3. Importance of fisheries in mountain countries of the world

3.1 Asia

Mountain countries and regions are characterized by the presence of cold waters, many of which harbour fish and support largely subsistence fisheries. Among the largest mountain systems of the world are the ranges of Hindu Kush, Karakoram, Pamir and Himalayas in Asia. The Himalayan ranges feed several large river systems including those of the Rivers Ganges, Brahmaputra and Indus. These rivers, together with their tributaries, support and at the same time threaten the livelihoods of millions of people in the region, before they flow to the sea. Countries situated in these mountains are characterized by poverty and very low level of development. While these mountains represent a unique and globally important ecosystem, they also contribute to the economic hardship of the people.

In Asia, the living aquatic resources of the mountain rivers, lakes and reservoirs constitute an important source of animal protein, but they have been rarely considered in rural development initiatives, perhaps because fish stocks are limited and easily overexploited. They are also vulnerable to activities resulting from human pressure on the environment, such as deforestation and water pollution. High altitude lakes, rivers and streams mostly have a low fish production and can be easily overfished. Even the large Lake Qinghai in Qinghai Province,  China, was overfished using industrial trawlers. Within several years the commercial stocks of naked carp (Gymnocypris przewalskii), a fish which requires 17 years to mature in this high altitude lake (3 200 m a.s.l.), were so reduced that the commercial fishery had to close down. In China, fisheries management, where applied in cold waters, has largely concentrated on introductions of fish for recreational and sport fishery, with mainly the exotic brown trout being stocked. At a lower altitude, especially in reservoirs, the exotic common carp and Chinese carps have been introduced. Carps are more productive than trout, and spawn can be produced in large quantities for stocking in reservoirs and ponds, where such can be constructed. Aquaculture has been on a limited scale, with the production based on rainbow trout (Oncorhynchus mykiss). By 1998, more than 500 rainbow trout farms were established in 22 provinces of China, and by 2000 they produced 10 000 tonnes of rainbow trout. There are now also 127 rainbow trout farms which serve tourism and recreational fishing, which is becoming an important economic activity, especially in the Beijing area. Regarding cold waters in remote areas, the potential for cold water fishery of some water resources in the mountains in the south and west of China still needs to be assessed. There is also considerable potential in northwestern China.

Xinjiang-Uyghur Autonomous Region of China, surrounded by high mountains, covers 1.6 million km 2. The average altitude of Xinjiang is about 1 000 m above sea level, with the highest mountains of Tien Shan and Kunlun reaching over 6 000 m. The fishery developed rapidly from the 1950s, and in 2000 the production reached 58 835 tonnes, of which aquaculture produced 49 761 tonnes, i.e. 84.6 percent of the total. The capture fisheries concentrate predominantly on Lake Bosten and Lake Ulungur, and Rivers Ertix (other spelling: Irtysh), Yili (other spelling: Ili), and Tarim. As the fisheries are still developing, many problems are emerging, such as lowering of the ground water level, eutrophication, disappearance of the local fish species, spread of fish diseases. The increasing rate of water diversion and water consumption for irrigation and other purposes is partly responsible for this. For an arid region such as Xinjiang water is the most essential resource for human activities.

Due to the fast population and economic growth, the demand for water has substantially increased, especially for irrigation, industries, and municipal uses. As a result of this, the lower courses of rivers have been receiving less water, and some sections have desiccated completely. The level of ground water has been declining. Terminal lakes are receiving less water or no water at all as the river and stream water no longer reaches them. Soils are getting more alkaline, and water more saline. The large scale irrigation efforts have destroyed the environment of

the original fish fauna, and as a consequence indigenous fish species have gradually disappeared; overfishing has also contributed to this.

Photo 1: Lake Qinghai, 3 200 m above sea level, Qinghai Province, China. (Photo: T. Petr).

Photo 2: Naked carp (Gymnocypris przewalskii, Cyprinidae), from Lake Qinghai, China, is a major commercial fish species. (Photo: T. Petr).

The aquatic ecosystems of mountainous Nepal offer excellent habitats for at least 186 indigenous and 11 exotic fish species of high economic, environmental and academic value. Among the total of 186 fish species, 59 are considered as cold water fish. The most important indigenous cold water fish species are mahseer/sahar (Tor spp.), katle (Barbodes hexagonolepis) and snow trout (Schizothoraichthys spp. and Schizothorax spp.). They are excellent from an economic and sport fishery point of view, but many other species are fished for subsistence.

Photo 3: Mahseer (Tor putitora), a common cold water fish of Nepal. (Photo: G. Marmulla).

Photo 4: Snow trout (Schizothorax sp.) are important fish in subsistence fisheries in the cold water rivers of Nepal. (Photo: G. Marmulla).

Box 1: Nepal - An example of a highly mountainous country with predominantly subsistence fisheries

Mountains and hills make up 83 percent of the area of Nepal while the lowland Terai occupies only 17 percent. The Himalayas in the north strongly influence the climate of Nepal. The aquatic ecosystems of Nepal offer excellent habitats to at least 186 indigenous and 11 exotic fish species of high economic, environmental and academic value. They are distributed from the lowlands called Terai, through the hills to the Himalayan mountains up to the altitude of ca. 4 000 m a.s.l. They inhabit rivers and lakes of mid hills and mountains, with water temperature of 10°-20° C. The large-scaled cyprinids (sahar/mahseer - Tor spp., and katle - Barbodes hexagonolepis) may tolerate a wider range of temperature. Fifty-nine native and two exotic species are considered as cold water fish. The most important indigenous cold water fish species are katle (Barbodes hexagonolepis), snow trout (Schizothoraichthysspp. and Schizothorax spp.) and sahar (Tor spp.), fished both by the subsistence and sport fishers. Two exotic fish species of food and sport value are rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta). Rainbow trout was introduced in 1968 and 1971 from India, and in 1988 from Japan, while brown trout was introduced in 1971 from England and Japan. Subsistence and sport fisheries are practised at different levels of intensity on different rivers. Most of the captured fish are consumed around the catch site. In order to increase the fish resources in large inland water bodies (lakes and reservoirs), selected fish species are stocked. Fish selected for stocking are both those that do not reproduce naturally outside their original area of distribution, such as the Chinese silver, bighead and grass carps, and those that self-reproduce, such as common carp, sahar and katle. Fish stocks in the lakes of the Pokhara Valley and Indrasarobar reservoir are enhanced by the stocking, with both the fisheries officers and the local fisherfolk communities participating.

Photo 5: Mahseer (Tor putitora), the main species in fish catches from the Modi River (Nepal). (Photo: G. Marmulla).

Cold water fisheries offer a great opportunity for self employment and income generation among poor people living along rivers, lakes and other natural waters. They are widely scattered and not well organized. In Nepal, about 400 000 people are engaged in this subsector, both full and part time.

Box 2: Lake Phewa, Nepal - Information gathered by an FAO mission in 2001

Some 40 years ago, the water level of Lake Phewa in Pokhara Valley in Nepal was artificially raised by about 2 metres. This was followed by siltation, which has reduced the size of the lake to the present 520 ha. The current annual fish catch from Lake Phewa is estimated at 60 tonnes, and the lake also has cage culture which produces 50 tonnes per year. Capture fisheries is dominated by silver and bighead carps and by mahseer (Tor sp.). The major fishing gear are gill nets of various mesh sizes. The number of gill nets per fisher is limited to 20, and each fisher pays a gill net tax to the Government. In order to be allowed to fish, the fisher must be a member of the Fishers Cooperative (for angling such a condition does not apply). Gill nets are usually set for approximately 12 hours per day, between 15.00 - 16.00 hours, and removed at around 04.00 hours. Fish larger than 2 kg are sold to a fish processing plant while smaller fish can be sold directly by the fishers. There are usually two persons per fishing boat, usually a man and a woman.

While women also may fish, their main activity is selling fish which gives them better control over the earned money. In 2001, the wholesale price for Chinese carp was about 60 Nepalese rupees/kg (less than US$ 1.00/kg), and 120 rupees/kg for mahseer. The retail prices ranged from 90 to 200 rupees per kilo. During the rainy season the income of a fisher is 50 to 60 rupees per day. During the high season it is around 120 rupees per day. In 2002, 1 US$ was equivalent to approximately 77.5 NRs.

Photo 6: Lake Phewa (742 m a.s.l.) in Nepal, supports subsistence and small-scale fisheries as well as small-scale cage culture production. The lake is threatened by heavy siltation. (Photo: G. Marmulla)

Photo 7: Approximately 40 years ago, the water level in Lake Phewa (742 m a.s.l.) was raised by a dam. (Photo: G. Marmulla).

Photo 8: Fishtail Mountain (Machha puchhre), as seen from Pokhara, Nepal. (Photo: T. Petr).

Photo 9: The cage culture production site of the Lake Phewa Fish Growers Association of Kaski District, Nepal. (Photo: G. Marmulla).

Photo 10: Experimental cage culture station on Lake Phewa. (Photo: G. Marmulla).

Photo 11: Fish cage culture in Phewa Lake, Pokhara Valley, Nepal. (Photo: T. Petr).

Photo 12: Fishing in Lake Rupa, Pokhara Valley, Nepal. (Photo: T. Petr).

Photo 13: Experimental fish ponds of the Begnas Fisheries Research Centre, Pokhara Valley, Nepal. (Photo: F. Marttin).

Photo 14: Kakani trout farm, Nepal. (Photo: G. Marmulla).

Box 3: Socio-economic status of fisherfolk in the Koshi river basin, Nepal

In Nepal about 51 000 traditional fisherfolk families as well as others are involved in culture fisheries, with total active persons of over 200 000. This represents nearly 1 percent of the total population of Nepal, contributing 0.81 percent to the national GDP. The national records of capture fisheries show that the production is increasing per unit area, but the rate of increment is very low (11 kg/ha/yr and 12.5 kg/ha/yr in 1997/98 and 2000/01, respectively). The increment per unit area is the effect of a higher fishing intensity.

Fishing in the Koshi River, one of the largest rivers of Nepal, has been an age-old source of livelihood for thousands of riparian fishers. They are more apt to have the traditional social structure suited to existing conditions. They provide for their every need by fishing and marketing the catch. To introduce new and suitable management is socially difficult. The cultural values are so firmly established that any attempt at change in this superstitious, educationally-backward fishing community will run up against accepted social habits, beliefs and attitudes. However, such barriers can be surmounted through a rational programme of extension, education and training. A socio-economic study of the fishers communities in ten villages of the Koshi basin showed similar social structures, with minor variations in caste titles and life styles. All of them depend basically on the capture fishery. The socio-economic status of the fishers communities was the lowest in the society. Forty-six percent of families were found to be landless while 54 percent of the population owned less than 0.2 ha of land. Ninety-three percent of respondents earned less than NRs. 5 000 per annum, while 7 percent earned NRs. 5 000 10 000 (in 2002: 1 US$ equivalent to approximately 77.5 NRs). Improving the social status of the fishermen communities is urgently needed. Two of the major problems are the damage caused to catchments and overfishing. Both problems require urgent attention.

In the upper Sunkoshi River in the River Koshi basin there are 45 full-time, 211 temporary and more than 500 occasional fishers. Fishing spot visits and market surveys estimate an average of 22 tonnes of fish harvest per year from 800 ha of the river water surface area, with 27.5 kg per hectare, which is considered to be rather low. Full time fishing covers only 49 percent, and part-time fishing 27 percent of the basic needs of life. Due to the gradual decline in catches the young people in such communities in Nepal have been leaving the fishing profession and moving to towns in search of work.

Photo 15: Fishing gear stored on the balcony of a peasant's dwelling on the Andhi Khola River, Nepal. (Photo: G. Marmulla).

Photo 16: Nepalese fisher on the Koshi River. (Photo: G. Marmulla).

Photo 17: Catching fish with paso, a special method used in the Trishuli River, Nepal. (Photo: S. Thapa)

Photos 18, 19, 20: Andhi Khola River valley, Nepal. Floodplains (Photo 18) and steep gorges (Photo 19) in the middle reach; rice terraces near the confluence with the Kali Gandaki River (Photo 20). (Photos 18 20 by G. Marmulla).

Photo 18

Photo 19

Photo 20

Photo 21: Temporary hut of a fisher on the Sunkoshi River, Nepal. (Photo: T. Petr).

Photo 22: Asla (Schizothorax sp.) traps on the Sunkoshi River, Nepal. (Photo: T. Petr).

Photo 23: Kulekhani reservoir, Nepal, showing a major drawdown area. Note an experimental fish cage. (Photo: T. Petr).

In a number of mountain countries of Asia fish introductions have been a common management approach to enhancing fish stocks in mountain regions. Lake Sevan (1 900 m altitude) in Armenia was famous in the past for the presence of the salmonid Sevan trout (Salmo ischchan), but the extreme water manipulation has led to an almost complete disappearance of this species in Lake Sevan. Fortunately, it was successfully transferred to the high altitude (1 608 m) Lake Issyk-kul in another mountain country, Kyrgyzstan, in Central Asia. While this transfer probably saved this fish from extinction, it has negatively impacted on the indigenous fish species of Issyk-kul. The introduction of piscivorous Sevan trout was done with full understanding of its biology and with the purpose of better utilisation of the existing fish stocks which were not considered of such high quality as Sevan trout.

Kyrgyzstan is a mountain country with a range of altitudes from 400 m to 7 400 m, with about half of the country's territory being situated at an altitude of more than 3 000 m above sea level. Since its independence in 1990 the country has faced considerable problems in fisheries. The dissolution of the Soviet Union has led to a gradual decline in the Kyrgyzstan fisheries infrastructure, much of which was formerly dependent on supplies from other states of the Soviet Union. Kyrgyzstan's fisheries badly need financial support which has not been forthcoming for a number of years. Shortage of funds has resulted also in a shortage of formulated feed which has prevented the attainment of full capacity equal to the level prior to independence. Further assistance is needed for rehabilitation of infrastructure of hatcheries and fish farms, for equipment and for fish transport. The future of Kyrgyzstan fisheries appears to be in pond fish aquaculture.

Box 4: Lake Issyk-Kul, an example of fish stock manipulation using introductions

Lake Issyk-kul (altitude 1 608 m) in Kyrgyzstan, Central Asia, is situated in a basin surrounded by the high mountains of Tien Shan. This slightly saline lake (6 g/litre) covers 6 236 km 2, has a maximum depth of 668 m, and a mean depth of 278 m. Although at 1 608 m a.s.l., the lake never freezes over. Its original fish fauna had a number of endemic species. Until the early 1970s, Leuciscus bergiwas the dominant fish, followed by L. schmidti. Other common indigenous fish species were Gymnodiptychus dybowskii, of which one form was migratory entering inflowing rivers for spawning. Snow trout or

marinka (Schizothorax pseudoaksaiensis), an omnivore, was known to reach up to 8 kg. Leuciscus bergi formerly represented up to 90 percent of the total catch, but as it was considered to be of low value, in the 1930s it was decided to introduce the Sevan trout (Salmo ischchan) into Lake Issyk-kul. Until the 1960s this species remained rare due to the shortage of suitable spawning grounds. Two hatcheries were then established on the Rivers Ton and Karakol, respectively. The seed material produced in hatcheries was released into rivers in the catchment basin, from where the young fish eventually reached the lake. The fry/fingerling mortality in rivers was high, and the return in landings was estimated to be only 2 percent of the releases. In the 1990s the total annual catch of the Sevan trout was 40 to 50 tonnes. Following its introduction, Sevan trout became an active predator on other fish and its growth rate was 4-6 times higher than that in its original environment, i.e. in Lake Sevan in Armenia. In Lake Issyk-kul it matures earlier and its fecundity has increased fivefold. The limiting factors for this species in Issyk-kul are food resources and habitat for reproduction.

In the 1950s, there were further introductions of fish species in order to increase species diversity, especially the introduction of species feeding on phytoplankton and zooplankton, aquatic macrophytes, and benthic fauna. Among the introduced fish were bream (Abramis brama orientalis) and carp (Cyprinus carpio). Along with the latter species tench (Tinca tinca) and crucian carp (Carassius carassius) were inadvertently also introduced. The piscivorous pikeperch (Sander lucioperca) was also introduced. The fish food base was successfully enriched by the introduction of mysids, which became targeted by the introduced coregonids:Coregonus lavaretus was introduced from Lake Sevan, and from Lake Baikal came C. autumnalis and C. peled. The fish grew faster than the same species in Lake Sevan, and they also started maturing at an earlier age. However, the coregonid fry was heavily preyed upon by the indigenous fish fauna.

Fisheries in Lake Issyk-kul started in the 1890s, with the indigenous fish and common carp forming the bulk of catches. This led to a depletions of Leuciscus schmidti, and in the 1930s the fishery started targeting the common fish Leuciscus bergi. As the fishery mainly targeted the spawning fish gathering in shallows, catches started falling by the late 1970s and at the same time the introduced pikeperch became a major commercial fish species. To increase the total fish production from the lake it was proposed to increase the stocking rate so as to be able to satisfy the increasing demands of recreational fisheries. The present total annual fish catch is estimated at 1 000 to 1 200 tonnes but according to the Issyk-kul biological station of the Academy of Sciences, the commercial fishery should not harvest more than 250-300 tonnes.

The high mountain lakes in Indian Kashmir, situated at altitudes from 3 200 to 3 820 m, receive water largely from snow-melt from glaciers on the surrounding mountains. These lakes have a low productivity and therefore are largely unsuitable to support fish in any large quantities. In Pamir, four of the several hundred lakes situated predominantly in Tajikistan, all at 3 220 m to 4 260 m, have a medium productivity, and in some of them the northern whitefish (Coregonus peled) have been stocked. Few of these lakes are fished. Some of the Pamir lakes serve as sanctuaries for the preservation of cold water fish species which have been threatened in their original habitat.

Photo 24: A trout river in Kashmir, India. (Photo: T. Petr).

Photo 25: Jogigund trout farm, Kashmir, India. (Photo: T. Petr).

Photo 26: Siltation ponds of the Achabal trout farm in Kashmir, India. (Photo: T. Petr)

Floodplain lakes of Kashmir Valley (India) are at an altitude of 1 537 - 1 587 m, and are considerably more productive, supporting good fish stocks and fisheries. The fish fauna is dominated by cyprinid species of genera Schizothorax, Crossocheilus, Labeo and some others, but also by the introduced common carp, which has invaded all the meandering rivers, floodplain lakes and wetlands, and has become a major commercial fish in Kashmir Valley. Kumaon lakes situated in the Himalayan foothills of Uttar Pradesh (India) at 1 220 - 1 937 m altitude also support cyprinid fish stocks, dominated by common carp, Indian major carps and schizothoracine carps. Some of these lakes are favourite tourist destinations and subject to boating, swimming and pollution, all of which interfere with the fish and fisheries.

The most productive water body in the foothills of the Indian Himalayas is Gobindsagar reservoir in Uttar Pradesh, where suitable conditions combined with good fisheries management practices have provided a regular fish supply to the surrounding markets. The Fisheries Department has helped about 1 000 fisher families to be actively engaged in fisheries and supporting activities, with regulations being successfully enforced during the breeding of some commercially important fish species. Several welfare schemes, such as provision of subsidies for purchase of fishing equipment and a personal accident insurance scheme introduced by the Government, have helped the communities to raise their status.

The indigenous mahseers (Tor spp.) of the carp family are regarded as the best sport fish and also the most sought-after food fish. In the Himalayas due to human-induced deterioration of the environment and overfishing, mahseer stocks have sharply declined. To rehabilitate this fish induced spawning and artificial propagation have been undertaken in order to contribute to the production of seed in hatchery conditions. Artificial breeding of mahseer is still on a small scale, with the rehabilitation of fish stocks in rivers being a slow process. Experiments continue with the production of other endemic fish species, such as schizothoracine carps, but there are still hurdles on the way, especially in achieving a reasonable growth rate under hatchery and fish farm conditions.

Photo 27: Lake Dal, rich in submersed aquatic plants, is threatened by pollution (Kashmir, India). (Photo: T. Petr).

Photo 28: Wular Lake, Kashmir Valley, India, is a shallow lake rich in fish. (Photo: T. Petr).

Photo 29: Lake Bhimtal, Kumaun Himalaya, India. (Photo: T. Petr).

Photo 30: Lake Bhimtal, India, fishing among dense aquatic plants. (Photo: T. Petr).

Photo 31: Gobindsagar reservoir, India, with water level drawn down before monsoon rains. (Photo: T. Petr).

Photo 32: Silver carp (Hypophthalmichthys molitrix) from Gobindsagar reservoir, India. (Photo: T Petr).

Photo 33: Mahseer (Tor putitora) from Gobindsagar reservoir, India. (Photo: T. Petr).

Photo 34: Loading the catch for transport at Gobindsagar reservoir, India. (Photo: T. Petr)

Box 5: Mahseer (Tor spp.), a threatened fish of the mountains and foothills

The Hindu Kush-Karakoram-Himalayan region has a population of more than 140 million, and protein can be scarce in mountain areas. Fish such as the mahseer, much prized by game fishers, can also contribute to the diets of rural communities, both in the mountains and in the plains downstream. Mahseer, a member of the carp family, is a versatile fish, surviving from just above sea level to 2 000 m altitude. But its versatility has not prevented this fish from being threatened with extinction. The exponential increase in human population is the root cause for the depletion of mahseer stocks: human activities including pollution have led to the degradation of the aquatic environment and there has been indiscriminate fishing of broodstock and juveniles, resulting in a serious depletion of fish stocks, especially the valuable fish species, such as mahseer.

Restocking, if done with care, can rehabilitate mahseer as a source of valuable food for mountain communities. Artificial propagation of the fish by stripping the spawners is not always possible unless they are dependably obtainable from natural waters. To overcome this difficulty mahseer fingerlings of all the species can be raised to maturity in captivity in small ponds. Breeding of four major species of mahseer, with and without hypophysation, in brood fish ponds using manipulation of water flow, and feeding high protein pelletised diet, has been successfully carried out in India. Wild fish stocks can be supplemented by hatchery-reared juveniles/fingerlings. The hatchery-reared seed of mahseer are released into the wild with reliance on their homecoming instinct for recapture. Mahseer's short-range migration for breeding and feeding means that they burn less fat while travelling back to their parent rivers.

Construction of dams has blocked a number of rivers in mountain countries, and this has interrupted migration of a number of valuable fish, including Tor spp. and schizothoracines. Fish passes constructed at some weirs and dams have been largely unsuccessful as they have not been tested for the endemic fish before their construction. New designs are needed and environmental regulations in a number of mountain countries now require that an efficiently working fish pass is constructed at each dam.

Photo 35: The dam of the Kali Gandaki "A" Hydroelectric Project (Nepal) will impound the waters of the rivers Kali Gandaki and Andhi Khola as it is situated immediately downstream of the confluence of these

rivers. The dam will block the migratory route of fish species that are important for the river fisheries. (Photo: F. Marttin).

Photo 36: Confluence of the rivers Kali Gandaki (left) and Andhi Khola (right) (Photo: G. Marmulla).

Photo 37: Weir of the hydropower station on the Modi River (a tributary to the Kali Gandaki), Nepal. The fish pass (circle) on the left side of the weir (in downstream direction) does probably not function well

because of its inappropriate dimensions and the low attraction flow. (Photo: G. Marmulla)

Photo 38: Schematic presentation of the water conduit of the Andhi Khola Hydroelectric Plant from the weir on the Andhi Khola River to the outlet into the Kali Gandaki River. (Photo: F. Marttin).

Photo 39: Fish pass at the weir of the Andhi Khola Hydroelectric Power Plant, now empty for maintenance of the water intake channel of the power plant. The fish pass may not function well due to its

doubtful design. (Photo: G. Marmulla).

Photos 40, 41, 42: Fish pass on the Trijuga River (Nepal). This fish pass may not function well because it is of an inappropriate design. The lower entrance into the pass is too steep (Photo 41). Fish cannot easily move from the last pool into the impoundment because of the high drop between the weir crest and the first pool (Photo 42). (Photos 40-42: G. Marmulla)

Photo 40

Photo 41

Photo 42

Box 6: Fishways, fish passes

There are a large number of obstructions to fish passage on rivers and streams. The ever increasing number of weirs, barrages and dams have had a harmful effect on the ecological well-being of the native fish populations, preventing many fish species from reaching their traditional areas of spawning and feeding. As a result of such disturbances, many fish species have declined in numbers, and in the worst situations, some species have become extinct in some rivers. Fishways (or fish passes) are an important means of redressing parts of the detrimental effects of obstructions. They assist in allowing fish to move over a dam or a weir to reach their breeding and feeding areas, or to reach the lower stretches of the river or the sea. Ensuring the free passage of fish protects stocks for future generations. To design the right type of fishway, one has to understand the requirements of the individual fish species, and these vary from species to species. Designing fishways requires skill in the fields of both biology and hydraulics, such as the swimming ability of migrators, and also their behaviour when faced with obstruction. Hydraulic and civil engineering must fully guarantee that the facilities will work throughout the usual range of river discharge experienced during the migration season. A recent visit to several dam sites in Nepal has shown that most of the existing fish passes require modification to be effectively used by the native migratory fish species. This will also require a better knowledge of the biology and the behaviour of the indigenous species, especially of the behaviour in relation to obstacles and the fish's capacity to negotiate them. While this knowledge is available for salmonid stocks frequenting temperate waters of the northern hemisphere, little is known on such behaviour of

non-salmonids inhabiting rivers of the Himalayas, Karakoram, Hindu Kush and some other mountains of Asia. As a result, valuable fish stocks are being lost.

We know how to construct well-functioning fish passes, but it is mainly the more affluent countries which pay increasingly more attention to the need for maintaining good fish stocks, which involves considerations of their safe passage over obstacles placed in a river course. Legislation in developed countries now states that fish passage must be enabled wherever a new dam or weir is built, and wherever a fish passage is impeded by older constructions that are devoid of fish passage facilities or equipped with inefficient fishways. This also includes the need for monitoring programmes and evaluation of fishways. Upstream passage technologies are well developed for anadromous species such as salmonids and clupeids in North America and Europe. Fish passes in developed countries of temperate regions have largely been constructed for salmonids and other diadromous species, and they continue to serve this purpose. They have also benefited the so-called coarse, potamodromous species and there is good evidence that they can accommodate a wide spectrum of fish species when designed and operated properly. Construction of fishways may prove highly beneficial in the mountain countries of the world, when adapted to the local hydrological conditions and with the knowledge of the biology and behaviour of the indigenous fish species. Fish passes contribute to maintaining fisheries and biodiversity of fish stocks, and therefore bring economical and social benefits to the local fisherfolk.

On the following four pages, examples of the major categories of fish passes are shown. They are all well designed and well functioning for their target species and thus help fish negotiating the obstacles that could not be removed for various reasons.

Photo 43: Dattenfeld fish pass of the rocky-ramp type (general view of the bottom sill with incorporated fish ramp). River Sieg, Germany. This type of fish pass has proved to be very effective. (Photo: G.

Marmulla).

Photo 44: Detailed view of Dattenfeld fish ramp from downstream (Photo: G. Marmulla).

Photo 45: Unkelmühle fish ramp of the embedded-boulder type. River Sieg, Germany. This is one of the best types of fish passes to provide mitigation for salmonids and other European fish species at weirs of up

to 3.5 m. (Photo: G. Marmulla).

Photo 46: Unkelmühle fish ramp, on River Sieg, Germany. View of the embedded boulders, creating pools in which fish can rest while swimming upstream. (Photo: W. Jarocinski)

Photo 47: Fish pass as by-pass channel on a dam of the Siikajoki River, Finland. The fish pass imitates a natural stream that most indigenous species can negotiate easily. (Photo: G. Marmulla).

Photo 48: Vertical slot fish pass at Mauzac dam on the Dordogne River, France. (Photo: M. Larinier)

Photo 49: Fish lift at Tuilières on the Dordogne River, France. (Photo: U. Schwevers).

Aquaculture in the Trans-Himalayan mountain countries produces mainly the exotic rainbow trout. Trout hatcheries in the Himalayan region are of a moderate size, and some are exposed to the vagaries of climate, siltation and pollution. Considerable bilateral and other international assistance has been provided for trout culture development in countries such as Pakistan, India, Nepal and China. This has included transfer of technology, import of eyed eggs, and inputs into the production phase. However, in the less developed mountain countries and regions, due to the production cost trout remains on the menu of only the more wealthy segment of the population as well as supplying fresh fish to the tourist industry.

While the exotic brown trout is successfully established in the mountain rivers and streams of northern Pakistan and is fished there on a subsistence basis, a number of hatcheries for rainbow trout production have been constructed in the Northwest Frontier Province and Northern Areas. There is a potential for trout production in Afghanistan mountain regions.

While Bhutan is rich in cold water streams, rivers and lakes, the fish distribution in them is poorly known, and fish exploitation minimal. Apart from indigenous fish with fisheries potential, such as Schizothorax spp. and Tor spp., the exotic brown trout is also present in some rivers where it has established self-reproducing populations. Only controlled and limited sport fishery for mahseer (Tor sp.) is allowed. The fishing equipment employed are hooks or spoons, as nets are not permitted. This is to avoid catching fish on a large scale, which would negatively affect fish stocks within a very short period of time. There is aquaculture of warm water fish on a small scale. The breeding and culture of cold water fish species has yet to be developed. As farming in Bhutan

is done mostly in valleys where river system exists, there is potential for cold water fish culture involving farmers, which would increase income at the rural household level. Starting cold water fish culture could also have complementary benefits, such as contributing to eco-tourism and export earning.

Photo 50: Tarbela dam on the Indus River, Pakistan. (Photo: T. Petr).

Photo 51: Schizothorax sp. (snow trout) captured in cold water discharged from the Tarbela dam, Indus River, Pakistan. (Photo: T. Petr).

Photo 52: Another catch from the Indus River below Tarbela dam, Pakistan. (Photo: T. Petr)

In the remote mountains of the northern Viet Nam FAO and UNDP are jointly supporting the Viet Namese Government in its efforts to achieve food security and to alleviate poverty in three provinces through aquaculture development. The project, which makes use of various participatory extension methods, has trained more than 5 000 farmers in simple aquaculture techniques over the last few years. The results have been remarkable, i.e. many of the poor farmers who started aquaculture now produce more than enough fish to cover household consumption needs, guaranteeing a large share of the total protein intake of the household members. Most of the farmers are now even able to market up to 70 percent of their production. The species most often cultivated are grass carp, common carp, Indian major carps, bighead carp, silver carp, tilapia and Colossoma. Aquaculture development is continuing steadily, with more farmers starting to produce fish and with the already established farmers increasing their production. Grass carp is the most preferred fish, as the overall input costs, apart from the purchase of fingerlings, are very low. All feed for the fish is grown on their own farm, and often all family members are involved in cutting grass and feeding the fish, making it a joint activity that does not require too much time from each individual household member. All fish farming households consume part of the fish production within the household. The decision on which fish should be marketed and which consumed at home is generally based on the market price of the fish and/or the ease of catching. Fish species with a high market value, such as common carp and grass carp, are primarily sold, while tilapia and silver carp are commonly consumed at home and are therefore not seen very much at the market. The Indian major carps mrigal and rohu are considered very tasty and are sometimes consumed at home. Aquaculture has a bright future in the northern mountains of Viet Nam. Freshwater fish has become an established product among a traditionally meat-consuming population. The increasing living standard of the urban mountain population and the related increasing spending power has led to a boost in fish sales of between 20 to 100 percent per year. The fish farmers in the rural areas are the direct beneficiaries of this trend.

Photo 53: Sông Da (Black River), Son La Province, Viet Nam. (Photo: U. Tietze).

Photo 54: Sông Ma River, Hoa Binh Province, Viet Nam. (Photo: U. Tietze).

Photo 55: Rice-cum-fish culture (mainly carp and indigenous species) in Hoa Binh Province, Viet Nam. (Photo: U. Tietze).

Photo 56: Fish pond in Lai Chau Province, Northern Viet Nam. (Photo: U. Tietze).

Photo 57: Carp hatchery, Viet Nam. (Photo: J. Prado).

Photo 58: Fish harvest in pond, Viet Nam. (Photo: J. Prado).

Summary on fisheries in mountain countries of Asia

The indigenous and exotic fish species in the countries situated in the Caucasus, Himalayas, Karakoram, Tien Shan and in some other mountains and hills contribute to the livelihood of the rural population. Unfortunately, the fish are threatened by environmental degradation and human activities. Countries, such as Armenia, Bhutan, China, India, Kyrgyzstan, Nepal and Pakistan, are making efforts to utilise cold water fish for the reduction of poverty, and some successful strategies are emerging. Other countries, such as Viet Nam, with mountain areas situated in the sub-tropics and tropics, concentrate on aquaculture of a mix of temperate water and warm water fish species.

Using fishery resources in mountain countries to facilitate rural development and poverty alleviation requires that aquatic resource management interventions be based on the understanding of socio-economic conditions and livelihoods of fisher communities. To achieve success requires promotion of local ownership of fisheries and locally based management arrangements and solutions to fisheries management problems. An example of this approach is the direct involvement of Phewa Lake fishers and local Buddhist monks in restocking this Pokhara Valley lake in Nepal. Promotion of inter-sectoral cooperation and coordination between fishery and other sectors concerned with rural development and water resource development is another way of achieving success in fisheries. Fish stock protection must be balanced with needs such as nutrition and hydropower.

The strategies for aquaculture and fisheries development should consider a broad ecosystem approach with plans for both subsistence and commercial development. There are many options for development in the mountain regions, such as aquaculture, capture fisheries, sport fisheries and ornamental fisheries, involving both cold water and warm water fish species. Rehabilitation and development of capture fisheries and development of aquaculture should be a vital component of overall development plans that address social, economic and conservation issues, and as such should be integrated with developments such as hydropower and irrigation.

The Kathmandu Symposium in 2001 has called for better information on fish stocks and exploitation, and assessment of steps already taken to manage fisheries and reconcile their needs with those of other water users. It has highlighted the need for investigation of the role of fisheries in the region and how they might contribute more to poverty alleviation. To safeguard the sustainability of fisheries the Symposium stressed the need for promotion of local ownership and management of fishery resources, restricted fishing seasons, and protection of spawning grounds. Investigation of alternative livelihoods for rural people, where fisheries are already fully exploited, is essential.

As a number of problem areas are common and resources are shared among bordering countries, collaborative action on a regional scale is probably the most cost-effective way to address the common problems and to share experiences. The highest priorities for action common to most mountain countries in Asia are research into aquatic ecosystems especially the biology and behaviour of cold water fish stocks, migration patterns and environmental impacts; strengthening of data collection and dissemination; training and education in specialised fields; policy development especially in integrated watershed development, gender equity and community management; and regular monitoring, paying close attention to the management of fisheries resources through enhancement. There is also an urgent need for a consolidated effort to promote fish conservation and to develop and implement effective management strategies for maintaining healthy fish stocks and for their utilisation towards improvement of the rural economy in the region. To achieve this will require better sharing and exchange of skills and experiences, technical cooperation, and international support in some regions establishment of a coordination centre in a suitable country within the region, would be advisable.

Literature:

Marmulla, G. (ed.) 2001. Dams, fish and fisheries. Opportunities, challenges and conflict resolution. FAO Fisheries Technical Paper. No. 419. Rome, FAO. 166p.

Petr, T. (ed.) 1999. Fish and fisheries at higher altitude: Asia. FAO Fisheries Technical Paper. No. 385. Rome, FAO. 304p.

Petr, T. & Swar, D.B. (eds.) 2002. Cold water fisheries in the trans-Himalayan countries. Proceedings of the Symposium on Coldwater Fishes of the Trans-Himalayan Region, 10-13 July 2001, Kathmandu, Nepal. FAO Fisheries Technical Paper No. 431. Rome, FAO. 376p.

Report. 2001. Report of the Symposium on Coldwater Fishes of the Trans-Himalayan Region, 10-13 July 2001, Kathmandu, Nepal. HMG of Nepal, FAO, NACA, etc. Kathmandu. 53p.

Shrestha, J. 1994. Fishes, fishing implements and methods of Nepal. Published by: Smt. M.D. Gupta, Lalitpur Colony, Lashkar (Gwalior), India. Craftsman Press, Bangkok. 150p.

Shrestha, T. K. 1995. Fish catching in the Himalayan waters of Nepal. Published by: Bimala Shrestha, Kuleswor, Kathmandu, Nepal. R. K. Printers Pvt. Ltd., Kathmandu, Nepal. 247p.

Van Anrooy, R. 2001. Fish marketing in the northern mountains of Viet Nam. FAO Aquaculture Newsletter No. 28: pp. 8-10.

3.2 Latin America

A long chain of mountain ranges stretches through Mexico, Central America and South America. These mountains, with their cold water resources, support a variety of cold water fish, which until recently were harvested predominantly by artisanal fisherfolk. To maintain sustainability of the stocks of native fish and to increase fish production most countries now practise stock enhancement and aquaculture. As most countries include also subtropical and tropical zones, this gives excellent opportunities for warm-water capture fisheries and aquaculture. Due to the higher inherent productivity of warm water, some countries have concentrated more on the development of fisheries in warm waters, and with the exception of trout aquaculture, aquaculture in cold waters is not practised. Cold water capture fisheries at higher altitudes are, with a few exception, such as in Lake Titicaca and a few other larger lakes and reservoirs, mostly of subsistence character.

Only a few native Latin American cold water fish species are of economic importance. In Argentina, pejerrey (Odontesthes bonariensis) has been grown in fish farms for stocking purposes since the beginning of the twentieth century, and today Brazil, Uruguay, Bolivia, Chile and Peru also produce the Argentinean pejerrey to stock for subsistence and recreational fisheries. In most countries of Latin America, the introduced rainbow trout and brown trout dominate recreational and sport fisheries, the major fisheries in cold waters. Rainbow trout and some other salmonids are also the only fish produced in cold water fish farms.

The native pejerrey is a common fish in Argentina and in Uruguay. From there it has been introduced to lakes and reservoirs in mountains and foothills in other countries. In Argentina in the 1990s eleven hatcheries produced fingerlings of pejerrey of the Patagonian silverside (Odontesthes hatcheri). In Bolivia, pejerrey has been present in a reservoir at 2 500 m altitude since the 1940s, and since the 1960s in Lake Poopo at 3 700 m, from where it migrated through the 280 km long Desaguadero River into Lake Titicaca. In the late 1980s approximately 46 percent of fish sold in La Paz and 70 percent sold in Cochabamba were pejerrey, while only 5 percent in La Paz were trout. In Bolivia rainbow and brown trout are produced at 3 555 m altitude in the Province Cochabamba, from where they are stocked into 20 lakes.

In Chile, five Andean river basins studied for the distribution of cold water fish showed rainbow trout representing 48 percent of all specimens collected and being present in 80 percent of the rivers. The lack of natural enemies, rapid adaptation to the habitat, abundance of food organisms and small number of competitors led to a rapid and successful acclimatization of trout in Chile. Many cold waters Andean lakes in Chile are now inhabited by brown trout, rainbow trout, the indigenous perch (Percichthys trucha) and species of the family Atherinidae. Other successful introductions have been the common carp and tench (Tinca tinca). There has been a rapid growth in rainbow trout production in aquaculture, which is in third place after the culture of two other salmonids,Oncorhynchus kisutch and Salmo salar.

In Colombia, Lake Tota (3 020 m a.s.l.) is populated by the native Trichomycterus bogotense and Grundulus bogotensis, and rainbow trout, which was introduced in 1939 into this lake and in some other inland waters. In Lake Tota fisheries is practised by approximately 3 000 part-time fishers, with women fully participating in semi-commercial and subsistence fisheries and in fish marketing in some areas. Commercial trout farms are also situated in the mountain areas, and the produced fingerlings are stocked in natural lakes, ponds and reservoirs and also for fish production in net cages. Colombia has eight research stations located on cold plateaus. Between 1988 and 1997, Colombia demonstrated good growth of freshwater trout production, both in terms of volume and value. Production increased thirteen fold, and a sales value increased from US$ 4 million to US$ 43 million. Trout aquaculture in Colombia is made up of approximately 35 companies, which generate more than 2 750 direct and indirect jobs. Most production is sold locally, although a significant quantity has been exported. In Colombia, the competitiveness of trout farming is reduced by the high cost of feeds. This is despite the fact that Colombia offers great potential for expansion of the activity, including year-round fingerling supplies and available technology.

Seventy-seven percent of the Colombia's 26 million population live in the basin of the Magdalena River, which is a tropical river system with periodically inundated plains. The country's main industries are also located there. Pollution, deforestation, modification of the river for navigation, and land management for agriculture and cattle ranching on the floodplain are the chief ecological impacts. The basin of the Magdalena River contributes 85 percent of Colombia's production of freshwater fish, with 166 species, of which 26 species are economically significant. The catchment rivers, including the Magdalena, and their floodplain lakes are the mainstay of the significant fishery during the low water season. A new reservoir at the junction of the Magdalena and Yagura Rivers has exotic tilapias (Oreochromis niloticus, Tilapia rendalli) and common carp, in addition to the indigenous fish, but the dam has led to several migratory species disappearing from the upstream stretches of the rivers.

In Peru, cold water subsistence fisheries are situated mainly in Andean rivers and lakes. On Lake Titicaca, where there is a capture fishery of economic importance, the immigration of pejerrey in 1966 created a self-sustaining population. Later on, pejerrey fingerlings were transferred from Lake Titicaca to other high mountain lakes in Peru, and pejerrey is now also present in a number of rivers. The introduced rainbow trout is suspected of being responsible for the disappearance of the small fish Orestias agassizii from Lake Langui-Layo (3 875 m a.s.l.). Trout is also present in some reservoirs, such as Pasto Grande. Trout aquaculture is practised by a number of fish farms. For example, in Lake Suches during the period 1997-2000 the annual production from an extensive culture of rainbow trout was between 43 and 52 tonnes.

Box 7: Lake Titicaca

This lake is an example of a large high-altitude water body with cold water fisheries. It is situated at an altitude of 3 812 m on the altiplano of the Bolivian and Peruvian Andes, covers some 8 100 km 2, and has a volume of 866 km3. Despite being situated close to the equator, the climate of the basin is cold and semi-arid. The lake comprises two interconnected basins, Great Lake, which is eutrophic, and the oligotrophic Small Lake. Fish are most abundant in the Bolivian part. Of the three

indigenous genera of fish the genus Orestias is the most common, with 23 species being endemic to Lake Titicaca. The native fish contribute most to the total fishery production, with the rest consisting of rainbow trout and the cold water pejerrey, also called silverside (Odontesthes bonariensis), imported from Argentina.

In the 1940s brown trout, lake charr and rainbow trout were stocked to improve the commercial fishery. Silverside introduced to Lake Poopo in Bolivia in 1946 migrated from there through the Desaguadero River into Lake Titicaca in 1955. Rainbow trout reproduces in the middle and upper reaches of the inflowing rivers during the dry season, usually in June and July. Silverside starts spawning in January, with the maximum spawning in May. In the past poor enforcement of regulations led to fishing for spawning trout in the inflowing rivers, especially in Peru, where most spawning streams and fish canneries were located. This eventually resulted in the closure of canneries, as trout became too scarce to support them. Trout tend to be susceptible to overfishing because they spawn in running water.

About six thousand of the several hundred thousand peasant households that live close to the lake, divided almost equally between Bolivia and Peru, are engaged in small-scale fisheries. At the end of the 1990s approximately 800 commercial fishers were in Bolivia. About two-thirds of the total catch from Lake Titicaca is represented by the native genus Orestias. While the total fish biomass of Lake Titicaca has been estimated at 91 000 tonnes, in the late 1980s the stocks of especially silverside appeared to be underfished. Deep water fish stocks were not fished due to the lack of a suitable fishing gear. Net cage culture for trout was initiated in the 1970s both in Peruvian and Bolivian waters, eventually being practised by 50 local rural communities, associated in fishery cooperatives. The production faced constraints such as shortage of suitable nets, fry and feed, heavy mortality of transported fingerlings, fluctuating water temperature, water pollution, and the high cost of the marketed fish. In the markets around Lake Titicaca producers had to compete with the fresh trout from the lake and the much cheaper and quite popular pejerrey, and only a small fraction was marketed in Lima or La Paz and in mining camps. Most of the production was exported to Europe and the United States.

Photo 59: Rainbow trout cage culture in Lake Titicaca, Peru/Bolivia, which is situated at an altitude of 3 812 m. The lake is an example of a large high-altitude water body with cold water fisheries. (Photo: U.

Barg).

Uruguay started stocking silverside imported from Argentina already in 1917. Rainbow trout has been stocked mainly for recreational fishery. In Venezuela rainbow trout is produced in aquaculture and brook trout is established in waters in the Paramo region where it has enriched the diet of the local people.

Summary on fisheries in mountain countries of Latin America

In the mountains of the countries of Latin America fish come from cold water bodies. While the major source of animal protein in the region is the widely farmed livestock, in many areas fish from open waters provide an important supplemental animal protein source, usually harvested by subsistence or artisanal fishers. Introduced fish form the mainstay of many cold water fisheries and aquaculture, with the rainbow trout aquaculture being the dominant producer in many mountainous countries with cheap supply of high protein content fish feed. The pejerrey, introduced from Argentina to a number of countries, has been most successful in open waters, especially in Lake Titicaca. At low altitudes warm water capture fisheries and aquaculture are well developed and expanding and often of industrial character.

Trout is farmed both in cold freshwater and in cold marine water conditions. Countries in Latin America tend to focus on freshwater rainbow trout (over 21 000 tonnes in 1997), but the culture of sea rainbow trout is an important business in Chile, where aquaculture is highly dominated by the industrial ocean cage culture for Atlantic salmon (Salmo salar). Small quantities of rainbow trout are produced in aquaculture in almost all mountain countries of Central America and South America, and in Mexico. In Argentina, in the late 1990s the aquaculture rainbow trout production reached 800 tonnes/year as there was a ready market in larger cities. However, the deteriorating economic situation has recently led to a decline. Cold water trout production in some countries has been hindered by the dependency on expensive imports of fish meal or feed ingredients for trout feed. Improvement in marketing, as well as training in administration and aquaculture technology for cold water fisheries, are needed.

Latin America's cold freshwater fish fauna evolved in the almost complete absence of piscivorous predators, facilitating successful invasion of freshwaters by introduced trout and other salmonids. But growing awareness of the possible serious impact of introduced fish species has led to an increasingly careful scrutiny of proposed introductions and a tightening of rules and regulations related to them. In Chile and Uruguay, for example, there are now special regulations for the protection of the environment.

Predictions of the potential production from open cold waters are difficult to make. It is believed that there is potential for an increase in silverside production in Bolivian lakes, and some lakes in Chile and Argentina. In most countries there is still potential in aquaculture for an increase in production of exotic salmonids, mainly rainbow trout. For example, in Venezuela the potential for trout production in the Andean region was believed to be approximately 6800 tonnes in 1990, but the production was only 300 tonnes. Between 1988 and 1997 Chile, Colombia, Mexico and Peru contributed 91.4 percent of the total production in Latin America. Carp production concentrates on silver carp (Hypophthalmichthys molitrix) and common carp (Cyprinus carpio), but the aquaculture production is in the warm regions, mainly in Brazil, Cuba and Mexico, with 97 percent of the carp producing farms situated there and which produced 67 000 tonnes in 1997.

In Latin America aquaculture is generally perceived, by both the public and private sectors, to be a favourable and profitable activity. Rural aquaculture development is dependent on government support and the allocation of scarce funds is based on the level of poverty in the rural community in question. Small-scale and subsistence aquaculture producers have been greatly affected by decreased government support. The combination of privatisation, government budgetary reductions for investment and reduced international cooperation programmes have made it difficult for farmers to obtain the degree of technical assistance that is needed to support their production activities. Rural aquaculture farmers need to find other alternatives to support sectoral development. Such alternatives include public and private joint ventures, new extension approaches, credit and market support, support for low-input aquaculture and tax credits.

Further development of aquaculture in mountain countries of Latin America follows six important objectives: increased foreign exchange earnings, increased employment, increased protein consumption, decreased rural migration, poverty alleviation, and increased food security. Aquaculture will continue developing, especially in warm waters due to their higher productivity and potential for producing products of high value, such as penaeid prawns. The adjacent ocean aquaculture of Chile will continue producing high quantities of Atlantic salmon, coho salmon (Oncorhynchus kisutch), and sea rainbow trout, largely for export. A welcome initiative is the growing number of fish farmers producing prawns in small scale-rural aquaculture, as for example in Nicaragua, Mexico and Brazil.

As the immediate potential for freshwater cold water species to contribute to exports is limited, the first objective applies predominantly to commercial fish production of trout and warm water fish. However, the five above-listed objectives closely relate to fish aquaculture in the mountain areas. Aquaculture plays an important role in increasing employment. Not only does it lead to direct and indirect job creation, but it also achieves this in areas that have traditionally low employment. The potential for aquaculture to continue benefiting employment, especially in rural areas, will depend upon the government's participation in and assistance to aquaculture development in the countries of Latin America. Aquaculture activities play an important role in reducing the rate of rural migration to urban city centres, a situation that creates overcrowding and social problems. The creation of opportunities for investment and increased employment in rural areas are means of decreasing this problem. Aquaculture production in mountain areas has demonstrated its capacity for providing social and economic benefits for the people. The continued growth and development of aquaculture will play an important role in the future, contributing to food security, land diversification, and employment.

The cooperation of regional organizations such as FAO, CPPS (Commisión Permanente del Pacífico Sur) and OLDEPESCA (Latin American Organization for Fisheries Development), combined with the external aid (e.g.

Italian and Spanish Cooperation, European Commission and UNDP) will also have a positive impact on the success of aquaculture development in the countries of Latin America.

Literature:

Brenner, T. 1994. Las pesquerías de aguas continentales frías en América Latina. COPESCAL Documento Ocasional. No. 7. Roma, FAO. 32p.

Reartes, Jorge L. 1995. El pejerrey (Odontesthes bonariensis): métodos de cría y cultivo masivo. COPESCAL Documento Ocasional. No.9. Roma, FAO. 35p.

3.3 Africa south of the Sahara

Ethiopia is a tropical mountain country in eastern Africa, with a number of lakes, covering 7 500 km 2. The largest, Lake Tana, covering 3 200 km2, lies at an altitude of 1 829 m. Eight other lakes are situated above 1 500 m. Marine fisheries were providing by far the greatest quantity of fish to markets until the end of the 1970s, after the independence of Eritrea, which resulted in a drastic drop in marine fish supply, freshwaters became the major source of fish. By the end of the 1980s the per caput fish supply was estimated to be only 0.01 kg. A meagre 20 tonnes was fished annually from Lake Tana, far exceeded by up to 1 330 tonnes per annum from Lake Ziway (1 848 m altitude, surface area 434 km2). As both Lake Tana and Lake Ziway have a water temperature ranging from 22 to 27° C, their fish stocks are a mix of warm water cyprinids, catfish and tilapias.

Despite substantial water resources, for a long time fish production in Ethiopia was stagnating for a long time under 5 000 tonnes per year due mainly to the lack of tradition in fishing and related activities. Since the 1980s fisheries in both lakes have undergone remarkable development, with the Government placing emphasis on the development of the fishery sector. With the support of external assistance, and as a result of the growth in the number of fishers due to unemployment in other sectors, fishing activities have been increasing substantially. The contribution of fish to food security is still very small; only in a small radius around water bodies does it reach approximately 10 kg/year per caput. Lately, fish catches have been increasing, especially from lakes Ziway and Chamo, as a result of the combination of several factors: a good supply of fishing gear, a healthy demand for the product from the private sector, and easier conditions for obtaining credit making it easier to purchase gear and boat engines. Both lakes have well organized fishers groups who have been able to benefit from gears provided through external assistance. Lake Ziway produces high quality tilapia close to Addis Ababa, and Lake Chamo produces Nile perch, which gives a higher profit margin for entrepreneurs. However, because of the open access to the fishery and no controls on effort, in some cases fish stocks have collapsed or overall catches have declined.

On Lake Tana the fishery is dominated by traditional reed boats which contribute over 70 percent of the estimated landings made, which in the 1990s exceeded 1 100 tonnes. Of these, Oreochromis niloticus (Nile tilapia), Barbus (barb) sp., Clarias gariepinus(catfish) and Varicorhinus beso (beso) contributed 35, 32, 32 and 1 percent, respectively. It is estimated that there is little scope to increase the fishery except for tilapia. Two projects assisted with provision of motorized boats which has allowed fishers to operate on the entire surface of the lake. Also, some repair and maintenance facilities have been provided, as well as a net manufacturing unit with trained women. After the introduction of motorized fishery, large piscivorous barbs have become the target group of species of the commercial fishery, and they form roughly a third of the total commercial catch. A small barb zooplanktivore, Barbus tanapelagicus, inhabits offshore deep waters, and together with B. trispilopleura, a more littoral species, is the major prey fish for the eight species of piscivorous large barbs.

Photo 60: A small reservoir in Ethiopia used for subsistence fishery. (Photo: G. Marmulla).

Photo 61: Fishers with their catch of the day, mainly Tilapia, locally called carp (Ethiopia). (Photo: G. Marmulla).

Photo 62: Tilapia from a small water body in Ethiopia. (Photo: G. Marmulla).

Aquaculture in Ethiopia is still in its initial stages, despite favourable physical conditions. The high central plateau above 2 500 m, which represents 11 percent of the total area of Ethiopia, could be appropriate for all year round farming of cold water species. The surrounding central highlands present temperature characteristics favourable to production of a large number of cold water and warm water species. And the lowlands (33 percent of the total area) offer ideal temperature conditions for warm water species, but are unfortunately water-deficient zones. Water storage micro dams could, however, be employed for fish production. Aquaculture fish production has been constrained by low prices and at present is considered to be economically unviable.

Cold water fisheries in the mountainous parts of Africa south of the Sahara is largely limited to fish farming of exotic trout. This has been practised in Zimbabwe, Malawi, Kenya and various provinces of South Africa. In the eastern Zimbabwe uplands close to the Malawi border the water temperature allows rainbow trout culture. Originally, brown trout, and later on rainbow trout were introduced during the colonial system. Most of the trout fishing in Zimbabwe is in, or around the Nyanga National Park and the Parks Department fish farming activities are centred on producing fish to restock fishing areas within the park. In the early 1990s the surplus fingerlings were sold to ongrowers for the table market. Open water recreational fishing in the park is practised both in streams and in numerous small dams. It is rather unusual as one may be in the company of not only birds and antelopes, but also an occasional lion or leopard. The fish are rarely over 600 grams, but of a superb quality. In the early 1990s the Zimbabwean trout farming was successful, with many farms being established with or without foreign assistance. The fish were marketed to the tourist establishments, such as lodges, but were also produced for food, as in a project established with German assistance which was trout farming for the Tangent people. The Niangua Trout Fish Farm was estimated to have a potential production of 100 tonnes in concrete raceways, circular tanks and D-ended raceways. The fish were delivered to another company for smoking, canning or freezing. The total trout production potential in Zimbabwe was estimated to be up to 250 tonnes per

year. Trout farming in Zimbabwe seems to have a reasonable future provided that supplies of feed and fingerlings can be maintained or increased both in quantity and quality.

In the early 1990s Kenya had three large commercial trout farms, of which two were on the lower slopes of Mount Kenya and within 50 km of the equator. Melting snow from the mountain ensured a year-round supply of good quality cold water. The third farm was situated on the lower slopes of the Aberdare Range. The farms had a problem ensuring good quality water, which during rains is loaded with soil and silt as a result of deforestation in the upper catchment. This was solved by constructing silt traps which are situated upstream. The estimated annual production of rainbow trout in Kenya in 2000 reached 470 tonnes.

The biggest rainbow trout aquaculture producer in Africa south of the Sahara is South Africa, which in the year 2 000 produced 5 176 tonnes, while Malawi produced only 18 tonnes in the same year. In the Western Cape Province of South Africa many dams have been constructed for water storage for summer irrigation. Many of these dams are suitable for aquaculture and since 1996, several small-scale rainbow trout producing projects have been implemented, proving that trout can be reared successfully in enclosed systems such as irrigation dams. It further promoted the cause for multiple-use of water resources. The experience from this venture is the first step in bringing small-scale aquaculture to the rural populace. The total annual production from the dams is around 400 tonnes and is expected to increase as some of the farms are either expanding or becoming more efficient.

In the mountain country of Lesotho the completion of the Kate Dam provides an environment for cold water fish such as rainbow trout and several indigenous species. The indigenous Barbus avenues is abundant throughout the reservoir and could support a subsistence fishery. The catches of larger trout and the outstanding scenery suggest that a tourist sport fishery could be developed on the reservoir based on natural recruitment supplemented, if necessary, by stocking hatchery-reared fish.

Summary on fisheries in mountain countries of Africa south of the Sahara

The relatively high water temperature at high altitudes in tropical and sub-tropical areas of Africa ensures year-round fast growth rates of cold water fish such as trout, but makes it difficult to establish a viable broodstock. In some countries eyed eggs have to be imported each season from abroad, especially from Europe or Australia. Another problem facing trout producers in Africa is shortage of raw materials such as fish meal. The short shelf life of the feeds in the hot climate further aggravates the situation. Another aspect is the thin air at high altitudes. With temperatures occasionally exceeding 20° C, this results in low dissolved oxygen levels. Faster flows or aeration is therefore essential during the hot months.

Marketing also presents its problems. The selling price of the farmed trout may be outside the financial reach of the average consumer, because of the high cost of feed used in production. Most marketed fish reach those who can afford them, but this is beneficial, as in Africa trout supports the tourist industry. Disease prevention is also an important aspect of successful trout production in mountain countries of Africa, Latin America and Asia.

Warm water fisheries in mountain countries of Africa are the major providers of fish for markets, where they can be purchased by a great majority of consumers for an affordable price.

Literature:

Bossche Vanden, J.P. & Bernacsek, G.M. 1991. Source book for the inland fishery resources of Africa, Vol.3. CIFA Technical Paper, No. 18.3. Rome, FAO. 219p.

Agius, C. & Balarin, J.D. 1982. Farming trout on the equator. Fish Farming International 9(5): 10-11.

De Graaf, M., Dejen, E., Sibbing, F.A. & Osse, J.W.M. 2000. Barbus tanapelagius, a new species from Lake Tana (Ethiopia): its morphology and ecology. Environmental Biology of Fishes 59(1): 1-9.

Jauncey, K. 1990. Trout farming in Zimbabwe. Aquaculture News July 1990.

Kenmuir, D. 1990. New angle on farming. Fish Farming International, June 1990, pp. 38-39.

3.4 The South Pacific

Among the Pacific islands New Guinea, situated close to the equator, has large areas covered with high mountains. The highest peak of 5 030 m (Puntjak Jaya) is covered with a small glacier. In the eastern half of the island, which forms part of the country Papua New Guinea, Mt. Wilhelm being the highest peak at 4 509 m, there are a number of mountain ranges almost reaching or slightly exceeding an altitude of 4 000 m. In the past the poor stocks of indigenous cold water fish were of minor importance as a subsistence source of animal protein. Over 84 percent of the population of Papua New Guinea lives inland and has no direct access to marine fishery resources. However, it does have direct access to freshwaters and to its fish. On a per caput basis, inland catches are very low, and in many highland regions, especially in the north of the main island, catches are negligible due to the extreme poverty of fish there. In the 1980s the Government of Papua New Guinea realized that the yields could be considerably improved by introducing fish into the Sepik River, to boost the production in the joint Sepik-Ramu river system.

Photo 63: The Sepik River (Papua New Guinea) with its floodplains. (Photo: T. Petr).

A FAO/UNDP/Government project successfully introduced in the lowlands Tilapia rendalli, a fish which feeds on aquatic plants, which are in abundance in lowland swampy and lake areas. Alongside two other exotic fish, i.e. tilapia Oreochromis mossambicusand common carp Cyprinus carpio, inadvertently introduced earlier, T. rendalli has become an important component of fish catch. In the 1990s a follow-up project concentrated on

fisheries improvement through introduction of a number of species into the cool waters of highland rivers and reservoirs, as well as continuing to stock the lowlands with additional fish species. The rationale for both projects, supported by FAO/UNDP, was to establish a reliable sustainable, maintenance free food base in a country where the inland human population depended largely on imported canned fish. Over a period of less than ten years, both projects together introduced seven species of exotic fish and several of them have become a regular component of fish catches (see Box 8).

Box 8: Enhancement of highland fish stocks through introductions in Papua New Guinea

In the mid-1990s introduction of a number of fish species to the highland rivers and reservoirs of Papua New Guinea was used as a strategy for creating new fisheries in waters deficient in exploitable fish stocks. A four-year government project, supported by FAO/UNDP, appraised possible environmental impacts of introductions by following international codes of practice, and finding them negligible, it introduced seven fish species using quarantine and health management facilities outside and in the country. For this purpose it also established a hatchery, raised the fish through sensitive life history stages, and released the fish into appropriate inland waters which lacked species upon which to base sustainable inland fisheries to benefit rural people. The project stocked fish in rivers and reservoirs, focusing on mid-altitude rivers from lowlands to about 800 m elevation, and highland reservoirs and rivers (above 800 m) in the Sepik-Ramu basin. At altitudes above 800 m generally no fish are found except migrating eels. Thus, the species diversity and biomass of fish in Papua New Guinean highland rivers are much lower than in the rivers of mainland Asia. Three cold water species (Tor putitora, Barbodes hexagonolepis and Schizothorax richardsonii) were introduced from the foothills of Himalayas, three warm water species (Osphronemus goramy, Barbonymus gonionotus, Piaractus brachypomus) from Indonesia and Malaysia, and one species from Latin America (Prochilodus argenteus). The project demonstrated that fish introductions can be environmentally safe. Fish released through the project have started appearing in the catches of local people and the fish are well accepted. But only a thorough monitoring will show full success of this pioneering approach to increasing food security in remote mountain areas of a large Pacific island.

Photo 64: Fishing in Yonki reservoir, Papua New Guinea Highlands. (Photo: T. Petr).

Photo 65: Fish hatchery at Yonki reservoir, Papua New Guinea Highlands. (Photo: T. Petr).

Photo 66: Tanks for fish fry and fingerlings in the Yonki fish hatchery, Papua New Guinea. (Photo: T. Petr).

Photo 67: Ayura fish hatchery for common carp production, Papua New Guinea. (Photo: T. Petr).