- Email: [email protected]
Emerging scope, technological up-scaling, challenges and governance of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) production in Himalayan region
Journal Pre-proof Emerging scope, technological up-scaling, challenges and governance of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) production in Himalayan region
Atul K. Singh PII:
S0044-8486(19)32653-5
DOI:
https://doi.org/10.1016/j.aquaculture.2019.734826
Reference:
AQUA 734826
To appear in:
aquaculture
Received date:
7 October 2019
Accepted date:
3 December 2019
Please cite this article as: A.K. Singh, Emerging scope, technological up-scaling, challenges and governance of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) production in Himalayan region, aquaculture (2019), https://doi.org/10.1016/ j.aquaculture.2019.734826
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© 2019 Published by Elsevier.
Journal Pre-proof Emerging scope, technological up-scaling, challenges and governance of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) production in Himalayan region
Atul K. Singh* Former Director ICAR-DCFR & Emeritus Scientist National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow-226002
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(Uttar Pradesh) India
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*Email: [email protected]
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Abstract
Rainbow trout is one of the promising cultivable fish species in coldwater and has enormous
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scope for its expansion in the Himalayan region. Being a low volume high value commodity, the
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trout has good potential for domestic consumptions as well as foreign export. In spite of having excellent positive traits and prosperity, the development and expansion of trout farming in
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Himalayas has yet to be intensified for large-scale productions. There are enormous aquatic
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resources in the form of river, reservoirs and lakes in the Himalayan region yet agricultural production of trout is very limited. This paper presents the available trout production system, available
infrastructure
and
production
trend
highlighting the need
of improved
feed,
infrastructure, improved strain, application of triploid trout production for stocking in cages and pens and also the possibilities of organic trout farming so as to clinch the production intensification, environmental management and trout promotion objectives on scientific. Based on 15 years experience of trout culture in India, potential success in trout production could be acquired through technological modernization, better governance and significant improvement in
Journal Pre-proof the management practices. The knowledge needed to form a comprehensive trout-farming ecosystem beyond farm activities has been suggested in this paper which will be useful not only to the country but also to the transboundary Himalayan countries where trout farming is still rudimentary.
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Keywords: Rainbow trout; culture system; triploid; organic trout; governance
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1. Introduction
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Rainbow trout Oncorhynchus mykiss is a member of the salmonid family that is an important
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aquaculture species of major economic importance raised in both hemispheres and on all continents. Rainbow trout is native to the Pacific drainages of North is now widely introduced to
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over 100 countries worldwide including India (DIAS 2019). FAO database for aquaculture
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production does not show any production data of rainbow trout in India, China, Thailand, Malaysia, Indonesia, Nepal, New Zealand, Pakistan and Sri Lanka although data for the top ten
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trout producing countries are available (FAO 2016). Most likely, rainbow trout farming in many
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of these Asian countries has not yet been commercialized and is still in the research and development phase. Trout farming in India is over three decade old and there are several species of trout in the country (Singh and Lakra, 2011) but rainbow trout is a species of choice of aquaculture. Rainbow trout is relatively easy to culture and has better growth and maximum cultivable traits (Joshi et al., 2005). This amazingly versatile species can tolerate a wide range of water temperatures (from 0-23˚C) and there are numerous freshwater sources in which they can be grown. They thrive in water originating from aquifers, springs and streams – as well as in lakes. In India, rainbow trout farming is although an old endeavor, its farming is now getting
Journal Pre-proof organized as there is vast scope. In J&K state of the northwest Himalaya the trout farming project was established during 1984 at Kokernag with the assistance of European Council (EEC) and it happens to be one of the largest trout-farming infrastructure in the Asia while in Himachal Pradesh, trout farming started during 1991 with the help of Indo-Norwegian assistance. Of late, it has been realized to venture rainbow trout culture in the state of Uttarakhand located in central
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Himalaya and Sikkim as well as Arunachal Pradesh in the eastern Himalaya (Figure 1).
Figure 1: Trout farming states in Indian Himalayan Region (IHR)
Journal Pre-proof The Himalayan region of India possesses plentiful aquatic resources in the form of river, reservoirs and lakes. A GIS based information on various aquatic resources was generated for different Himalayan States, which is summarized here (Table 1). The generated information has given a clear picture that there are enormous aquatic resources in the form of rivers, reservoirs and lakes in the Himalayan region, which have high potential of rainbow trout farming. It is to mention here that ponds and tanks created along the river streams only are being used for trout
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culture while abundant scope of raising trout in the river, lakes and reservoirs utilizing modern
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aquaculture tools such as cages and pens exists for enhancing production manifold. Assuming
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that even if 2% of the existing resources are utilized under trout farming, the production can go
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several folds high. Based on the available aquatic resources, it is assessed that 957 km long river streams, 2826.6 ha of reservoirs and 963 ha of lakes can be utilized for trout culture in different
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Himalayan states (Table 1) whereas it is estimated that not even 20 ha of water area is utilized
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under trout farming in India at present. The significance of the study aims to find problems and prospects of trout farming in Himalayan region to help developing beneficial policy and
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governance for appropriate implementation, regulations and support. The paper presented
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various critical areas to be covered while promoting rainbow trout culture along with environmental knowledge needed to form a comprehensive trout-farming ecosystem beyond farm activities. The knowledge generated will be useful not only to the country but also to the transboundary Himalayan countries where trout farming is still rudimentary.
Journal Pre-proof Table-1: State wise water resources in Indian Himalayan Region (IHR) (Source: modified after
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Himachal Pradesh
Uttarakhand
Rivers
(ha )
(ha)
(km)
137275. 3
4087.3
10893.5
(2745)
(88)
(222)
27.2
31320.2
10464.3
(0.5) 212 (4) Sikkim
1004.5
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2
Jammu & Kashmir
Total Lakes Reservoirs
(626)
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1
State Name
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S.N
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Prem Kumar et al., 2017; Singh, 2019)
16864
10657.8
(337)
(213)
--
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(21)
Arunachal Pradesh
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Total
2792
3298.1 (66)
--
(56) 2826.5
(209)
12351 (247)
963
957
Note: Values in parentheses are assessed potential water areas for trout culture
2. Production System Rainbow trout is a fast growing, coldwater fish in India that typically growing to sizes of 0.3-1.2 kg. It is most commonly grown in cemented raceways where it contributes over 90% of total production, although earthen ponds and other structures made of other materials are also used (Singh et al., 2017). Few trout growers of Arunachal Pradesh and J&K are practicing trout
Journal Pre-proof farming in earthen raceways for trout rearing. The use of a variety of aquaculture systems i.e., ponds, raceway, RAS, net cage, are available widely in scale of adoption in the country. However, in trout farming, the size of trout raceways varied between different Himalayan States. However, for adopting a uniform policy of extending financial support to the private trout growers by the central sector, a standard size of 10x3x1 m has been fixed for consideration. In concrete raceways, the trout farms are horizontally constructed and spread and are arranged in
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series and/or in parallel with water flowing along a downhill gradient.
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Since Himalayan states have a forest cover of about 45.5% the accessibility to water
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resources from the main habitation is difficult. Moreover constructing cemented raceways is not cost effective endeavor due to difficulties in carting of building material and hiring labour at an
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elevation of 2000 to 2500 masl where trout farms are clustered. Along with tilapia, catfish, and
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bass, in the plains, trout is a very popular fish for consumption in IHR. In view of hardships faced by the private trout farmers, an experiment was designed and executed to raise rainbow
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trout in FRP tanks. In Kumaon region in the Nainital district at Bhimtal it was found that raising
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trout fingerlings (5 gx100 no) in FRP tank of size 2x1x1m in triplicate with running water 8 l/minute could produce 47 kg of fish in just 7 months. However, using such fabricated recirculating system with FRP tanks provided 15-20% more production with economical use of water and its re-use. The used fabricated technology can be scaled-up for commercialization of trout farming in IHR.
At present the scale of farm’s production is limited as most of the trout farms are traditional type having flow-through systems, in which the water is taken in via a damming of the adjacent water
Journal Pre-proof course and water then passes through the farm by gravity. Regardless of the water source, the flow-through nature of raceway systems necessitates that water exchange and turnover rates should be high in order to maintain water quality (Fornshell et al., 2012). In general, a trout farm requires little land conversion as a result the intensive production is achievable in flow-through raceways and ponds.
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The Himalayan states in India are typically producing nearly 600 kg of trout per raceway; while
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production of 1000 kg was also achieved at some farms. While extrapolating the production, it
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comes equal to 200 tons/hectare/year and competes with any other highly productive aquaculture
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species and the system available in the country. Even large farms producing 1,000 tons annually would only need roughly 3.33 ha of water in existed raceways, and some space for support
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buildings (Woynarovich et al., 2011). Therefore, it is estimated that production of over 1100 tons
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of trout in India during 2019 is roughly available from not more than 20 ha of culture water, whereas the Himalayan region is endowed with huge water resources in terms of river, reservoirs
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and lakes (Table 1) and consequently there is enormous scope of enhancing trout production
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manifold provided adequate infrastructure, quality feed and better strain of trout are made available. An understanding of the economic drivers influencing the trout farming activities in the IHR has been generated based on field information, literature and self-experience. The majority of the farms studied have shown profitability primarily due to advantages of premium price of the fish and favourable climate conditions.
The factors behind the heterogeneity of growth in different states could not be assessed since comparable economic data at farm level are not available and would be useful in identifying the
Journal Pre-proof critical gaps behind this heterogeneity of growth. In an ideal world of trout culture, it is to mention that data pertaining to economic performance conforming to internationally compatible standards in order to examine the cost structure, profitability information about the costs and returns of trout farming is rarely available except at a few countries such as Norway (Asche & Bjorndal, 2011) and Denmark (Statistics Denmark 2014) annual data are collected at farms to
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assess performance (Tobias et al., 2017).
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The optimal conditions for the survival and growth of fish necessitate not only adequate
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amounts of water which should be as much as 86,000 m3 to produce 1 ton of fish, but also
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requires optimal temperature varying from 12 to 18°C and highly well oxygenated quality water. The availability of bulk of required water availability at trout farms varied highly in IHR
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consequently the stocking density also varied from farm to farm. However, it was observed that a
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flow rate of 4 l/sec can support up to 20 kg/m3 fish, though higher volume and higher quality may allow stocking densities as high as 35 kg/m3 or even more as was found in some special
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cases in J&K as well as Kullu in Himachal Pradesh.
Trout aquaculture needs specific chemical and biological conditions too, which are difficult to be fully understood by the private trout growers as they are devoid of the data of the physico-chemical parameters of water quality. Because the chemistry of water provides much information about the metabolism of a given ecosystem and explains general hydro-biological relationships in relation to growth and overall productivity of the farms. Further, the intensive trout producing farms do not have idea of impurities and contaminants produced in the trout farming which are derived from metabolites secreted by fish (through gills and with urine) or
Journal Pre-proof from degradation of feed and suspended particles. It is estimated that in the intensive systems of aquaculture, only 20–40% of feedstuff mass are built into fish bodies, whereas the remaining part is excreted. In all such systems of trout farming, part of these wastes is discharged with postproduction waters; however, their quantity and quality differ depending on the culture system. In the flow systems, all dissolved contaminants and solid impurities are released into the environment. It is assumed that the amount of wastes generated by fish farms may be less at
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farms using standard flow systems however, future intensification of the trout farming activities
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will require precautionary approaches and water quality monitoring to make the trout farming
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environmentally sustainable.
Northwestern regions of India the J&K as well as Himachal Pradesh have progressed well in
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rainbow trout farming due to most suitable climatic condition and topography for creation of
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suitable trout farming infrastructures. Trout farming in these states has become a major economic activity. Trout farming has now expanded from northwestern states to Uttarakhand in central
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Himalayas to Arunachal Pradesh, Sikkim and of late Nagaland in eastern Himalayas. Besides, its
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culture in Ooty and Munar southern part of the country although very old yet rudimentary now is reviving. At present different Himalayan States have got 64 government farms and over 1380 trout units in the private sector. Besides, there are 30 hatcheries having capacity to produce 14 million fry (Table 2).
Journal Pre-proof Table 2: State wise details of trout infrastructures in IHR Infrastructure Sr.
No. of Private
Hatcheries
Feed
Culture status
State No.
1.
Govt.
trout
farms
Units
45
533
mills
J&K
Govt. 14
&
private
&
private
&
private
&
private
3
5
572
5
Pradesh Uttarakhand
4.
15
Sikkim
Arunachal 3
Tamil Nadu
7.
Kerala
1
5
2
sector Govt. sector Govt. sector Govt. farm only
2
Nil
1
-
1
Nil
-
2
1
Nil
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6.
-
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Pradesh
249
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5
5.
3
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4
Govt.
2
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3.
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Himachal
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2.
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sector
Govt. farm only Farms
(Private
sector)
With the present infrastructures for trout farming available in the government and private sector, the present rout production is just over 1100 tons in the country where J&K is contributing over 600 tons followed by Himachal Pradesh while Sikkim is contributing around 120 tons per anum (Figure 2).
Journal Pre-proof Figure 2 (A&B): Status of trout production in IHR
700
2011-12 2015-16
600
2012-13 2016-17
2013-14 2017-18
1200
2014-15 2018-19
31%
1000
500
Tons
800 400
600 300
400 200
200
100
2018
2004
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0
0
Himachal
Sikkim
others
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J&K
B. Annualized growth in production
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A. State wise production
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There has been over 31% annualized growth in the trout production over the last 15 years which could be possible due to advancement of the technical knowledge on trout farming and
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improvements in the artificial diets, management and also breeding and propagation. It is
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important to mention here that involvement of private trout growers and improvements in input quality (seed and feed) and governance brought about a very encouraging growth in trout
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farming promotion. Nevertheless, limited infrastructure available in the country needs to be
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revamped as creating larger infrastructure facility, catering the need of fingerlings requirements, improved quality of feed and better management practice will certainly boost up trout production.
With the available trout hatcheries, hardly 14 million trout fry could be produced whereas we need large number fry and fingerlings round the year to raise trout production after enlarging trout production units. Likewise culture facility should also be multiplied through adequate financial support to the trout growers as erecting infrastructure for trout farming is cost intensive
Journal Pre-proof and it is difficult for farmers to come forward for developing trout farms on their sloe investments. At the same time it is also proposed to raise trout culture in lakes, rivers and reservoirs using cages besides intensifying culture in raceways and also using RAS technology.
3. Trout farming in cages and RAS Because the country is having limited culture facility, there is need to tap the existing
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highland lakes, river streams and other aquatic bodies above 2500 masl as these water bodies are
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under exploited for aquaculture (Singh, 2019). There are several lakes and river streams devoid
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of any fishery activity. Besides trout farming can also be taken up in cages fixing them in lakes
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and reservoirs. One of such initiative was taken up in east Sikkim where a battery of 9 cages having dimension of 9x4x3 m was fixed in Memencho Lake and stocked with fingerlings
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weighing 5 g. It grew up to 150 g in six months. The production is very encouraging yet the
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practice has to be standardized for commercial application.
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The production of rainbow trout (Oncorhynchus mykiss Walbaum 1792) is practiced in different
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production systems which are mostly extensive system (ES), however, recirculating aquaculture systems (RAS) can be used for intensive trout production (Samuel-Fitwi et al., 2013). Since extensive trout production systems practiced in India which is based on limited requirements of resource and hence subsequent output and emissions may not impact the environment (Andre Meriac et al., 2014). Nevertheless, intensifying trout culture may possibly impact the environment besides adequate usage of water and resources as feed. It is therefore, strongly proposed to adopt RAS based intensive production of trout in India as well. A semi-commercial (32 m3 capacity) RAS system consisting of larger culture tanks (7 m3 water volume) and smaller
Journal Pre-proof (0.5 m3 ) experimental tanks designed by the ICAR-DCFR, Bhimtal have been assessed for demonstration of recirculatory aquaculture system technology, which minimizes the usage of land and water in rainbow trout culture.
For strengthening such endeavour, recently a
memorandum of understanding (MoU) has also been signed between Government of J&K and government
of Denmark
for
transferring
of Recirlculating
Aquaculture
System (RAS)
technology, automatic feeds, brood equipment and for rearing trout Fish production. Such
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initiative of RAS technology and also cage culture in trout farming will certainly help
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intensifying rainbow trout production in IHR.
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4. Triploid trout production
The occurrence of precocious maturation (early onset of puberty) in commercial grow-out
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systems is a prevalent constraint that leads to post-pubertal growth rate, carcass yield, flesh
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quality, market value and lower return to farmers (Piferrer et al. 2009). Moreover, when trout farms being proposed adjacent to natural streams or other water sources especially culture in
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cages, there is all possibility of their escapes in natural systems. The escape of domesticated
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rainbow trout into the wild may be a serious environmental concern as the escapee fish can contaminate and disrupt the receiving ecosystem (Benfey, 2015). The remedy for overcoming the farming intensification of trout in river streams, reservoirs and lakes may be the socking of triploid stocks which is the induction of reproductive sterility. The most practical and effective way to produce sterile rainbow trout is the manipulation of chromosome sets (induced polyploidy). The usage of triploid fish for commercial purposes has numerous advantages as it contains three sets of chromosomes and is genetically sterile consequently it provides ecological safety to the aquatic bodies which are pristine and untapped in the higher Himalayan reaches
Journal Pre-proof where aquaculture activity is still rudimentary. A triploid fish has reduced gonadal development since the energy is directed towards the somatic growth for the development of flesh quality (Kizak et al. 2013; Kim et al., 2017). These characteristics have drawn the attention of the scientists in India recently determined to produce triploid rainbow trout. The production technology is being standardized at ICAR-DCFR, Bhimtal by using thermal and pressure shock to produce triploidy. Once the developed technology reaches at commercial scale of adoption, it
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will be a safe approach to stock the untapped natural water bodies in higher reaches beyond 2500
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masl in Himalayas.
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5. Improved strain and stock:
To facilitate sufficient and better quality inputs, we need to develop improved practice of brood
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management and breeding strategy (Lhorente et al., 2019). Since rainbow trout is an introduced
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species in India, its scientific management especially of the brood stock is very essential. The first culture strain of rainbow trout imported was European strain while the other was Norwegian
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strain. Although European strain was initially propagated, attempts were made to determine how
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the two different strains performed in the country and the same was evaluated (Barat et al., 2014). It was documented that both the stocks have considerable amount of genetic variability, yet there is need for pedigree breeding strategies so that future chances of inbreeding can be minimized using many pairings and equalization of family size to maximize effective population size. It is imperative that systematic breeding plan can significantly improve the profitability of production. Breeding experience has shown that the so-called partly factorial mating design fetches optimum benefits of the crossings in relation to inbreeding, diseases etc. This design means that the sperm from one male is used to fertilise half of the eggs from each of two
Journal Pre-proof females. Thus, each female is fertilised by two males. Likewise successful attempt has also been made in cryopreservation of milt of superior males and crossbreeding with it for upgrading the stocks. Whatsoever is the performance of the existing stocks, state departments and the research institution have been demanding for better strain since there is a possibility of better genetic improvement of the existing stocks by introducing newly selected strains and enhancing aquaculture productivity in the coldwater regions (Barat et al., 2014).
Recently J&K state
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imported rainbow trout seed from Denmark during January 2019 to boost the production of the
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fish from present 600 tons to 5000 tons per year over next five years. A consignment of 2.25 lacs
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eyed ova of rainbow trout was successfully imported from Billud in Denmark Rever Roheamger
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and being reared at Beerwah trout farm in J&K for developing a better brood stock in the state.
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6. Improved Feed
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A major issue in trout culture is the unavailability of improved feed as the stakeholders are not getting desired growth in fish and also on affordable price. The increasingly scarce
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supply of fish meal and its high market price has made it necessary to seek a cost effective
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replacement of fish meal to supply dietary protein in trout feed. One of the promising alternate to fishmeal has been considered to be plant based protein, which is rich in protein and generally low in phosphorus (Geurden et al., 2013). Trout is a predatory fish, although it consumes and assimilates plant protein, however its intensity of growth on such food is much lower. In the plant origin feed, the protein deficiency of amino acids like lysine and methionine usually occurs.
Protein digestibility remains in lower side when diet containing soybean protein due to
anti trypsin factors. Current research shows that feed performances and digestibility can be increased with the use of enzymes and balancing amino acid profiles that enhance plant protein
Journal Pre-proof use (Guerden et al., 2013). State Fisheries departments especially in J & K and Himachal Pradesh produce several forms of dry and moist trout feeds. The variation in nutrient composition of available trout feeds is not farmers friendly and are not suiting to the requirement consequently low cost diets need to be produced by developing diets with reduced food conversion ratios (FCR) and less dependence on fish meal by improving palatability and
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digestibility of raw ingredients.
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Our recent study at ICAR-DCFR, Bhimatl for developing trout feed has been conducted which is
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based on Protein extracts from single cell protein (SCP) sources from different types of
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unicellular microorganisms, such as fungi, bacteria, yeast, and algae. These microorganisms need varied carbon sources for the generation of new proteins and other metabolites, such as fats, High protein distiller’s dried grains derived from rice (HDDG) and
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vitamins, and carbohydrates.
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a bacterial meal derived from methane oxidizing bacteria (String Pro) is under study for investigations on fishmeal replacement to produce low cost feed in India. In terms of nutritional
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composition, HDDG has 62-65% crude protein, 1.5-3% crude lipid, 9-12% starch, 2.5-6% fibre
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and 2.5-6% ash. String Pro meal had 72.5% crude protein, ~8% crude fat, 3.3% starch, 3.8% fibre and 7% ash. Lysine and cysteine-methionine content was lower than that of fish meal, but all the other amino acids were in equal or excess levels. For further studies on these alternate protein sources, the ICAR-DCFR has signed a memorandum of understanding with S.P.Y. Agro Industries Ltd., Nandyal, Andhra Pradesh (high protein HDDG producer) and String Bio Pvt. Ltd., Bengaluru, Karnataka (methanotrophic bacterial meal producer). In the first feeding trial under this study, the potential of HDDG has been evaluated, a by-product obtained in the process of producing alcohol or neutral spirit in modern grain based distillery units, as a Fish meal (FM )
Journal Pre-proof substitute in trout feeds. For that, triplicate groups of juvenile rainbow trout (mean initial weight ~ 30 g) either of five experimental diets (Control, completely FM based; 25R, 25% FM replacement; 25S+, 25% FM replacement + limiting nutrients + phytase; 50R, 50% FM replacement; and 50S+, 50% FM replacement + limiting nutrients + phytase) were fed for 12 weeks. The trial has been conducted in an experimental RAS system developed locally, with water temperature maintained at 17 ± 2°C. So far the findings of this study are in process of
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generating data on growth (weight gain, SGR and TGC) and feed utilisation (feed intake and
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FCR) indices, analyses of amino acid profile in feed and whole body samples. Based on growth
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and feed utilisation, it may be concluded that it is possible to partially replace FM in trout feeds
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using HDDG, without any nutrient supplementation.
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7. Organic farming
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Organic trout farming has been introduced in several European countries since the 1990s. The main producers are France (2,300 tons), Denmark (1,634 tons) and Italy (1,000 tons) (European
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Union 2017). Among other countries, Spain, Germany and the UK are also producing organic
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trout (EU 2017). In India, the production of organic rainbow trout has recently shown interest and promises especially in fully declared organic states like Sikkim and Uttarakhand. The available methods of organic farming of trout delineates that in the raceways should be physically separated and there should be separate water supply. Closed recirculatory systems are not permitted in organic farming (Zubiaurre, 2013). Recirculation (incl. heating/cooling) may be used for hatcheries and for fry production. However, only mechanical aerators are permitted and preferably they should be run by renewable energy. Pure oxygen is only permitted in critical situations to secure fish welfare. Feed pigment such as Astaxanthin from natural sources is
Journal Pre-proof permitted within the physiological requirements of the fish. Fish density should be low maximum of 25 kg/m3 . Medication if needed may be done just twice a year for life cycles > 1 year.
Furthermore, some ethics have also to be followed when producing organic trout, which
are given as below:
To create a more ethical method of sustainable production by using local resources and
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natural processes that help maintain the natural cycle (i.e., maintain balance in nature).
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Specific requirements for oxygen content, pH, nitrogen (daily/weekly measurements),
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veterinary control, treatment with antibiotics (once during the organic fish life), and a positive list of chemical additives.
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Accordingly, the use of formaldehyde, Chloramin-T, and copper sulphate are not
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allowed. Only the LT type of fishmeal, which is a wholemeal, produced from absolutely
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fresh fish ensuring an extremely low level of biogenic amines should be used; no fish offal is used due to its phosphorus content. Furthermore, no GMO ingredients in the feed
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and no etoxyquine for feed preservation are allowed.
of water.
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For organic on-growing production, a range of open systems, from flow through to re-use
Oxygen saturation at outlet should be minimum 70% Maximum increase from inlet to outlet (calculated from Qmm) should be 2 BOD should not exceed 1mg/l Suspended solids should not be more than 3mg/l Suspended solids should not be more than 0.05mg/l Ammonia-N should not exceed 0.4 mg/l
Journal Pre-proof Total nitrogen should not exceed 0.6 mg/l
By the given methodology once organic trout farming comes into existence in the Himalayan states, it will add value to the product. Though organic fish farming will involve additional expenses on the whole farm’s structure and management since following arrangements will be required for organic certification and labeling: a) rearing units’ preparation and juveniles input,
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b) feeding (GMO free organic feed), c) monitoring, control, water changes, etc., d) harvesting
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and post harvest fish processing. The trout growers in Himalaya are struggling for improving the
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economical returns as the buyers are not paying suitably so it is imperative that organic trout will tend to attract higher premiums. It is therefore, important to create consumer’s level knowledge
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about ecolabel organic trout farming and the aesthetic quality comparable to conventional trout
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products available so as to attract them. Also ecolabeled rainbow trout will generally appear to
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be more demanding than conventional products. Organic farms in India may face challenges of high feed costs and comparatively low productivity with mixed success. It is therefore necessary
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to create different processing units for organic fish, which will facilitate more marketing
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channels for the primary producers. In Denmark organic rainbow trout is primarily purchased in supermarkets. Likewise, introduction of the Organic Cuisine Label in India, will attract much attention at the food service-sector such as canteens, restaurants and additional public catering.
8. Governance So far governance for trout culture is very limited owing to scanty number of trout growers and state governments do not have any mandatory mechanism to extend technical backstopping to the private trout growers. Nevertheless, some governance issues are flagged below to cater the
Journal Pre-proof immediate need: i) The regulations governing site selection and construction of trout farm should be supported robust and environment friendly, and should not disturb overall maintained functionality of the habitats where trout farms are intended to be sited. It is therefore, the government department and research institute should take responsibility to identify suitable areas for raising future farms culture in IHR and guiding the trout farmers.
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ii) Some farming standards with regard to economical water use, organic trout farming
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module, stocking of triploids in natural aquatic bodies, breeding protocols and brood
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raising as well as feed and environmental regulations owing to climate change need be
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developed for implementation and promoting of water recirculation, stocking density, stocking size, feeding schedule, management practices, environmental management and A detailed developed guideline on these aspects should be made available
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brood raising.
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to the trout farmers and stakeholders.
iii) For trout farming intensification it should be ascertained that chemicals and pollutants
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arising out of trout culture should not disturb ecosystem functionality and in turn affect
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habitats. It is important that the research institutions should develop a standard on trout farm management to regulate water quality especially the water chemistry of used water from trout farms so as to develop regulations. iv) In trout farming use of antibiotics is very common consequently there is possibility of bio-available antimicrobials be discharged and present in the receiving water body. It is thus based on available literature and findings, mitigation way outs should be developed for regulatory limits of chemical type and antibiotic doses to enforce them accordingly.
Journal Pre-proof 9. Conclusion Rainbow trout fish farming is one of the promising industries related to agriculture sector in the Himalayan region. It generates not only the income to the farmers but also creates employment opportunities to the people living in the mountainous and hilly region. In addition, it has potential of export of trout overseas and earn foreign currency. Rainbow trout can also attract internal tourist as well as foreigners and provides fresh fish in restaurant as well as food courts.
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In order to expand the industry, government should initiate and take extra interest providing Trout farming
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adequate infrastructures and technical support to the farmers and stakeholders.
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should be intensified in IHR in a very planned way utilizing modern culture technologies i.e,
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cages, pen and RAS. Integrated trout farming may further be supported to increase the farm produce in comparison to the traditional farming. However, lack of adequate inputs, technical
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knowledge, planning and difficulties regarding the development of infrastructure are the serious
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problems that must be strengthened to encourage and involve large number farmers for trout farming. Due to limited production, it is fairly costly to the local inhabitants and also limited to
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certain hotels, restaurants, and some of the diplomatic offices only. Thus, rainbow trout which is
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being cultured on limited scale holds a great future promises in view of vast coldwater resources available in the country and invigorating its culture by adopting sound technological skills so as to support a skills of production to meet out domestic consumption and export promotion generating foreign currency.
Further, managing environmental constraints owing to climate change and limiting effluent discharge which are of public concerns are the primary requisites toward trout industry expansion. Given water quality and quantity requirements for trout, development of new
Journal Pre-proof facilities should be based on current production techniques. Therefore, production must be strengthened from modern added operations as discussed above for increased efficiency. Development of improved strains, high-performance feeds, triploid stocks, management for environmental control, better governance and new production technologies will add potential for increased production. Value-added products through organinc farming will increase revenues and the product development and marketing will further be key to support large sales since
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consumers increasingly demand quality products that are easily available and healthy. The
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governanve and environmental regulations so developed will be useful not only in the country
Conflict of interest and Ethical Approval
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but also help help neighbouring countries such as Nepal and Bhutan.
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The author declares that he has no conflict of interest. Further, the article does not contain any
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source for this work.
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Practices for Aquaculture (pp. 331–388). Ames, Iowa: Blackwell Publishing. Fornshell, G., Hinshaw, J. M., & Tidwell, J. H. (2012). Flow-through Raceways. In J. H. Tidwell (Ed.), Aquaculture Production Systems (pp. 173-190). John Wiley & Sons, Inc. Geurden I, Borchert P, Balasubramanian MN, Schrama JW, Dupont-Nivet M, et al. (2013) The Positive Impact of the Early-Feeding of a Plant-Based Diet on Its Future Acceptance and Utilisation in Rainbow Trout. PLoS ONE 8(12): e83162. doi:10.1371/journal.pone.0083162 Hong Seab Kim, Ki-HwaChungand Jung-Ho Son (2017).Comparison of different ploidy detection methods in Oncorhynchus mykiss, the rainbow trout. Fisheries and Aquatic
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375-402. Doi:10.1111/raq.12337. Rai A K, R.C. Bhujel, Basnet S.R. and G.P. Lamsal (2005). Rainbow trout (Oncorhynchus mykiss) culture in the Himalayan kingdom of Nepal a success story. Published by AsiaPacific Association of Agricultural Research Institutions (APAARI) FAO Regional Office for Asia and the Pacific Bangkok, Thailand APAARI publication: 2005/1. 34pp. Rico, Andreu et al. (2012). “Use of Chemicals and Biological Products in Asian Aquaculture and Their Potential Environmental Risks: A Critical Review: Environmental Risks of Asian Aquaculture.” Reviews in Aquaculture 4.2: 75–93.
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Sindilariu, P.D. (2007). Reduction in effluent nutrient loads from flow-through facilities for trout
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2109.2007.01751.x
Singh A.K. and Lakra, W. S. (2011). Risk and benefit assessment of alien fish species of the
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aquaculture and aquarium trade into India. Reviews in Aquaculture 3, 3–18
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Singh A. K. (2019). Coldwater Fisheries in India: Priorities, Policy, Institutional Support and Challenges.Advanced Agricultural Research & Technology Journal Vol. III Issue 2 JULY 2019, COSFAD-2019 Special The Danish AgriFish Agency (2014). The Danish AgriFish Agency’s Aquaculture register. Available at http://webfd.fd.dk/stat/Akvakultur_tab/prod_art_12_eng.html Tobias Lasner, Alexander Brinker, Rasmus Nielsen and Ferit Rad (2017). Establishing a benchmarking for fish farming –Profitability, productivity and energy efficiency of German, Danish and Turkish rainbow trout grow-out systems. Aquaculture Research, 2017, 48,
Journal Pre-proof 3134–3148 Woynarovich, A.; Hoitsy, G.; Moth-Poulsen, T. (2011). Small-scale rainbow trout farming. FAO Fisheries and Aquaculture Technical Paper No. 561. Rome, FAO. 2011. 81 pp. Zubiaurre, C. (2013). The Current Status and Future Perspectives of European Organic
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Journal Pre-proof Highlights
Development and expansion of trout farming in Himalayas has yet to be intensified for largescale productions.
Need of improved feed, infrastructure, improved strain, triploid trout , organic farming and environmental management are highlighted. Technological modernization, better governance and significant improvement in the
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management practices has been suggested.
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Atul K. Singh PII:
S0044-8486(19)32653-5
DOI:
https://doi.org/10.1016/j.aquaculture.2019.734826
Reference:
AQUA 734826
To appear in:
aquaculture
Received date:
7 October 2019
Accepted date:
3 December 2019
Please cite this article as: A.K. Singh, Emerging scope, technological up-scaling, challenges and governance of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) production in Himalayan region, aquaculture (2019), https://doi.org/10.1016/ j.aquaculture.2019.734826
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Journal Pre-proof Emerging scope, technological up-scaling, challenges and governance of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) production in Himalayan region
Atul K. Singh* Former Director ICAR-DCFR & Emeritus Scientist National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow-226002
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(Uttar Pradesh) India
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*Email: [email protected]
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Abstract
Rainbow trout is one of the promising cultivable fish species in coldwater and has enormous
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scope for its expansion in the Himalayan region. Being a low volume high value commodity, the
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trout has good potential for domestic consumptions as well as foreign export. In spite of having excellent positive traits and prosperity, the development and expansion of trout farming in
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Himalayas has yet to be intensified for large-scale productions. There are enormous aquatic
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resources in the form of river, reservoirs and lakes in the Himalayan region yet agricultural production of trout is very limited. This paper presents the available trout production system, available
infrastructure
and
production
trend
highlighting the need
of improved
feed,
infrastructure, improved strain, application of triploid trout production for stocking in cages and pens and also the possibilities of organic trout farming so as to clinch the production intensification, environmental management and trout promotion objectives on scientific. Based on 15 years experience of trout culture in India, potential success in trout production could be acquired through technological modernization, better governance and significant improvement in
Journal Pre-proof the management practices. The knowledge needed to form a comprehensive trout-farming ecosystem beyond farm activities has been suggested in this paper which will be useful not only to the country but also to the transboundary Himalayan countries where trout farming is still rudimentary.
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Keywords: Rainbow trout; culture system; triploid; organic trout; governance
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1. Introduction
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Rainbow trout Oncorhynchus mykiss is a member of the salmonid family that is an important
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aquaculture species of major economic importance raised in both hemispheres and on all continents. Rainbow trout is native to the Pacific drainages of North is now widely introduced to
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over 100 countries worldwide including India (DIAS 2019). FAO database for aquaculture
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production does not show any production data of rainbow trout in India, China, Thailand, Malaysia, Indonesia, Nepal, New Zealand, Pakistan and Sri Lanka although data for the top ten
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trout producing countries are available (FAO 2016). Most likely, rainbow trout farming in many
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of these Asian countries has not yet been commercialized and is still in the research and development phase. Trout farming in India is over three decade old and there are several species of trout in the country (Singh and Lakra, 2011) but rainbow trout is a species of choice of aquaculture. Rainbow trout is relatively easy to culture and has better growth and maximum cultivable traits (Joshi et al., 2005). This amazingly versatile species can tolerate a wide range of water temperatures (from 0-23˚C) and there are numerous freshwater sources in which they can be grown. They thrive in water originating from aquifers, springs and streams – as well as in lakes. In India, rainbow trout farming is although an old endeavor, its farming is now getting
Journal Pre-proof organized as there is vast scope. In J&K state of the northwest Himalaya the trout farming project was established during 1984 at Kokernag with the assistance of European Council (EEC) and it happens to be one of the largest trout-farming infrastructure in the Asia while in Himachal Pradesh, trout farming started during 1991 with the help of Indo-Norwegian assistance. Of late, it has been realized to venture rainbow trout culture in the state of Uttarakhand located in central
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Himalaya and Sikkim as well as Arunachal Pradesh in the eastern Himalaya (Figure 1).
Figure 1: Trout farming states in Indian Himalayan Region (IHR)
Journal Pre-proof The Himalayan region of India possesses plentiful aquatic resources in the form of river, reservoirs and lakes. A GIS based information on various aquatic resources was generated for different Himalayan States, which is summarized here (Table 1). The generated information has given a clear picture that there are enormous aquatic resources in the form of rivers, reservoirs and lakes in the Himalayan region, which have high potential of rainbow trout farming. It is to mention here that ponds and tanks created along the river streams only are being used for trout
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culture while abundant scope of raising trout in the river, lakes and reservoirs utilizing modern
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aquaculture tools such as cages and pens exists for enhancing production manifold. Assuming
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that even if 2% of the existing resources are utilized under trout farming, the production can go
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several folds high. Based on the available aquatic resources, it is assessed that 957 km long river streams, 2826.6 ha of reservoirs and 963 ha of lakes can be utilized for trout culture in different
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Himalayan states (Table 1) whereas it is estimated that not even 20 ha of water area is utilized
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under trout farming in India at present. The significance of the study aims to find problems and prospects of trout farming in Himalayan region to help developing beneficial policy and
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governance for appropriate implementation, regulations and support. The paper presented
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various critical areas to be covered while promoting rainbow trout culture along with environmental knowledge needed to form a comprehensive trout-farming ecosystem beyond farm activities. The knowledge generated will be useful not only to the country but also to the transboundary Himalayan countries where trout farming is still rudimentary.
Journal Pre-proof Table-1: State wise water resources in Indian Himalayan Region (IHR) (Source: modified after
3
Himachal Pradesh
Uttarakhand
Rivers
(ha )
(ha)
(km)
137275. 3
4087.3
10893.5
(2745)
(88)
(222)
27.2
31320.2
10464.3
(0.5) 212 (4) Sikkim
1004.5
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4
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2
Jammu & Kashmir
Total Lakes Reservoirs
(626)
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1
State Name
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S.N
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Prem Kumar et al., 2017; Singh, 2019)
16864
10657.8
(337)
(213)
--
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(21)
Arunachal Pradesh
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5
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Total
2792
3298.1 (66)
--
(56) 2826.5
(209)
12351 (247)
963
957
Note: Values in parentheses are assessed potential water areas for trout culture
2. Production System Rainbow trout is a fast growing, coldwater fish in India that typically growing to sizes of 0.3-1.2 kg. It is most commonly grown in cemented raceways where it contributes over 90% of total production, although earthen ponds and other structures made of other materials are also used (Singh et al., 2017). Few trout growers of Arunachal Pradesh and J&K are practicing trout
Journal Pre-proof farming in earthen raceways for trout rearing. The use of a variety of aquaculture systems i.e., ponds, raceway, RAS, net cage, are available widely in scale of adoption in the country. However, in trout farming, the size of trout raceways varied between different Himalayan States. However, for adopting a uniform policy of extending financial support to the private trout growers by the central sector, a standard size of 10x3x1 m has been fixed for consideration. In concrete raceways, the trout farms are horizontally constructed and spread and are arranged in
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series and/or in parallel with water flowing along a downhill gradient.
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Since Himalayan states have a forest cover of about 45.5% the accessibility to water
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resources from the main habitation is difficult. Moreover constructing cemented raceways is not cost effective endeavor due to difficulties in carting of building material and hiring labour at an
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elevation of 2000 to 2500 masl where trout farms are clustered. Along with tilapia, catfish, and
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bass, in the plains, trout is a very popular fish for consumption in IHR. In view of hardships faced by the private trout farmers, an experiment was designed and executed to raise rainbow
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trout in FRP tanks. In Kumaon region in the Nainital district at Bhimtal it was found that raising
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trout fingerlings (5 gx100 no) in FRP tank of size 2x1x1m in triplicate with running water 8 l/minute could produce 47 kg of fish in just 7 months. However, using such fabricated recirculating system with FRP tanks provided 15-20% more production with economical use of water and its re-use. The used fabricated technology can be scaled-up for commercialization of trout farming in IHR.
At present the scale of farm’s production is limited as most of the trout farms are traditional type having flow-through systems, in which the water is taken in via a damming of the adjacent water
Journal Pre-proof course and water then passes through the farm by gravity. Regardless of the water source, the flow-through nature of raceway systems necessitates that water exchange and turnover rates should be high in order to maintain water quality (Fornshell et al., 2012). In general, a trout farm requires little land conversion as a result the intensive production is achievable in flow-through raceways and ponds.
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The Himalayan states in India are typically producing nearly 600 kg of trout per raceway; while
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production of 1000 kg was also achieved at some farms. While extrapolating the production, it
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comes equal to 200 tons/hectare/year and competes with any other highly productive aquaculture
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species and the system available in the country. Even large farms producing 1,000 tons annually would only need roughly 3.33 ha of water in existed raceways, and some space for support
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buildings (Woynarovich et al., 2011). Therefore, it is estimated that production of over 1100 tons
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of trout in India during 2019 is roughly available from not more than 20 ha of culture water, whereas the Himalayan region is endowed with huge water resources in terms of river, reservoirs
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and lakes (Table 1) and consequently there is enormous scope of enhancing trout production
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manifold provided adequate infrastructure, quality feed and better strain of trout are made available. An understanding of the economic drivers influencing the trout farming activities in the IHR has been generated based on field information, literature and self-experience. The majority of the farms studied have shown profitability primarily due to advantages of premium price of the fish and favourable climate conditions.
The factors behind the heterogeneity of growth in different states could not be assessed since comparable economic data at farm level are not available and would be useful in identifying the
Journal Pre-proof critical gaps behind this heterogeneity of growth. In an ideal world of trout culture, it is to mention that data pertaining to economic performance conforming to internationally compatible standards in order to examine the cost structure, profitability information about the costs and returns of trout farming is rarely available except at a few countries such as Norway (Asche & Bjorndal, 2011) and Denmark (Statistics Denmark 2014) annual data are collected at farms to
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assess performance (Tobias et al., 2017).
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The optimal conditions for the survival and growth of fish necessitate not only adequate
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amounts of water which should be as much as 86,000 m3 to produce 1 ton of fish, but also
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requires optimal temperature varying from 12 to 18°C and highly well oxygenated quality water. The availability of bulk of required water availability at trout farms varied highly in IHR
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consequently the stocking density also varied from farm to farm. However, it was observed that a
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flow rate of 4 l/sec can support up to 20 kg/m3 fish, though higher volume and higher quality may allow stocking densities as high as 35 kg/m3 or even more as was found in some special
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cases in J&K as well as Kullu in Himachal Pradesh.
Trout aquaculture needs specific chemical and biological conditions too, which are difficult to be fully understood by the private trout growers as they are devoid of the data of the physico-chemical parameters of water quality. Because the chemistry of water provides much information about the metabolism of a given ecosystem and explains general hydro-biological relationships in relation to growth and overall productivity of the farms. Further, the intensive trout producing farms do not have idea of impurities and contaminants produced in the trout farming which are derived from metabolites secreted by fish (through gills and with urine) or
Journal Pre-proof from degradation of feed and suspended particles. It is estimated that in the intensive systems of aquaculture, only 20–40% of feedstuff mass are built into fish bodies, whereas the remaining part is excreted. In all such systems of trout farming, part of these wastes is discharged with postproduction waters; however, their quantity and quality differ depending on the culture system. In the flow systems, all dissolved contaminants and solid impurities are released into the environment. It is assumed that the amount of wastes generated by fish farms may be less at
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farms using standard flow systems however, future intensification of the trout farming activities
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will require precautionary approaches and water quality monitoring to make the trout farming
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environmentally sustainable.
Northwestern regions of India the J&K as well as Himachal Pradesh have progressed well in
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rainbow trout farming due to most suitable climatic condition and topography for creation of
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suitable trout farming infrastructures. Trout farming in these states has become a major economic activity. Trout farming has now expanded from northwestern states to Uttarakhand in central
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Himalayas to Arunachal Pradesh, Sikkim and of late Nagaland in eastern Himalayas. Besides, its
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culture in Ooty and Munar southern part of the country although very old yet rudimentary now is reviving. At present different Himalayan States have got 64 government farms and over 1380 trout units in the private sector. Besides, there are 30 hatcheries having capacity to produce 14 million fry (Table 2).
Journal Pre-proof Table 2: State wise details of trout infrastructures in IHR Infrastructure Sr.
No. of Private
Hatcheries
Feed
Culture status
State No.
1.
Govt.
trout
farms
Units
45
533
mills
J&K
Govt. 14
&
private
&
private
&
private
&
private
3
5
572
5
Pradesh Uttarakhand
4.
15
Sikkim
Arunachal 3
Tamil Nadu
7.
Kerala
1
5
2
sector Govt. sector Govt. sector Govt. farm only
2
Nil
1
-
1
Nil
-
2
1
Nil
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6.
-
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Pradesh
249
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5
5.
3
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4
Govt.
2
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3.
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Himachal
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2.
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sector
Govt. farm only Farms
(Private
sector)
With the present infrastructures for trout farming available in the government and private sector, the present rout production is just over 1100 tons in the country where J&K is contributing over 600 tons followed by Himachal Pradesh while Sikkim is contributing around 120 tons per anum (Figure 2).
Journal Pre-proof Figure 2 (A&B): Status of trout production in IHR
700
2011-12 2015-16
600
2012-13 2016-17
2013-14 2017-18
1200
2014-15 2018-19
31%
1000
500
Tons
800 400
600 300
400 200
200
100
2018
2004
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0
0
Himachal
Sikkim
others
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J&K
B. Annualized growth in production
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A. State wise production
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There has been over 31% annualized growth in the trout production over the last 15 years which could be possible due to advancement of the technical knowledge on trout farming and
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improvements in the artificial diets, management and also breeding and propagation. It is
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important to mention here that involvement of private trout growers and improvements in input quality (seed and feed) and governance brought about a very encouraging growth in trout
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farming promotion. Nevertheless, limited infrastructure available in the country needs to be
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revamped as creating larger infrastructure facility, catering the need of fingerlings requirements, improved quality of feed and better management practice will certainly boost up trout production.
With the available trout hatcheries, hardly 14 million trout fry could be produced whereas we need large number fry and fingerlings round the year to raise trout production after enlarging trout production units. Likewise culture facility should also be multiplied through adequate financial support to the trout growers as erecting infrastructure for trout farming is cost intensive
Journal Pre-proof and it is difficult for farmers to come forward for developing trout farms on their sloe investments. At the same time it is also proposed to raise trout culture in lakes, rivers and reservoirs using cages besides intensifying culture in raceways and also using RAS technology.
3. Trout farming in cages and RAS Because the country is having limited culture facility, there is need to tap the existing
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highland lakes, river streams and other aquatic bodies above 2500 masl as these water bodies are
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under exploited for aquaculture (Singh, 2019). There are several lakes and river streams devoid
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of any fishery activity. Besides trout farming can also be taken up in cages fixing them in lakes
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and reservoirs. One of such initiative was taken up in east Sikkim where a battery of 9 cages having dimension of 9x4x3 m was fixed in Memencho Lake and stocked with fingerlings
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weighing 5 g. It grew up to 150 g in six months. The production is very encouraging yet the
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practice has to be standardized for commercial application.
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The production of rainbow trout (Oncorhynchus mykiss Walbaum 1792) is practiced in different
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production systems which are mostly extensive system (ES), however, recirculating aquaculture systems (RAS) can be used for intensive trout production (Samuel-Fitwi et al., 2013). Since extensive trout production systems practiced in India which is based on limited requirements of resource and hence subsequent output and emissions may not impact the environment (Andre Meriac et al., 2014). Nevertheless, intensifying trout culture may possibly impact the environment besides adequate usage of water and resources as feed. It is therefore, strongly proposed to adopt RAS based intensive production of trout in India as well. A semi-commercial (32 m3 capacity) RAS system consisting of larger culture tanks (7 m3 water volume) and smaller
Journal Pre-proof (0.5 m3 ) experimental tanks designed by the ICAR-DCFR, Bhimtal have been assessed for demonstration of recirculatory aquaculture system technology, which minimizes the usage of land and water in rainbow trout culture.
For strengthening such endeavour, recently a
memorandum of understanding (MoU) has also been signed between Government of J&K and government
of Denmark
for
transferring
of Recirlculating
Aquaculture
System (RAS)
technology, automatic feeds, brood equipment and for rearing trout Fish production. Such
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initiative of RAS technology and also cage culture in trout farming will certainly help
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intensifying rainbow trout production in IHR.
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4. Triploid trout production
The occurrence of precocious maturation (early onset of puberty) in commercial grow-out
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systems is a prevalent constraint that leads to post-pubertal growth rate, carcass yield, flesh
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quality, market value and lower return to farmers (Piferrer et al. 2009). Moreover, when trout farms being proposed adjacent to natural streams or other water sources especially culture in
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cages, there is all possibility of their escapes in natural systems. The escape of domesticated
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rainbow trout into the wild may be a serious environmental concern as the escapee fish can contaminate and disrupt the receiving ecosystem (Benfey, 2015). The remedy for overcoming the farming intensification of trout in river streams, reservoirs and lakes may be the socking of triploid stocks which is the induction of reproductive sterility. The most practical and effective way to produce sterile rainbow trout is the manipulation of chromosome sets (induced polyploidy). The usage of triploid fish for commercial purposes has numerous advantages as it contains three sets of chromosomes and is genetically sterile consequently it provides ecological safety to the aquatic bodies which are pristine and untapped in the higher Himalayan reaches
Journal Pre-proof where aquaculture activity is still rudimentary. A triploid fish has reduced gonadal development since the energy is directed towards the somatic growth for the development of flesh quality (Kizak et al. 2013; Kim et al., 2017). These characteristics have drawn the attention of the scientists in India recently determined to produce triploid rainbow trout. The production technology is being standardized at ICAR-DCFR, Bhimtal by using thermal and pressure shock to produce triploidy. Once the developed technology reaches at commercial scale of adoption, it
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will be a safe approach to stock the untapped natural water bodies in higher reaches beyond 2500
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masl in Himalayas.
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5. Improved strain and stock:
To facilitate sufficient and better quality inputs, we need to develop improved practice of brood
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management and breeding strategy (Lhorente et al., 2019). Since rainbow trout is an introduced
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species in India, its scientific management especially of the brood stock is very essential. The first culture strain of rainbow trout imported was European strain while the other was Norwegian
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strain. Although European strain was initially propagated, attempts were made to determine how
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the two different strains performed in the country and the same was evaluated (Barat et al., 2014). It was documented that both the stocks have considerable amount of genetic variability, yet there is need for pedigree breeding strategies so that future chances of inbreeding can be minimized using many pairings and equalization of family size to maximize effective population size. It is imperative that systematic breeding plan can significantly improve the profitability of production. Breeding experience has shown that the so-called partly factorial mating design fetches optimum benefits of the crossings in relation to inbreeding, diseases etc. This design means that the sperm from one male is used to fertilise half of the eggs from each of two
Journal Pre-proof females. Thus, each female is fertilised by two males. Likewise successful attempt has also been made in cryopreservation of milt of superior males and crossbreeding with it for upgrading the stocks. Whatsoever is the performance of the existing stocks, state departments and the research institution have been demanding for better strain since there is a possibility of better genetic improvement of the existing stocks by introducing newly selected strains and enhancing aquaculture productivity in the coldwater regions (Barat et al., 2014).
Recently J&K state
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imported rainbow trout seed from Denmark during January 2019 to boost the production of the
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fish from present 600 tons to 5000 tons per year over next five years. A consignment of 2.25 lacs
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eyed ova of rainbow trout was successfully imported from Billud in Denmark Rever Roheamger
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and being reared at Beerwah trout farm in J&K for developing a better brood stock in the state.
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6. Improved Feed
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A major issue in trout culture is the unavailability of improved feed as the stakeholders are not getting desired growth in fish and also on affordable price. The increasingly scarce
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supply of fish meal and its high market price has made it necessary to seek a cost effective
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replacement of fish meal to supply dietary protein in trout feed. One of the promising alternate to fishmeal has been considered to be plant based protein, which is rich in protein and generally low in phosphorus (Geurden et al., 2013). Trout is a predatory fish, although it consumes and assimilates plant protein, however its intensity of growth on such food is much lower. In the plant origin feed, the protein deficiency of amino acids like lysine and methionine usually occurs.
Protein digestibility remains in lower side when diet containing soybean protein due to
anti trypsin factors. Current research shows that feed performances and digestibility can be increased with the use of enzymes and balancing amino acid profiles that enhance plant protein
Journal Pre-proof use (Guerden et al., 2013). State Fisheries departments especially in J & K and Himachal Pradesh produce several forms of dry and moist trout feeds. The variation in nutrient composition of available trout feeds is not farmers friendly and are not suiting to the requirement consequently low cost diets need to be produced by developing diets with reduced food conversion ratios (FCR) and less dependence on fish meal by improving palatability and
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digestibility of raw ingredients.
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Our recent study at ICAR-DCFR, Bhimatl for developing trout feed has been conducted which is
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based on Protein extracts from single cell protein (SCP) sources from different types of
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unicellular microorganisms, such as fungi, bacteria, yeast, and algae. These microorganisms need varied carbon sources for the generation of new proteins and other metabolites, such as fats, High protein distiller’s dried grains derived from rice (HDDG) and
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vitamins, and carbohydrates.
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a bacterial meal derived from methane oxidizing bacteria (String Pro) is under study for investigations on fishmeal replacement to produce low cost feed in India. In terms of nutritional
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composition, HDDG has 62-65% crude protein, 1.5-3% crude lipid, 9-12% starch, 2.5-6% fibre
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and 2.5-6% ash. String Pro meal had 72.5% crude protein, ~8% crude fat, 3.3% starch, 3.8% fibre and 7% ash. Lysine and cysteine-methionine content was lower than that of fish meal, but all the other amino acids were in equal or excess levels. For further studies on these alternate protein sources, the ICAR-DCFR has signed a memorandum of understanding with S.P.Y. Agro Industries Ltd., Nandyal, Andhra Pradesh (high protein HDDG producer) and String Bio Pvt. Ltd., Bengaluru, Karnataka (methanotrophic bacterial meal producer). In the first feeding trial under this study, the potential of HDDG has been evaluated, a by-product obtained in the process of producing alcohol or neutral spirit in modern grain based distillery units, as a Fish meal (FM )
Journal Pre-proof substitute in trout feeds. For that, triplicate groups of juvenile rainbow trout (mean initial weight ~ 30 g) either of five experimental diets (Control, completely FM based; 25R, 25% FM replacement; 25S+, 25% FM replacement + limiting nutrients + phytase; 50R, 50% FM replacement; and 50S+, 50% FM replacement + limiting nutrients + phytase) were fed for 12 weeks. The trial has been conducted in an experimental RAS system developed locally, with water temperature maintained at 17 ± 2°C. So far the findings of this study are in process of
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generating data on growth (weight gain, SGR and TGC) and feed utilisation (feed intake and
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FCR) indices, analyses of amino acid profile in feed and whole body samples. Based on growth
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and feed utilisation, it may be concluded that it is possible to partially replace FM in trout feeds
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using HDDG, without any nutrient supplementation.
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7. Organic farming
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Organic trout farming has been introduced in several European countries since the 1990s. The main producers are France (2,300 tons), Denmark (1,634 tons) and Italy (1,000 tons) (European
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Union 2017). Among other countries, Spain, Germany and the UK are also producing organic
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trout (EU 2017). In India, the production of organic rainbow trout has recently shown interest and promises especially in fully declared organic states like Sikkim and Uttarakhand. The available methods of organic farming of trout delineates that in the raceways should be physically separated and there should be separate water supply. Closed recirculatory systems are not permitted in organic farming (Zubiaurre, 2013). Recirculation (incl. heating/cooling) may be used for hatcheries and for fry production. However, only mechanical aerators are permitted and preferably they should be run by renewable energy. Pure oxygen is only permitted in critical situations to secure fish welfare. Feed pigment such as Astaxanthin from natural sources is
Journal Pre-proof permitted within the physiological requirements of the fish. Fish density should be low maximum of 25 kg/m3 . Medication if needed may be done just twice a year for life cycles > 1 year.
Furthermore, some ethics have also to be followed when producing organic trout, which
are given as below:
To create a more ethical method of sustainable production by using local resources and
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natural processes that help maintain the natural cycle (i.e., maintain balance in nature).
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Specific requirements for oxygen content, pH, nitrogen (daily/weekly measurements),
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veterinary control, treatment with antibiotics (once during the organic fish life), and a positive list of chemical additives.
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Accordingly, the use of formaldehyde, Chloramin-T, and copper sulphate are not
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allowed. Only the LT type of fishmeal, which is a wholemeal, produced from absolutely
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fresh fish ensuring an extremely low level of biogenic amines should be used; no fish offal is used due to its phosphorus content. Furthermore, no GMO ingredients in the feed
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and no etoxyquine for feed preservation are allowed.
of water.
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For organic on-growing production, a range of open systems, from flow through to re-use
Oxygen saturation at outlet should be minimum 70% Maximum increase from inlet to outlet (calculated from Qmm) should be 2 BOD should not exceed 1mg/l Suspended solids should not be more than 3mg/l Suspended solids should not be more than 0.05mg/l Ammonia-N should not exceed 0.4 mg/l
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By the given methodology once organic trout farming comes into existence in the Himalayan states, it will add value to the product. Though organic fish farming will involve additional expenses on the whole farm’s structure and management since following arrangements will be required for organic certification and labeling: a) rearing units’ preparation and juveniles input,
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b) feeding (GMO free organic feed), c) monitoring, control, water changes, etc., d) harvesting
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and post harvest fish processing. The trout growers in Himalaya are struggling for improving the
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economical returns as the buyers are not paying suitably so it is imperative that organic trout will tend to attract higher premiums. It is therefore, important to create consumer’s level knowledge
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about ecolabel organic trout farming and the aesthetic quality comparable to conventional trout
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products available so as to attract them. Also ecolabeled rainbow trout will generally appear to
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be more demanding than conventional products. Organic farms in India may face challenges of high feed costs and comparatively low productivity with mixed success. It is therefore necessary
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to create different processing units for organic fish, which will facilitate more marketing
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channels for the primary producers. In Denmark organic rainbow trout is primarily purchased in supermarkets. Likewise, introduction of the Organic Cuisine Label in India, will attract much attention at the food service-sector such as canteens, restaurants and additional public catering.
8. Governance So far governance for trout culture is very limited owing to scanty number of trout growers and state governments do not have any mandatory mechanism to extend technical backstopping to the private trout growers. Nevertheless, some governance issues are flagged below to cater the
Journal Pre-proof immediate need: i) The regulations governing site selection and construction of trout farm should be supported robust and environment friendly, and should not disturb overall maintained functionality of the habitats where trout farms are intended to be sited. It is therefore, the government department and research institute should take responsibility to identify suitable areas for raising future farms culture in IHR and guiding the trout farmers.
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ii) Some farming standards with regard to economical water use, organic trout farming
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module, stocking of triploids in natural aquatic bodies, breeding protocols and brood
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raising as well as feed and environmental regulations owing to climate change need be
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developed for implementation and promoting of water recirculation, stocking density, stocking size, feeding schedule, management practices, environmental management and A detailed developed guideline on these aspects should be made available
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brood raising.
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to the trout farmers and stakeholders.
iii) For trout farming intensification it should be ascertained that chemicals and pollutants
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arising out of trout culture should not disturb ecosystem functionality and in turn affect
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habitats. It is important that the research institutions should develop a standard on trout farm management to regulate water quality especially the water chemistry of used water from trout farms so as to develop regulations. iv) In trout farming use of antibiotics is very common consequently there is possibility of bio-available antimicrobials be discharged and present in the receiving water body. It is thus based on available literature and findings, mitigation way outs should be developed for regulatory limits of chemical type and antibiotic doses to enforce them accordingly.
Journal Pre-proof 9. Conclusion Rainbow trout fish farming is one of the promising industries related to agriculture sector in the Himalayan region. It generates not only the income to the farmers but also creates employment opportunities to the people living in the mountainous and hilly region. In addition, it has potential of export of trout overseas and earn foreign currency. Rainbow trout can also attract internal tourist as well as foreigners and provides fresh fish in restaurant as well as food courts.
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In order to expand the industry, government should initiate and take extra interest providing Trout farming
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adequate infrastructures and technical support to the farmers and stakeholders.
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should be intensified in IHR in a very planned way utilizing modern culture technologies i.e,
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cages, pen and RAS. Integrated trout farming may further be supported to increase the farm produce in comparison to the traditional farming. However, lack of adequate inputs, technical
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knowledge, planning and difficulties regarding the development of infrastructure are the serious
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problems that must be strengthened to encourage and involve large number farmers for trout farming. Due to limited production, it is fairly costly to the local inhabitants and also limited to
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certain hotels, restaurants, and some of the diplomatic offices only. Thus, rainbow trout which is
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being cultured on limited scale holds a great future promises in view of vast coldwater resources available in the country and invigorating its culture by adopting sound technological skills so as to support a skills of production to meet out domestic consumption and export promotion generating foreign currency.
Further, managing environmental constraints owing to climate change and limiting effluent discharge which are of public concerns are the primary requisites toward trout industry expansion. Given water quality and quantity requirements for trout, development of new
Journal Pre-proof facilities should be based on current production techniques. Therefore, production must be strengthened from modern added operations as discussed above for increased efficiency. Development of improved strains, high-performance feeds, triploid stocks, management for environmental control, better governance and new production technologies will add potential for increased production. Value-added products through organinc farming will increase revenues and the product development and marketing will further be key to support large sales since
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consumers increasingly demand quality products that are easily available and healthy. The
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governanve and environmental regulations so developed will be useful not only in the country
Conflict of interest and Ethical Approval
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but also help help neighbouring countries such as Nepal and Bhutan.
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The author declares that he has no conflict of interest. Further, the article does not contain any
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Singh A. K. (2019). Coldwater Fisheries in India: Priorities, Policy, Institutional Support and Challenges.Advanced Agricultural Research & Technology Journal Vol. III Issue 2 JULY 2019, COSFAD-2019 Special The Danish AgriFish Agency (2014). The Danish AgriFish Agency’s Aquaculture register. Available at http://webfd.fd.dk/stat/Akvakultur_tab/prod_art_12_eng.html Tobias Lasner, Alexander Brinker, Rasmus Nielsen and Ferit Rad (2017). Establishing a benchmarking for fish farming –Profitability, productivity and energy efficiency of German, Danish and Turkish rainbow trout grow-out systems. Aquaculture Research, 2017, 48,
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Aquaculture. Aquaculture Europe volume 38 (2).
Journal Pre-proof Highlights
Development and expansion of trout farming in Himalayas has yet to be intensified for largescale productions.
Need of improved feed, infrastructure, improved strain, triploid trout , organic farming and environmental management are highlighted. Technological modernization, better governance and significant improvement in the
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management practices has been suggested.
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