Phase III- Interactive enabling of created database to respond to need based queries of the farming community through latest IT techniques
A. Research
1. Standardizing fish stock enhancement protocols in floodplain wetlands
The Institute has been carrying out studies on various aspects of stock enhancement in Assam for many years with a view to standardizing their stock enhancement protocols. These have more than 25% of water-spread area covered by floodplain wetlands in the country. As part of the study, field data were collected from 8 beels of Lower Brahmaputra Valley (LBV) Sub-zone of Assam (Barundanga, Rowa, Dahor-Jogra, Harinchora,
Tariachora, Motirkuti, Bhoispuri, Paborchara), ten beels of Central Brahmaputra Valley Sub-zone (Jaluguti, Dandua, Kachadhara, Charan, 47 Morakolong, Deorah, Damal, 46 Morakolong, Lakhanabandha, Borghuli) and six beels of Barak Valley Sub-zone (Korkoria, Fulbari anoa, No. 26 Sibnarayan anoa, Baraknadi anoa, Chri anoa, Baskandi anoa) during 2011-13. Stock enhancement was practiced in all the beels except in 47 Morakolong beel (because of fear of possible floods)
to increase their fish yield. Among the selected beels, Damal beel, Paborchaora beel and Siri anoa were very small in size (<20 ha), Fulbari anoa and Singra beel were medium-sized (114-146 ha) whereas the remaining beels were small in size (20-99 ha). Seven of the selected beels were closed and the remaining were seasonally open ones. Supplementary stocking has been practiced in the selected beels since the past 10 years or more except in Chiri anoa, Baskandi anoa (since the past 3- 4 years), and in Rowa beel (from last year). All beels were under the administrative control of the Assam Fisheries Development Corporation.
Fish production: Fish production from both stocked and natural fish stocks in the selected closed beels ranged from 149.3 (Puthimari beel) to 1387.8 kgha-1yr-1 (Damal beel). Contribution of stocked fishes to fish production in varied from 134.3 to 832.7 kgha-1yr-1. In seasonally open beels, total fish production varied from 41 (Kapla beel) to 528.8 kgha-1yr-1 (46 Morakolong beel). The contribution of stocked fishes to fish production varied from 24.6 (Kapla beel) to 416 kgha-1yr-1 (Bhoispuri beel).
Both total fish production and contribution of stocked fishes to fish production was higher in closed beels than that in seasonally open ones.
Contribution of stocked and natural fish stocks:The contribution of stocked fishes to total fish production was 60% or more in all the closed beels indicating that culture-based fisheries was practiced in these beels. In seasonally open beels, the contribution of stocked fishes to total fish production was as low as 25% (Baraknadi anoa) to 30% (Singra and Charan beel), which were regularly flooded from the adjoining rivers. In the remaining seasonally open beels, it ranged from 40% (Akra beel) to 80% (Dandua, Jaluguti, Bhoispuri, Chiri anoa). The contribution of stocked fishes to total fish production was 50% or more in 11 out of 17 seasonally open beels indicating that culture-based fisheries was practiced in these beels.
Determination of optimal stocking density: Data on fish production and related aspects was collected from seven beels of LBV sub-zone of Assam and also from six more beels of Central Brahmaputra valley zone of Assam were analyzed for standardizing fish stocking density during the report period. Fish production from both stocked and natural fish stocks in the selected closed beels
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ranged from 149.3 to 1387.8 kgha-1yr-1. Based on the field data, optimal stocking density was estimated at 3000 and 3600 fingerlings/ha for closed and seasonally open beels, respectively.
Impact of stocking on fish yield: A case study was conducted in Charan beel, Morigaon district, Assam for assessing the impact of stocking on fish yield. Yield rates in this seasonally open wetland having 60 ha water spread area was estimated at 228 kg/ ha/ yr during 2000-01, which was exclusively from natural fishes with major and minor carps contributing 31.32%, large carnivores contributing 15.78% and small economic fishes contributing the major share of 52.9%. Fish stock enhancement was practiced in this beel during 2010-11 as a result of which fish yield rates increased by 324% (740 kg/ ha/ yr). The share of major carps increased to 62.8% during this year.
While the share of large carnivores remained relatively unchanged (11.4%), the share of small economic fishes drastically reduced to 25.8%.
Assessment of habitat variables, aquatic communities and fisheriesin selected wetlands of Manipur
Four wetlands (Takmu pat, Ungamlen pat, Utrapat and Sanapat) form Bishnupur district and one wetland (Waithou pat) from Thoubal district of Manipur was assessed for their habitat variables, aquatic communities and fisheries during the period. Except in Takmu pat which was under the administrative control of the Department of Fisheries, Govt. of Manipur, all the other wetlands faced the problem of encroachment for agriculture or Pisciculture in the peripheral areas of the lakes. Takmu pat and Ungamlen pats are moderately (15-35%) infested with macrophytes, while the other three pats were heavily (>80%) infested with macrophytes. Some of the edible aquatic plants of the wetlands having economic importance to the people living around are Zizania latifolia, Carex sp., Saccharum spp., Setaria pumila, Alpinia nigra, Hedychium spicatum, Narenga, Trapa natans,Euryale ferox,Nelumbo nucifera, Nymphoides indicum,Nymphea pubescence, etc. The water quality parameters assessed in the pats were pH (6.6-8.4), DO (2.1-7.4 mg/l), CO2 (3.8-11 mg/l) and alkalinity (25-30 mg/l). Soil texture in all the pats were predominantly sandy (88-93%) in nature.
Soil was acidic, organic C (%) ranged between 1.43- 1.58, PO4 between 1.3- 1.61 mg/kg and pH ranged from 6.5- 7.3. In these wetlands, the fisheries comprised of common carp, grass carp, tilapia, IMCs and other small indigenous fishes. Some of the endangered indigenous fishes in the pats were Anabas testudinus, Anguilla bengalensis, Acanthophthalamus punctatus, Channa orientalis, Botia bagarius, Barilius dogarsinghi, Garra graveli, Ompok bimaculatus, etc.
Utrapat in Bishnupur district, Manipur Encroachment for Pisciculture on the periphery of Ungamlen pat in Bishnupur district, Manipur.
121 2. Demonstration of enclosure culture technology
A pen culture demonstration was carried out in Takmu pat of Bishnupur district for assessing the technological feasibility in Manipur valley conditions. The pen measuring approximately 0.1 ha was constructed using nylon net (25 mm mesh size) with bamboo supports in collaboration with the Directorate of Fisheries, Govt. of Manipur during March, 2012. The pen was stocked with yearlings of Indian major carp, minor carp and exotic carps @ 5 fingerlings/ m2. The number of fish stocked, average length and weight were as follows: Labeo rohita (1000, 14.8 cm, 38.6 g), Catla catla (750, 16.1 cm, 39.0 g), Cirrhinus mrigala (1000, 16.2 cm, 41.9 g), Hypophthalmichthys molitrix (1250, 14.2 cm, 30.3 g), Ctenopharyngodon idella (100, 22.4 cm, 115.2 g), Cyprinus carpio (500, 14.8 cm, 55.1 g) and Osteobrama belangeri (500, 9.4 cm, 10.6 g). The stocked fishes were fed with commercially available pelleted feed (23.4% crude protein) at the rate of 5% of body weight twice a day. Water in the pen was characterized by favorable temperatures (23.8-28oC), clear water (Secchi disc visibility 85-95 cm), pH (6.6-6.8), optimal dissolved oxygen (6.5-7.0 mg/l), low free carbon dioxide (undetectable) concentrations and moderate total alkalinity (25-30 mg CaCO3/l). The seed were reared in the pen for 180 days. The highest average weight gain percent (±SD) was recorded for pengba (1107.55±2.92), followed by grass carp (785.42±53.21), catla (738.82±16.78) mrigal (323.39±7.6), rohu (251.19±6.97), common carp (191.08±4.88) and lowest weight gain was recorded for silver carp (123.01±4.6). Similarly, the highest specific growth rate (SGR) was recorded for pengba (1.38) and lowest for silver carp (0.45) indicating suitability of culturing O.
belangeri, a high-demand indigenous minor carp in pen enclosure in Takmu pat, Manipur. Grass carp and catla were also found to be suitable for culturing in pen enclosures. In conclusion, net pen enclosures can be used for culturing different fish species having local demand either for rearing them up to advanced fingerling size for their subsequent release into wetland-proper or table fish for consumption in large water bodies such as Takmu pat.
Adoption of pen culture technology developed by CIFRI in Sonitpur district of Assam
A field survey was conducted in four sites in Sonitpur district of Assam where pen culture is being practiced to assess the adoption of pen culture technology developed by CIFRI. Nayanjyoti Self help group (SHG) of Parmaighuli, Balipara Block, Sonitpur Dist., Assam took up pen culture practice in Rangapani Jan beel in April 2010 with the partial financial assistance of District Fishery Development Office (DFDO), Sonitpur Dist., Tezpur, Assam. The area covered under pen culture was 1 ha with an average water depth of 5.5 ft. The pen area was encircled with split-bamboo screen (height 8 ft) lined with polyethylene netting from inside. Stocking was done with Labeo rohita, Catla catla, Cirrhinus mrigala, Cyprinus carpio and Labeo gonius following species ratio of 30 Catla: 30 Labeo spp.: 30 C. mrigala&10 C. carpio at stocking density of 5000 fingerlings/ ha.
The total cost including construction, seed and feed was 1.06 Lakhs of which 85% was borne by the DFDO. Another pen culture activity was undertaken by a Non-governmental Organization (NGO) known as Maandal in Kachu beel, Morabhalari, Chiloni, Sonitpur Dist. covering an area of 1.35 ha during 2009-2010. The total cost involved in this case was 3,73,950.
Refinement of cage culture
The Institute carried out cage culture experiments at Charan beel, Morigaon district, Assam with a view to refine the technology during 2011-12.
Optimization of stocking density in cage culture: The Centre conducted one cage culture experiment at Charan beel, Morigaon, Assam with a view to standardizing stocking density of Cirrhinus mrigala fry. A battery of twelve cages (individual cage dimensions 2 x 2 x 2 m) were stocked with C. mrigala fry (av. length 4.18 ± 0.07 cm, av. weight 0.71 ± 0.03 g) at six different
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stocking densities, viz. 50 (SD1), 100 (SD2), 150 (SD3), 200 (SD4), 250 (SD5) and 300 (SD6) fry⁄
m3 with two replicates each. Fishes were fed twice daily with a formulated mashed feed (34.61%
CP) for three months. The stocking density of 100 and 150 fry per m3 showed better growth performance compared to other groups in terms of final weight, weight gain percent (WG) and specific growth rate (SGR). Since the survival percentage in SD6 was statistically insignificant with the groups having higher growth rates (SD2 and SD3), a stocking density of 300 fry/ m3 may be considered optimal for raising C. mrigala seeds in Charan beel. In view of the present findings, stocking densities higher than 300 fry/ m3 may also be tried for raising C. mrigala fry.
3. Fish assemblage, habitat preference and assessment of exotic fishes in inland open waters.
Data were collected from Takmu lake, Bishnupur district, Manipur; Umiam lake, Meghalaya;
Dumbur reservoir, Dhalai district, Tripura and six beels of Dhubri district, Assam on the occurrence of exotic fishes in the lakes/ reservoir. The catch from both the lakes (Takmu and Umiam) suggest dominance of exotic fishes especially Cyprinus carpio. The local people also have preference for the exotic fishes. The catch from Dumbur reservoir suggested that Cyprinus carpio (common carp) is the only exotic fish caught from the reservoir and its contribution to the total catch is negligible (0.5%). The major contributors were indigenous fish Chanda spp. (70%) followed by Amblypharyngodon mola (10%), which also had higher demand due to its low price ( 30-60/kg).
Indian major carps were reported to contribute only 4% of the total catch. From Dhubri district, Assam, data were collected from Harinchora, Barundanga, Paborchora, Kalidanga, Matirkuti and Tariachora beels. In all beels, seeds of Indian major carps (IMCs) and exotic carps were stocked annually and in one beel (Tariachora) Chitala chitala seeds were stocked. But the percentage catch of exotic carps were higher than the IMCs indicating that the exotic carps have established in the beels better than IMCs. The local people in the district have high preference for small indigenous fish species, followed by exotic carp and IMC.
4. ICAR Outreach Activity on Fish Genetic Stocks
As part of the activity led by the National Bureau of Fish Genetic Resources (ICAR), Lucknow, the Institute was entrusted the task of assessing genetic stocks of catla, rohu and mrigal occurring in R.
Brahmaputra. As part of the activity CIFRI Regional Centre, Guwahati collected data on length and weight and reproductive parameters for the targeted species. A total of 95 fish samples (15 Catla catla, 24 Labeo rohita, 11 Cirrhinus mrigala and 45 Clarias batrachus) were collected during the period 2011-12 from different landing centres of R. Brahmaputra (Uzanbazar, Dhubri, Tezpur and Kolongpar).
5. ICAR Outreach Activity on Nutrient Profiling of Fish
As part of the activity led by CIFRI, Barrackpore, CIFRI Regional Centre, Guwahati collected samples of selected fish species (Tenualosa ilisha, Amblypharyngodon mola and Puntius sophore) from Uzanbazar, Amingaon, Panikhaiti and Tezpur landing centres of R. Brahmaputra during three different seasons (pre monsoon, monsoon and post monsoon). These were analyzed for their moisture, protein, lipid and ash contents for determining their nutritional values. Seasonal variation in proximate composition of the fishes was observed. During the monsoon season, all fishes recorded lower lipid content. There may be possibilities of the fish storing more fat prior to breeding for development of gonads. It is also possible that the fishes build up body fats during active feeding seasons and the stored energy is used up during low feeding season. Except for A.
mola, the protein content also decreased during the monsoon season, whereas it was similar during the other two seasons in all the fishes. Slight variation was seen in the moisture content of the fishes
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both seasonally and among the fishes. From the above findings, it can be concluded that these fishes have high nutritional values in terms of lipids and proteins contents during the pre- and post- monsoon seasons, whereas, the nutritional values were reduced during the monsoon season.
6. Central Sector Scheme on ‘Development of Inland Fisheries Statistics’.
Field surveys were conducted for collecting data on inland fisheries resources in nine blocks of Nagaon district, Assam. The data collected were collated with existing information available with the District Fisheries Office, Nagaon district, Assam as part of standardization of protocol for collection of inland fisheries statistics. A total of 40, 066 ponds have been recorded and reported from the district in the range of 0.01 to 3 ha. The density was worked out at 29.14 ponds per village.
Analysis of data collected/ validated showed that majority of the ponds (94.85% of total 40,066 ponds) currently available in the district were in the range of 0.02 to 0.26 ha.
7. NICRA project on ‘Assessment of spawning behaviour of major fish species in inland environment with a view to harness the beneficial effects of the temperature’.
A total of 438 IMC brooders (67 male & 89 female rohu, 39 male & 58 female catla and 90 male &
95 female mrigal) were collected from selected carp seed farms of Assam and Tripura during 2011- 12 and their reproductive biology was studied. The studies showed that maturity of the IMCs advanced by nearly one month (from April to March) and the spawning season also extended for nearly one month (from July to August). A total of 150 hatcheries of Assam and 7 hatcheries of Tripura state were surveyed. Analysis of the data showed that a number of minor carps (L. calbasu, L. bata, L. gonius), new exotic fishes (Barbonymus gonionotus and Hypophthalmichthys nobilis)and indigenous catfishes (Pangasius pangasius and Ompok pabda) were used in addition to IMCs and exotic carps. Drastic reduction in the fecundity (up to 50%) was reported by some hatchery owners in the last few decades.
During 2012-13, a total of 432 fishes (75 male & 69 female rohu, 90 male & 54 female catla and 65 male & 79 female mrigal) were collected till March 2013 from Assam and Tripura.
Majority of mrigal collected (85% of males & 87.54% of females) were found to be in matured stage followed by rohu (46.85% of males & 68.23% of females) and catla (34.54% of males &
29.57% of females). Length and weight of male rohu, catla and mrigal brooders ranged from 33.2- 48.6 cm & 210-1120 g; 34.3-50.5 cm & 250-2050 g and 29.1- 41.3 cm & 180-540 g, respectively.
The length, weight and absolute fecundity of female rohu, catla and mrigal brooders ranged from 31.4-50.5; 340-1500 and 51634-269328 ova; 33.3-49.5, 450-1820 and 75216-191280 ova and 31.8- 42.7, 170-640 & 34585-124621 ova, respectively. The GSI values of the collected specimens were found to be in the range of 0.514-3.912, 0.113-3.284 and 0.179-3.602 for male rohu, catla and mrigal, respectively. Similarly for the female specimens of rohu, catla and mrigal the range was between 0.612-16.942, 0.578-13.5, 0.911-22.812, respectively.
Similar to the observations made in 2011-12, the maturity of IMCs in the study areas advanced by one month i.e. from April to March and the period extended upto one month i.e. from July to August during 2012-13. Incidences of abnormal gonadal development in case of C. mrigala such as presence of single-lobed ovary and retarded growth of one lobe of the ovary were observed in the present year.
124 8. Contract research work initiated in the region
i) ‘Investigation of minimum environmental flow required for the sustenance of ecology and biodiversity in Nyamjang Chhu river in Arunachal Pradesh’ as part of a consultancy project sponsored by Bhilwara Energy Ltd.
ii) ‘Investigation and suggestive measures in fish migration in river Kameng’ in Arunachal Pradesh as part of a CP sponsored by GMR Londa Hydropower Private Ltd.
iii) ‘Study of minimum environmental flow requirement for aquatic life in river Dri and Tangon’ in Arunachal Pradesh for Etalin hydroelectric power project and ‘Study of minimum environmental flow requirement for aquatic life in river Tangon’ in Arunachal Pradesh for Attunli hydroelectric power project.
B. Training and extension activities