7. MADHYA PRADESH

Situated in the centre of India, Madhya Pradesh is the largest geographic unit of the country. Except for the valleys of the Narmada and Tapti, Madhya Pradesh is mainly plateau land, with a mean elevation of 488 m above sea level, interspersed with mountains of the Vindhya and the Satpura ranges. With an average rainfall of 76 to 150 cm, the State gives birth to four great rivers of the country, viz., Narmada, Tapti, Mahanadi, and Mahi and it also contains sub-catchments of the Ganga, Yamuna, Godavari and Brahmani rivers.

Rivers originating from the highlands of Madhya Pradesh drain out in three different directions. The great Narmada basin with its mainstream runs across the State from east to west, receiving tributaries on either side. The rivers Chambal, Betwa and Son descend from the northern slopes of the Vindhyas, feeding the Ganga river system. The Mahanadi flows eastwards and the Tapti cuts across the State diagonally in a southwesterly direction to enter the Bay of Bengal. The rivers, tributaries, rivulets and streams in the State have a combined legth of 12 000 km.

During the monsoons, all the rivers in Madhya Pradesh turn into raging torrents, carrying enormous quantities of water. During the dry season, they shrink to rivulets. Thus, harnessing of water for irrigation and power generation is more relevant in the State, than anywhere else in India and its track record in tapping the water resources has been impressive.

7.1 RESERVOIR FISHERIES RESOURCES OF MADHYA PRADESH

Madhya Pradesh, with its 0.46 million ha of reservoirs, has the maximum waterspread under man-made lakes of all Indian States. Gandhisagar reservoir is the second largest reservoir (in area) in the country, next only to the Hirakud of Orissa. However, the State is all set to top the table when the proposed Narmadasagar reservoir (91 348 ha) becomes a reality.

The State Fisheries Department of Madhya Pradesh does not have an account of all man-made water bodies. The enumeration is especially poor in respect of the small reservoirs. However, the Statistics Wing of the State Fisheries Department maintains records on total area under different categories of inland water bodies by districts. The Department has classified the inland water bodies into four size groups, viz., <10 ha, 10 to 500 ha, 501 to 1 000 ha and > 1 000 ha. The water bodies less than 10 ha in size are ponds and small tanks which are excluded from the purview of this study. The remaining three categories, by and large, comprise man-made impoundments, with very few exceptions. Among them, the second and third groups together represent small reservoirs (<1 000 ha), as defined in this study. Reservoirs of the fourth group include both medium and large reservoirs.

Within limitations of the available data, an attempt has been made to separate various categories of impoundments and place them under the present classification. The small, medium and large reservoirs in the State are estimated at 172 575, 169 502 and 118 307 ha respectively with a total of 460 384 ha (Table 7.1). Raipur district with 11 327 ha and Guna with 7 310 ha have the largest areas under small reservoirs, while Narasingpur, (552 ha), Hoshangabad (861 ha) and Khandwa (814 ha) have the least. The five large reservoirs of the State are in Raisen, Mandsaur, Jabalpur, Chindwara and Raipur districts, while 19 districts have medium reservoirs.

Description of 32 reservoirs comprising 6 small, 21 medium and 5 large (Fig. 7.1), covering a total area of 173 901 ha, is available. The average size of these small, medium and large reservoirs is 350, 2 527 and 23 661 ha respectively (Table 7.2).

Fish production trends are available for 25 reservoirs, 20 of which belong to the medium category. The Sarni reservoir (1 012 ha) in the district of Betul, producing 61.95 t of fish (61.21 kg ha^-1) is the most productive medium reservoir, followed by Kolar (40.0 kg ha^-1) and Maniyari (25.75 kg ha^-1). Bhimgarh (0.51 kg ha^-1) and Manoharsagar (1.13 kg ha^-1) have the poorest yield. The three large reservoirs, viz., the Gandhisagar, Barna and Totladoh for which catch data are available, produce 9.21, 13.40 and 60.80 kg ha^-1 respectively. Yields of only two small reservoirs, viz., the Govindgarh (59.64 kg ha^-1) and Loni (28.99 kg ha^-1) are known (Table 7.3).

Commensurate with the size of the resource and its pivotal role in inland fisheries development, reservoirs of Madhya Pradesh received considerable research attention, compared to other States. Excepting Tamil Nadu, no other State has subjected as many reservoirs to scientific research as Madhya Pradesh did. At least 16 reservoirs find a place in the literature dealing with some aspects or another, be it ecology or fisheries management. Some reservoirs like Gandhisagar, and Ravishankarsagar are well researched. Efforts have been made in the State to develop the reservoir fisheries on scientific lines.

7.2 GANDHISAGAR RESERVOIR

Gandhisagar reservoir is impounded on the river Chambal, which is the largest tributary of Yamuna, a component of the Ganga river system. The river, at the dam site, receives catchment from the Vindhya ranges in the south and Aravalli in the northeast, covering a drainage area of 23 025 km². Important tributaries that discharge water into the Chambal are Shipra, Chhoti, Kalisindh, Ansar, and Rupniya on the eastern side and Tilsoi, Edar, Retum and Shivna in the west. The 513.6 m long, 64 m high dam has a gross storage capacity of 7 744 m m³, covering 66 000 ha at FRL (Fig. 7.2). The mean depth is 11.73 m, shore development index 4.78, and volume development index 0.601 at the full level. Situated between the geographical ordinates, 24°44' N and 75°33' E, at an elevation of 399 m above MSL, the maximum length and width of the reservoir are 67.8 and 26.1 km respectively. Gandhisagar is one among the four hydraulic structures conceived as a part of the Integrated Chambal Development Programme, the other three being Ranapratapsagar, Jawaharsagar and the Kota barrage.

Figure 7.2. Gandhisagar reservoir, Madhya Pradesh

Gandhisagar has been the subject of scientific studies for at least a dozen research papers, the notable among them being the pre-impoundment study by Dubey and Mehra (1959) and the post - impoundment studies by Dubey and Chatterjee (1976), Rao et al. (1988, 1990) and Kartha and Rao (1990 and 1993). Physico-chemical attributes of water have been described by Dubey and Chatterjee (1976). In the absence of the details on seasonality, the vertical profile and the diurnal behaviour of these parameters, it is difficult to characterise the productive propensities of the water body. Nevertheless, the available information indicates that the reservoir is productive. For instance, the incoming water from the extensive catchment areas of the reservoir has nitrate nitrogen (0.9 mg 1^-1) and phosphate (0.3 mg 1^-1) which is high for Indian reservoirs. Total alkalinity (82 to 124 mg 1^-1) and total dissolved solids (170 to 200 mg 1^-1) are relatives high as well. Free carbon dioxide is not present, at least at the top of the water column, the photosynthetic requirement being met from the bicarbonates as in the case of other productive reservoirs of South India. The pH is always alkaline of 8.2 to 8.9. Unni (1993) throws light on some additional attributes like total hardness (> 100 mg 1^-1) and calcium (36 mg 1^-1), which are conducive for productivity.

The reservoir water has a moderate to high rate of primary productivity up to 102 mg C m^-3 hr^-1., at an annual average of 40.83 and 36.75 mg C m^-3 hr^-1, at the surface and sub-surface water column respectively, corroborates the positive attributes of water. This matches with a rich standing crop of phytoplankton which attains densities up to 3 211 units 1^-1 during the peaks (Rao and Choube, 1990). Diversity of phytoplankton species is notably rich, comprising 12 species of Cyanophyceae, 22 of Bacillariophyceae, 3 of Chlorophyceae and one species of Dinophyceae. In harmony with the other productive, warm, hardwater reservoirs of the country, there is one plankton pulse each during the summer and post-monsoon seasons. The planktonic organisms reach their highest density during the summer months when, due to the low water levels, productive areas of the lake are exposed to sunlight. The high temperature and a relatively stable water level aid the production process during this period. The flourishing standing crop of summer is disturbed and dislodged due to the torrential inflow and outflow during the monsoons. Nevertheless, the influx of nutrients results in another pulse of plankton, soon after the monsoon inflow.

Macrobenthic community of the reservoir is dominated by gastropods (70%), followed by bivalves, insects and oligochaetes. The molluscs colonise the littoral region. Kartha and Rao (1993), after observing 11 main fish collection centres, reported the presence of 41 species of fish, caught mainly by bottom and mid-water trawling and gill netting. This ichthyofauna comprises, among others, the commercially important carps, Catla catla, Cirrhinus mrigala, C. reba, Labeo rohita, L. calbasu and Tor tor. The predatory species comprise the murrels (Channa marulius, C. striatus and C. punctatus) and catfishes such as Wallago attu, Aorichthys aor, A. seenghala, Bagarius bagarius and Silonia silondia. The fish fauna also includes the less important commercial fishes, Labeo boggut sp., L. bata, L.gonitus, Rhinomugil corsula, Glossogobius giuris, Xenentedon cancila, and Notopterus notopoterus along with the uneconomic species, Osteobrama cotio, Barilius bendelisis and Chanda spp. The transformation of fluviatile environment into a lentic one during the impoundment has had an impact on the fish species of Gandhisagar. Dubey and Mehra (1959) recorded 54 species of fishes in the river stretch during the pre-impoundment survey and soon after impoundment, only 39 native species were seen by Dubey and Chatterjee (1976). This included the major carps, C. mrigala and L. calbasu, and the mahseer, T. tor.

Fisheries

Gandhisagar is the best-managed reservoir in the State. Stocking, though inadequate has been regular ever since the programme was iniated in 1959–60 (Table 7.4). The impact of stocking has been phenomenal. Catch particulars are available for the period from 1963–64 to 1980–81 and 1984–85 to 85–86.

(After Dubey and Chatterjee, 1976)

The catch structure could be brought to a reasonably desirable level over the years by inducing a shift in favour of Catla catla (Table 7.5). However, the improvement in the percentage composition of rohu and mrigal was not commensurate with the stocking rate. Catla seems to be breeding in the lake, and this autostocking, catalysed by the stocking support, has resulted in the steady increase of its stock. The indigenous C. mrigala, is on the decline, in all probability due to the deep nature of the reservoir which retards the utilization of its favourite food, the detritus. Labeo rohita has staged a recovery in recent years.

The fish yield from the reservoir fluctuated from 0.51 kg ha^-1 during 1962–63 to the level of 12 to 13 kg ha^-1 during 1978–79 and 1979–80 (Table 7.6). During the two years when the percentage of catla has been the highest (76 to 77%), the yield was also high. A close examination of Tables 7.4 to 7.6 bears out that the fluctuation in the catch is a function of stocking, more precisely the stocking of catla. It has been reported that the production of 1 342 t (20 kg ha^-1), was achieved at a stocking rate of 4.6 million fingerlings (70 ha^-1). The State Government plans to increase the stocking rate to 200 ha^-1 to achieve a target of 2 640 to 3 960 t (40 to 60 kg ha^-1). September, the best month for fishing, brings in the maximum catch. This is attributed to the turbidity and the post-breeding sluggishness of fish (Dubey and Chatterjee, 1976). Fish catch during January and February is also high. From March onwards, the catch declines due to the heavy wind action, which renders gill nets less effective.

(After Dubey and Chatterjee, 1976; kartha and Rao, 1993)

(After Dubey and Chatterjee, 1976; Kartha and Rao, 1993; Srivastava et al., 1985)

Size groups represented in the catch are worth-noticing. Catla in the size groups 75 to 80 and 80 to 85 cm dominated the catch during 1972–73 and 73–74. This has shifted to 85–90 and 90–95 cm class during the next year. Catla, in this size group, represents IV and V year class and thus has a comfortable position vis-a-vis population. There seems to be scope for increasing the fishing effort for this species (Table 7.7). A similar shift in the size group of Labeo rohita from 45–50 cm to 50–55 cm has been reported. Continued domination of larger C. mrigala suggests that their population in the reservoir is larger than what is reflected in the catch composition. If so, they are probably not caught in adequate numbers in the gill nets, which entangle more catla due to the latter's presence in the water column for feeding on plankton.

Mode of exploitation

The fishing rights for the reservoirs were handed over to a public sector corporation in 1980. Prior to that, fishing was done either by the cooperative societies or a group of fishermen from whom a royalty ranging from Rs. 0.80 to Rs. 3.50 was charged by the Government. The royalty rate varied with fish groups. While Rs.2 to 3.50, was levied on a kg of major carps, Rs. 1.50 to 2.00 was the rate for local major species (such as catfishes and mahseers) and rohu. The local minor species, comprising small-sized miscellaneous fishes attracted a royalty of Re.0.80 to Rs.1.00 per kg. Fish merchants, through middlemen and local agents, purchased the fish from the cooperative societies or the groups. The fishermen generally got wages for their daily labour.

There were two types of cooperative societies, viz., the primary cooperatives and apex society, the former engaged in fishing and the latter taking care of the marketing and providing marketing infrastructure and logistics. However, the apex society often failed to discharge the market functions and the private merchants succeeded in making inroads into the system. The royalty system had many drawbacks, such as:

1. the fishermen did not get adequate income.

2. middlemen and merchants made considerable profit.

3. the cooperatives could not effectively undertake the market functions, and

4. non-payment by the merchants/societies deprived the Government of its income in the form of royalty. It is estimated that while the Government earned Rs.2.87 million on royalty, more than one million was spent on its collection.

Since 1980, the Madhya Pradesh State Fisheries Development Corporation (MPSFDC), a public sector undertaking has taken over the functions of the apex cooperatives. The primary societies are now actively involved in fishing, their members fishing on a catch-sharing basis.

Craft and gear

Submerged obstructions in the reservoir restricts the use of many of fishing gear and the gill net remains the mainstay of the fishing tackle employed in the reservoir. On an average, 20 gill nets, each 3.0 m in length are operated from one boat. Nylon twines of 210 d/1/3, 210 d/2/3 and 210 d/3/3 are used for the webbing, the hanging coefficient being 0.5. The mesh size ranges from 25 to 225 mm bar. Generally, the large-meshed nets of 100 to 125 mm bar are used for the capture of large catla and mahseer during winter months and the smaller ones during summer for the other fish species. In addition to gill nets, long lines with live bait are employed to catch murrels and catfishes. Cast nets are also used along the margin.

(After Dubey and Chatterjee, 1976)

A plank-built, flat bottomed canoe, 2 to 3 m in length and 0.6 to 0.7 m in width, is the most popular fishing craft. The other, less common variety, is the Bengal type dinghy, which is 5 to 7 m in length, introduced by the repatriates from the erstwhile East Pakistan. The dinghy has the additonal facility for setting sails for wind propulsion. There are about 300 boats in the reservoir, each operated by 2 to 3 fishermen. The cooperative societies arrange loans for procurement of boats to those fishermen who could afford to own one and have the capacity to repay. Cooperative societies also use mechanised boats, provided by the Department of Fisheries on rental basis, for navigation and fish transport.

Kartha and Rao (1990) report their interesting findings on the efficacy of various types of trawling in increasing the productivity of commercial carps and checking the predator and weed fish populations. After experimental trawling with single-boat bottom trawling, two-boat bottom trawling and two-boat mid-water trawling under different speeds, it has been found that more than 92% of the total catch consisted of economic fish such as catla, rohu, murrels, mullets and featherbacks in two-boat mid-water trawling. This was in sharp contrast to the bottom trawling, of both single boat and two boat variety, which yielded mostly (64 to 91%) the non-commercial species of fish. The authors have recommended two-boat mid-water trawling at a speed of 3 to 4 knots for exploitation of commercial species and single and two-boat bottom trawling at 2 to 3 knots for eradication of uneconomic species of fishes.

Conservation

The State Government prohibits fish capture from rivers and reservoirs including Gandhisagar, during 16 June to 15 August. The upper stretches of the river Chambal and its tributaries such as Chhoti Kali Sindh and Shipra falls on the inter-State border with Rajasthan and lack of jurisdiction and diverse conservation rules of the two States often pose difficulties in the strict enforcement of the closed season. A 10 km stretch of the river Shipra, where the fish congregrate for breeding is declared as a sanctuary. Exploitation of under-sized fishes has been checked by the mesh and fish size regulations. Use of nets below 25 mm bar is not allowed, and this is being enforced without any difficulty. Capture of rohu, mrigal, mahseer and common carp below 1 kg is prohibited under the law. The upper size limit for catla is 4 kg.

7.3 RAVISHANKARSAGAR

Ravishankarsagar reservoir was formed in 1978, on the river Mahanadi, at 20° 38' N, 81° 34' E, 92 km south of the city of Raipur. A multi-purpose reservoir, serving irrigation, hydro-electric power-generation and the industrial requirements of the Bhilai Steel Plant, it has an area of 9 540 ha at the FRL of 348.7 m above MSL. The lowest waterspread during the lean season is 3 220 ha. Total catchment area is estimated at 3 620 km², of which 625 km² is intercepted by the upstream dam, Dudhawa and 486 km² by Murumsilli reservoir (Fig. 7.3). At full level, the reservoir holds 909 million m³ of water (mean depth of 9.53 m). Maximum depth is 32 m.

The Central Inland Capture Fisheries Research Institute has worked on the ecology and fisheries of this reservoir for five years from 1988. The details presented here are collected from various reports of the Institute with the permission from its Director. The reservoir has a shoreline of 102.4 m and a low shoreline development index of 2.0 which suggests a low productivity. One salient hydrographic feature of this reservoir is the continuous drawdown for industrial, irrigation and hydel purposes. The outflowing channels let out water in the order of 11 000 to 30 000 m³ per second in the peak season, the rate coming down to 230 ³ during the summer. However, at no time of the year, the outlets are closed completely preventing the formation of stagnant water. Water level fluctuates by 3 to 5 m in a year. The sediments of Ravishankarsagar is poor in nutrients and organic matter. With respect to the available nitrogen (12 to 30 mg 100 g^-1) and organic carbon (0.2–1.2%), the reservoir has a low productivity, but the level of phosphorus (2.7 to 8.0 mg 100 g^-1) suggests a high productivity.

Figure 7.3 Ravishankarsagar, Dudhawa and Murumsilli reservoirs Madhya Pradesh

Unlike the thickly forested catchment of Gandhisagar, the Ravishankarsagar reservoir derives water from rocky terrain or deforested areas. There are several impoundments above Ravishankarsagar which deprives it of suspended matter. enrichment of the reservoir by allochthonous nutrients is limited. The physico-chemical attributes of water bear out this fact well. Free CO₂ is present in the surface during most part of the year, indicating that it is not utilized for photosynthesis. Only during April-July the CO₂ is depleted with a corresponding increase in the values of dissolved oxygen, suggesting a higher rate of photosynthesis. Overall ionic build-up is rather moderate, as expressed by the values of total alkalinity (38 to 94 mg 1^-1; mean 66.5), specific conductivity (44 to 100 μmhos; mean 67.2) and total dissolved solids (22.0 to 50.0 mg 1^-1; mean 33.5). Total hardness (CaCO₃ of 48.7 mg 1₁, calcium of 37.9 mg 1¹ and magnesium of 10.8 mg 1^-1 place the lake under medium hard water category. Phosphate and nitrate are either below detectable levels or very low (mean 0.05 mg 1^-1 nitrate, 0.08 mg 1^-1 phosphate) (Table 7.8).

Thermal stratification is very weak, with the temperature dropping 2 to 3 °C in a column of 16 m. During a period of three years, except for one month (April 1992) the oxygen depletion in the tropholytic zone was negligible. Similarly, there is no appreciable decrease in pH or increase in total alkalinity and specific conductivity with depth, as is common in the eutrophic warm water reservoirs. All the limno-chemical attributes suggest a low to moderate rate of organic productivity, compared to other reservoirs in the similar geo-climatic regimes.

The low productivity of the reservoir can also be seen from the low rates of carbon synthesis and a low standing crop of plankton and benthic communities. Gross primary production rate is estimated at 16 to 62 mg C m³ hr^-1, which is equivalent to 197 to 750 mg C m^-3 day^-1, the yearly mean being 285 mg C m^-3 day^-1. Total plankton count ranges from 812 to 3 455 units 1^-1, the higher values normally recorded for a brief period in summer months, when the reservoir is relatively stable. The main component of the net plankton being zooplankton (88%), the photosynthesis is carried out mainly by the nannoplankton. Phytoplankton is dominated by Microcystis, Coelosphaerium, Pediastrum, Microspora, Navicula, Fragilaria and Synedra and there are 25 genera of zooplankton mainly Diaptomus, Cyclops, Daphnia, Diaphnosoma Bosmina, Keratella, Brachionus, Difflugia and Arcella. Benthos is rich, when compared to the plankton communities. Dipteran larvae (52.6%), gastropods (30.6%) caddis worms (13.7%), bivalves (2.6%) and oligochaetes (0.5%) are the major groups. The botton biota is particularly rich during the months with minimum water level fluctuation. The annual average density of benthic macrofauna is 254 individuals m^-2, but the figure doubles during the years of less water movements (550 individuals m^-2 in 1991–92).

The fish yield potential estimates, vary from 160 to 200 t or 25 to 33 kg ha^-1 yr^-1. Against this, the present yield is round 8 kg ha^-1. Fish production has registered a four-fold increase during the last five years (Table 7.9). Catch structure is biased in favour of predatory catfishes, mainly Aorichthys aor, A. seenghala and Wallago attu. Their higher percentage, along with the other predators like Channa spp. and Notopterus spp. lowers the fish production by diverting the energy through a longer food chain. Predatory fishes along with the uneconomic species always outnumber the carps and the stocking done so far has had only a limited impact on the catch structure.

(CICFRI Barrackpore)

MC=Major carps, CF=Catfishes, Misc=Miscellaneous
^*(low yield due to non-fishing; only 89 days fishing during Nov.-Jan.)

The stocking done so far, though erratic both qualitatively and quantitatively, has been on a large scale compared to many other Indian reservoirs. Annual stocking figures during 1983–84 to 1990-91 range from 1.2 to 3.3 million, which is equivalent to 198 to 516 ha^-1 (Table 7.10).

The species-mix of stocking material changes during different years, but the number of fingerlings stocked has been considerable (14.2 million in eight years, i.e.., @ 278 ha^-1 yr^-1). Poor impact of stocking on the catch structure is attributed to the presence of predatory catfishes which take a heavy toll of the stocked fingerlings. Breeding of economic carps such as Calta catla, Labeo rohita, L. calbasu, L. fimbriatus and Cirrhinus mrigala, has been reported to be hampered due to want of submergence of breeding grounds in the upper stretches. The breeding failure, coupled with the predatory pressure, results in the undesirable species ratio of the commercial catches.

Management

Fishing rights of Ravishankarsagar vest with the Madhya Pradesh State Fisheries Development Corporation (MPSFDC) since 1984–85. There are two modes of fishing operations viz., direct fishing and contract fishing. Under the direct fishing system, the corporation provides all fishing implements to the fishermen and procures the fish brought ashore by them on payment of remuneration, fixed on the basis of the size and category of fish they catch. These rates are periodically revised by the Corporation. The rates prevalent during 1991–92 are as follows:

Under the contract fishing system, the full reservoir or a part of it is let out to contractors who, in turn, hire fishermen on daily wages for fishing. The contractors are free to sell the fish in the private market. A royalty is levied on the contractor at the rate fixed by the Corporation, the current rate (1991–92) being Rs. 14.00, 12.00 and 8.50 per kg for the major carps, local major and the local minor categories respectively.

Craft and gear

The gear applied are mostly gill nets, although drag nets, traps and a triangular dip nets (pelna) are used occasionally. Everyday, 50 to 60 country boats operate in the reservoir. They are either owned by the fishermen or rented from the MPSFDC. There are six cooperative societies operating in the reservoir, to which the loyalties of 225 fishermen are divided. The cooperatives get their revenue either from the fishing contract deals with the MPSFDC or from the members in the form of commission charged on their earnings. The societies also advance loans, procure fishing gear and arrange bank loans for the member fishermen. Despite a relatively low production capacity, the reservoir's fish yield could be substantially enhanced by adopting the following measures as perceived by the Central Inland Capture Fisheries Research Institute, Barrackpore:

1. A stocking rate of 400 to 500 ha^-1, with an allowance of 60%, to make good the loss due to the predators and the escapement through the outflowing channels.

2. Rationalisation of the species-mix in stocking to build up good fish stocks of desirable species. Catla and rohu should be around 30 and 20% respectively. With the subdued presence of plankton communities, emphasis needs to be laid on the detritivores, such as, Cyprinus carpio and Cirrhinus mrigala.

3. Selective fishing is to be adopted employing suitable gear to control the population of predatory and weed fishes. Drag netting with a provision to release the carps of smaller sizes back to the reservoir would be a welcome step.

4. Stricter enforcement of fishing restrictions during monsoon is required as a conservation measure.

5. Under the contract system, the reservoir should be leased out only to cooperatives, lest the private contractors exploit the fishermen.

6. The MPSFDC should create and extend post-harvest and market infrastructure facilities to the fishermen/ cooperatives as an incentive.

7.4 GOVINDGARH

Govindgarh is one of the oldest reservoirs of Madhya Pradesh, construction of which was started in 1856 and completed in 1916. It is a typical small irrigation reservoir of the State, created by blocking the small streams in the upper catchment of a tributary of the Ganga river system called the river Bichia. This is the type of water body, usually designated as tank in South India. The 307 ha Govindgarh reservoir has a small local catchment of 25.12 km³ from the adjoining hills of Kaimur ranges, receiving 111 cm yr^-1 of rain. Situated 22 km south of Rewa, (geographical ordinates, 24° 24'N and 81° 15'E), the reservoir has a live storage capacity of 8.69 million m³. Water quality, primary productivity and plankton are described by Mathew (1975, 1977 and 1985). Not much is known about its ichthyofauna and fisheries management.

Physico-chemical profile of the reservoir presents a rather enigmatic picture, with certain parameters indicating an oligotrophic regime while others pointing towards eutrophy. The water is uniformly warm throughout the year with an upper temperature limit of 30.5°C and the lower values never sliding below 18.6°C. Higher pH values, transparency and dissolved oxygen also indicate the reservoir's propensity towards productivity. However, low total alkalinty and nutrients suggest an unfavorable environment for a high rate of primary productivity. Considering the age of the reservoir, this poor build-up of nutrients is intriguing (Table 7.11). The heavy rainfall in the catchment and the high flushing rate result in washdown of nutrients and standing crop of plankton and benthos over the sluice gates. This not only disturbs but also arrests the process of primary community succession.

The low rates of dissolved solids and nutrients do not seem to have effect on the production. The rate of primary productivity, though not very high, does not portray a picture as bad as reflected by some of the chemical indicators. Annual average gross production of carbon for the years 1968 and '69 was estimated by Mathew (1977) at 1.104 and 1.482 g C m^-3 day^-1, respectively, assuming a photosynthetic activity for 12 hours a day. This is equal to 404 and 541 g C m^-3 for the two years respectively. The primary production also exhibits a seasonality, with a spurt in this activity during July-August in consonance with the water renewal. Total alkalinity during this period is the highest, thus suggesting the importance of allochthonous input of salts. Rapid utilization of phosphate and nitrate is also indicated during this period. This seasonality of carbon fixation rate confirms the role of water renewal pattern in retarding eutrophication in a shallow, and warm tropical lake.

Figures for 1969 neg- negligible (After Mathew, 1975)

Given the level of certain parameters indicating oligotrophy, the community structure and total count of the plankton are rather good. Mean density of plankton ranged from 1 030 to 1 185 units 1^-1 during 1968 and 1969; the share of phytoplankton being 898 and 1 048 unit 1^-1 respectively (Table 7.12). Mathew (1975) suggests the presence of Microcystis, Anabaena, Melosira and Ceratium among the plankton as an indication that the reservoir is on its road to eutrophication. The contention is fortified by the absence of desmids and pennales, and a high rate of photosynthesis. A good standing crop of plankton, despite a low ionic concentration and available nutrients, is not uncommon in tropical lakes.

(After Mathew, 1975)

A perusal of fish catch statistics of Govindgarh reservoir from 1961–62 to 1968–69 and 1974–75 to 79–80 (Table 7.13) reveals sharp fluctuations in yield rates, varying from 0.4 to 26.4 kg ha^-1 at an average of 15.92 kg ha^-1. Indian major carps, Catla catla, Labeo rohita, Cirrhinus mrigala and Tor tor constitute 90% of the catch (Mathew, 1975) and the predators are very few. It is not known whether Indian major carps constitute a part of the indigenous ichthyofauna of the reservoir by virtue of its connection with Ganga river system, since they are also stocked regularly. They are reported to be breeding in the reservoir (Bhatnagar et al., 1977). T. tor is one of the local species which contributes substantialy to the catch. Carps, especially catla, registers impressive growth, specimens weighing 12 kg being a very common sight in the reservoir. A giant catla weighing 40 kg is reported have been caught. Average sizes of rohu and mrigal in the catch are 3 and 5 kg respectively, while the mahseer, T. tor grows to a smaller size but outnumbers the other fishes in the catch. According to various estimates, the fish production potential of the reservoir varies from 67.79 to 128.38 t and thus only 4 to 7% of the potential is presently harvested.

Mathew (1975) emphasised the need to increase the stocking rate to enhance productivity. However, details of stocking during that period are not known. Srivastava et al. (1985) reported stocking of 5 704, 6 000 and 121 000 fingerlings during the three years from 1972–73 to 1974–75. This is equivalent to 19, 20 and 394 fingerlings ha^-1, a very low rate, considering the size and category of the reservoir.

A waste weir limits the water level of the reservoir to 30.05 m allowing the excess water to flow down to the Jhiria nala, a stream which ultimately joins the Ganga river system through the Bichia river. This open overflow not only results in loss of fish eggs, but also may be letting out a considerable number of young fish, depriving the reservoir of its stock strength. Necessary allowances have to be made while estimating the stocking density. Moreover, a stocking and harvesting schedule needs to be evolved, allowing the stocked fish to grow for a maximum period of time during the non-overflow months, even at the cost of some reduction in the size at harvest. In such a system, larger stock-density can be maintained to make good the production loss due to early harvest.

7.5 MANSAROVAR (Fig. 7.4)

Mansarovar, situated in the heart of the city of Bhopal, is a typical example of a reservoir subjected to man-induced eutrophication. The 79.7 ha man-made lake is created on a tributary of Kaliasole river and a local stream near a thickly populated southern part of the city. Although the main source of water is rain-fed catchment comprising 8.29 km², the storm water channels and domestic wastes of a very high order from the city find their way into the lake. This heavy organic load and the shallow basin (mean depth: 2.87 m) set the ideal conditions for hyper-eutrophication (Kulshrestha et al., 1992).

Suspended particles inhibit the light penetration which is limited to 11 to 41 cm and the pH exhibits extreme temporal and spatial variations. During the heavy inflow of waste water in the rainy season the water turns acidic. Similarly, low pH values are recorded at the sewage discharge points, compared to other areas of the reservoir. On account of accumulation of oxidisable organic matter and the consequent demand on oxygen, the O₂ level drops to 1.2 mg l^-1 with a corresponding build-up of CO₂ (up to 150 mg l^-1). Specific conductivity ranges from 560 to 9 900 μmhos cm^-1, against total alkalinity which goes up to 760 mg l^-1. This clearly illustrates the presence of various ionisable salts in water, other than the carbonates and bicarbonates. Similarly, the hardness of 30 to 350 mg l^-1 (calcium 28 to 195 mg l^-1; magnesium 1.14 to 71.15 mg l^-1) reflects the chlorides and other anions. Phosphate loading of 4.0 to 13.5 mg l^-1 is phenomenal. High BOD and COD values have also been recorded (Adholia, 1991, 1992).

Eutrophication, though conducive to fish production within certain limits, can hamper productivity if the organic loading continues unchecked to the level of hyper-eutrophication. Carbon fixation through phytoplankton gets retarded on account of poor light penetration, thick infestation with water hyacinth and low pH.

Although the phytoplankton community is rich (2 080 to 30 240 units l^-1) and diverse (63 species), an equally luxuriant macrophytic growth including littoral, emergent, and floating types competes for nutrients and the sunlight. On many occasions, the reservoir gets completely choked with weeds with a consequent collapse of plankton communities which gets restored only on weed clearance. Weed choking, especially with the obnoxious water hyacinth, if left unchecked, can lead to swamp formation and destruction of the aquatic ecosystem.

The 19 species of fishes recorded from the reservoir include 10 from the family of Cyprinidae and representatives from the following families: Clupeidae, Notopteridae, Siluridae, Bagridae, Clariidae, Channidae, Belonidae and Mastacembelidae. On account of the organically polluted nature of the water body, air-breathing fishes (Clarias batrachus, Notopterus notopterus) and catfishes (Aorichthys seenghala) dominate the ichthyofauna, along with the detritophagous Labeo calbasu, L. fimbriatus and L. bata.

Ecosystem recovery programme through pollution abatement measures should precede any attempt to develop fisheries in the lake.

7.6 KULGARHI RESERVOIR

Commissioned in 1966 across a seasonal stream Durha nalla of the Ganga basin, in Satna district, the 193 ha Kulgarhi is much akin to Govindgarh in its size, catchment particulars and water quality. The catchment, covers only 27.69 km² and water is impounded with the help of a waste weir. Despite its small size and low mean depth (4.5 m), the water has a low productivity (Dwivedi et al., 1986). The catchment with acidic soil (pH 6.6), with low calcium carbonate (2.28%) and organic carbon (0.61%), is very poor in nutrients such as phosphorus (0.20 mg 100 g^-1) and nitrogen (0.081 mg 100 g^-1). The water quality can be categorised, at best, as medium productive, depending on total alkalinity (47.7 to 140 mg l^-1) and total hardness (42.5 to 125.3 mg l^-1). The water pH (8.0 to 8.3) and dissolved oxygen (5.9 to 11.5 mg l^-1) are high while the nutrients like phosphate (tr-0.08 mg l^-1), and nitrate (tr-0.05) in water are of low order (Table 7.14).

Figure 7.4. Mansarovar reservoir, Bhopal, Madhya Pradesh

The reservoir has a fairly good standing crop of plankton, comprising up to 75% (by number) of phytoplankton and a high rate of primary productivity. Plankton consists of Peridinium, Melosira, Synedra, Fragilaria, Microcystis, Anabaena and other eutrophic species. During the period between 1968 and 1972, the plankton density ranged from 91 to 210 units l^-1 and the average gross primary productivity was estimated at 11.4 g C m^-3 day^-1. Both the plankton count and carbon fixation rate go up substantially during the summer months. The reservoir fish production ranged from 363 kg to 812 kg, the average being 517 kg (7.4 kg ha^-1). The fish catch represented by Catla catla (75.6%), Cirhinus mrigala (11.5%), Labeo rohita (8.3%) and hybrids carps (2.5%). Dwivedi et al.(1986) stressed the need for proper management measures to be taken to improve the fish yield rate.

tr= traces

Kulgarhi is the first reservoir in India, where the exotic silver carp, Hypophthalmichthys molitrix was first introduced on an experimental basis. A small consignment of 229 fingerlings in the size range 121 to 216 mm was released in the reservoir on 11–2–1969 and eight specimens were recovered during the period between 2–12–1969 and 4–6–1971. The growth rate registered by recovered silver carp was remarkable, the fastest being 404 mm in 293 days or 1.4 mm day^-1. Even the slowest growth was 597 mm in 783 days, i.e., 0.76 mm day^-1 (Rao and Dwivedi, 1972). Karamchandani and Mishra (1980), while evaluating the impact of the coexistence of silver carp with the indigenous Catla catla, observed that the two fishes shared a common niche and competed with each other for food. The percentage composition of phytoplankton in the guts of both silver carp and catla caught during the same period, was more or less the same (18.24 and 15.24% respectively). Zooplankton, the favourite menu of catla, formed 21% of the gut contents of silver carp. Comparing the growth performance of the two carps, the authors concluded that the silver carp negatively affected the growth of catla in the reservoir and advocated caution before undertaking large-scale stocking in Indian reservoirs. A detailed discussion on the impact of silver carp population on catla is given elsewhere in this publication.

7.7 OTHER RESERVOIRS

At least a dozen more reservoirs in the State of Madhya Pradesh have been subjected to investigations by scientists. Loni reservoir (350 ha) has medium-soft, nutrient–poor water with moderate primary productivity and plankton count (Anon., 1968). Macrophytes, weed associated fauna and the benthic invertebrates form the mainstays of biotic communities through which the energy transformation takes place. Hydrilla, Vallisneria, Najas, and Potamogeton are particularly abundant among the aquatic plants which colonise the littoral region up to 3.15 m depth during post-monsoon months (Gupta, 1976). The nutrients brought in along with the monsoon inflow are better utilised by the aquatic plants, than the plankton. There is an equally rich community of benthic macrofauna, chiefly represented by molluscs, annelids and insect larvae. The mean density of macrobenthos in Loni varies from 1 829 (in 1969) to 2 386 individuals m^-2 (in 1968). Benthic community exhibits a strong seasonal and spatial rhythm. Commercially important fish of the reservoir comprise small clupeids, detritophagous and predatory catfishes. Among them, biological traits of Puntius sarana (Sinha, 1972; 1976) and Labeo calbasu (Pathak, 1975; Pathak and Jhingran, 1977) are known.

Bergi (27 296 ha), Tawa (20 055) and Barna (7 705 ha) are three large and Sarni (1 012 ha) and Sukta (1 350 ha) are two medium reservoirs in the Narmada river basin. Some limnological attributes of these lakes are reported by Unni (1993). Sarni reservoir has organic carbon, available phosphorus and available nitrogen of 0.2–1.2%, 2.7 to 8 mg 100^-1 respectively. In Sukta reservoir, Desai (1992) reported a phenomenal increase in fish yield from 0.2 kg ha^-1 in 1980–81 to 32 kg ha^-1 in 1985–86 along with a shift in population in favour of major carps. Percentage composition of catla, rohu, mrigal, mahseer, Labeo calbasu and common carp increased from 3% to 20% during the above period.

Sampna, Undasa and Yeshwantnagar are the three small reservoirs on which cursory studies have been made. The 520 ha Sampna reservoir is built on the river Sampna which receives local catchment from the cultivated fields. Specific conductivity (114 to 220 μmhos), phenophthalein alkalinity (2 to 10 mg l^-1), methyl organge alkalinity (70 to 168 mg l^-1) and pH (7.9–9.4) of the reservoir water indicate medium productivity, but the phosphate content is very low (10 to 20 μg l^-1). The algal flora is very rich with regular blooms of Ankistrodesmus, Anabaena or Ceratium hirudinella (Unni, 1982). Undasa reservoir is a 176.5 ha small irrigation impoundment, created by erecting embankments to gather the local catchment. The nutrient content of the reservoir is reported to be very high (Singh, 1986). Yeshwantnagar, another minor irrigation impoundment, created to gather the local catchment for irrigation is a hard water (total hardness 106 to 130 mg l^-1) reservoir, rich in phosphate (0.14 to 0.22 mg l^-1) and nitrate (1.3 to 2.5 mg 1^-1) (Sharma and Diwan, 1989).

Table 7.19 gives water quality and associated data in respect of Halali, Kolar and Dahod reservoirs of Madhya Pradesh (Unni, 1993).

7.8 STATUS OF RESERVOIRS IN MADHYA PRADESH

In total, 5 large, 6 medium and 8 small impoundments have been studied. Irrespective of the size of the water bodies and the elevation at which they are situated, the reservoirs have medium to low productivity. Even smaller shallow lakes usually are not eutrophic. This is basically due to geo-climatic reasons. Madhya Pradesh, in a higher latitude, receives less incident solar radiation and the reservoirs, in general, are situated at a higher altitude, than their counterparts in Andhra Pradesh and Tamil Nadu. The average altitude of the reservoir in Madhya Pradesh is 488 m above MSL. Sharp fluctuations between the summer and winter air temperature have the impact on the thermal and nutrient regime of the water bodies, affecting their biogenic potential. Above all, the geo- chemical make up of catchments play and important role in determining the water quality. Soils of Madhya Pradesh are normally deep black, medium black, shallow black, mixed red and skeletal, low in nitrogen and low to medium in phosphorus (Dubey, 1994).

While the reservoirs in the plains of Andhra Pradesh and Tamil Nadu, spreading over the limestones and other calcareous rocks, have a predominantly hard-water regime, those of Madhya Pradesh are soft to medium soft in nature. However, this does not mean that they are actually poor in biotic communities. Under the Indian conditions, even the lakes categorised as less productive on the basis of morphometric and limno-chemical characteristics are often found to be rich in terms of primary, secondary and fish productivity due to the relatively high turnover rate. The small reservoirs of the State, except those receiving organic enrichment through effluents, are as a rule, less eutrophic than the larger ones.

Gandhisagar, with a relatively low nutrient status, harbours a rich standing crop of plankton with a moderate to high rate of primary production, which is reflected in the fish yield. This reservoir receives its drainage from a vast, forest covered drainage and its large; deep basin facilitates storage of allochthonous nutrient and mineral inputs. Large deep reservoirs have a good percentage of their water as dead storage and their flushing rate is low. The low level of available nutrients, measured in the water phase could be due to the immediate utilisation, on their release into water.

The small reservoirs with small catchments and low volume water have a high water renewal rate, especially during the monsoon. Thus, they rapidly flush out the incoming nutrients rather than storing them. Reach blooms of blue-green algae are much less common in Madhya Pradesh, than in the reservoirs further south where most of the small, shallow reservoirs have summer blooms and many of them have a permanent bloom of Microcystis.

The oligotrophic tendencies character of the reservoirs in Madhya Pradesh are compensated by the sheer magnitude of the resource. Madhya Pradesh will further increase its water surface area on completion of all the Narmada basin projects. The State has realised the importance of reservoir fisheries way back in 1962 and initiated several steps to increase their fish production. During the Vth Five Year Plan (1975–76 to 1979–80), the reservoirs were categorised into five groups according to size and their rate of stocking was specified (Table 7.15).

The stocking targets could not be achieved due to constraints in seed production. In order to fulfil the stocking requirements, the State required 180 million fish seed, but could produce only 10 million (Srivastava et al., 1985).

In some reservoirs like Gandhisagar, Ravishankarsagar and Sukta, there has been a considerable improvement in productivity through good management. Gandhisagar registered a four-fold increase in the yield rate from 0.5 kg to 20 kg ha^-1 during the last three decades and Ravishankarsagar increased its fish production from 13 to 50.3 t (1990–91) in four years. Sukta a small reservoir increased its yield rate from 0.2 kg to 32 kg ha^-1 within a period of five years. The Government, realising the importance of the resource, has entrusted the management of many reservoirs to the Madhya Pradesh State Fisheries Development Corporation. Total fish production from the reservoirs in the state during 1979–80 was 1 251 t, which increased to 2 000 t during 1989–90. This production is still low. The current yield is just 8.9 kg ha^-1, indicating enough room for further increase through effective management.

7.9 IMPOUNDMENTS IN THE NARMADA BASIN

The Narmada river basin is well-poised for water resources development of an unprecedented magnitude. The large number of multi-purpose reservoirs to be created in the basin will soon earn Madhya Pradesh the most prominent place on the reservoir map of the country.

Narmada basin, from Omkareswar to Harinphal receives an average rainfall of 1 000 mm with the maximum of 2 030 mm at Panchmarhi. The Narmada cascades down from east to west with an average slope upto 1:1 000 at the origin to 1:10 000 in the lower reaches (Table 7.16). Most of the rainfall occurs during 2 to 3 months of the year. Narmada basin comprises 95 726 km², out of which 81% is situated in Madhya Pradesh. Twenty of the 45 districts of the State are in the Narmada basin, receiving 22 of the 41 principle tributaries of the Narmada. Thus, a substantial part of the reservoirs will be situated in Madhya Pradesh.

(After Dubey, 1994)

(After Dubey, 1994)

The 29 major projects planned include 21 irrigation, 5 hydroelectric and 3 multi-purpose schemes. This is in addition to the 450 medium and 3 500 minor irrigation schemes (Table 7.17) also planned. All the 3 979 structures when completed, will create an additional waterspread of 260 000 ha in Madhya Pradesh alone. Three large reservoirs viz., Tawa (20 055 ha), Barna (7 705 ha) and Bargi (27 296 ha), 20 medium and 975 small reservoirs have already been created and many others are in various stages of completion. One of the dams that awaits completion is the 91 348 ha Narmadasagar, which will be the largest reservoir of India (Figs. 7.5 and 7.6). All dams on the main river are in Madhya Pradesh, except the Sardar Sarovar which is just across the border with Gujarat. More than 55% of the huge 37 030 ha Sardar Sarovar reservoir, however, will lie in Madhya Pradesh. A list of 30 projects with their waterspread is given in Table 7.18.

Figure 7.5. Narmada basin and the main impoundments

Figure 7.6. Diagrammatic representation of the cascade of reservoirs on the river Narmada

Source: Narmada Planning Agency

tr= traces

Courtesy: Mr.A.R.Qureshi, Asst.Director of Fisheries, Raipur;
Mr.Aslam Khan, Asst.Fisheries Officer, Sikasar reservoir;
The Regional Manager, MPSFDC, Raipur;
Mr.R.P.Varma, Fisheries Inspector, Kharkora, Durg;
The Executive Engineer, Itiadoh Irrigation Division;
Mr. K.S.Sengar, Asst. Fisheries Officer, Rajnandgaon;
The Manager, MPSFDC, Bilaspur;
The Asst.Fisheries Officer Bilaspur;
Mr.S.K.Jain, Manager, MPSFDC, Morena;
Mr.S.K.Sinha, Manager, MPSFDC, Gwalior;
Mr.G.S.Sinha, Asst. Director of Fisheries, Khandwa;
The Regional Manager, MPSFDC, Gandhisagar Dam;
Mr.P.K.Singh, Asst. Director of Fisheries, Betul;
Mr.R.R.Siddiqui, Asst.Director of Fisheries, Sehore;
Mr.M.E.Khan, Asst. Director of Fisheries, Bhopal;
Mr.Laxman Singh, Investigator, Rewa;
Mr.P.S.Rao, Manager, MPSFDC, Totladoh.

Figure 8.1. Distribution of reservoirs in Orissa