8. ORISSA

Orissa, a coastal State with a coastline of 480 km, is situated in eastern India, between West Bengal in the north and Andhra Pradesh in the south. The entire State lies in the tropical zone and is divided into four distinct parts, viz., the northern plateau, the Eastern Ghats, the central part and the coastal plains. Three great rivers of the subcontinent viz., Mahanadi, Brahmani and Baitarani drain the State, along with a number of east-flowing smaller rivers.

The Mahanadi discharges annually 66 640 million m³ of water into the Bay of Bengal. The river basin comprises 7 million ha of agriculture area, 22% of which is irrigated. India's largest (in area) man-made lake, the Hirakud, is situated on Mahanadi to irrigate 264 228 ha of land and to generate 270 MW of power. The river has a total catchment of 141 600 km², of which 46.5% is in Orissa. The Brahmani has a total length of 800 km, of which a 540 km stretch and 57% of its catchment are in Orissa. The Brahmani carries 18 310 million m³ of water and the basin comprises 1.7 million ha of cultivated area, 17% of which is irrigated. The State's second largest reservoir, the Rangali is on the Brahmani. The Baitarani and its tributary, the Salandi have a drainage area of 1 793 km². Dams and barrages on these rivers irrigate 61 920 ha. Matai is another tributary of Baitarani. The proposed Bhimkund and upper Baitarani multi-purpose projects envisage many more dams across this river and its tributaries to provide irrigation to more than 100 000 ha. Orissa has a surface water potential of the order of 9.9 million m², which is considered to be sufficient for meeting all irrigation needs of the State. However, only a negligible percentage of the potential is currently utilised, leaving enough room for creating more water storage reservoirs.

8.1 RESERVOIR FISHERIES RESOURCES

According to the State Fisheries Department, Orissa has a total waterspread of 256 000 ha in the form of major, medium and minor reservoirs. Unlike Tamil Nadu, Andhra Pradesh and Karnataka, the State does not designate man-made lakes as tanks. All the small irrigation impoundments above 10 ha are probably listed as reservoirs and hence the higher hectarage in this category. However, information on the number of reservoirs in each category is not available. The Department of Fisheries surveyed the State in 1982–83 and identified 1 442 reservoirs, covering an area of 197 198 ha, which are suitable for fisheries development activities (Table 8.1).

There are three large reservoirs, Balimela in Koraput district (19 440 ha), Hirakud in Sambalpur (71 963 ha) and Rangali in Dhenkanal district (28 000 ha). Of the total six medium reservoirs, two are in Kalahandi (Sunder and Batrajore), and one each in Koraput (Upper Kolab), Sambalpur (Gohira), Sundargarh (Mandira), and Keonjhar (Salandi) (Fig. 8.1). All the remaining 1 433 reservoirs are small (<1 000 ha) with a combined waterspread of 65 047 ha. So far, the Department of Fisheries has initiated stocking and other management measures only in 62 reservoirs (Table 8.2).

Very little scientific information is available on the ecological attributes and production dynamics of the reservoir ecosystems in the State. The only man-made lake studied in detail is the Hirakud.

* Handbook on Fisheries Statistics, Orissa. (1992–93)

8.2 HIRAKUD

Hirakud is one of the earliest major multi-purpose river valley projects in India. The reservoir was commissioned in 1957, on the river Mahanadi, a little below the confluence with its tributary, Ib (Fig. 8.2). Situated within the geographical ordinates of 21° 30' and 21° 50' N, and 83°30' and 84° 05' E, the reservoir has a waterspread area of 71 963 ha at FRL. The 1 248 m long masonry dam has a height of 61 m and this, along with the earthem dams, has a combined length of 25.8 km (Table 8.3). Besides having an installed capacity of 270 MW power generation, the reservoir serves the irrigation needs of 264 038 ha of land and produces an yearly fish crop of 350 t.

The river Ib originating in Raigarh, Madhya Pradesh, has a total length of 251 km and drains a catchment of 12 447 km². It is rain-fed and hence nearly 80% of the runoff occurs during the monsoon months of June to October. Geologically, granite and gneisses underlie the catchment's soil mantle. A mixed red and black soil dominates the region surrounding the reservoir. With a long shoreline of 643 km, the reservoir has a high shore development index of 13.5. More than 65% of the vast catchment area (83 400 km²), stretching over the central Indian plateau is fertile land area. The total annual inflow (1981 figures) has been estimated at 2.22 × 10⁴ million m³ against an outflow of 2.31 × 10⁴ million m³. The average annual rainfall in the region is 152 cm.

Nutrient status and production functions

The 38 year old Hirakud reservoir has emerged out of the initial phases of trophic burst and trophic depression and has now entered into a stage of stabilised productivity. Morphometrically, the massive waterspread and high shore development index portray a positive influence on the productivity levels of the reservoir.

The water regime of the reservoir can be compartmentalised into three zones. The shallow upper zone (18 621 ha) retains, to certain extent, the lotic characteristics and serves as breeding and nursery grounds of commercial carps. The lower zone, next to the dam (40 338 ha), is lacustrine in nature and supports a fishery round the year. The middle zone (13 004 ha) also sustains an year round commercial fishery.

High transparency of water is a remarkable feature of the reservoir, especially during October to May. It decreases during the floods in June to September. Hirakud, by virtue of its location within the tropics, is subjected to intense sunlight. Usually cloudless sky prevails from October to May. The reservoir, during this period, experiences algal blooms, chiefly of Microcystis. The high primary production rates (gross: 900–2 250 mg m^-3 d^-1 ; net: 765–2 025 mg C m^-3 d^-1) suggest the rich density of primary producers in the reservoir. Physico-chemical variables of water (Table 8.4) also reflect the moderate to high productivity status of the reservoir (Yadava and Sugunan, 1992). Hirakud has a rich species diversity in terms of phytoplankton. Thirty nine species of phytoplankton at a density range of 2 590 to 42 474 units 1^-1 have been reported (Dash et al., 1993). There is a preponderance of blue-green algae represented by 12 species including Microcystis aeruginosa, Oscillatoria spp. and Merismopedia sp. There is a serious concern about the discharge of alkaline effluents into the reservoir from three paper mills (Dash et al., 1993).

The reservoir experiences a steep decline in water level during April to June. Based on satellite pictures, the reservoir area is estimated at 46 381 ha during pre-monsoon and 55 243 ha during post-monsoon seasons. Alternate drying and wetting of the margins help mineralization and adds to the nutrient content of the water. The high surface runoff also adds considerable quantity of allochthonous nutrients. Heavy deforestation and poor soil conservation measures in the catchment have resulted in siltation (at the rate of 23.14 million m^-3 yr^-1) of the reservoir bed, affecting the basin topography. The washed off soil input is also responsible for reducing transparency during the monsoon months.

Figure 8.2. Hirakud reservoir, Orissa

(After Yadava and Sugunan. 1992)

(After Yadava and Sugunan. 1992)

Fish and fisheries

The fish fauna of the Hirakud reservoir, including that of the parent rivers comprises both plain and hill river species with sizeable representation of carps and catfishes. A survey conducted in the 1950s recorded 86 species belonging to 20 families, of which 24 were of economic significance. Migratory fishes like Tor mosal and Rhinomugil corsula and prawns. (Macrobrachium spp.) have been affected adversely by the dam, while Indian major carps and bagrid catfishes have adapted well to the lentic conditions. The euryhaline sciaenids form a lucrative fisheries in the reservoir now. Presently, the commercial fishery comprises 40 species:

Before the impoundment, a comprehensive fisheries survey was conducted in a stretch of river Mahanadi by Job et al. (1955). More than 103 species were recorded, of which 24 were of commercial importance. Puntius sarana, Tor mosal, Labeo fimbriatus, L. calbasu and Gangetic major carps were the most common carps. Interestingly, Wallago attu, the major predator today, was very rarely encountered before the reservoir formation. The two indigenous species, viz., T. tor mahanadicus and T. mosal were protected in temple tanks which later on submerged.

An evaluation of the commercial fisheries of the reservoir since inception indicates progressive increase in the fish catch (Table 8.5). From 51.9 t in 1961–62, the present yield has increased to 489.5 t (19990–91), with an annual average of 350 t for the period 1985–91. The gradual increase in effort (number of fishermen) from 184 numbers in 1968 to 2 044 in 1987–88 is primarily responsible for the enhanced catch during the latter phase.

The yield from the reservoir has been estimated at 6.95 kg ha^-1 (based on the area allotted to cooperative societies and the government sector). This is very low, against the State average of 12 kg ha^-1 yr^-1 and the national average of 20 kg ha^-1 yr^-1. However, the catch accounted for the estimation of the present yield level excludes a sizeable quantity harvested through illegal fishing.

Although a sound database for proper stock assessment of Hirakud is lacking, the available information indicates a decreasing trend in the populations of carnivores (catfishes and featherbacks) and Catla catla. The omnivores among the carps have, on the contrary, registered an increase (Table 8.6). Aorichthys seenghala and Silonia silondia among catifishes and C. catla among carps dominated the catch during 1978 and 1979 (Table 8.7).

Data on catch per unit of effort are not available in respect of all fishing units. Based on the available information, as depicted in Table 8.8, with the progressive increase in effort, the maximum production of 843.1 t was achieved against deployment of 1 609 individuals. However, with the increase in number of fishermen, the catch per unit of effort (CPUE) decreased. In 1990–91, with the total catch of 489.5 t, the CPUE was only 239 kg. This shows the over-exploitation in the reservoir.

The low yield and the undesirable species-mix is the result of poor management. The State Fisheries Department has now initiated a stocking programme under which a total of 4.26 million fingerlings of Indian major carps were stocked during the period 1988–89 to 1990–91. This low stocking density of 10 to 47 fingerlings ha^-1, has had little impact on improving the catch structure. Better stock management and adequate conservation measures are necessary to reach the MSY, keeping the present effort level static.

Source: Nair et al. (1981)

The fishing rights of Hirakud were transferred to the State Fisheries Department in 1960. The reservoir is divided into six sectors, of which five are leased to the cooperative societies at the rate of Rs. 100 mile^-2 yr^-1. The sector adjacent to the dam (sector III) is not fished for security reasons. However, experimental fishing and licensed non-commercial fishing are permitted in this sector. More than 94% of the approximately 3 000 fishermen dispersed over 120 peripheral villages have fisheries as the major means of sustenance.

Locally built canoe, (dingi; 5.5 to 6 m size) is main fishing craft. The Central Institute of Fisheries Technology (CIFT) has introduced a wooden mechanised boat of 9.1 m length and a fibre glass, flat bottomed craft into the reservoir (Khan et al., 1992).

Effort = number of fishermen

Fishing and post-harvest operations

Gill nets, drag nets, cast nets, stake nets and long lines are the major fishing gear operated in Hirakud. Gill nets, mainly of 3 types, are operated within 3 to 10 m depth. Drag nets of 4 to 5 types, shore seines of different sizes and hooks and lines are used round the year. Varying mesh sizes (130 mm to 203 mm) are regularly used. Use of gill nets of < 100mm mesh size is prohibited.

The presence of numerous underwater obstructions limits the use of active gear like trawls, seines and drift nets in most parts of the reservoir. The choice is well neigh limited to gill nets. Extensive siltation has, however, eased the operation of dragged gear in some areas of the reservoir. Recent trials on trawling by the CIFT have given results.

George (1979) reports increased availability of S. silondia in the middle reaches during summer, and Labeo fimbriatus during June and July in the same fishing grounds. Catla catla and C. mrigala are more evenly distributed. Fish population in the reservoir being sparse, in relation to the volume of water stored, the chances of fish being caught in gill nets are reduced. Thus, the entangling nets such as frame, vertical line and trammel nets are much more effective. Activity periods of fishes such as Gudusia chapra, Osteobrama cotio cotio and E vacha suggest that they are best caught in gill nets during 00.00 to 06.00 hrs. (Varghese et al., 1993).

The monsoon months of August and September witness a maximum and the period April to July records minimum catch in the reservoir and more than 70% of the fish are caught in entangling nets (Sulochanan et al., 1960). Commercial fishermen set the gill nets at night and hauling them next morning. During the period September to November, a large number of juveniles of Indian major carps in the size range 5 to 25 mm are caught by shore seines. It is thus necessary to impose seasonal restrictions on the use of shore seines. Larger boats are used for transportation. Mechanisation of boats may make the fishing operations more remunerative.

The fish catch of the individual fisherman/party is handed over to the cooperative society, which is sold to traders. Barring a small percentage that is sold locally, the entire catch is despatched to Howrah and urban agglomerates in Orissa as well as neighbouring States. A flourishing trade of dried and smoked fish exists in the region, where the involvement of women fisherfolk is very high. Unmarketed surplus is usually dried and the dry fish is sold in 1 kg cans, the cost ranging from Rs. 20 to Rs. 40 per can. Post-harvest channels are largely influenced by the traders or the middlemen. Their influence also promotes direct disposal of catch to the agents by the fishermen, leading to unaccountability. This also leads to erosion of the functions of cooperatives, ultimately resulting in their collapse.

Cooperatives and their management

Fishing activities in Hirakud are under the cooperative sector. The five sectors of the reservoir, where commercial fishing is permitted, have been leased out to the respective local primary fishery cooperative society (PFCS). Their share capital is supplemented by a government share and subsidies (Table 8.9).

*Excluding 68 sq. km area reserved for dam security

The Mahamadpur PFCS has the maximum operational area (11 655 ha), and Lachhipali has the minimum (4 144 ha.). Based on the average catch for 1989–90 and 1990–91. Thebra attained maximum yield (11.02 kg ha^-1) from its area (Table 8.10). The societies appoint merchants to lift the catch from the landing centres. Price of fish is fixed according to its size class i.e., carps big, carps small, non carps big, non-carps small, Channa etc. The societies normally reimburse the sale price of fish to the fishermen after deducting a commission ranging from Rs. 0.5 (Channa) to Rs. 3.00 (carps big). The procurement price of fish and the commission vary from society to society.

Established in 1979, the Lachhipali primary fishermen's cooperative society has 379 members. The scheduled caste and scheduled tribes constitute 51.45 and 31.33% of the total membership respectively. The society fishes 4 144 ha of the reservoir, most of which dries up during summer months due to drawdown. While fishing activity is at its peak during August to September, it is adversely affected from April to July every year. About 50% of the members of Lachhipali society solely depend on reservoir fisheries for a living.

A variety of fishing gear is in used, including surface gill nets, drag nets, shore seines (operated by 10 to 15 people), hook and line, cast nets, and a variety of traps. The annual fish catch by the members of the society varied from 22.3 t in 1989–90 to 49.7 t in 1991–92. The society charges a commission of Rs. 2 per kg for big carp, small carp and big cat fish; Rs. 1.00 per kg of small cat fish and Rs. 0.50 per kg of miscellaneous fishes.

*Average of 1989–90 and 1990–91

Under a scheme sponsored by the National Bank for Agriculture and Rural Development (NABARD), the society received financial assistance of Rs. 608 400. The scheme, intended to extend assistance to the fishermen for procuring craft and gear, supported 36 fishing units in the reservoir at the rate of Rs. 2 500 for boat and Rs. 1 440 for nets each unit comprising three fishermen.

Situated at the Lakhimpur block of District Sambalpur and established in 1964, the Thebra primary fishermen cooperative society is the oldest society in the Hirakud reservoir and has a total membership of 657, which includes members belonging to the scheduled castes (233) and scheduled tribes (324). Enjoying the fishing rights over 11 137 ha of the reservoir area, it is the most prosperous among the cooperative societies and receives subsidy of Rs. 304 150. Most of the fishermen operating in the area are active and wholly dependent on the reservoir for their livelihood.

The Thebra Society collects a commission from the fishermen @ Rs. 3 for carps, Rs. 2 for catfish and Rs. 1 for small catfishes. In the 1985, the society received financial assistance from the National Cooperative Development Corporation (NCDC) in the form of a loan and share capital worth Rs. 1 107 000. A total of 357 members benefitted from the NCDC loans. The package included a pick-up van and 2 motor launches for facilitating easy transport of catch by the society. Thebra Society is logistically well-equipped for undertaking the marketing of fish to the Howrah wholesalers. But, surprisingly, it leaves the catch at the disposal of private merchants who take away large chunks of the profit. The diesel pick-up van and the motor launch are kept idle, to the detriment of fishermen's interests.

The total fish landings from the area under the control of Tamdei PFPS varied from 28 570 kg in 1989–90 to 30 455 kg in 1990–91 and yield ranged from 3.35 to 5.27 kg ha^-1. The society normally deducts commission at a flat rate of Rs. 1 per kg of fish.

Mahamadpur is the largest Primary Fishermen's Cooperative Society in Hirakud, both in terms of membership and the area of water under its control. The society's fishing territory is confined to sector 2 and handles the lowest catch among all the cooperatives, varying from 14 132 kg in 1988–89 to 32 076 kg in 1989–90, with the corresponding yields of 1.75 kg ha^-1 to 3.85 kg ha^-1.

More than 73% of the members of the Ib IPFCS belong to the scheduled castes and 17.34% to the scheduled tribes. Annual fish catch by the members varied from 15 525 kg in 1988–89 to 39 978 kg in 1989–90, equivalent to 2.04 and 3.59 kg ha^-1. The reservoir area under the control of Ib society covers one of the important sectors of the reservoir from biological and economic point of view. This stretch provides breeding grounds for major carps and it acquires significance while formulating conservation norms. The Ib sector also receives the maximum pollution load. A paper mill in Brajraj Nagar discharges effluents into the Ib river which find their way into the reservoir. Fish kills have been reported on account of pollution. Broodstock ascending the Ib river for breeding is susceptible to over-exploitation and strict vigil is needed to protect the fishes on their breeding run.

Development strategies

Hirakud, despite being the largest man-made watersheet in the country, remains one of the least researched in terms of its fishery potential. The fish production from this large water body is also one of the lowest. This reservoir has been in existence for the last 35 years and having passed through the initial phases of trophic burst and trophic depression, has now stabilised, but at a very low level of fish productivity. Fish species subsisting on higher links in the food chain and uneconomic varieties now dominate the catch, which results, in the poor conversion of the primary energy into fish flesh.

The main accent on development of fisheries in the Indian reservoirs has been on optimum utilisation of the inherent production potential through stock manipulation. Since the lake has already crossed its formative years, any attempt towards substantial change in fish stock is difficult. Nevertheless, a holistic may the fish production. The key parameters identified for sustainable development of Hirakud reservoir fisheries include:

1. a better appreciation of the scientific attributes influencing productivity at different trophic levels

2. appropriate stocking and harvesting policies

3. adequate post-harvest infrastructure

4. strong cooperative base and

5. sound conservation measures.

As the limno-chemical propensities of any water body largely govern its productivity rhythm, a deep insight into the production functions is essential before management measures are formulated. Hirakud with a poor database in terms of soil and water quality, needs a detailed scientific study to assess the flux of nutrients and related production dynamics.

More accurate and reliable data on total catch, effort, catch per unit of effort and size composition of the catches are essential for a proper understanding of the available resources, their extent of exploitation and the effect on the abundance on fish stock. This, in turn, will enable estimation of the level at which the stock has to be maintained for obtaining a sustainee yield. A proper assessment of tbe existing populations of fishes, on the basis of a statistically designed, survey is needed. Such studies would form the basis of a long- term stocking and harvesting policy for the reservoir. This would, inter alia, include the stocking density, stocking schedule, species mix, gear selection and mesh size regulations.

Gear selection is an important component of fisheries management. Sufficient information exists on the efficacy of different fishing gear suitable for large water bodies, mainly through the experiments conducted by the Central Institute of Fisheries Technology. This expertise has to be utilised while formulating guidelines for gear selection.

Fisheries of Hirakud reservoir are totally under the cooperative sector as the societies enjoy the fishing rights of the entire reservoir. However, middlemen have an upper hand in the post-harvest operations, leading to erosion of profit earned by the societies. Market function has been performed by the private fish merchants without any valid reasons. There is a need for an apex body to coordinate the activities of the cooperative societies and to pool and share the resources available at the disposal of different societies. All the market functions including procurement of fish from the fishermen, their transport by water to the landing centres, and trade with the wholesale merchants at Howrah should be done under a properly organised cooperative network.

Since capture fisheries development depends heavily on the biotic communities present in the ecosystem, the management norms for such water bodies centre around principles of habitat conservation and optimum exploitation of the wild stock. Intervention in the ecosystem management should be restricted to augmentation of stock through artificial recruitment and fishing effort manipulations. Pollution from industries, agricultural wastes, thermal power plants and domestic effluents are the common causes of environmental degradation in reservoirs. Hirakud reservoir is already threatened with environmental hazards from:

1. industrial effluents from a paper mill, refractories and cement factories,

2. wastes from collieries,

3. thermal wastes from power plant,

4. river bed modification through removal of gravel,

5. pesticide residues from agricultural operations in the peripheral areas of the reservoir.

The Ib river is a possible route to link carp breeding grounds with the reservoir. This and other areas having a bearing on the carp breeding run need to be studied to determine areas for sanctuaries for the conservation of desirable species.

8.3 RANGALI

Rangali reservoir, on the river Brahmani, is the second largest man-made lake in Orissa, covering 37 840 ha at full reservoir level and 28 000 ha at the mean level, storing 4 400 to 5 150 million m³ of water. The reservoir has a catchment of 25 250 km², comprising mostly forests and wasteland and the nitrates during the rainy season are 0.32 to 0.52 mg 1^-1. The water temperature (20.25 to 29.0 °C) and p^H (8.2) are conducive to reasonably high organic productivity (Pati and Sahu, 1992). This is further confirmed by the rich plankton community, dominated by Cyanophyceae (Microcystis, Oscillatoria, Phormidium, and Lyngbya), Microcystis being the most dominant form among them. The abundance of phytoplankton has a definite correlation with the inflow on account of the allochthonous input of nutrients (Pati and Sahu op. cit.).

The fish catch is estimated at 14.5 t, which is equivalent to 0.52 kg ha^-1, based on the average area (28 000) of the reservoir. No stocking has so far been done.

8.4 STATUS OF RESERVOIR FISHERIES IN ORISSA

Reservoirs of Orissa produce 4 192 t of fish. A district-wise break-up is given in Table 8.11. Yields vary depending on the size of the reservoir. Fifty-three small reservoirs in 10 districts range from 0.77 to 152.75 kg ha^-1 (Table 8.12). Medium reservoirs produce fish at the rate of 0.51 to 5.13 kg ha^-1 and the large reservoirs 0.52 to 15.74 kg ha^-1 (Table 8.13). Yields of small, medium and large reservoirs in Orissa are estimated at 25.85, 12.76 and 7.62 kg ha^-1. This is just 4.5% of the total inland fish production. Considering that the 1 442 reservoirs (197 198 ha) in the State produce only 4 192 t of fish (21.26 kg ha^-1), there is much scope to increase the production through rational management.

The 65 047 ha of small reservoirs could produce 6 505 t of fish and the medium and large reservoirs could add an equal quantity with the final effect of 50 kg ha^-1. This would increase the share of reservoirs to inland fish production from the present 4.5% to 14%. If the total reservoir area of 256 000 ha is taken into account at the above mentioned yield rate, the production can go up to 18 991 t or 20% of the total catch. The reservoirs can play a vital role in increasing the fish availability in the State as their fisheries development is labour-intensive, environment-friendly and socially rewarding, compared to the aquaculture activities. The capital cost involved in producing a similar quantity of fish through aquaculture will be astronomical and the profit is siphoned off by a few investors, whereas the benefits accrued by the fisheries development percolate down to some of the weakest sections of the society. This is especially applicable to Orissa, considering the demographic and social conditions of the areas where these reservoirs are situated.

The Department of Fisheries and the Orissa Fish Seed Development Corporation (OFSDC) stock the reservoirs regularly. The district-wise details are given in Table 8.14. The OFSDC stocked 9 reservoirs in the year 1987–88 and by 1992–93, the number of reservoirs under its fold rose to 30. Total number of fry stocked in various reservoirs during the years 1985–86 to 1992–93 is given in Table 8.15.

Perusal of Tables 8.14 and 8.15 indicates that the stocking rate has been arrived at without any rationale. Perhaps, the easy availability and the nearness to fish seed farms were the criteria for stocking. Details of qualitative composition of stocking are also not known.

Table 8.14. Stocking of reservoirs in Orissa during 1985–86 to 1992–93

Stocking figures in thousands Figures in parantheses-number of reservoirs