Fish and fisheries at higher altitudes: Asia.
The 13 papers review fish stocks and fisheries of mountainous areas of Asia: Himalayas (Bhutan, Nepal, northern states of India within the Himalayas), Western Ghats (India), Karakoram-Hindu Kush (Pakistan, Afghanistan), Pamir (Tajikistan), Tien Shan (Kyrgyzstan, Kazakhstan), Altai (Kazakhstan, Mongolia, China), high altitude lakes of Mongolia and those of western China (provinces of Qinghai and Xinjiang and Xizang) and Caucasus (Armenia, Georgia, Azerbaijan). From south to north, fish fauna complexes change from Oriental to Palaearctic. Cool and coldwater streams and rivers support subsistence and/or recreational/sport fisheries, with commercial fisheries practised only in some lakes and reservoirs. While fishing of streams and rivers is largely unmanaged, considerable management effort has gone into some lakes and reservoirs, especially in Kazakhstan, Kyrgyzstan and India in order to maintain reasonably high fish catches. The management measures have included translocation and stocking of exotic fish species and regulation of fisheries. For recreational fishery, brown trout has been stocked in rivers and streams of the southern slopes of Himalayas, rainbow trout in some streams of Western Ghats. A number of countries are pursuing the development of hatchery technologies for indigenous fish, with success achieved with mahseer (Tor spp.) in India and Nepal. Overfishing has become a problem in many streams and rivers as well as in the large lakes of western China, Mongolia, Kyrgyzstan and India-administered Kashmir. Deterioration of catchment soils by inappropriate agricultural practices and deforestation and pollution inputs are reducing the water quality in streams and rivers, making them unsuitable for many coldwater fish species. Some natural lakes such as Dal and Wular in India-administered Kashmir are undergoing reduction in their size as a result of eutrophication, increased sedimentation and intensified aquatic plant growth, as well as encroachment of agriculture into their margins. In higher altitudes of Asia coldwater fish culture of market-sized fish has been largely limited to rainbow trout and common carp.