for conditioning.
1 After 1-2 hours of conditioning, inject the breeders w~th suitable inducing
agents and dose, release them to the breeding pool. remove the hapa and run the shower(s).
.1 After 4-5 hours of injection, allow the flow1 circulation of water in the breeding
pool, open the outlet valve, allow the water to pass from breeding pool through the hapa of the eggs1 spawn collection tank to the outside. If eggs
released from the fishes, they are collected and removed by the hapa in the eggsl spawn collection tank. The water current and whirling effect is created in the breeding pool by regulating the water flow through the inlets and outlet.
.1 In hatching pool fix the screen on the FRP socket, fix the PVC drain pipe in the center of the tank to drain excess water, the height of the drain pipe in the pool is maintained at 0.9m so that, up to that height water level can be maintained, give water circulation in the egg incubation chamber through
duck-mouths (inlets) .L
Collect the released eggs from the egg1 spawn collection tank by hapa time to time, measure them and release to the egg incubation chamber of the
hatching pool. The egg release generally stops within 8-10 hr from injection to breeders.
.1 Remove the breeders from breeding pool once the breeding is over, they
may be released to the pond after dipping them in 5 ppm KMn04, clean the breeding pool by KMn04 solution and then by water.
.1 On release of eggs maintain the flow rate in the hatching pool in such a way that the eggs float in the water (can be checked by putting light from a torch from the top of water), periodically check the eggsl spawn, clean the filtering
mesh by a brush with long handle from the side of inner chamber to avoid water choking.
On 4Ih day from the egg release, collect the spawn through hapa in the eggsl spawn collection tank by opening the outlet valve connected to the outer wall
of the hatching pool. .1
After spawn removal the hatching pool and the eggsl spawn collection tank are cleaned by KMn04 solution and then by water.
L To avoid direct sun light to the pools and tank, over the hatchefy unit a shed
may be erected.
Economics of FRP Carp Hatchery Operation
Hatchery unit of "one million spawn productron per operatron" consists of one breeding pool associated with one hatching pool. In this hatchery the spawn (final product from hatchery) is harvested on 4Ih day during operation. Because the fertilized eggs are kept in hatching pool for incubation and it takes 14-18 hours for hatching, and then after 72 hours for transformation to spawn. Thus four days are required for spawn production from one million capacity unit. Similarly hatchery for "two million spawn capacity" means one breeding pool associated with two hatching pools and "three million capacity" includes one breeding pool with three hatching pools. In case of two million capacity hatchery, the eggs produced from two consecutive fish breeding operations can be incubated in two hatching pools, thus two times the seed can be harvested (totalin to two million seed production from two operations) i.e., on 4'"nd dh days from initial hatchery operation. Once one hatching pool is free afler harvest, the next breeding programme can be taken up. In case of three million capacity hatchery, three times the seed can be harvested (totaling to three million seed production from three operations) i.e., on 4", 5th and 6Ih days from initiation of hatchery operation. Thenafler operations can continue with serial harvesting of spawn from hatching pools
3.
4.
0.
I 1 1001day for 8 man- I I I I
1. 2. 3. 4.
days per operation le., 4 days)
tank 1 HP single phase mono block pump set (2 nos) Miscellaneous accessories Sub-total Variable Cost per Cycle Brood fish (@ 50kg) Electricity and fuel Inducing agent Wages (@ Rs.
10,000
5,000
1.30,OOO
1,000 200 325 800
10,000
6,000
1,63,000
10,000
7,000
2,33,000
2,000 300 650 800
3,000 400 975 800
13,000 fixed capital @ 10%
Interest on fixed capital @lo% per
FRP Hatchery Installation and Demonstration i n the Country
- 350 5.525
1,10,500
6 CIFA, Bhubaneswar, Orissa in 2003. O Peninsular Aquaculture Division of CIFA, Bangalore, Karnataka in
2003 & 2006. Sahbhagi Vikash Abhiyan (SVA), Biienjore. Nuapada District, Orissa through NR international and Western Orissa Rural Livelihoods Project (WORLP) for fish breeding and seed supply in 2005. The first breeding of fish in the system was done during 24 June, 2005. Divyan Krishi Vigyan Kendra of ICAR, Rama Krishna Mission, Morabadi, Ranchi, Jharkhand State in 2005.
9 Reg~onal Research Center of CIFA, Vijayawada, Andhra Pradesh in 2005.
0:- Two complete sets of hatcheries to Himalayan Environmental Studies and Conservation Organization (HESCO), Dehradun, Uttarakhand in 2005. One set got installed and demonstrated at Uttarkashi and the other at Rudraprayag.
5
C. 1.
175 2,500
50,000
Miscellaneous Sub-total Total Costs Total var~able costs
250 4.000
80.000
State Fisheries Department, Imphal, Manipur for development of fisheries in North-East Hill Region of India in 2005. Another two more sets were supplied for installation in 2006. Flve sets at Birsa Agriculture University, Ranchi, Jharkhand State in 2006. Regional Research Centre of CIFA, Rahara. West Bengal in 2006. Uttar Banga Krishi Vidyapeeth. Cooch Behar, West Bengal in 2006. The fish farm of Mr Trilochan Swain in Jagatsingpur, Orissa in 2006. Agriculture Research Station, Raichur of University of Agricultural Sciences, Dhanvad , Karnataka in 2006. Banaras Hindu University, Varanasi, Uttar Pradesh in 2006 & 2007. Ramakrishna Mission Samaj Sevak Sikshanamand~r, Belur, Howrah, West Bengal in 2006. ICAR Research Complex for Eastern Region, Patna, Bihar in 2006. Central Inland Fisheries Research Institute, Barrackpore, West Bengal in December, 2006. National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh in December. 2006. Further one more set in 2007. One set with additional two more hatching pools to Sher-E-Kashmir Agriculture University, Srinagar, Jamu and Kashmir in 2006. Genetics Division of CIFA, Bhubaneswar in 2006. Two sets to DBT Project, CIFA for lnstallat~on In Kendrapara and Keonjhar Districts, Orissa in 2006. Central Agricultural Research Institute, Port Blair, Andaman & Nicobar Islands in 2006. Sardar Vallabh Bhai Patel University of Agriculture and Technology, Modipuram, Meerut, Uttar Pradesh in 2007. West Bengal Citizens Forum, East Basanti Island, Sunderbans Delta, 24 Parganas, West Bengal in 2007. West Utkal Agricultural Center, Diptipur, Bargarh District, Orissa in collaboration with NR International, United Kingdom in 2007. Two sets in State Fisheries Department, Nihoto and Kohima, Nagaland in 2007. State Fisheries Department, Itanagar, Arunachal Pradesh in 2007. Two sets in State Fisheries Department, William Nagar and Shilong, Meghalaya in 2007. College of Fisheries, Dholi, Muzaffarpur District, Bihar in May, 2008 College of Fishery Science, Maharashtra Animal and Fishery Science University, Seminary Hills, Nagpur, Maharashtra State in May, 2008 Assam University, Silchar, Assam in May, 2008
Responses Received from Users
The FRP carp hatchery un~ts installed in different locations of India are operating successfully for production of fish seed for aquaculture. Some of them (one each from NGO, farmer, KVK and lnstltute Center) are highlighted here.
The unit supplied to NR international to install it under the Western Orissa Rural Livelihoods Project (WORLP) at Sahbhagi Vikash Abhiyan (SVA), Biienjore, Nuapada District, Orissa for fish breeding and seed supply operated very successfully. The first breeding of fish (mrigal) in the system was done on 24 June, 2005. Then after several operations were undertaken in the system and fish seed produced were supplied to the local aqua- farmers. Several publications (namely Fish in our watersheds; and Bigger fingerlings) of WORLP published in July 2006 by STREAM, C/o NACA, Bangkok highlighted these achievements. The Official Appreciation received from NR lnternational states that "The operationalization of the portable hatchery unit at Biienjore is a wonderful example of multi-agency collaboration. We in WORLP believe that this will have a great positive impact on the overall development of freshwater aquaculture in the western Orissa region. This in turn has the potential to contribute to enhancement of livelihoods of the poorest sections of western Orissa." The NR International in its letter to ClFA dated 27 April, 2007 stated that "Based on the merits of the FRP hatchery, its acceptability by the community and promoting bigger fingerlings in WORLP operation areas, the project through its Small Project Fund (SPF) component proposes to set up similar structure in Bargarh District, Orissa." An agreement was signed for a Consultancy Project between CIFA and WORLP MC for establishment of FRP carp hatchery in Diptipur, Bargarh. Under the project the hatchery complex got established and successfully operated at Diptipur in 2007 and also in 2008.
A farmer Mr Trilochan Swain, Badalahanga, Jagatsinghpur, Orissa purchased one hatchery unit from ClFA in May, 2006 and put it for operation in that year. His acknowledgement to ClFA dated 20 April, 2007 states "I am glad to inform you that, I had obtained FRP carp hatchery system from ClFA in 2006. It was put to use in the same year for grass carp breeding. We found it very handy for operation for both carp and magur after a small modification. We obtained an average of ten lakh spawn per cycle for carps and forty thousand for magur".
The FRP carp hatchery was installed for demonstration and fish seed production at KVK, Ramakrishna Mission, Morabadi, Ranchi, Jharkhand in
July, 2005 Its performance report indicates, "During 2006-07, fifteen thousand fingerlings have been harvested in this FRP carp hatchery and distributed to the farmers' pond. The performance of FRP carp so far IS satisfactory". Then after the hatchery is running there successfully
At Peninsular Aquaculture Division of CIFA, Bangalore the FRP carp hatchery was installed in September, 2002. This is the only hatchery that the Division has, and regularly the peninsular carps are bred in it year after year The secretary, DARE and Director General, ICAR visited the Division on 30 April, 2005. On his visit to the FRP eco-hatchery, he was happy to see the hatchery process of rohu eggs, which had been bred much ahead of the normal breeding season. Its successful operation demanded to add one more breeding pool with three more hatching pools to the Center in 2006
Technology Commercialization
Technology Release
Publication of Technology
i Portable carp hatchery for carp seed production. In: Technologies on Livestock and Fisheries for Povertv Alleviation in SAARC Countries. SAARC Agricultural Information Centre, Dhaka: pp 132-135 (in 2004)
> Portable FRP carp hatchery. In: ClFA Technolwies, Central lnstitute of Freshwater Aquaculture (ICAR), Bhubaneswar: pp 22-23 (in 2004).
I Parigaman~ya (poflable) FRP Carp Hatchery In ClFA PradyoprKs Central Institute of Freshwater Aq~aculture (ICAR) Bhubaneswar pp 27-30 (in 2005)(in Hindi).
> Portable plastic carp hatchery. In: Aeuaculture Technol~ies for Farmers. Indian Council of Agricultural Research, New Delhi: pp 55-58 (in 2005).
Z Portable FRP carp hatchery: An aid for rural aquaculture. ~roceedings International Conference on Plasticutture and Precision Farming. NCPAH. Govt. of India. November 17-21, 2005, New Delhi. India: 515522.
i Portable plastic hatchery for carps. In: Fish Farminq and Technoloqies for the North Eastern Reqion: Pond to Plate. lndian Council of Agricultural Research, New Delhi: pp 39-42 (in 2006)
i Portable FRP carp hatchery technology. Successful adopt~on in India. Fishing Chimes, 28 (4): 48-52 (in 2008)
Conclusion
The system is so designed that it creates the environment suitable for fish breeding in the field conditions for 10-12 kg of carps in one operation. In one run 1.0-1.2 million spawn can be produced from the system. This much spawn in the field condition can be used as stocking material for 30 hectare of water area for biomass (fish) production. In lean season the system can be used for ornamental fish rearing or common carp breeding or water storing. This hatchery can be used as a tool for fish biodiversity conservation also. The unit can be operated by unemployed youth, Gram panchayat and Cooperative Society on self-operational I rental basis.
Acknowledgement
The financial support from All India Coordinated Research Projed on Application of Plastics in Agriculture, Indian Council of Agricultural Research, New Delhi is duly acknowledged.
Familiarization of Fibre Reinforced Plastic Processing Techniques and Their Maintenance
Bikash Sarkar, Dukhia Majhi and B.C. Mohapatra
Central Institute of Freshwater Aquaculture (Indian Council of Agricultural Research)
Kausalyaganga, Bhubaneswar-751 002, Orissa, lndia
Introduction
Glass Fibre Reinforced Plastic (GRP) has emerged as one of the important class of construction material for making load bearing structures and products. More than 35,000 products are being made out of these materials and the applications are spread in almost all fields of engineering A thorough understanding of the materials and their property are essential for their effective utilization. Over the years several new materials have been developed by man for his technological needs and comforts. As the technology became more and more sophisticated, correspondingly the materials used also have to be made more efficient. The conventional materials may not always be capable of meeting the demands. New materials are being created for meeting these performance requirements. The glass-reinforced plastic (GRP) otherwise known as FRP is one class of such materials developed for the modern technological applications.
FRP production in lndia is currently estimated at 35,000 tonnes which is fabricated out of about 22.500 tonnes of resin. The application-wise percentage break-up is summarized below:
FRP usaqe in lndia bv application
Chemical Process E ui ment 32% Buildin /Civil En ineerin 20% Trans ort 17% Electrical E ui ment 12% Defence A riculturelA uacuiturelothers 18%
The per capita consumption of fibre-reinforced plastics in lndia is very small in relation to the consumption in other countries. There is abundant scope for the growth of this sector. All the resins are locally manufactured. Excess capacity for glass fibre production exists in the country with 4 major producers
Glass Fibre Reinforced Thermoset Plastic
Thermosets are cross-l~nked polymers, which cannot be reshaped or reworked subsequently. They are initially available in linear polymer form, which can be cross linked using heat and/or catalyst. Unsaturated Polyester, Phenolics, Epoxies, Furan, Amino resins, Polyamides. Melamine, Polyurethane, Silicones, etc. are the thermoset resins used for making GRP. Out of these resins, polyesters and epoxies that account for the bulk of the composite. Composite material are made up of by combining two or more materials in such a way that the resulting material has certain desired or improved properties. The example is the Glass Reinforced Plastics (GRP).
Composite materials are made out of glass fibre and thermosets by 18 different processing methods. These methods give a wide range of material structure and help to make products of different complexities. The properties of the composites made by these manufacturing methods also differ considerably. The choice of a particular composition of GRP and the manufacturing methods depend on the type of product and the property requirements. Composites have several properties and features that make them to stand above all other conventional materials both in their performance efficiency and manufacturing adaptability. Some of these attributes are given below:
Fibrous composites have generally high specific strength and specific modulus Composites are multifunctional materials. Composites are generally energy efficient. Composites generally can be made corrosion resistant and weather resistant. The composites can be designed to give properties for specific design conditions. By proper orientation of fibres, directional properties can be obtained. Products of complex shapes can be easily molded without any material wastage.
Basic Features of GRP Product Design
Design of GRP product differs in two respects from the design of products made out of other conventional materials. In the case of conventional product design, ready-made materials like steel, aluminum, timer, etc are used. The materials generally do not undergo any chemical changes during the product manufacture. In the case of thermoset matrix GRP, the geometrical arrangement of fibres is being made during the product manufacture and resin generally undergoes chemical changes.
The second feature of GRP product design is the role played by the material design as a part of the overall des~gn. Since the material can be designed to have combination of properties required for specific deslgn situations. material design bring considerable freedom and efficiency in the product design.
Material Considerations i n the Design Selection
The First step in a designing process is the selection of a set of design parameter, which can be listed as follow.
Overall shape, sizes and dimensions of the product Selection of raw materials likes fibre, resin, filler, etc. Selection of the structural concepts like beams, un-stiffened panels, stiffened panels, sandwiches, panels, etc. Selection of the material microstructure . Selection of interconnection of various structural elements and support arrangements. Selection of the processing1 fabrication I erection method Selection of finish, color, texture, fittings and accessories etc
Process Description (Hand-Lay uplcontact Molding)
This is the most popular method of manufacturing of large and complex items. It requires minimum equipment and inexpensive moulds. Moulds are made of reinforced plastics, plaster of paris, wood, etc. Only one mould, male or female is used and the articles produces have finish on the side that comes in contact with the mould. Resins used are of polyester and epoxy. Resin is mixed with a catalyst or hardener if working with epoxy; otherwise it will not cure (harden) for days/ weeks. Next, the mould is wetted out with the mixture. The sheets of fiberglass are placed over the mould and rolled down into the mould using steel rollers. The material must be securely attached to the mould; air must not be trapped in behveen the fiberglass and the mould. Additional resin is applied and possibly additional sheet of fiberglass. Rollers are used to make sure the resin is between all the layers, the glass is wetted throughout the entire thickness of the laminate, and air pockets are removed. The work must be done quickly enough to complete the job before the resin starts to cure. Various curing times can be achieved by altering the amount of catalyst employed. The lay-up normally cures at room temperature. The schematic of the lay-up process is given in Fig.1.
- Painting
Trimming
Curing and releasing the mould - Lay-up process - Gel coats
r Mould release agent
Wax coats - Plywood mould
I Fig. 1 Lay-up process of Fibre Reinforced Plastics I Selection of Hand Lay-up as a Fabrication Process
When only one side smooth finish is required. Slight thickness variation is permissible Labour charges are not prohibitively high
w When the product is large in size and very complex in shape .When only few numbers of moldings are required and the number of
molding does not justify the use of costly metal dies and press molding.
Advantages of Hand Lay-up Process
This method is largely used in FRP industry for boat manufacturing, automotive components, corrugated and flat sheets, tanks, etc.
0 No costly machinery is required, and tools like plain brushes and rollers, and accessories like mug, knives, disc sander, hand tools and drill are used. Colors and decorative finishing can be obtained to individual liking and this flexibility ensured a large market for hand lay-up products. Hand lay-up method requires comparatively a very low investment of capital and is ideally suited for small fabrication unit. Today hand lay-up is most popular method in India and practically every FRP fabricator is equipped with the lay-up process.
Limitations
. This technique is labour intensive and quality of the product depends largely on one finished surface and is unsuitable if finish is required on both surfaces.
r For mass productions, normally it cannot compete with press molding. Thickness cannot be controlled with any degree of accuracy It is difficult to obtain uniform glass to resin ratio
GRPl FRP Making
Stepl: Design of Mould
Mould is the prime requirement for making any FRP product. A suitable mould must be made before any molding process is undertaken. This is one of the most important steps, since it affects the quality of the molding. When wide ranges of possible molding processes are available, many different types of moulds are required. This can be made from wide varieties of materials including wood, plaster of paris, concrete, sheet metal, epoxide, polyester resins, non-ferrous metals and steel or a combination of these factors, which affect choice of mould materials, include the number and size of the moldings to be produced, the type and finish required and the molding process. While designing the mould, several parameters like material selection, mould thickness, mould trim line size, mould taper, etc are to be considered.
Step -2: Construction o f Mould
Open mould processes of FRP fabrication make use of only the male or female half of the mould. Since pressure is not applied in hand lay-up or spray-up methods, the moulds need not be as strong as the moulds used in compression molding. Also, when heating is not required metallic moulds are not essential. Wooden mould requires finishing work on moulds after every cycle of molding. FRP moulds are ideal for intricate shapes. When heating or pressing is required the metallic mould has to be coated with wax and releasing agent. For trimming some allowances may be allowed, which is slightly larger than the product dimensions.
Step - 3: Seal the Mould
The mould must be sealed to keep the resin from sticking on to it. Sealers also tend to make the mould surface smoother. Mould sealed with polyester resin is thoroughly dried. The plastic resin produces the best sealer finish. It buffed to give a higher polish on the molded laminate.
Step - 4: Wax the Mould
After the mould is properly sealed, hard paste wax is appl~ed on it hvice. A good automobile wax, one that contains Carnauba, IS desirable. Polishing should be done on the mould as to an auto body, using a clean soft cloth.
Step - 5: Apply Mould Release
Mould release (PVA) is to be applied over the paste wax to make the separation of mould and product quite easy. The separation should be at the wax line, but if the mould release is not present, the heat of cure may destroy the wax. Water-soluble film forming of paste type mould release may be used as mould releasing agent and applied with brusheslsponge. It will dry after 3- 4 hours of application and form a thin plastic film, which can be removed with water.
Step - 6: Apply Get Coat o f Resin
Mix the gel resin first with the colour pigments (10%) and then 1-2% accelerator (Cobalt naphthanate) is added to this mixture. Then add 2% catalyst (MEK) peroxide to it and mix again. Brush the resin mix in a thick coat on the mould surface. Allow it to cure. The first coat should be as thick as possible without severe drainage. It makes a nice surface with polish. These gel coats are allowed to cure before any other materials are added to the laminate. Sand the cured gel coat or rough lightly with steel wool before the next coat is applied to prevent the delamination.
Step - 7: Appllcation o f Resin
The resin is mixed with the normal amount of accelerator and catalyst, and applied over the cured get coat. This resin coat will hold the glass material in place, and also help to keep out air bubbles.
Step - 8: Apply First Layer o f Glass Material
Cut chopped stand mat (300 g/m2) to the shape of the product (allow enough on all sides to grasp the material and pull out the wrinkles) and lay it over the mould, which has just been covered with resin. Lay it down from one side to prevent air from being trapped in it.
Step- 9: Additional Glass Material Layers
Additional layers of material (300 glmZ or 450 glm2) either chopped stand mat or woven moving placed over the mould in the same manner as the first ones. This layer may be of different kind of material than the first. Greater
strength is achieved with each add~tional layer. Be sure to remove all air pockets between the layers. Layers will stick well if each layer is added in the right manner.
Step - 10: Final Resin Coat
A final coat of resin with colour is added after the laminate is cured properly. This coat is needed to get a better finish on the outer side of the product.
Step-11: Curing the Laminate
The fiberglass reinforced plastic laminate is allowed to be cured until it is hard. If the laminate is removed from the mould before the plastic is cured. the layers of glass fabric may separate from each other. The usual time of curing is from 16-24 hours and it could be adjusted with catalyst concentration to reduce the curing period. In some cases it is desirable to remove the laminate from the mould before it is completely cured, as slight flexib~lity of the laminate at this stage w~l l allow easier removal1 separation from the mould.
Step -12: Removal of the Product from the Mould
Remove the laminate from the mould w~th as much care as possible. It is easy to damage the laminate and the mould at this point. An inexpensive putty knife with the end ground well may be used for this purpose. Several thin pieces of wood may be pushed between the mould and the laminate. Water will soften the film forming mould release for easier removal. A son mallet may be used for this purpose.
Step-13: Trim and Finish the Edges
The edges of the laminate are very rough when it is removed from the mould. The extra fabric and plastic resin dripping is removed with hand wood working or metal cutting hand tools. The trimmed edges is planned with a hand plane, filed with wood or metal files, and sanded with wet or dry sand paper. Afler sanding, the edges may be coated with resin. This is not always necessary, but, it improves the appearance of thicker laminates. It will seal the edges and improve the color. If the edges are not sealed, they are to be buffed.
Step -13: Strength of the Materials/ Laminates
When fiberglass materials are combined with plastic resins and the resins are cured, the greatest strength is produced. It is possible only when the correct balance is kept between the two materials. In general, the larger the
volume of glass in the product the greater the strength achieved to the product.
Conclusions
It is difficult to quantify the growth prospects for composites, but qualitatively it can be predicted that with increasing emphasis on strength, light weight, chemical resistance, heat resistance and corrosion resistance, etc. the demand for FRP is bound to grow significantly for such appl~cations. Overall it can be obsewed that the demand for thermosets, which is around 80,000 tones at present, is expected to rise to 2,60,000 tones by the year 2010.
Site Selection for Installation of FRP Carp Hatchery and Design of Seed Rearing Ponds
K. K. Sharma
Central Institute of Freshwater Aquaculture (Indian Council of Agricultural Research)
Kausalyaganga, Bhubaneswar-751 002, Orissa, India
Carp Hatchery
The most important aspect of aquaculture is the production of quality seed for different culture species. The source of seed should be dependable one, which could insure production of required quantity of seed at right time and right place. The technologies of brood stock development, induced breeding, multiple breeding of carps, etc, are standardized for this endeavor. In different regions of the country, establishment of a standardized hatchery is the pre-requ~site for commercial seed production.
Essential Components of a Hatchery Complex
Fishponds varying between 0.1-1.0 ha for rearing and management of carp bloodstock
D Hatchery unit for spawn production Water supply system to the hatchery . Treatment unit for recalculating of hatchery used water Nursery ponds for raising of fry Rearing ponds for raising of fingerlings Packing and marketing unit Store- cum- field laboratory
Site for lnstallatlon of Hatchery
The site, which fuffills the following objectives and criteria, naturally or inexpensively, will be most suitable for installation of a hatchery.
The water retention of the soil of the site should be very good to hold water in ponds for longer duration The soil preferably should be clay-loam to loam and water retention capacity more than 85% There should be dependable source of perennially available water in adequate quantity at the hatchery site There should be scope for making self draining ponds for brood and seed rearing
The gravity flow should be utilized wherever possible to reduce pumping cost The physical and chemical properties of the water should be within acceptable limits . The site should be easily access~ble by road Building material for construction should be available nearby to reduce cost of transport Susceptibility of the site to flooding Proximity of good market for sale of seed and fish Availability of suitable manpower to operate the farm Availability of transport for the dispatch of fish Availability of electricity Availability of brood fishes for the hatchery Potential impact on neighbors and environment
Planning for Construction of Fish Seed Farm
Before construction of fish seed farm, it requires proper planning. It is essential that the site be examined carefully in respect of climatic conditions, soil conditions and water ava~lability. It is necessary to dig 2.5 m deep pits at fairly close range along a grid and examine soil samples for their physical and engineering properties. The deep profile of the soil can also be studied by drilling bore at different locations to understand the ground water contours. It is also essential to examine the size of the water source which can provided sufficient quantity of the water round the year. Required test may be carried out. A detailed contour survey of the site is an essential part for preparing a master plan of the layout of the site for installation of hatchery, nursery ponds and water supply and drainage system of the fish seed farm.
Facilities Required for Installation of FRP Carp Hatchery
Platform
Proper installation of the FRP hatchery unit at one place for a longer period requires a platform. The platform should be strong to withstand the pressure of the hatchely unit placed over it. The height of the platform should be such that eggslspawn are collected in collection tanks through pipes by gravity flow only. For stability construct the periphery wall with brickshtones masonry (1:4) from 2 feet below the earth surface up to 1.5-2 feet above the ground level. Fill the platform with sand up to 2 feet to give the strength. The top surface of the platform may also be provided with 4 inch concreting (1:4:8) to make more durable and strong.
The size of the platform is to be dec~ded as per the size of the hatchery unit. It is essential to keep at least 0.5 m distances around each pool as a working space. Hence, the size of the platform can easily be calculated as per the size and number of breeding and hatching pool to be kept over ~ t . For example a hatchery unit (breeding pool 2.15 m diameter and incubation pool 1.4 m diameter) requires a platform of size 6.0 x 4.0m (Fig.1).
Overhead Tank
One tank of 2,000 1 or two no of tanks of 1,000 1 capacity each can solve the purpose. Based on the capacity of the hatchery and operational needs, the size of the tank is to be decided. These tanks can be made of any material like PVC, RRC, bricks, etc. The height of the tank should not be less than 10 feet to provide required flow and velocity in the hatchery for its effic~ent operation.
Pump and Water Supply
One 1.0 HP pump set is required to fill the tanks periodically and to supply water to hatchery. In case of I : ? ratio FRP hatchery unit ( one breeding pool and one hatching pool) the water supply to the unit may be provided with 25 mm (ASTM) pipes from the tanks. In case of 1:3 unit it may be provided through 50 mm pipe for getting required water flow.
Open Well/ Bore Well
A well of 30,000 llhr yielding capacity is required for the smooth operation of hatchery and seed farm. However, the water from the bore well should not be fed directly to the hatchery. It should be stored in a pond for 1-3 days for release of obnoxious gases and correction of water quality.
Pump House
A pump house is also required to keep pump, starter and also can be used as a store for keeping feed, fertilizer, medicines, nets, hapa, etc.
Shed
A semiopen type shed of required size is to be provided for housing the breeding and incubation pools.
Design o f Nursery Ponds
.The pond orientation should take into account of the direction of the prevailing wind. The longer sides of rectangular ponds should be oriented
PORTABLE FRP CARP HATCHERY FIG. I Water outlet
10.0m , ~ , . 4
I 1 Water inlet --, 1 I
Cross sectional view of the FRP Carp Hatchery overhead water storage tank
Brceding Pool Hatching Pool Platfonnn ( ~ 8 s 2.IS.n and ht.l.0 m) (~ i . 1.4 m anrl 1tl.l.Om)
Inner Channhrr /
,,,,,,<
Frnnt ~ i r w nf the FRP C%rn Hatchrrv
,arallel to the general prevailing wind direction (most probably south to north) to Increase the pond water aeration as a result of wind d~ffusion through increased surface turbulence.
,Referring to contours (level of the ground), the larger ponds should be positioned on lower contours and smaller ponds like nurseries requiring less depth may be positioned proportionately high levels in view of limiting the depth of earth excavation to make the construction economical. Farm buildings like hatcheries, oftice, store, etc. should be laid out on higher lands in the area.
#The layout of channels and dykes are fitted as closely as technically possible for existing land slopes and undulation channels should be at a suitable contour for making possible of gravity flow to all sections of farm area. Farm discharge outlets along with main drainage channel should be located at lower level of s~te, wh~ch is also connected with other catch water drains in the farm.
Shape, Size and Type of Ponds
-The pond shape and size mainly depends on the purpose of its use. whether it is for nursery, rearing, grow-out or for any other culture system to be employed and also upon the topography of the area. Ponds can be constructed different shapes such as circular, square, rectangular and triangular. Circular and square shape ponds are economical from the construction point of view, but large circular and square size ponds are not suitable from management and operation point of view, as the circular ponds create problems in layout. However, small square and rectangular ponds are suitable for nursery and rearing purposes.
.For aquaculture mainly two types of ponds preferably square and rectangular are required and accordingly one type is used for nursery and other is used for growth of fishlprawn. The suitable size for nursery pond is 20m x 20m or 10m.
Pond Bed
.For Aquaculture purpose the pond bed should be flat with an uniform slope. The pond bottom is provided with a slope between 1000:l and 1000:5 towards the drainage outlet to facilitate the water flow during culture, harvest and drainage. The pond bottom may be designed above or below the ground water table as per the site condition, requirement and economic point of view, but it may be considered that, effective drying of pond bottom is essential for pond preparation. A well constructed pond is normally designed to drain out the water completely.
Pond Depth
.Depth of a pond has an important bearing on the physical and chemical parameter of water. It is established that below 3-4 m water, there IS not much photosynthetic activity to keep the deeper water oxygenated and water temperature is low containing less plankton.
.As per the present state of culture practices, suitable pond depths excluding free board are suggested below:
Ponds Depth of pond (m) Water loaqedlirriqated areas Rain fed (plains and hills)
Small oonds
Free Board
.Free board IS the additional height of the pond dyke above maximum water level. It is generally provided as safety factor to prevent overtopping from wave action, heavy ra~nfall and for other causes. It is the vertical distance between the elevation of the water surface in the pond at deslgned depth and the elevation of dyke1 embankment after dyke settlement. A free-board of 0.5-1.0m is usually necessary to keep the carps1 prawns safe from water management point of view. Therefore, in culture ponds at maximum water level an ovefflow or outlet arrangement is provided.
Pond Dyke
.The design of the dyke should be strong enough to hold the water upto the maximum level and be safe against hydraulic pressure. The stability of the dyke should be checked by drawing the hydraulic gradient line (slope of seepage line). The base should be sufficiently wide, so that the seepage line do not appear above the toe on the downstream side of dyke. It is desirable to have earth of about 0.3-1.0m above at downstream of the dyke to guard against any percolation through the dyke. The base width at bottom of dyke on the depth of water in pond and top width depends on the type of soil.
Tvoe of soil Slope of seepaae line (hlv 1 Clav soil 3.1 sandy loam soil 5.1 Sandy soil 6.1
Top Dvke Width He~qht of dyke (m) Minimum top w~dth (m)
Under 2.0 1.5 Under 2 5 2.0 2.5 - 5.0 3.0 5.0 - 8.0 4.0
Dvke Side Slope Tvpe of soil Slide slope (hh l Clav soil 1: l - 1.5:l ~0a i - n~ soil 1.5: 1 - 2 : l Sandy soil 2:l - 3:l
Inlets and Outlets
Each pond should have a separate inlet and outlet. Screens should be provided at inlet and outlet to prevent entry of trash fish and loss of stocked fish. The diameter of inlet and outlet pipe should be at least 15 cm. Pond constructions should be made in such a way that, they could be drained indiv~dually, completely and rapidly.
CROSS SECTION
Carp Seed Raising: An Economically Viable Enterprise
J. K. Jena and P. C. Das
Central Institute of Freshwater Aquaculture (Indian Council of Agricultural Research)
Kausalyaganga, Bhubaneswar-751 002, Orissa, India
Introduction
Availability of adequate quantity of seed of the desired species at the appropriate time is one of the prime factors that determine the success of aquaculture operation. Though remarkable success has been achieved over the years in spawning the carps, the techniques of seed rearing st111 needs improvisation. Fish seed are classified on the basis of size as spawn, fry, fingerlings or juveniles, and multitired rearing systems are practiced for their production. The nursery rearing involve nurturing of 72-96 hours old spawn which have just begun to eat and continues for a period of 15-20 days, during which they grow to fry of about 25-30 mm. The rate of growth of fish at their earlier stages are quicker and show different biological characteristics from adult, particularly in terms of feeding habits and habitat preference.
The method of food intake and the structure and function of the digestive organs improve as the fish grow. The newly hatched ones nourish themselves with egg yolk for the first 3-4 days after which they begin to take food from the environment. The stage between the yolk absorption and commencement of feeding is most critical. At this stage they feed continuously and non-availability of adequate quantity food in the ecosystem leads to mass mortality resulting poor survival. Both the Indian major carps and exotic carps at the adult stages through have distinctly different feeding habits, yet in the early stages all prefer zooplankton. Thus, the management of nurseries is an important step and the main objective of carp nursery management is to get maximum sulvival by eliminating the various factors causing mortality during rearing.
Factors Responsible for Survival and Growth
Survival and growth rates of carp spawn are affected by the presence of predatory and weed fishes, aquatic weeds, lack of adequate quantities of natural food, adverse physico-chemical conditions of water, non-availability of balanced supplementary feed, excess population density, long rearing periods, improper handling and transportation methods, disease and quality of spawn stocked itser. The management measures adopted in rearing the seeds are to eliminate these factors by providing proper eco-biological
conditions. The various management measures followed dur~ng the rearing period are directed to meet the above principle.
Rearing Environment
The spawn is delicate and requires special attention. Small water bodies of 0.02-0.10 ha with depth of 1.0-1.5 m are preferred for nurseries though areas up to 0.5 ha are also used for commercial production. Drainable or non- drainable earthen ponds, cement cisterns with a soil layer of 15-20 cm at the bonom for better mineralisation of manures are the different systems used for nursery rearing of fry. In larger water bodies, pens and cages are used as alternatives for ponds. Plastic and fiberglass pools or modular rearing systems with incorporation of various water management practices like aeration, water recirculation, water exchange, biofiltration, etc. are provided in Hi-tech super intensive rearing systems for seed production.
The favourable conditions for seed rearing in the pond are water temperature 25-32"C, transparency 15-20 cm, pH 7.5-8.5, dissolved oxygen 4-8 mgll, and total alkalinity 80-100 mgll.
Pond Preparation
Clearance of Aquatic Vegetation
An abundant growth of vegetation is undesirable in fish ponds as they absorb nutrients arresting the pond productivity, help in harbouring the predatory and weed fisheshnsects hindering the free movement of fish and netting operations. Hence aquatic weed clearance is the first operation in pond preparation. Generally manual methods are only used in nursery and rearing ponds as they are shallow and small in size. In bigger ponds mechanical, chemical and biological methods can be used for eradication of aquatic weeds.
Eradication o f Predatory and Weed Fishes
Various predatory animals like snakes, tortoise, frogs, birds, otters, etc, and predatorytweed fishes present in ponds pose problems with regard to survival of young fishes besides competing them for space and oxygen. The commonly encountered species of predatory fishes are murrels, magur, singhi Wallago, Mystus, Glossogobius, Ompok, Pangasius etc. The common weed fishes include Puntius, Barbus, Oxygasier, Anabas Amblyphaiyngodon, Colisa, Aplocheilus, etc. The methods adopted for eradication of predatory and weed fishes are dewatering and drying. repeated netting or application of suitable piscicides. Piscicides of plant origin like mahua oil cake (200-250 ppm) are preferred. However, a time lag of three weeks are required for the total detoxification of water. The oil cake
serve as an organlc manure after decornpos~t~on and adds to Increase natural product~v~ty Bleaching powder 1s a chem~cal p~sc~c~de wh~ch at 10 ppm chlorine 1s effectlve In k~ l l~ng the fishes This works out to applicat~on of commerc~al bleachlng powder (30% chlorine) at dosage of 350 kglha-m of water The quant~ty of bleachlng powder can be reduced to half wlth the comblnatlon of urea at 10 pprn level (100 kglha-m) appl~ed 18-24 hours before the bleachlng powder appllcat~on Anhydrous ammonla at 20-25 ppm has been found as an effectlve fish toxlcant
Pond Fertilization
The natural and preferred fish food organlsrns, the plankton are produced by fertlllzlng the fish culture ponds The ponds used for seed product~on are first limed after the removal of unwanted predatory and weed fishes depend~ng on the pH of so11 After llmlng the ponds are treated either w~th organlc manures such as cowdung, poultry dropp~ng or lnorganlc fertlllzers or both one following the other The doses of fertlllzers or manures depend upon the fish polson used If rnahua 011 cake 1s used as fish polson the amount of manure applicat~on IS reduced to only 5 tonneslha but wlth other polsons havlng no rnanur~als value, cowdung IS applied generally at the rate of 10 tonneslha Spaced manurlng w~th initial basal dose 15 days prlor of stocklng and second appl~cation after a week of stock~ng able to malnta~n sustained product~on of zooplankton B~ogas slurry at 30 Vha is a good substitute to raw cattle dung Phased manurlng used a mlxture of deoiled groundnutcake, rlce bran, slurry of anlmal excreta and s~ngle super phosphate has shown to be sustaining plankton levels M~xture of groundnut 011 cake at 750 kg, cowdung 200 kg, and slngle super phosphate 50 kglha is found be effective In product~on of deslred plankton Half of the above amounts after belng m~xed thoroughly by addlng water to make a thlck paste are spread throughout the nursery 2-3 days prlor to stocklng The rest amount 1s applied In 2-3 spllt doses depend~ng on the plankton level of the pond
Control o f Aquatic Insects in Nurseries
Aquatlc Insects and thelr larvae, whlch compete for food wlth the young growing fish have been observed to cause large scale destruct~on of hatchlings stocked In nurseries A slmple and effectlve methods to k~ l l the aquatlc a~r-breath~ng Insects IS the appllcatton of soap-011 emulslon (cheap vegetable 011 @ 56 kglha wlth 113 ~ t s we~ght of any cheap soap) Kersoene @loo-200 1 or d~esel @75 1 and llqu~d soap @ 560 ml can be used as substitute to make the emulslon As the dragon fry larvae are 9111-breathers and are sensalve to chlorlnatlon of pond water at 3 ppm level, bleachtng powder can be used effectively 67 days before stocklng to eradicate them Insecbc~des lhke gammexane @O 01 ppm or malath~on @ 0 5 ppm also IS
effectlve to klll the aquatlc Insects, whlch however are not advocated for
control of insects at present due to their harmful affects an the pond environment.
Stocking of Ponds
ARer three days of hatching when the yolk is completely absorbed and mouth is developed the spawn are transferred to the nurseries. The stocking is done preferably during the cool hours of the day, i.e, in the morning or evening by acclimatizing them to the new environment. Determination of the rate of stocking is an important aspect, which depend mainly on the pond productivity and the type of management measures to be followed. The normal densities of stocking in nursery and rearing ponds are 3-5 million spawn and 0.1-0.3 million fty per hectare, respectively. However, higher densities of 25-50 million spawnlha have also been experimented in cement cisterns, plastic and FRP pools in intensive rearing with encouraging results. While nursery phase is limited to monoculture, rearing phase involve polyculture of different carp species similar to that of grow-out production.
Post Stocking Pond Management
Under heavy densities of stocking, the plankton production in the pond cannot be maintained even with regular manuring. Finely powdered feed in dry or wet forms @ 6 kglmillion for the first 5 days and 12 kglmillion for the subsequent days is used in nurseries. A feeding rate of 5-10% followed for fingerlings rearing. Locally available materials such as groundnut cake, mustard cake, soybean cake, rice polish, wheat bran, fish meal, silk worm pupae, etc. have been used to compound the feed, under different experimental trials incorporating vitamins, mineral and micronutrients. However, in most of the cases the supplementary feed is limited to the mixture of groundnut oil cake and rice bran at 1 : l ratio by weight. When grass carp is stocked, duckweeds like Wolffia, Lemna, Spirodela and aquatic fern Azolla are to be provided. The nutrient requirement for carps are 40-47% of protein; 4-6% of fat; 22-26% of carbohydrate; 0.1% of vitamin B complex, 600 mglkg vitamin C and 200 lUlkg diet of vitamin A. The feed is formulated to the required levels of nutrients in pellet form and broadcasted all over the pond. Better results are obtained when feeding frequencies increased.Specific rearing periods advocated to get optimum survival and growth in the 3-tier seed rearing system are 15 days for nurseries and 2-3 months for fingerlings raising. To increasing the survival rates, prolonged retention of seed should be avoided by harvesting or thinning out the population.
Wtth adoption of sctentific methods of rearing, the fry attain the deslred slze of 20-25 mm wlth survival of 50-60% and the fingerlings attain 80-100 mml8- 10 g with a survival of 70-90% under nursery and rearing pond conditions, respectively. The best-suited time for harvest is the cool hours of the morning or evening. Since nursery-rearing period IS limlted to 15 days, the same nursery can be utilized for multiple cropping, at least for raising 3-4 crops in case of earthen ponds and 5-6 crops in case of cements cisterns.
Water Quality Management in Carp Brood Ponds, Rearing Facility and Hatchery
S. Adhikari and K.C. Pani
Central Institute of Freshwater Aquaculture (Indian Council of Agricultural Research)
Kausalyaganga, Bhubaneswar-751 002, Orissa, India
Introduction
High quality water and suitable bottom soil condition are essential ingredients for successful pond aquaculture. Some problems with pond soil and water quality are related to site characteristics. Bottom so~ls may have undesirable properties such as potential ac~d sulfate, high organic matter content or excessive porosity The water may be of poor quality, viz., highly acidic, rich in nutrients and organic matter, high in suspended solids or polluted with industrial or agricultural chemicals. However, even if a good site is available, large inputs of nutrients and organic matter as a result of feeding very often lead to poor water and bottom soil conditions. Therefore, soil and water quality problems are common in aquaculture ponds, and many methods are used for the purpose of improving pond soils and water.
Water Quality Management
Fish are in equilibrium between potential disease organisms and their environment. Changes in this equilibrium such as deterioration in water quality (environment) can result in fish becoming "stressed" and vulnerable to disease. It is, therefore, very important to know something of the water quality parameters and their management that have influence on growth and survival of aquatic organisms.
Dissolved Oxygen
The optimum dissotved oxygen (DO) content of pond waters should be in the range of 5 mgll to saturation level for good growth of fish. Below are some guidelines for dissolved oxygen for fish production:
5.0 mgil - optimum for normal growth and reproduction in tropical waters; 1.0-5.0 mgll- may have sub-lethal effects on growth, feed conversion and tolerance to disease; 0.34.8 mgA - lethal to many species if sustained for a long period.
Oxygen depletion In water 1s rectlfled by the following aeratlon methods
Manual: In thls method, water surface IS splashed wlth bamboo stlcks Th~s helps In dlssolvlng atmospherlc oxygen In water Mechanical: A dlesel water pump 1s operated through th~s method Water IS pumped out and s~multaneously sprayed In agaln Into the water body Thls helps In d~ssolut~on of atmospherlc oxygen Aerators: Aerators are mechanical floatlng devlces Thelr rotatlng blades churn the water helplng In d~ssolutlon of abnospherlc oxygen In water Depending upon the concentration of oxygen In waters, the number and placement of such aerators are determined
Other steps taken to control the oxygen level are
Care should be taken to feed fish In the afternoon or evenlng In heavlly stocked pond systems as oxygen requirement In fish after feeding Increases and dissolved oxygen IS mlnlmum In pond dur~ng early mornlng . Organlc manure appllcatlon In a water area should be done carefully as organlc materlal consumes oxygen durlng decompos~t~on Therefore, the quallty of manure to be applled w~thout the rlsk of oxygen deplet~on can be calculated taklng Into conslderatlon the avallablllty of d~ssolved oxygen durlng the 24 hr perlod Durlng collapse of phytoplankton bloom, decomposltlon occurs and In the process oxygen requlrements of microorganisms Increase Thus, speclal care has to be taken durlng thls tlrne Speclal care has to be taken as fish requlre more oxygen wlth lncreaslng of temperature
Temperature
Temperature sets the pace of metabolism by controlling molecular dynamlcs (d~ffus~b~l~ty, solub~l~ty, fluldlty) and blochemlcal reactlon rates Under favourable condltlons, the optimum temperature range for many coldwater and warm water fishes are 14-18" and 24-3O0C, respectively Water temperatures can be adjusted to optlmum levels In controlled system such as hatcheries It IS dlmcult to adjust water temperature In large water bodles Operation of aerator during calm and warm afternoon helps to break thermal stratlficatlon by mtxlng warm surface water wlth cool subsurface water Plantlng of trees on pond banks to glve shade will reduce stratlficatlon but at the same tlme, reduces the beneficla1 effects of wlnd mlxlng and restricts solar energy for photosynthes~s
Turbidity
Turbidity in culturable water is the resultant effect of several factors like suspended soil particles, planktonic organisms, humus substances produced through decomposition of organic matter, etc. Turbidity is measured by Secchi disc visibility. Optimum Secchi disc visibility in fish ponds IS
considered to be 40-60 cm. Turbidity resulting from plankton is generally desirable. Guidelines for suspended soil particles value for fish production are:
Up to 10 000 mgll Freshwater carps, Tilapia sp. and catfishes are tolerant to this level, however, the effect will depend upon the nature of the suspended particles. Pond waters turbid wlth suspended soil particles can be controlled by application of 500-1,000kglha organic manure. 250-500 kglha gypsum or 25-50 kglha alum.
Ammonia
The total ammonia concentration in water comprises two forms, namely: NH3 = unionized ammonia (Free ammonia) and NH4' = Ionized ammonia
They maintain equilibrium as per the equation: NH, + H20 -+ NH4' + OH'
The un-ionized ammonia fraction IS more toxic to fish and the amount of the total ammonia in this form depends on the pH and temperature of the water. As a general rule, the higher the pH and temperature, the higher is the percentage of the total ammonia present in the toxic un-ionized form Below are guidelines for un-ionized ammonia level for fish growth:
0.02-0.05 mgll -safe concentration for many tropical fish species; 0.05-0.4 mgll - sub-lethal effects depending on the species; and 0.4-2.5 mgll - lethal to many fish species.
There are a number of measures to maintain safe ammonia concentration in pond water. Normally at high dissolved oxygen and high carbon dioxide concentration, the toxicity of ammonia to fish is reduced. Some recommended measures to reduce the effects of ammonia are:
Aeration will increase the dissolved oxygen concentration and decrease the increasing pH, thereby reducing toxicity. Healthy phytoplankton populations remove ammonia from water. Care should be taken while using fresh manure with high ammonia content.
Biological filters may be used to treat water for converting ammonia to nitrite and then to harmless nltrate through nitrification process. A high quality feed that contains no more nitrogen (crude protein) and phosphorus than actually needed by fish should be used in ponds and also over-feeding should be avoided Excessive liming should be avoided as it raises pH and high pH favours ammonia toxicity to aquatic animals. Water exchange can reduce ammonia concentrations in ponds. From both economic and environmental perspectives, water exchange should only be used when necessary. Formalin can be used to remove ammonia from fishponds.
Nitrite
Nitrite is an intermediate product in the biological oxidation of ammonia to nitrate, a process called nitrification. In most natural water bodies and in well maintamed ponds, nitrite concentration is low. In water bodies with high organic pollution and low oxygen concentration, nitrite concentration may increase. Guidelines for nitrite value for fish growth are as follows:
0.02-1.0 mglL - sub-lethal level for many fish species; 1.0-10 mglL - lethal level for many warm water fish species
Measures to maintain safe nitrite level in water are:
Correct stocking, feeding and fertilization practices should be maintained. The ponds should be kept well oxygenated. Bio filtration is done through special filters by which biological conversion of nitrite to harmless nitrate occur.
Hydrogen Sulphide
Freshwater fishponds should be free from hydrogen sulphide (HzS). Hydrogen sulphide is produced by chemical reduction of organic matter that accumulates and forms a thick layer of organic deposit at the bottom. Unionized hydrogen sulphide is toxic to fish, but the ions resulting from its dissociation are not very toxic. Guidelines for hydrogen sulphide value for fish growth are:
0.01-0.5 mgA - lethal to fish and any detectable concentration of hydrogen sulphide in water creates stress to fish;
e 0.1-0.2 mgA - prawn lose their equilibrium and create sub-lethal stress; 3 mgll - prawn die instantly.
Measures to rectify increase in hydrogen sulphide levels include:
Frequent water exchange to prevent building up of hydrogen sulphide in the water body; When l~ming increases pH of water, the toxicity of hydrogen sulphide decreases
pH is a measure of the hydrogen ion concentration in water and indicates how much acidic or basic the water is. Water pH affects metabolism and physiological process of fish, pH also exerts considerable influence on toxicity of ammonla and hydrogen sulph~de as well as solubility of nutrients and thereby water fert~llty Guidelines for pH value for fish production are given in Table 1 below:
Tablel.Effect of pH on fish.
pH Effect 4 Acid death po~nt 4-6 Slow growth 6-9 Best for growth 9-1 1 Slow growth, lethal to fish over
long per~od of t~me 11+ Alkal~ne death point
Measures for rectifying alkaline and acidic water bodies are provided below.
Alkaline Waters
. Ensuring good water management may rectify rapid fluctuations in pH caused by excessive phytoplankton populations. Water body should have an alkalin~ty of more than 60 mgll as CaCO3. Application of acid forming fertilizers.
Acidic Waters
Calcium carbonate (CaC03), calcium hydroxide (Ca (OH) 2), calclum oxide (CaO) or dolomite IS used to rectify the acidic water bodies depending upon the pH. Salt water like seawater may be flushed through water bodies of coastal f a n s to neutralize acidity.
Total Alkalinity
Alkallnlty refers to the concentratlon of bases In water and the capaclty of water to accept ac~d~ty 1e the buffer~ng capacity In most waters bicarbonates and carbonates are the predominant bases Guldellnes for alkal~nlty for fish growth are
300 mgll - create stress to fish; 75-300 mgll - ideal for fish; <75 mgll - create stress to fish
Low alkalinrty can be rectified by treatment with lime
Total Hardness
Contents of alkali earth metals; mainly calcium and magnesium constitute the total hardness of a water body. Guidelines for hardness value for fish growth are given below:
60 mgll - satisfactory for pond productivity and helps protect fish agalnst harmful effects of pH fluctuations and metal ions; 4 0 mgll - creates stress to fish.
Measures for rectification of low hardness:
Ponds with low hardness can be treated wlth lime for rect~fication.
Carbon Dioxide
Carbon dioxide is present in the atmosphere in very small quantity. For this reason, in spite of its high solubi l i in water, its concentration in most water bodies is low. It occurs in water in three closely related forms, namely: (a) free carbon dioxide, (b) bicarbonate ion (HCOj), and (c) carbonate ion ( c o t ) . The amount of each form presents, depends on the pH of water. For example, in neutral or acidic waters high concentrations of free carbon dioxide, i.e., the toxic form is frequently found. Guidelines for carbon dioxide value for fishponds are:
12-50 mg/L - sub-lethal effects include respiratory stress and development of kidney stones (nephrocalcinosis) in some species; 50-60 mglL - lethal to many fish species with prolonged exposure.
Measures for controlling high carbon dioxide concentration include:
Repeated aeration of water;
. Increasing the pH of water by hydrated lime can control high carbon- dioxide concentration. Experiments have shown that 1.0 mgll of hydrated lime can remove 1.68 mgll of free C02; and Correct stocking, feed~ng and fertilization should regulate phytoplankton population and the organlc loading in a water body.
Water Exchange
There are reasons to exchange water in specific instances, such as to reduce salinity, to flush out excessive nutrients and plankton or to reduce ammonia concentrations. However, daily water exchange usually does not improve water quality in ponds, and pumping costs are a liability. Ponds are highly efficient in assimilating carbon, nitrogen and phosphorous inputs not converted to fish or prawn flesh, but if water exchange is great, these substances are discharged from ponds before they can be assimilated. Thus, the pollution potential of aquaculture ponds increases as a function of increas~ng water exchange. From both economic and environmental perspectives, water exchange should only be used when necessary.
Role of KVKs for Dissemination of Proven Aquaculture Technologies to the End Users
Balaram Behera, Suresh Chandra and Sukantl Behera
Krishi Vigyan Kendra Central lnstltute of Freshwater Aquaculture
(Indian Council of Agricultural Research) Kausalyaganga, Bhubaneswar-751 002, Orissa, lndia
Introduction
lndia is blessed with vast and diverse aquatlc resource which along with other uses could be suitablly used for fisheries activities. A large untapped potential through aquaculture could improve the livelihood of millions of people in rural areas. Still a large gap exists between technology generated at institutions level and the~r transfer to farmer's field. Adoption of effectlve extension methodologies coupled with proper utilization of water resources. inputs like feed, seed, fertilizers and marketing of produce play important roles in making agricultural activity more profitable, farmer's friendly and sustainable. In the freshwater aquaculture three technologies namely induced breeding of carps, nursery and pond rearing management practices and composite carp culture have virtually revolutionized freshwater aquaculture in the country and brought it from a level of backyard activity confined to few states to that of fast growing well organized industry. To improve farming systems and quality of llfe of farmers, KVK Khurda has been actively engaged in dissemination of the freshwater aquaculture technologies to the rural farmer, unemployed youth and grass root extension workers by organizing first llne demonstration, farmers meet, exhibitions, exposure visits, training, publication of extension materials, etc. involving large number of Scientists and Subject Matter Specialist of the institute to develop effective scientist-farmer and farmer-farmer linkage.
Rural Extension for the Sustainable Development
In the most recent couple of decades, the output of the Indian aquaculture has been steadily increased by 7% annually. The total national production stands the second in the world with a total production of more than 6.4 million tonness and average share reaches over 9 kg per capla. However, the improvement of the farming systems, the enhancement of the farming technologies and the input of the research findings are the key factors in increasing fish production, but they further demand effective extension methodologies that bridge the research and the farmers, thus, converting the research outputs to the production power at the farmers' level and sustaining the development of aquaculture.
lnstltutions Engaged i n Aquaculture Extension
In the country about 550 KVKs, 429 state Fish Farmers Development Agencies (FFDA). 39 Brackish water Development Agencies (BFDA), 93 ICAR research institutions, untversities, other central and state government agencies, NGOs and busmess houses are promoting aquaculture development in the country.
Identification o f Technology
Depending upon the available resources, topography of the area, local need of the farmers market and other social factors are considered before operation of any extension programme on a targeted individuals or group balancing the relat~ons between the economical returns and environmental impacts. Beneficiaries never believe anything without successful examples obse~ed with their own eyes. To mobilize and lead the farmers to a new fish farm~ng practlce for better production is one of the important steps in extension.
Transfer o f Freshwater Aquaculture Technologies
Over the years KVK and ClFA has successfully disseminated various technologies namely carp and catfish seed production, nursery and rearing methods, composite carp culture, prawn farming, utilisation of oganic wastes in aquaculture, fish farm~ng in sewage water, portable FRP carp hatchery for seed production.
Transfer of Portable Carp Hatchery Technology- KVK Perspective
Seed is a critical input in the any agricultural activity. With the fast growth of aquaculture in the country, demand for seed is increasing day by day. In many disadvantageous, remote hilly and tribal areas, where means of transport are not sufficient, unvaiiability of carp seed is still a limiting factor and aquacultue is not coming in a big way. To develop freshwater aquaculrure in these areas, a sustained timely supply of fish seed is the prerequsite. To meet this demand, establishment of portable FRP carp hatchery in the identified area suitable for fish culture can play an important role in this endeavour. Vast network of KVKs spread throughout the country could be utilised for dissemination of this technologey particularly in disadvantageous areasin the country.
Participatory Approcah
Under this approach local knowledge available with fish farmers and the scientific knowledge of researchers are combined together to find suitable
solutions for a partrcular problem In th~s approach extenslon personal facllltate the lnteractlon between farmers and researchers to bulld the capac~ty of farmers to Improve thelr l~vel~hood Researchers present varlous flsh farm~ng systems to the farmers for evaluat~on locally Th~s part~c~patory technology development (PTD) approach has been found vely effecttve In aquaculture
Extension Science Studies
Well-tested quality research outputs and practical farmers experience act as powerful extension methodologies before reaching the farmers. A team of the extension personnel will be able to establish the extension programmes and able to help the farmers, select appropriate technology aside from important considerations on the needs of the ind~vidual farmers, local commun~ties. Impact of the environment, etc. Upgradations of the subject matter knowledge along wlth extension sk~ll of the extension personnel should be at regular basts so that they can better understand the changing trend. This will help in motivation and mobilization of fish.
Strengthening Extension Services
Technology transfer to rural people demands a good quality extens~on team, which is always available for the farmers. Extension workers with poor knowledge, lack of extenslon means, less access to the fresh knowledge leads to failure of the programmes. In the extension process an extension staff should be able to apply what they have learned in the fields and show to the farmers in a better way. In culture practice an extension personal should be able to make proper stocking density, stock~ng of big sized healthy seed, right species selection, appropriate manuring and feeding, health monitoring. etc Similarly in induced breeding of carps, good select~on of the brooders, hormones, injection methods, response time, fertilized egg collection, hatching, etc should be made known to farmers. A good extens~on worker always generate congenial and a strong ground among the farmers.
Good communication is an effective means in contacttng with the farmers. The extension people should be active in speaking their minds, fluent wording, easy to probe the problems, etc. Of course it demands good communication skills. On the other hand, the extension people can not only help the farmers to find out their own problems, but also, be able to help the farmers to propose new projects in development, collecting Information for seed supply and marketing channels.
