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