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Environmental problems of Northern Eurasia

The Aral Sea

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Delta Areas

The delta areas of the Amudarya and Syrdarya rivers have been transformed due to the lack of water, adversely affecting flora, fauna, and soils. Reduced flows of water have resulted in the fragmentation of lakes in the deltas and a decline in the overall area occupied by lakes (Table 22.5).

Table 22.5 Changes in the number and area of natural lakes in the Amudarya and Syrdarya deltas (1936-80)

The native tugai forests have been severely degraded as ground water levels in the deltas have fallen (by 10-15 m in some places) and floodplains are no longer inundated. The tugai is characterized by extremely rich floral plant communities, containing 576 higher plant species of which 29 are endemic to Central Asia (Chapter 12; Glazovsky, 1995b). Fifty-four of these species were on the verge of extinction in the mid-1990s. Several species of waterlily and fern had already disappeared.

These areas were also economically important, providing grazing for livestock, and opportunities for hunting, trapping, and reed harvesting for local industries (UNEP, 1992a). About 420 000 ha of hay meadows were used in the Amudarya delta in 1960, but by the end of the 1980s just 70 000 ha remained and their productivity had been reduced by the increasing salinity of the soils. Commercial hunting and trapping has virtually disappeared as conditions in the deltas have become unfavourable for such game as hog and muskrat. The lower reaches of the Syrdarya yielded 70000-230000 muskrat skins during the 1950s, but hunting ceased in 1978. In the 1970s, up to 50 000 muskrat skins were taken each year in the Amudarya delta, but hunting stopped in the early 1980s.

Deterioration of the habitat has harmed many other faunal populations. The Bukhara deer has virtually disappeared from its degraded tugai habitat and most of the deltas' migratory bird populations no longer visit these areas as habitats have changed and food sources, such as the Aral Sea's fish population, have been depleted (Novikova and Zaletayev, 1985). The number of bird species commonly found in the lower Syrdarya has been reduced from 173 in 1960 to 38 in thirty years (Glazovsky, 1995b).

One positive aspect of these ecological changes from the human viewpont is a decline in the range of the Asiatic Migratory locust. The reedbeds of the Amudarya delta were formerly one of the most important permanent breeding centres of this locust that represented a significant pest to irrigated cropland during outbreak years, but the decline in reed area has dramatically reduced their breeding capability. However, conditions have become more favourable for the Italian locust which has replaced the Asiatic Migratory locust as a periodic threat to the cotton crop (Latchininsky and Gapparov, 1996).

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