Ministry of Agriculture, Integrated Area Development Project, Gelephu, Bhutan
While Bhutan is rich in cold water streams, rivers and lakes, the fish distribution in them is poorly known, fish exploitation minimal, and aquaculture of cold water fish species does not exist yet. Apart from indigenous fish with fisheries potential, such as asla and mahseer, 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. It is proposed to establish a cold water fish hatchery, both for the production of stocking material for releases in rivers and lakes, as well as for production of table-sized fish.
Unlike other Trans-Himalayan countries, the Kingdom of Bhutan is a small landlocked country of 46 500 km2 which lies in between China in the north and India in the east, west and south. Almost 90 percent of the land is mountains, the rest consists of foothills in the south, with some plains stretching from east to west.
Numerous rivers, most of them fed with snow- and ice-melt from Himalayan glaciers, flow from north to south and drain into the Indian plains of Assam and West Bengal. Among them, three major rivers, the Amo chu (Torsa), Pho chu Mo chu (Sunkosh) and Dangme chu (Manas), form the main river system of Bhutan. These rivers are rich in fish. The main indigenous fish are Himalayan trout (Barilius spp) and Mahasheer (Tor spp). Exotic brown trout (Salmo trutta) was introduced and is a common fish in some rivers and streams of Bhutan. Bhutan has also a number of large and small lakes scattered throughout the country. Most of these lakes are situated at altitudes above 2 000 m and are covered by ice during the winter months. With a view to propagating cold water fish especially trout, the Royal Government has initiated stocking trout yearlings in lakes. The yearlings required for stocking in the lakes have been obtained from rivers of Bhutan by capturing them in nets.
The fish stocks in the rivers of Bhutan have not been properly assessed but among cold water fish species brown trout predominates. As the government does not permit catching of fish on commercial scale fish catch statistics are not available. During the non-breeding seasons the Royal Government issues sport fishing permits for certain areas.
Previous assessment of cold water fish and fisheries potential of Bhutan was presented in two FAO reports (Dubey, 1978; FAO, 1987), and the situation was also reviewed by Petr (1999).
The aquaculture industry in Bhutan is still in its infancy and only few farmers are involved in fish culture of warm water fish species. The breeding and culture of cold water fish species has so far not been initiated. As mentioned above, very few people obtain fishing permits, which is mandatory for everyone catching fish. 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.
2.1 Human impact on native cold water fish
The impact of human intervention on aquatic ecosystems and eventually on the native cold water fish community is viewed as a serious problem. Problems arising from siltation and pollution are not common in Bhutan since almost all the river systems have their origin in the snow fed mountains and pass through thick forests where there is less erosion. Siltation due to flash floods during the monsoon season or melting of snow has only a negligible impact on fish. Several hydro-power projects, some of them with a capacity of 1 000 MW, are under construction, but it is anticipated that they will have only a minute impact on fish fauna, due to the location of these projects. Overfishing and introduction of exotic fish species may have direct impact on indigenous fish, and this needs to be studied.
2.2 Conservation and mitigating measures
The Royal Government has initiated very few conservation and mitigation measures so far. However, as precautionary measures the government does not encourage import of fish species or fish seed for stocking in ponds, rivers and lakes. The only cold water fish species imported and introduced in the rivers of Bhutan was brown trout, which was brought in 1958. Lakes and rivers are not yet fished or used for fish culture. The government regulations help to conserve the fish species, as indiscriminate fishing is not permitted, and other types of fishing are limited.
2.3 Domestication of economically important fish
A small fish-breeding farm in the western part of the country was established in the early 1970s. The farm was established with the objective of breeding brown trout to be released in rivers and lakes to enhance production of fish fauna in natural water bodies. The farm remained functional for about 15 years and was closed by the government due to unforeseen reasons. An FAO Mission visited Bhutan in 1987, reviewed the situation, and put forward a proposal for a model hatchery for the cold water indigenous fish asla and for the exotic trout (FAO, 1987), but there has been no follow-up.
Based on the availability of natural water bodies comprising rivers and lakes and reservoirs created as a result of hydropower development there is good potential for the development of cold water fishery in Bhutan. Cold water trout and mahseer capture could be expanded on a trial basis, and the Royal government in collaboration with other countries could initiate a water trout aquaculture pilot study for which perhaps some lakes could be used. Other cold water fish species, such as mahseer, could be also tried for farming. This could be supplemented by establishing a trout farm for trout seed production.
As farming in Bhutan is done mostly in valleys where rivers exist, there is potential for cold water fish culture involving the farmers, which would in turn 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.
Regional cooperation with SAARC countries in the field of fishery development to exchange technical know-how needs to be established.
Cold water fishery in Bhutan does not exist and no work has been done as far as culture is concerned. Trout breeding and breeding of indigenous fish species on a small scale specifically for stocking rivers and lakes can be carried out for conservation of biodiversity. The country has good potential for development of cold water fishery in rivers, lakes and reservoirs. Current plans and proposal include the establishment of a trout hatchery and its culture by starting a pilot project in northern Bhutan.
Dubey, G.P., 1978. Survey of the waters of Bhutan. Physiography and fisheries potential. Report. FAO, Rome. 38p.
FAO, 1987. Small-scale cold-water fisheries: fact finding and project idea formulating mission to mountainous regions of Bhutan, India and Nepal (31 March - 12 May 1987). Report. Based on the work of T. Petr, X. Lu and K.G. Rajbanshi. FAO, Rome. 63p.
Petr, T., 1999. Coldwater fish and fisheries in Bhutan. FAO Fisheries Technical Paper. No. 385: 6-12. FAO, Rome.