Uttar Pradesh, the northern province, is the most populous State of India, occupying 9% of the total geographical area of the country. The State is surrounded by Nepal in the north, Himachal Pradesh in the northwest, Haryana in the west, Rajasthan in the southwest, Madhya Pradesh in the south and southwest and Bihar in the east. Uttar Pradesh has three distinct regions viz., the Himalayan mountains of the north, hills and plateaus of the south and the Gangetic delta in between. The lofty Himalayas embrace Uttar Kashi, Chamoli, Pithorgarh, Tehri-Garhwal, Garhwal, Almora Nainital, and Dehra Dun, covering about one sixth of the total area of the State. The southern hilly tracts lie at an altitude of 300 m above MSL. Between the two uplands lies the vast homogenous alluvial plain, one of the largest in the world.
Main rivers of Uttar Pradesh are the Ganga and its tributaries viz., the Yamuna, Ramganga, Gomti, and Ghagra. All of them except Gomti emerge from the Himalayas. The Ganga being too large to be tamed, no major irrigation projects have been created on its mainstream. The irrigation needs are being met by canal projects constructed early this century. In recent years, some of the northern and southern tributaries of Ganga and their minor feeder streams have been tamed, creating a few reservoirs. Nevertheless, the fourth largest State in India has a sparesely dotted reservoir map (Fig. 12.1).
Sixty-six reservoirs with an area of 137 034 ha are distributed among 17 districts and this list is not exhaustive. The four large reservoirs, viz., Rihand, Malhatila, Kalagarh, and Saradasagar, occupy 71 196 ha. Sonbhadra district with 52 000 ha has the largest area under reservoirs on account of the imposing presence of Rihand reservoir. The medium impoundments, having a total waterspread of 44 993 ha, are distributed in the districts of Jhansi, (5), Varanasi, Sonbhadra, Banda (3 each), Mirjapur (4), Hamirpur (2), Bijnaur and Pilibhit (1 each). Forty small reservoirs have been documented with a total area of 20 845 ha, dispersed almost uniformly in the districts. Mirjapur (7) Hamirpur (6) and Gonda (6) districts have the maximum number of small reservoirs (Table 12.1).
The State Fisheries Deparment classifies the water bodies in the State based on the area. Accordingly, total areas under small (<1 000 ha), medium (1 000 to 5 000 ha), and large (> 5 000 ha) reservoirs are 162 000 ha, 31 840 ha and 271 000 ha, respectively. Thus, the State has 464 840 ha of water bodies (individual units above 10 ha in size). But, this also includes the natural water bodies such as oxbow and upland lakes. By deducting the estimated 130 000 ha of natural lakes (Saxena, 1986), the total water area under man-made impoundments becomes 334 840 ha.
Present fish yield from the reservoirs is estimated at 8 to 10 kg ha-1. Only very few reservoirs of Uttar Pradesh have been studied. Rihand was a part of the All India Coordinated Project on Reservoir Fisheries. Between 197 1 and 1981, fisheries ecology of the reservoir was investigated in detail (Natarajan et al., 1982).
Figure 12.1. Distribution of reservoirs in Uttar Pradesh
|District||Small <1 000 ha||Medium 1 000–5 000 ha||Large > 5 000 ha||Total|
|Mirjapur||7||2 666||4||11 878||-||-||11||14, 544|
|Jhansi||3||1 789||5||9 262||-||-||8||11 051|
|Hamirpur||6||1 347||2||2 960||-||-||8||4 307|
|Banda||2||1 672||3||5 556||-||-||5||7 228|
|Bijnaur||-||-||1||1 214||1||7417||2||8 631|
|pillibhit||-||-||1||4 089||1||6 880||2||10 969|
|Gonda||6||2 494||-||-||-||-||6||2 494|
|Nainital||4||7 962||-||-||-||-||4||7 962|
|Total (Listed)||40||20 845||22||44 993||4||71, 196||66||137 034|
|Grand Total||334 840|
Area based on mean reservoir level Source: Department of Fisheries Uttar Pradesh
Also known as Gobind Ballabh Pant Sagar (GB Sagar), Rihand reservoir was created on the river Rihand, a tributary to Sone, which in turn joins the Ganga on its right flank. The dam is located at 24° 1' N and 83°E. The river originates from the hills of Madhya Pradesh, draining a catchment of 13 344 km2. Commissioned in 1962, the reservoir has a capacity of 10 625 million m3 at the FRL of 268 m above MSL and a surface area of 46 538 ha, which shrinks to 13 759 ha at the dead storage (mean 30 149 ha). It has a maximum length of 48 km and the mean depth at FRL is 22.8 m. Annual rate of inflow is estimated at 6 301 million m3.
Based on texture, the bottom soils of the reservoir are classified as clay to clay loam. The soil pH ranges from 6.0 to 8.0 with the maximum during post-monsoon months. The low values in pre-monsoon months denote the higher rate of organic decomposition producing more carbon dioxide, which in association with water, gives carbonic acid, lowering the pH values of soil. The available nitrogen ranges from 15.68 to 30.52 mg 100 g-1, being higher during post-monsoon months. The level of available phosphorus (1.10 to 2.30 mg 100 g-1) is more or less uniform throughout the year. The organic carbon is high (1.19%) in the deeper region, compared to the shallows (0.50%) due to the low rate of organic decomposition. CaCO3 is high (2.307 to 4.377%) during the post-monsoon period.
Figure 12.2. Rihand reservoir, Uttar Pradesh
The water remains moderately warm, the mean winter and summer temperatures being 19.9 and 31.1 °C respectively. Mean transparency of the reservoir water is low (14.58 cm), the range in values being 1.8 to 28.5 cm. It is neutral to alkaline in reaction (pH 7.0 to 8.8), and the lower values are recorded normally during monsoon months due to carbon dioxide-rich inflow. Range in dissolved oxygen is within 3 to 10 mg 1-1, with a saturation level of 50 to 107%. Free carbon dioxide values are from 3.5 to 34.0 mg 1-1.
Carbonates being absent in the presence of free CO2, total alkalinity is in the form of bicarbonates with values ranging from 28.0 to 60 mg 1-1 (average 43.87 mg 1-1). Total hardness of 8.4 to 21.6 mg 1-1 confirms the low rate of dissolved salts. Phosphate (traces to 0.65 mg 1-1) and nitrate (0.15 to 0.70 mg 1-1) indicate a conducive nutrient status. Silicate is recorded in higher concentration (14.0 mg 1-1) during the post-monsoon months. The specific conductivity with an average of 92.24 μmhos suggests reasonably high productivity levels.
Despite the low total alkalinity and hardness, the total ionic concentration and the phosphate phosphorus create suitable conditions for primary productivity. A well-defined thermocline exists in May and June. The difference between surface and bottom temperatures is 8 to 10 °C. However, the thermal stratification is short-lived and broken by the influx of flood waters in July and August. No thermal stratification is observed in winter.
The weak chemical stratification indicates a low rate of tropholytic activities. While dissolved oxygen, pH, bicarbonates and specific conductivity decrease from surface to bottom, free carbon dioxide registers a reverse trend. Despite the presence of a strong thermocline, there is only a slight decrease in oxygen towards the bottom (8.3 to 5.1 mg 1-1), with enough oxygen dissolved in depth, indicating low oxygen demand for organic decomposition. This is further corroborated by the pH values which do not vary much in the tropholytic layer.
The mean primary productivity rates are 387.04 mg C m-3 day-1 (gross) and 161.44 mg C m-3 day-1 (net). The rate of carbon fixation was much higher during the initial years (1972–73), when Microcystis formed blooms (Singh and Desai, 1980).
Cyanophyceae, represented by Microcystis dominate the phytoplankton. Other forms, recorded occasionally, belong to Chlorophyceae, Bacillariophyceae and Dinophyceae (Singh et al. 1980). The mean annual plankton density is the highest (70 units 1-1 in 1976) in lentic sector, followed by intermediate (63 unit 1-1), and lotic sectors (54 units 1-1). Plankton density in the reservoir, as a whole, was low, ranging from 4 to 41 units 1-1 during the 6 year period from 1972–73 to 1977–78.
The benthic invertebrate community is poor, with densities of 32 to 70 individuals m-2, mainly represented by the dipteran larvae, Chaoborus and Chironomus, caddis fly larvae, mayfly nymphs, dragonfly nymphs, and oligochaetes. Occasionally, the bivalve Corbicula sp. is encountered. The benthic macrofauna is richer in the lotic sector with an organically rich substratum, than in the intermediate and lentic sectors with gravelly and rocky bottom.
The original fish fauna of the river Rihand, before the impoundment, comprised 42 species (Hora, 1949). Motwani (1970) listed 44 species during the post-impoundment phase. Between 1971 and 1981, 44 species were present in the reservoir (Natarajan et al., 1982). The total number of species recorded by various workers before and after impoundment is 74. Cyprinidae, with 35 species shows the maximum species diversity.
Commercial fishing started in 1963–64, by deploying fishermen from Mirzapur. These fishermen were organised into a cooperative society, under the State patronage and provided with nylon yarn and other fishing inputs. Essential marketing infrastructure was also created.
Craft and gear: The most common fishing gear in the reservoir is the surface gill net, operated from a boat. A normal fishing unit comprises 25 gill nets, each measuring 50 × 6m, a boat and 2 to 4 fishermen. The boat used in the reservoir is a flat-bottomed country craft, 7.3 m long and 1.2 m wide.
A single 400 m long, multi-meshed giant drag net was also introduced in the reservoir. The oval shaped net is 6 m wide at the middle and the tapering ends measure 2 m. The mesh sizes (bar) vary from 15 to 50 mm. The net is operated by 16 to 17 fishermen with the help of 2 boats and a single haul lasts more than two hours.
Desai (1993) reports in detail, the fish yield trends of Rihand reservoir. Total catch from gill nets and the catch per effort ( effort = 50 m gill nets) during the last decade have been erratic (Table 12.2). The fish catch by gill nets increased progressively from 184.13 t in 1972–73 to 328.82 t in 1974–75 and declined thereafter. An unusually low catch was recorded during 1978–79 due to restricted fishing activities.
|Years||Total catch (t)||Yield ha-1 (kg)||Number of nets||Number Catch/of 50 m gill net||Percentage Increase|
|50 m unit (kg)||Effort||Catch|
|1972–73||184.13||6.11||126 597||75 285||2.44||-||-|
|1973–74||442.62||7.85||105 029||62 656||3.87||-16.77||+31.77|
|1974–75||328.82||10.91||245 626||147 375||2.23||+95.76||+78.57|
|1976–77||68.23||2.26||139 442||95 513||0.71||+26.87||-62.97|
|1977–78||83.49||2.76||144 095||86 457||0.96||+14.84||-54.65|
|1978–79||24.87||-||34 249||20 549||1.21||-72.71||-86.48|
|1979–80||148.15||4.91||410 106||246 063||0.60||+226.84||-19.54|
|1980–81||79.52||2.64||225 449||135 269||0.58||+78.08||-56.81|
Effort = Number of 50 m gill net
Desai (op. cit.) describes an inverse relationship between the water level and fish yield in the reservoir. The high production of 242.62 t (1973–74) and 328.82 t (1974–75) were achieved at low water levels of 248.55 m and 248.22 m respectively. There was a similar correlation between the water level and catch for 1971–72, 1972– 73 and 1975–76. Lower water level permits effective operation of gill nets, especially in areas of the reservoir, where column setting of gill nets becomes possible.
There is a progressive decline in catch per effort. During 1979–80, despite a catch level near to that of the first year (1971–72), the catch per effort was only 0.60 kg, compared to 2.44 kg for 1971–72. This is due to a three and half times increase in fishing effort.
The preponderance of Catla catla(73 to 99%) in the fisheries of Rihand is remarkable (Table 12.3). The other species are Cirrhinus mrigala,Labeo calbasu, L. rohita, L. bata, Puntius sarana, Wallago attu, Silonia silondia, Mystus spp., Bagarius bagarius, Notopterus chitala, N. notopterus, and Channa marulius.
Catch per unit effort (when 50 m gill net is taken as a unit) remained unchanged despite a two-fold increase in the number of units during the period 1972– 73 to 1974–75, indicating that the stock density of catla was not affected until mid 1970s. In 1975–76 and 1976–77, even with reduced fishing effort, the catch per unit effort declined (1.78 and 0.71 kg respectively) and the decline continued even when the fishing effort was raised. Thus, stock abundance in the reservoir is being affected.
A selective fishing practice is being followed by the fishermen who operate a large number of nets in the mesh bar range of 150 to 170 mm, targeted against larger size group of catla (900–1100 mm/ 14–25 kg). Percentage of catla in the large-meshed nets is high (97.2%), compared to the smaller nets (36.6%). This fact tempts fishermen to employ the former, as catla is at premium over the other fishes. Comparison of the catch structure of gill nets and drag nets is interesting (Table 12.4). The catch of carps in drag nets remains as low as 8.65%, the remainder being catfishes (S. silondia, W. attu, Aorichthys spp., B. bagarius) and other predators, viz., Notopterus spp., and Channa marulius. This brings out the role of drag nets in controlling the predators in the reservoir, that are getting a foothold among the ichthyofauna.
Breeding of major carps in Rihand, reported in July, is influenced mainly by the monsoon inflow during the month. During 1974 to 1977, the annual spawn collection (eggs) mainly yielded catla and mrigal (Table 12.5). However, the survival of the latter appears to have been poor.
|Gill nets||Drag net|
|no (%)||wt(%)||no (%)||wt(%)|
|Year||No. of eggs collected||Percentage of|
Stocking was initiated in Rihand reservoir during 1963–64, and by 1970–71 it was stocked with a total of 5.6 million fry/fingerlings at an annual average of 700 000 which works out to 23 ha-1, on the basis of an average reservoir area of 30 148 ha. During the subsequent 11 years ending 1981–82, the stocking rate declined to 13 ha-1.
Desai (op. cit.) reiterates the need for intensive stocking of Indian major carps, especially mrigal, rohu and L. calbasu to diversify the carp species spectrum. Despite its breeding success, catla is under threat as its spawn is vulnerable.
The limited availability of upstream spawning habitats leads to competition among carps for breeding grounds, resulting in the frequent occurrence of catla-rohu hybrids in the reservoir (Natarajan et al., 1976).
Natarajan et al., (1977) reports an interesting case of three ecological populations of Catla catla in the reservoir, distinguishable by the relative lengths of their pectoral fins and the body girth. Among the three sub-populations, the one with a medium pectoral fin merits special attention, as it is reported to feed mainly on phytoplankton, especially Microcystis aeruginosa, the ubiquitous blue-green alga of Indian waters.
The effluents from the Kanoria Chemicals (P) Ltd., Renukoot, located on the northern bank of Rihand, are discharged into the reservoir. The factory manufactures caustic soda, bleaching powder and benzene hexachloride. The highly acidic effluents are characterised by high chloride and free chlorine content. Arora et (1970) recorded fish mortality due to chlorine-bearing wastes. Panwar et al. (1979) confirmed this by reporting mortality due to toxic effluents from the same industrial unit. The affected fishes included Catla catla (2.5 to 3.0 kg), Aorichthys aor (0.3 to 0.6 kg), Cirrhinus mrigala (0.35 to 1.5 kg) and Clupisoma garua(72 to 85 kg). Plankton and benthic communities are also affected.
There are five thermal power stations along the banks of Rihand reservoir, including the three super thermal power plants, which produce 10 600 MW of electricity (Fig 12.3). Adverse effects of the heated discharge and the deposition of fly ash into the water have been discussed by Chandra et al. (1985). The temperature of heated dischargre ranges from 46 to 52 °C and the deposition of ash extends up to 500 m downstream of the outfall region. All the power plants are located near the intermediate and lotic sectors which are known for concentrations of fish (Desai, 1993).
Gulariya is a typical small reservoir of the Gangetic plain, situated in the Allahabad district. It is created over a small rivulet, Gulariya. The reservoirs covers 300 ha at FRL and shrinks to 6.7 ha during summer. It dries up completely during extreme summers. The catchment area of 38 km2 comprises rocky terrain with forest cover, receiving an average rainfall of 90 mm. The reservoir has a gross storage capacity of 9.3 million m3 at FRL. The 3 km long earthen dam is provided with a 228 m long escape channel. Constructed for the primary purpose of minor irrigation, the reservoir releases water through a 24 km long channel, serving a gross command area of 3 395 ha.
Mehrotra and Jhingran (1986) described the soil and water quality parameters of the reservoir in detail. The soil of Gulariya reservoir is predominantly sandy (64–73%), with some clay (10–16%) and silt (15–20%). Available nitrogen is fairly rich (12–33 mg 100 g-1), while values of available phosphorus are low (1.2–1.8 mg 100 g-1). The soil is neutral, the CaCO3 content is 1 to 2%. The allochthonous dissolved nutrients entering the reservoir are responsible, to a great measure, for the high productivity. The values of total alkalinity (25 to 80 mg 1-1), hardness (13 to 40 mg 1-1), and calcium (12 to 26 mg 1-1) indicate a conducive chemical environment for organic productivity. Loss of nutrients through irrigation channels is replenished from allochthonous sources. The water is warm due to the shallowness, which allows rapid growth of organisms.
Annual average production of carbon, estimated on the basis of primary productivity rate, is 2 266 to 2 462 t yr-1. The fish food organisms are abudant. Wishard and Mehrotra (1988) report total phytoplankton counts of 18 565, 13 766 and 12 084 1-1 during 1977, 1978 and 1979 respectively. Green algae dominate, followed by blue-greens. Occasional algal blooms and luxuriant growth of periphyton and macrophytes indicate organic enrichment.
Figure 12.3. Location of thermal power stations along the Rihand reservoir
Gulariya represented one of the earliest testing grounds for CIFRI's efforts to develop management packages for small irrigation impoundments. During summer months, Gulariya either dries up completely or else the water level gets drastically reduced leaving scope for over-fishing. This results in the depletion of broodstock and affects recruitment in the succeeding years. Thus, despite the possibilities for breeding of major carps within the system, autostocking and self-sustained stocks are not within the realm of possibility. Fish populations in the reservoir have to be built up by compensating the loss of natural recruitment through the introduction of desirable species. There is a direct correlation between the stocking rates and the catch per unit of effort from such small impoundments, where stock can even be maintained above the natural stocking capacity of the system through supplemental fertilization.
Jhingran et al. (1981), after considering various methods of assessing the potential yield from the reservoir used a thermodynamic model to estimate the production potential, based on the energy projections. With much of its nutrients derived from allochthonous sources, Gulariya is placed in the category of lotic reservoirs, where the morpho-edaphic approach has limited application. Presuming a yield potential of 234 kg ha-1, moderated to 200 kg ha-1, the stocking rate was calculated at 500 fingerlings ha-1, which included a 50% allowance for escapement through spillways. The annual stocking requirement was worked out to be 75 000, considering 50% of the area at FRL as the mean waterspread.
An important consideration was to allow maximum growout period between the date of stocking and the final harvesting, i.e.., before the levels go below the critical mark. The possible loss due to the low size at harvest was to be made good by the number. During 1976–77, the total fish harvest from the reservoir was 5 t. In 1977–78, 75 800 fingerlings were stocked in the reservoir which resulted in a harvest of 15.15 t. This, along with the residual stock netted out during the next year (7t) amounted to 22 t, i e.., 150 kg ha-1. Considering that the total catch from the reservoir ranged from 0.076 to 8 t during 1971–72 to 1976–77, there has been a three-fold hike in the production rate after introducing the new management package.
Bachhra reservoir is created on a small rivulet of the same name in Allahabad district. The reservoir covers an area of 140 ha at the FRL of 111 m above MSL, and a mean depth of 5.22 m. At full storage, the reservoir holds 7.42 million m3 of water which comes down to 0.03 million m3 at the dead storage level. During the dry season, the waterspread becomes 4 ha in area. The dam is a 558 m earthen embankment, provided with a 98 m long waste weir. The catchment comprises predominantly rocky terrain with forest land and pastures receiving a rainfall of 90 cm. The reservoir bed is undulating and strewn with boulders which obstruct the use of many a fishing gear.
Khan et al. (1989, 1990) investigated the reservoir and placed it in the eutrophic category, based on a number of physico-chemical attributes. Due to the nutrient enrichment from the rain washings, the reservoir is rich in total dissolved solids, nutrients and mineral salts. With a favourable temperature regime, coupled with rich bicarbonate alkalinity and hardness, the water is very conducive for primary productivity (Table 12.6).
|Parameters||Range in values|
|Total alkalinity (mg l-1)||72–167|
|Total hardness (mg l-1)||22–78|
|Ca++ (mg l-1)||18–25|
|Nitrates (mg l-1)||0.08–0.18|
|Phosphates (mg l-1)||0.06–0.25|
|Silicates (mg l-1)||0.73–15.0|
(After Khan et al., 1989, '90)
The estimated annual primary production in terms of carbon varies from 1 250 t to 1 402 t. The plankton community of the reservoir is rich with the total count going up to 4 762 units 1-1 during 1984. The major constituents of phytoplankton are Microcystis aeruginosa, Aphanocapsa sp., Coelosphaerium sp., Anabaena spp., Merismopedia sp;, (Cyanophyceae), Pediastrum spp., Eudorina sp., Pandorina sp., Scenedesmus sp., Ankistrodesmus sp., Oedogonium spp. Spirogyra sp., Ulothrix sp. (all Chlorophyceae), Melosira sp., Navicula spp., Surirella sp., Fragilaria spp. and Synedra sp. (all diatoms). The copepods (Cyclops, Diaptomus and their nauplii), rotifers (Brachionus spp., Keratella spp., Filinia sp., Polyarthra sp., and Lecane sp.), cladocerans (Bosmina Ceriodaphnia and Diaphanosoma) and Protozoa (Arcella and Actinophrys) represent the common zooplankton.
The rate of colonisation of periphyton and benthic macrofauna on the available substrata is reported to be very good. Ranges in density of periphyton on submerged objects had been reported as 30 to 2 500 units cm-2 during 1963 and 746 to 120 000 units cm-2 during 1987.
A progressive increase in the density of benthos is reported from 1982 to 1987 when the mean number of benthic invertebrates increased from 490 to 1 894 individuals m-2. Insect larvae (52 to 71%) and annelids (15% to 36%) together form a substantial component of the benthic fauna, followed by molluscs. Chironomidae, Phylopotamus, Culiocoides, Chaoborus and coleopteran larvae constitute the insect fauna and the worms are accounted by Aulodrilus plurisita and Branchiura sowerbyi. Pisidium, Gyraulus, Limnaea, Indoplanorbis, and Viviparus are the common molluscs encountered in the reservoir.
Fish and fisheries
The indigenous ichthyofauna of the river consisted mainly of rheophilic species of a low population density. After impoundment, the lentic water body harbours 51 species of fish, mainly belonging to the cyprinide and catfish families, and the prawn, Macrobrachium lamerrei.
The Irrigation Department auctioned the fishing rights in 1981 and the contractor fished out all the fishes by gill netting which was followed by poisoning. Therefore, during the ensuing year, the entire stock had to be rebuilt by stocking. The reservoir was again auctioned in 1986 for a sum of Rs. 63 000/- when the contractor could catch 4.85 t of fish, corresponding to a yield of 67.4 kg ha-1. The production increased to 10 t in 1988.
At the rate of 1.2% of the primary production, the fish yield potential of the lake was calculated as 240 kg ha-1, against which, an actual yield of 139 kg (10 t) was obtained in 1988, at a conversion efficiency of 0.580%. The main pathway of energy flow is considered to be the detritus chain, the two detritophagus fishes, viz., mrigal and calbasu forming 29.54% and 31.87% of the catch respectively.
The higher yield obtained in 1988 is the result of an optimum stocking density and maintenance of a rational stocking and harvesting schedule, as followed in the case of Gulariya reservoir. Economic evaluation of the fishing operations in Bachhra revealed that the fish business income was about four-fold of the fishermen's remuneration (Khan et al.,op. cit.). Considering the remuneration of fishermen and period of their employment (active fishing period restricted to March to June), only 12 fishermen could be employed at a subsistence level of income, i.e., Rs. 6 000 per annum. The seasonal nature of fishing in small reservoirs precludes the possibility of gainful employment for fishermen unlike the large reservoirs, where fishing activity is a year-round occupation.
Baigul (Sukhi) is a small tributary of the Ganga originating from the foothills of Kumaon Himalayas, which was harnessed in the year 1967 for irrigation purposes to form the Baigul reservoir. The dam is located at 28°56' N and 79°40' E, and provided with four gates and two sluices for outflow. The reservoir has an area of 2 995 ha at FRL of 211 m above MSL. The maximum spillway discharge amounts 566 m3 sec-1. The drainage area of 305 km2 is fed by the southwest monsoon, comprising mainly the Baigul basin and local catchment of wooded forests. The water temperature ranges from 14 to 33 °C, the transparency from 24 to 230 mm and the pH values from 7.0 to 8.2 (Khan, 1986). Alkalinity values are high throughout the year (86 to 107 mg 1-1). Plankton community of Baigul reservoir is rich, comprising 17 genera of green algae, 4 genera of blue-greens, 10 genera of desmids and 14 genera of diatoms (Salim and Ahmed, 1985).
Baghla is a small irrigation impoundment, created on the rivulet Barica in 1952. Situated at a distance of 55 km southwest of Allahabad, the reservoir covers 250 ha at the FRL of 119 m above MSL. The water retention capacity is 9.58 million m3 at FRL and 0.141 million m3 at DSL. Catchment comprises 32 km2 of hilly land, receiving a rainfall of 100 cm.
The Central Inland Capture Fisheries Research Institute conducted ecological studies on the lake from 1988 to 1991. The salient findings are presented below. The soil flooded by the reservoir is alkaline (pH 7.36 to 7.72) with a high specific conductivity of 322.5 μmhos, organic carbon (1.66%) and calcium carbonate (5.2%). Nutrients as well as the total ionic concentration indicate eutrophic conditions (Table 12.7). Thermal stratification in association with a drop in oxygen values in deeper layers was reported in 1990. Temperature dipped by 2 °C from surface (30.0 °C) to 1 m. Mean gross primary productivity was estimated at 98.58 mg C m-3 hr-1 in 1989–90 and 110.47 mg C m-3 hr-1 in 1990–91. The rich nutrients in water and soil enable luxuriant growth of plankton, benthos, periphyton and aquatic macrophytes. Average plankton density is 1 484, 4 363 and 3 075 units 1-1 for the three years from 1988–89 to 1990–91. Cyanophyceae dominate with Microcystis aeruginosa, Aphanocapsa sp., and Anabaena spp., the major constituents. Eudorina, Pediastrum, Pandorina, Scenedesmus, Ankistrodesmus and Spyrogyra represent the Chlorophyceae. Melosira, Synedra, Gyrosigma, Asterionella, Cymbella, Cyclotella and Navicula are recorded among diatoms and Ceratium is the sole representative of Dinophyceae. Zooplankton forming 19 to 35% of the plankton includes copepods, rotifers and cladocerans.
|Parameter||Range in values||Mean|
|Water temperature (°C)||19.0–32.5||25.10|
|Free Co2 (mg 1-1||nil–3.0||0.59|
|Carbonate (mg l-1)||nil–19.0||6.97|
|Bicarbonate (mg l-1)||40.0–96.0||60.50|
|Dissolved oxygen (mg l-1)||2.4–12.8||8.34|
|Sp. conductivity (μmhos)||63.0–292.0||107.24|
|Nitrate (mg l-1)||0.3–0.4||0.31|
|Phosphate (mg l-1)||0.2–0.4||0.30|
|Silicate (mg l-1)||2.4–4.9||3.27|
|Calcium (mg l-1)||14.0–22.0||18.24|
|Magnesium (mg l-1)||2.2–3.7||2.96|
Values pertain to 1988–89 to 1990–91 (CICFRI Barrackpore)
Benthic macrofauna comprises chironomid larvae, Phylopotamus sp., and Chaoborus sp., annelids Aulodrilus plurisita, Branchiura sowerbyi, and molluscs Pisidium, Corbicula sp., Gyralus, Lymnaea, Indoplanorbis, and Viviparus spp. The density of benthic organisms recorded during 1988–89 to 1990–91 ranged from 976 to 2 132 individuals m-2. Periphyton density is estimated at 144 to 545 415 individuals cm-2. Aquatic macrophytes are present during the months of May, November, December and January coinciding with the lesser rates of water level fluctuation. The population density (wet weight) ranges from 250 g to 2.2 kg m-2. The macrophytes harbour a rich associated fauna. Molluscs, prawns, hemipterans (Belostoma, Ranatra), other insect larvae, and molluscs are often encountered among weeds. Annual carbon production of the reservoir varies from 1 150 to 2 180 t, based on which the fish yield potential is estimated at 11.5 to 13.1 t. This is equivalent to 184 and 210 kg ha-1. Keeping in view the uneven, weed-infested basin, and the past experience, 60% of the potential yield is fixed as achievable target.
Fishing rights of the reservoir are auctioned by public bidding. The catch details are presented in Table 12.8.
|Year||Total fish production (t)||Percentage|
|Yield (kg ha-1)||Major carps||catfish||Misc.|
Keetham reservoir in Agra city was created in 1925. The 306 ha lake has a capacity of 9 million m3. The maximum depth is 7.2 m and the mean depth varies from 2.5 to 3.5 m. The climate of Agra is tropical, characterised by hot and dry summer. The catchment area of the reservoir receives a rainfall of 50 to 75 cm.
Dwivedi and Chondar (1980) report high total alkalinity (152 to 176 mg 1-1) in the reservoir. The other water quality parameters recorded are dissolved oxygen (3.8 to 17.6 mg 1-1), free carbon dioxide (0 to 11.28 mg 1-1), pH (7.2 to 9.2) and temperature (17.4 to 36.0 °C). The reservoir bottom soil is loamy sand with pH of 9.2 and organic carbon at the rate of 0.68%. Judging by the water and soil quality attributes, the reservoir is productive. The average primary productivity is 25 to 30.6 mg C m-3 hr-1.
Keetham attracted national attention during 1969–70 when a bumper fish production of 148.6 t was obtained from the lake. This unprecedented yield of 485 kg ha-1 was, however, short-lived and the yield rate started declining soon, reaching 25.7 t (84 kg ha-1) during 1974–75. This was attributed to the erratic stocking schedule. At present, major carps constitute 12% of the catch. Labeo gonius, contributes 39% of the catch, followed by Gudusia chapra (30%), catfishes (8%) and other miscellaneous groups (11%). Among major carps, Cirrhinus mrigala (by number) and L. rohita (weight) dominate.
Mahajal (a giant drag net), bisar jal (scoop net), drift gill net and hooks and lines are the common gear employed in fishing. Drag nets mostly bring in bigger fish including major carps, minor carps and catfishes, while the scoop net is mainly used for catching Gudusia chapra
Reservoirs of Uttar Pradesh have a relatively low fish yield. Examination of 31 small reservoirs covering 11 475 ha, under 10 districts showed yields ranging from 1.1 to 227 kg ha-1 (Table 12.9). The widest range of 3.2 to 227.3 kg ha-1 is observed in Hamirpur, which has a high district average of 19.8 kg ha-1. Bahraich district with 28 kg ha-1. Allahabad with 17.4 kg ha-1 (13.6 to 30.9 kg ha-1) and Jhansi with 21.2 kg ha-1 (5.8 to 34.8 kg ha-1) also have high yields.
The 44 ha Kabarai reservoir in Hamirpur district yielded 10 t (227.3 kg ha-1) of fish during 1992–93. It is the most productive reservoir in Uttar Pradesh. However, this is more of an exception than rule, as the next highest yield obtained at Kohargaddi, Gonda district is only 59.67 kg ha-1. On an average, the small reservoirs produce 14.6 kg ha-1.
Medium reservoirs (based on 13 reservoirs, covering 21 733 ha, located in seven districts across the State) have a yield range of 1.2 to 15.04 kg ha-1. Rihand is the only large reservoir, for which recent production trends are available. This 46 539 ha reservoir produced 50 t of fish during 1992–93, with the yield of 1.07 kg ha-1 (Table 12.10).
|District||Number of reservoirs examined||Yield range (kg ha-1)||Average yield (kg ha-1)|
|Medium reservoirs average:||7.17|
|Date of closure||1962||1967||1969|
|Area at FRL (ha)||46 538||2 995||300|
|Minimum area(ha)||13 759||-||64-73|
|Average area (ha)||30 149||-||15-20|
|Maximum length (km)||40.25||-||10-16|
|Volume (million m3)||10 625||-||9.24|
|Catchment area (km 2)||13 344||305||39.5|
|Elevation (m above MSL)||268||-||-|
|Length of shoreline (km)||561.33||-||1.2-1.8|
|Shore dev. index||7.04||-||-|
|Volume dev. index||0.89||-||-|
|Annual level fluctuations (m)||32||-||13|
|Maximum outflow (m3 sec-1)||209 317||-||340|
|Latitude (N)||24° 1'||28° 56'||25° 12'|
|Longitude (E)||83° 3'||79° 40'||82° 10'|
|Available N (mg 100 g-1)||15.5-30.5||-||1.2-1.8|
|Available P (mg 100 g-1)||1.1-2.3||-||-|
|Water temperature (°C)||19.9-31.1||14-33.5||18°-34°|
|DO (mg 1-1)||3.0-10.0||5.9-11.0||5.0-9.2|
|CO2 (mg 1-1)||2-34||-||0-5.2|
|Total alkalinity (mg 1-1)||28-60||-||25-80|
|Spec. cond. (μmhos)||92.24||-||-|
|Total hardness (mg 1-1)||8.4-21.6||-||13-40|
|Calcium (mg 1-1)||6.2-14.8||-||12.26|
|Nitrate (mg 1-1)||0.15-0.70||-||0.07-0.16|
|Phosphate (mg 1-1)||tr.-0.65||-||0.04-0.13|
|Silicate (mg 1-1)||14.0||-||5.0-14.0|
|Chlorides (mg 1-1)||6-20||7.4-19.8||2.2-4.8|
|Organic carbon (%)||-||-||2.2-4.8|
|GPP (mg C m-2 d-1)||37.17-1022||-||-|
|Date of closure||-||1980||1957||1925|
|Area at FRL (ha)||250||140||4 662||306|
|Average area (ha)||-||72||-||-|
|Mean depth (m)||3.9||5.22||-||2.5–3.5|
|Volume (million m3)||9.6||7.42||-||28 937|
|Elevation (m above MSL)||119||-||210||-|
|Inflowing river||Baghla nullah||Bachhra||Chuka||-|
|Water temperature (°C)||18.0–21.0||-||29.5–33.6||17.4–36.0|
|DO (mg 1-1)||8.80–12.80||-||6.6–7.8||3.80–17.0|
|CO2 (mg 1-1)||0||-||-||0–11.28|
|Total alkalinity (mg 1-1)||-||72–167||-||152.0–176.0|
|Spec. cond. (μmhos)||63–82.1||-||-||-|
|Total hardness (mg 1-1)||-||22–78||-||-|
|Calcium (mg 1-1)||-||18–24.5||-||-|
|Nitrate (mg 1-1)||0.29–0.36||0.085–0.18||-||-|
|Phosphate (mg 1-1)||0.27–0.33||0.06–0.25||-||-|
|Silicate (mg 1-1)||2.4–2.6||7.3–15||-||-|
|Chlorides (mg 1-1)||-||-||8.8–15.0||-|
|GPP (mg C m-2 d-1)||75–125||50–112||-||25.0–30.5|