Cold water Fisheries Development in Nepal (by T.K. Shrestha)

Department of Fishery, Kirtipur, Kathmandu

ABSTRACT

Nepal has a dense net of rivers and streams, as well as numerous lakes of cold water character. Fish stocks in these waters have been undergoing changes as a result of overfishing, poor land management resulting in siltation, damming, pollution and some other adverse impacts. The potential of cold water fisheries is not fully utilized and its is believed that with a proper management, introducing innovative methods, especially in the direction of a better protection of fish stocks, their enhancement through controlled and protected spawning, habitat improvements and some other management measures, the cold water fishery resources can be brought to a level which will allow their sustainable harvesting without further harming the fish stocks. The author puts forward twenty ideas as how to improve the current situation.

1. INTRODUCTION

Nepal covers an area of 147 181 km² and extends for 800 km along the southern slopes of the Himalayas, separating the arid Tibetan Plateau to the north from the fertile Gangetic Plain to the south. More than 80 percent of the land area is covered by rugged hills and mountains, which include Sagarmatha (Mount Everest) and seven more of the world's ten highest peaks. There are four main ecological zones: trans-Himalaya (a small, semi-arid mountain zone north of the main Himalayan axis), highlands, subtropical/temperate midlands and tropical lowlands or Terai. Nepal has 22 million people with 2.08 percent population growth per year (2001).

Nepal is a landlocked country, where snow-clad Himalayas, eternal glaciers, ice-cold torrents, clear-water and lakes contribute to much of its hydrosphere. These vast stretches of inland water support many and varied forms of freshwater life including fish. The need and opportunities for the study of the freshwater bioresource and its management are enormous.

The "high water" of highland Nepal forms the base of Trans-Himalayan hydrobiology. Up to this time our knowledge about the physical, chemical and biological features of these waters is only meagre. All forms of freshwater life are influenced by their complex hydrometeorological cycle. From the human standpoint its main influence is seen on climate, water supplies, forests, fisheries and navigation. Many wild and scenic rivers and lakes of Nepal provide opportunities for recreational fishing, wetland bird watching, fowl raising and aquaculture. More progressive, dynamic and imaginative management techniques have to be developed for sustaining harvest of fish from these waters and integration of aquaculture.

Nepal has considerable fishery resources, but these have not yet been properly assessed. At present (1999-2000) about 34 500 metric tons of fish are produced from water bodies of Nepal. The potential sources of inland fisheries lie in rivers, lakes, hill streams, ponds, tanks, reservoirs and paddies (Table 1). In these vast stretches of inland waters, fish stocks have been gradually declining owing to the lack of sound conservation measures and harmful fishing practices.

Table 1

Estimated water surface of Nepal available for fishery development (1986)

Fishes and aquatic life in the hill streams were studied by a number of ichthyologists, including Hora (1937, 1952), Taft (1995), DeWitt (1960), Menon (1974, 1999), Shrestha, J. (1981), Shrestha (1981, 1990, 1992, 1997) and Talwar and Jhingran, (1991). Shrestha,T.K. (1990a) and Shrestha J. (1999) gave an account and habitats of fishes of the Himalayan waters. Hill streams of Nepal are exploited for a diverse array of reasons including power generation, water abstraction for domestic, industrial and agricultural effluent disposal, fisheries and aquaculture. These fish habitats have also been altered by many human activities such as land drainage, flood protection and urbanisation. Many of these activities have interrupted, degraded or destroyed the functioning of hill streams, leading to loss of amenity and resource value for other users.

Aquatic resources of Nepal remain virtually uncontrolled. The major river systems supporting fish and other aquatic life are the Koshi in the east, the Gandaki in the central and the Karnali in the western part of the country. Each river system has numerous tributaries that run from north to south. These running waters abound with a great variety of fish and other living aquatic resources such as fresh water shrimps, crabs, prawns, edible frogs, molluscs and algae. A correct assessment of the composition and extent of aquatic resources is highly desirable for future aquaculture development (Shrestha, 1990).

The snow-fed hill streams of Nepal are still very little exploited for cold water sport fishery. Recreational fishing in hill streams can become a major tourist attraction and in the long run become an important source of foreign exchange (Table 2).

In remote places like upper Karnali valley, Kaligandaki, Sunkoshi, Khimti, Chatra and Chisapani there is some fishing for local consumption, but curing and refrigeration facilities remain to be developed. Some commercial fishery has been developed in Pokhara, Hetauda, Janakpur, Biratnagar and Rajbiraj but the limited supply cannot meet the growing demand.

2. PROBLEMS

Nowhere else in the Himalayan region could one find hundreds of kilometres of fine and cool crystal clear fishing waters, teeming with mahseer, snow trout, fresh water eel, and catfishes as in the upper reaches of the rivers Gandaki, Koshi and Karnali of Nepal. Angling in such beautiful waters amidst glorious scenery is a diverse, subtle and beguiling sport. Earlier, when fishermen set their little boats they could actually see the fish jumping about in abundance - some of them even leaping into the boat. Now the dancing, frolicking fish are a rare sight and the Himalayan rivers are no longer an angler's dream.

Cold water aquaculture development in Nepal has lagged behind due to lack of scientific and technological innovations and partly due to the lack of transport and communication facilities.

Table 2

Rare cold water fish of Nepal, showing the preferred habitat and distribution in the major rivers of Nepal

The status^[2] of each species is given as: in danger of extinction (ED), threatened (TH), restricted (R), widespread (WS). Economic and social values are indicated in parentheses after the common names of species: C, preserved in temple ponds due to cultural taboos, worshipped as Fish Goddess; F. used in folk medicine: G, game fish for angling; O, ornamental fish used by Buddhists. persistent problem combined with perishability of aquatic products and geographical isolation between the fishermen and the consumers prevents good use of the catch (Table 3). Lack of modern fish-processing plants means substantial losses between the time of fish capture and consumption. Seasonal glut of fish landed in rural areas is generally salted, sundried and smoked by using crude traditional methods of fish preservation. These processed products, due to rough packing methods, are liable to undergo quick microbial infestation and thus have short shelf life. Such processed fish fail to fetch good market prices. Due to the lack of expertise and knowledge of life history, breeding, migration and behaviour, the development of cold water fishery has remained underdeveloped in Nepal.

3. PRIORITIES

Realising the necessity of giving utmost attention to aquaculture development, the present author would like to draw attention to the following points: (i) Lake and reservoir fisheries need to be given serious concern. Fisheries in lakes and reservoirs may be developed by the introduction of fishing vessels of modern types. Introduction of power-driven fishing boats will enhance the fishermen's ability to take their catch to a landing place with an access road and therefore an access to good market. The better prices they would receive at such a landing point would be a stimulus to increase production. This would also increase the proportion of fresh fish reaching markets. (ii) At certain hydroelectric dams the cold tail waters could be used in fish hatcheries, fish pens, cages and fish spawning channels for the production of cold water fish. In such cold water fish hatcheries fed with running water of the river, controlled breeding or hormone-induced breeding of game fish such as golden mahseer (Tor putitora), deep-bodied mahseer (Tor tor), spotted snow trout (Schizothorax plagiostomus) and point nosed river snow trout S. progastus can be conducted with great ease. (iii). Confluence sites of river and creek are congregation points or staging areas of migratory and resident fish. Such areas should be converted into fish spawning channels by applying habitat simulation techniques.

Table 3

Fishermen community and their major catch

4.REMEDIES

The potential for increasing fisheries production can come from three areas: utilization of untapped species (aquatic plants), harvesting of hitherto unattractive aquatic resources (frogs, shrimps, crabs, mollusc and ducks), and development of novel methods of aquaculture and harvesting. In Nepal, the traditional fishing crafts used by native fishermen are outmoded. For better harvests, better fishing vessels, in particular the replacement of traditional crafts by powered boats, together with good storage and freezing facilities and extension of biotechnology, are highly desirable.

Many hydroelectric reservoirs and irrigation projects have been put into effect in Nepal during the last two decades. These projects have given scant attention to the possibilities of running water fish hatchery development; future projects should give due consideration to evolving management in such a way that no deleterious effect is produced on the fish fauna due to impact of dams. To facilitate seasonal migration of fish and other aquatic animals, fish passage (fish ladders and fish lifts) should be constructed along hydroelectric dams.

Conservation of rare fish of Nepal needs to be given proper attention and should be observed in context of international perspectives of a developing country. There ought to be a symbiosis between biologists and engineers in formulating the multiple policy of water use. Harmful fishing practices such as poisoning, electrofishing, dynamiting and rock striking must be stopped. Sections of rivers and reservoirs where fish congregate for spawning must be closed to fishing or declared fish sanctuaries or fish parks.

It is essential to determine whether the native cold water fish are superior to the introduced trout and other cold water fish. The impacts of introduced species such as carp, rainbow trout, tilapia, etc., upon the native ones should be thoroughly studied.

For the development of aquaculture, attention needs to be given to increased production through introduction of integrated aquaculture, techniques of induced breeding of fish and their faster propagation, and to ranching of migratory fish stocks. An international centre of cold water aquaculture and fishery development should be established for the mountain countries of Asia.

Fishermen in Nepal are mostly poor and landless people. They usually take to this profession on a part-time basis. If fishing could become more lucrative, more people would be engaged in fishing and marketing would commensurately develop further (Table 4). For this purpose fishing co-operatives should be developed.

5. INTERNATIONAL PERSPECTIVE FOR THE DEVELOPMENT OF AQUACULTURE

Aquaculture research in Nepal is still in its infancy. A long-term programme of both basic and applied aquatic ecology, genetics and biotechnology will resolve this problem. In all developing countries much constraint has been put on fish habitat and natural water courses by damming, silting, agricultural insecticides, industrial and domestic effluents. In order to protect aquatic life from adverse effects, a concerted effort of hydrobiologists, ecologists, fishery biologists and engineers is needed.

Bhutan, Nepal, India and Bangladesh share common water resources of the Himalayas. Besides these countries the mountain countries of the Hindu Kush - Karakoram - Himalayan region, i.e. Myanmar, Pakistan, Afghanistan and Iran also have considerable cold waters. Fish, turtles, dolphins, crocodiles are much threatened by dams, misuse and pollution. Therefore, effort should be made to draw up a dynamic fish and aquatic resource management policy to implement in international cold waters of these countries.

Table 4

Maximum weight of commercially important fish of Nepal used for food, game and recreation

The governments, in addition to fulfilling their responsibilities for the administration of laws pertaining to national, territorial and international fisheries, should collect and disseminate information on fisheries and should serve in an advisory capacity on regional fishery problems.

Many nations from the developed world like United Kingdom, United States, Canada, who share a rational fishery management have made conservation policies by means of multilateral approach and international agreements. In promulgating these treaties the signatory nations take into account the research and conservation measures undertaken by the component states and provinces.

Fisheries should be administrated on a nonpolitical basis and by specialists. Biological facts should receive primary consideration in the utilisation of fish stocks. The agency charged with the administration of the fisheries should be responsible for formulation of needed regulations. Public access to sport fisheries is important. Present public ownership of water frontage should be jealously guarded. Conflicts between sport, commercial and subsistence fisheries should be settled on basis of the pertinent facts in each case. In many instances waters will support all types of fisheries with mutual benefit. Where competition exists to the proved detriment of one fishery, an objective socio-economic appraisal should form the basis for the determination of proper regulations.

The success of any fisheries management policy, in private or in public waters, is in proportion to its basis on factual information. This is a clear demonstration of the prior requirement for research in all phases of fish stock management. Research must include detailed physiological studies on individual fish species as well as broad studies of relationships between fish populations and environment. Constructive programmes of research should be developed by universities and by administrative units to make the most advantageous use of available facilities and personnel. The comprehensive programmes made possible through such coordination of resources should encompass the necessary fundamental research in all related fields and the practical problems arising from the application of research findings.

Regulatory laws, stocking, hatchery development and habitat improvement are the recently recognised tools for management of most subsistence, commercial and recreational/sport fisheries. Laws for regulation of the catch should be based upon proved need, limited to those necessary for orderly management of fish stocks, and should be stated as simply as possible. The harvestable surplus of fish should be removed at the most desirable size and in the best condition.

Food, game and forage fish reared at public expense should be stocked only for public benefit; private fish culture should be encouraged to supply privately owned waters. Only fish free of diseases and parasites should be used for stocking. Periodic restocking is desirable in lakes and tail waters of dams that are washed by monsoon infrequently or in waters which are occasionally depleted by pollution, otherwise the stocking of the young of any species in waters having adequate spawning conditions is considered of doubtful value. The introduction of exotic species (tilapia, gourami, amago, mosquito fish) is proper where adequate biological investigation has demonstrated the benefits and the suitability of the environment including the possible effects on continuous waters.

Propagation and stocking of fish in waters where reproduction is lacking and where environmental deficiencies cannot be remedied, is recommended if those who benefit pay the cost of such stocking, or where such stocking contributes to the livelihood of the poor fisher communities. Elsewhere public agencies limit the harvest to maintain sustainable fish stocks. In heavily used waters, fishing for game species must be regarded as a source of recreation, not meat. Private fish culture should be encouraged to provide fish for the table and for those who must have and will pay for a full creel.

Habitat improvement includes creation of spawning channels, development of ranching centres, control of pollution (including soil erosion), and provision of additional shelter, food and spawning facilities for fish. Such work should be preceded by a physical and biological survey to determine the factors limiting fish production and the remedies to be applied. The watershed approach is recognized as logical and most efficient. Predators of fish such as dolphins, crocodiles, turtles should also come into the general picture of fisheries management although they are not a component of tangible fisheries. For this dual international fish parks or sanctuaries should be created along borders.

Fishery resource development should receive top priority in high dam and irrigation projects. Any plan to use water for power, irrigation, navigation or mining or to carry waste products should include maintenance of the fisheries as a co-equal objective and this shouldbecome part of the high dam project cost. Environmental Impact Assessment (EIA) studies are now being conducted for all new dams planned or being constructed in Nepal.

Wherever an agency plans any development that will impair either the quantity or the quality of water available for fish life, mitigation of fish losses should be the financial responsibility of the sponsoring agency. Local projects are government responsibilities. Inter-governmental and interstate problems should be solved by inter-governmental compacts.

The central agencies concerned with fisheries and public health should be responsible for conducting research in cooperation with the Government states or provinces on the effects of pollution and other water uses and on methods for preventing loss of fisheries.

6. RECOMMENDATIONS

For cold water aquaculture in the rivers and lakes long-term research and planning are necessary. The following measures are suggested;

1. The natural environment of major watersheds of the rivers has been greatly changed by deforestation, erosion and silting of river beds. To restore the ecological balance of watersheds monitoring and management must be practiced.

2. Regular ecological surveys should be made to monitor fish population changes in pristine rivers as well as river courses altered under the influence of man.

3. Habitat improvement is an essential factor for the fishery improvement. To avoid seasonal changes of water level, suitable pools should be created by constructing rock or boulder dams. Such a habitat restoration practice will improve the fish habitat quality and avoid the winter desiccation.

4. Water requirements for fish and river wildlife in the rivers of Nepal should be determined by constant monitoring. The water quality and volume should be well regulated to improve the habitat quality.

5. Areas downstream of dams are dewatered at many hydropower projects. Therefore consideration should be given for water release from the dam.

6. Biological considerations should be given to change traditional pond design by incorporating spawning and incubation channels at suitable places.

7. Fish ladders, fish lifts and fish guiding systems should be developed along the dams to allow fish, river dolphins, crocodiles and turtles to pass upstream and downstream.

8. Protective and catch-restrictive fishing regulations should be based on periodic assessments of fish stocks and the critical stages in fish life histories should be studied. Fishing law and bag limits, restricting the use of nets below 2 cm mesh size, should be enforced.

9. In the upland section of the rivers practice of electrofishing and tossing of dynamite into water is in vogue. Such destructive activities should be stopped.

10. In rivers the spawning and migration of fish usually take place in June-September. These two months should be declared as closed seasons by law.

11. To reduce the incidence of pollution in the rivers an adequate provision should be made through legislation to check the pollution caused by waste disposals from paper, beer and other factories.

12. Snow trout populations are declining owing to high fishing pressure in alpine waters. Therefore, it is highly desirable to establish "snow trout sanctuary" at suitable places. The breeding of snow trouts in a hatchery and releasing spawn or fry in rivers and streams will help to stabilize the snow trout populations.

13. The deep-water pools of rivers and their feeder streams should be declared mahseer sanctuaries. Such an establishment will help to protect spawners.

14. Collection of fish fry from rivers, reservoirs and tail waters of dams and spillage should be stopped. Such a commercial exploitation will deplete the fish stock.

15. To preserve fish stocks of mahseer and the snow trout gene bank a conservation programme should be developed.

16. Proper consideration should be given to develop environmentally friendly aquaculture and uplift socio-economic conditions of fishermen as well as fishermen education.

17. A nation-wide fish marketing network should be developed.

18. Introduction of exotics and transgenic species in native water should be conducted only after pilot studies and so that they do not disturb the ecosystem.

19. Enforcement of fishing laws and regulations should be implemented.

20. A national aquarium should be constructed to popularize the knowledge of fish and fisheries.

References

De Witt, H.H., 1960. A contribution to the ichthyology of Nepal. Stanford Ichth. Bull. 7(4): 63-88.

Hora, S.L., 1937. Notes on fishes in the Indian Museum XXIV, on a collection of fish from Nepal. Rec. Ind. Mus. 39: 43-45.

Hora, S.L., 1952. The Himalayan fishes, Himalaya, I (I): 66-74.

Menon, A.G.K., 1974. A checklist of the Himalayan and Indogangetic Plains. Inland Fisheries Society of India, Special Publication No. 1. Barrackpore.

Menon, A.G.K., 1999. Checklist of Fresh Water Fishes of India. Zoological Survey of India.

Shrestha, J.S., 1981. Fishes of Nepal. Curriculum Development Center, Tribhuvan University, Kathmandu, Nepal.

Shrestha, J., 1999. Coldwater fish and fisheries in Nepal. In: Fish and Fisheries at Higher Altitudes: Asia (T.Petr, ed.): 13-40. FAO Fisheries Tech. Paper. No. 385. Rome, FAO.

Shrestha, T.K., 1981. Wildlife of Nepal. Curriculum Development Centre, Tribhuvan University, Kathmandu, Nepal.

Shrestha, T.K., 1990. Resource Ecology of the Himalayan Waters. Curriculum Development Centre, Tribhuvan University, Kathmandu, Nepal.

Shrestha, T.K., 1990a. Rare fishes of Himalayan waters of Nepal. J. Fish Biol.. 37 (Suppl. A): 213-216.

Shrestha, T.K., 1992. Propagation of Mahseer in the Himalayan Waters of Nepal. In: Aquaculture and Schistosomiasis: 61-78. Proceedings of a Network Meeting held in Manila, Philippines, August 6-10, 1991. Nat. Academy Press, Washington, D.C.

Shrestha, T.K., 1997. The Mahseer in the Rivers of Nepal Disrupted by Dams and Ranching Strategies. Kathmandu, Nepal.

Shrestha, T.K., 1999. Overview on fish. In: Nepal Country Report on Biological Diversity (Shrestha, T.B. ed.): pp. 52-59, IUCN, Kathmandu, Nepal.

Taft, A., 1995. A survey of fisheries in Nepal (both present and potential TOICA). A 94. Kathmandu. 32p.

Talwar, P.K. and A.G. Jhingran, 1991. Inland Fishes. Vol. 1 & 2. Oxford & IBH Publishing Co. Ltd., New Delhi. 1158p.