Water Budget for Carp Culture Ponds in Odisha, India

S. Adhikari1, K.C.Pani2, and P. Jayasankar3

 

1 Principal Scientist, ICAR-Central Institute of Freshwater Aquaculture, P.O.-Kausalyaganga, Bhubaneswar-751002, India, Fax: 91-674-2465407, Phone: 91-674-2465446; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

2 Technical Officer, ICAR-Central Institute of Freshwater Aquaculture, P.O.-Kausalyaganga, Bhubaneswar-751002, India

3 Director, ICAR-Central Institute of Freshwater Aquaculture, P.O.-Kausalyaganga, Bhubaneswar-751002, India

 

Abstract

Water budget was calculated for 11 numbers of fish ponds in Gop, Odisha, India. Water sources considered include regulated inflow, precipitation and run-off, whereas water losses include evaporation, seepage and effluent discharge (harvested water). Indian major carps were cultured for 330 days starting from mid July 2012 to mid June 2013. The rainfall was 200±5.0 cm while the run-off was 12±0.2 cm in these ponds. Average evaporation was 0.33 cm/d while average seepage was 0.11 cm/d in these ponds throughout the culture period. The loss from the evaporation and seepage was compensated through the regulated inflow of groundwater from wells. The total amount of well water needed in an average year to compensate the water loss through evaporation and seepage was calculated and for the 1.0 ha pond, 5800±200 m3 of water was applied by the well. At the time of harvest, the drainage was 116±4.0 cm which was equivalent to 11600±400 m3 of harvested water. The production of these ponds was 6120±320 kg/ha. Consumptive water use in aquaculture consists of water removed at harvest, and water lost in seepage and evaporation. Accordingly, the consumptive water use was 2.38±0.04 m3/kg fish in these ponds. The total water used for the fish production was 4.41±0.18 m3/kg fish in these embankment ponds.

Keywords: water budget; aquaculture ponds.

 

Introduction

Availability of freshwater is shrinking day by day, and it is important to know about the minimum requirement of water for the production of one kilogram fish. Thus water budgeting is important for one kg of fish production. Water budget for some watershed has already been reported (Shelton and Boyd, 1993), e.g., for some experimental ponds of Alabama (Boyd, 1982), as well as for some ponds in the dry tropics (Green and Boyd, 1995). In all the cases, evaporation loss, seepage loss, annual rainfall, and water inflow-outflow had been considered. Thus, water budgets are useful for the estimation of requirements of ponds that rely on rainfall and runoff as primary water sources and for flow-through pond facilities. Such budgets will also be able to predict whether an existing of potential source will be able to meet the projected water demand of aquaculture facilities, and also in comparing the value of available water for different agricultural proposes (Nath and Bolte, 1998). So far as aquaculture pond is considered in India, no report on water budget for aquaculture practices is available. Thus, the present investigation was made to evaluate the water budget for carp culture practices in Odisha, India.

 

Materials and Methods

Management of ponds

Field studies were conducted in eleven ponds near Gop block of Puri district, Odisha, India in polyculture ponds of Indian major carps comprising three species of Catla catla (catla), Labeo rohita (rohu) and Cirrhinus mrigala (mrigal). All ponds were approximately 0.3 hectare in size. The age of these ponds were 18 years.

Filling of ponds was done with rainwater since June 2012 and continued till July. Sometimes, the canal water is used for the filling up of the ponds. The harvested water from the ponds is kept in other nearby empty ponds and this water are treated with lime to improve the quality and then used at the initial filling of the ponds. Sometimes, this harvested water are kept in the same pond and treated with lime and then used as initial filling. The water used either from the canal or from the harvested water at the initial filling of the ponds has not been taken into account in the water budget. In mid July, ponds were stocked with the fingerlings of catla, rohu and mrigal at a ratio of 1:1:1 at a stocking density levels of 8,000/ha. The average body weight of a mix of major carps was 9.0 ± 1.0 g at the initial stocking time. The cow dung @10,000 kg/ha/yr was applied to these ponds as organic fertilizer. At the time of pond preparation, 10% of total organic fertilizer was applied in the pond. Lime @ 200 kg/ha was applied at the time of pond preparation. The inorganic fertilizer, urea (46 %) was applied @ 200 kg/ha/yr and single super phosphate (SSP) (16 % P2O5) was applied @ 300 kg/ha/yr. The organic fertilizer was applied to these ponds in equal amounts at weekly intervals while inorganic fertilizers were applied to these ponds in equal amounts at fortnight intervals. The fish were fed with pelleted feed (30 % protein content). Feeding rate decreased from 4 % to 2% per day of estimated fish biomass as the growing season progressed. Lime was also applied to these ponds @ 200 kg/ha as and when required throughout the culture period.

The water level in these ponds initially was established at 150 cm through rainfall, run-off and canal water. The depth of these ponds was 240±10 cm in September and then reduced to 210±8 cm in December. Water level was further reduced to 187±7 cm in the month of January, 2013 and the level was lowered to 116±5 cm in the month of June, 2013. Well water was added until the water level dropped below 150 cm. The overall depth of these ponds was 192±6 cm. The storage change was 124±4 cm. The culture period was 330 days. At harvest time, the average weight of these fishes was 850 ± 150 g. The production level in these ponds was 6120±320 kg/ha/yr with a survival rate of 90 %.

 

Water budget

Rainfall was measured at the pond site using standard rain gauge and the data was collected from mid July 2012 to mid June 2013. Properly marked bamboo sticks were installed in each pond and water levels were measured periodically and after each rainfall event. The amount of well water added to ponds was calculated (Boyd, 1982) using the following equation:

W = (E + S + O +H) – (P + R)

Where W = water from well, E = evaporation, S = seepage, O = overflow, H = Pond water depth, P = precipitation (rainfall), R = run-off. Values for the above equation were in centimeters of water depth. In the present study, there was no overflow of water in any of the ponds. The pond dyke was well compacted and had grass cover. About 67 percent of rain falling on the dyke entered the ponds as run-off (Yoo and Boyd, 1994). The equation for determining run-off for a pond was as follows:

R = 0.67 (a/A) P

Where a = dyke area (m2) and A = pond surface area (m2).

Class A evaporation pan was used for the measurement of evaporation from the ponds in centimeters using the pan coefficient for evaporation as 0.81 (Boyd, 1985). The seepage was estimated in centimeters as the difference in the decrease in water level and evaporation. Data on inflows and outflows and well water additions calculated using the above equation were used to prepare water budgets for these ponds.

 

Results and Discussion

Water sources

Inflow and outflow in a fish pond refer to the amount of water which is added to or discharged from a pond through the direct operations of the farmer. The main water supply to these fish ponds is rainfall which occurs seasonally. In Odisha, rain starts during June/July and is continued till September. However, sometimes it extends up to October. During this period, the rainfall resulted in a rise of water level in a pond and is responsible for the initial filling of the ponds. When the water level reached about 150 cm, stocking is done. Where rainfall was less, water was pumped from the ground water using well into the ponds to fill them.

Inflow of water, precipitation and run-off are considered as water gain in these ponds, and 5800±200 m3 of water was added to the ponds over the course of the culture period, and amounted to 21.5% of the overall water gain in these ponds. Precipitation was the most significant source of water accounting for 74.1% of the water gain. Run-off gains in these ponds amounted to only 4.4% of the water gain and this may be due to small dyke area around the pond. Also 4.5% run-off as the water gain has been reported in the study at El Carao (Green and Boyd, 1995).

The maximum rainfall in the study period was in the month of August (Table 1). There were no rains in the months of November and December. In Gop block of Puri, Odisha, rainfall was the major source to maintain the water depth of the fish pond otherwise water inflow through well water was the largest contributor of water to these ponds. The ponds received a total of 200±5 cm of rain, averaging 0.60 cm/d over the cultured period. After the rainy season, winter and summer seasons follow. The winter season is similar to dry season, with low temperatures while the summer season is dry with very high temperatures.

 

Table 1: Rainfall, evaporation and seepage data for the period July 2012 June 2013 in the polyculture ponds (mean±SE)
Tab01

 

Water losses

The evaporation and seepage are mainly considered as the water losses which are part of outflows in the water budget (Table 1, 2). The average evaporation was 0.33 cm/d over the culture period. The maximum evaporation was 0.50 cm/d in the month of May while the minimum was 0.15 cm/d in the month of January. The average seepage loss was 0.11 cm/d over the culture period.

Evaporation was the main loss of water followed by the harvested water. Though evaporation was a major loss of water, but nutrients were not lost via this route (Boyd et al., 2007). Nutrients were mainly lost through the harvested water.

Evaporation and seepage contributed 75.4 % and 24.6% of the water loss in these ponds respectively. Evaporation and seepage loss varied from location to location. Evaporation contributed between 2.6 and 4.0 mm/d in Nyangera and Kusa villages around Lake Victoria in Kenya (Kipkemboi et al. 2007). They also reported about the seepage loss of up to 7.6 mm/d in Nyangera during the dry season of 2004. Nath and Bolte (1998) reported that evaporative loss was 0.45 cm/d in AIT (Asian Institute of Technology) ponds. The overall evaporative loss in the present study was 0.33 cm/d. The evaporation loss from the ponds depends on the weather conditions, mainly humidity, dry weathers, size and depth of the ponds. The seepage accounted for about 66% of the overall water loss for Auburn ponds, where seepage rates, varied from 0.48 to 0.79 cm/d (Boyd, 1985). The seepage rate varied from 0.27 to 0.69 cm/d (mean = 0.44 cm/d) in the AIT ponds (Nath and Bolte, 1998). The variation in seepage in different studies is mainly due to the type of soil and the method of estimation.

 

Table 2:  Water budgets for carp culture ponds
Tab02

 

Water budget and use

The total water use is the amount entering into an aquaculture pond through precipitation, run-off, and other natural processes like seepage in and water applied through well or canal for the management purposes. Total water use in the present study was 270±7.2 cm in a cultured period which was equivalent to 27000± 720m3 for a hectare of a pond.

Consumptive water use for an aquaculture pond consists of water losses due to evaporation and seepage. Accordingly, the consumptive water use was 146±2.6 cm during culture period which was equivalent to 14600±260 m3 for a hectare pond. The consumptive water use was 0.44 cm/d. The water use rates in eight brackish water shrimp ponds in Chachoengsao, Thailand varied from 0.63 to 0.95 cm/d (Braaten and Flaherty, 2000). The water use rates in catfish ponds in Alabama and fish ponds in Honduras were 1.16 and 0.87 cm/d, respectively (Boyd, 1985; Green and Boyd, 1995). The water use rate for coastal shrimp ponds was 0.71 cm/d in Thailand (Briggs and Funge-Smith, 1994).

Water use could also be computed in terms of production. Fish production was 6120±320 kg/ha in these ponds in the present study. Accordingly consumptive water use was 2.38±0.04 m3 /kg of fish, while total water use was 4.41±0.18 m3 /kg in these embankment ponds. It is evident that both consumptive as well as total water use could decrease with an increase in fish production without any negative impact on the environment could be one option for the losses requirement of water use.

 

Conclusion

The water budget model developed in the present study could be beneficial in regional-scale planning and evaluation of alternate water uses, where it can be combined with different weather datasets to predict water fluxes across large regions. In order to compare the costs and benefit of water use, the intensity and costs of water use for aquaculture versus various terrestrial agriculture activities could be considered.

 

Acknowledgement

The authors are grateful to the Director of ICAR-Central Institute of Freshwater Aquaculture for providing necessary facilities to carry out the present work. The authors are also grateful to the farmers for their generous help for carrying out the present study in their ponds.

 

References

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Boyd, C.E. (1985). Chemical budgets for channel catfish ponds. Transaction of American Fisheries Society 114: 291-298.

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Braaten, R.O. and Flaherty, M. (2000). Hydrology of inland brackishwater shrimp ponds in Chachoengsao, Thailand. Aquacultural Engineering, 23: 295-313.

Briggs, M.R.P., and Funge-Smith, S.J. (1994). A nutrient budget of some intensive marine shrimp ponds in Thailand. Aquaculture and Fisheries Management, 25: 789-811.

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Kipkemboi, J., Van Dam, A.A., Mathooko, J.M., and Denny, P. (2007). Hydrology and the functioning of seasonal wetland aquaculture-agriculture systems (Fingerponds) at the shores of Lake Victoria, Kenya. Aquacultural Engineering, 37: 202-214.

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Yoo, K.H., and Boyd, C.E. 1994. Hydrology and water supply for Aquaculture. Chapman and Hall, New York.