Lake Uromiyeh lies at 1,280 m in an inland drainage basin in western Azarbayjan, 60 km south-west of Tabriz. At c.140 km long (from north-west to south-east) and up to 55 km wide near the southern end, it is a vast hypersaline lake of great scenic beauty with extensive salt-encrusted flats and shingle beaches. The average depth is c.5 m, the level fluctuating by c.1–2 m depending on winter rains. The bottom is mud or silt, often covered by salt crystals. Salinities range from 80 to 280 p.p.t. and the water temperature from 3 to 30°C. There are several large areas of fresh to brackish marsh with abundant aquatic vegetation in the deltas of the many small rivers and streams which flow into the lake. The most extensive of these marshes is in the south at the mouth of the Jogatu Chay river. The lake includes 56, mostly small, uninhabited islands. The largest, Kabudan (Ghoyoon Daghi), comprises 3,125 ha of hilly steppe with scattered trees. The climate is semi-arid, with very hot summers and extremely cold winters (temperatures below -25°C). The lake supports an abundant growth of the alga Enteromorpha and there is a very rich algal bloom and build up of brine shrimp Artemia salina between early June and the end of September, but the lake itself is too saline to support any other plants or animals. The marshes and shorelines have typical saltmarsh plant communities of Suaeda, Atriplex and Frankenia with Juncus, some Phragmites at river mouths, and occasional stands of Tamarix. Remnant stands of Pistacia forest survive on the larger islands, notably Kabudan and Ashk, together with Rhamnus bushes and Artemisia shrubs. There are rolling wheat-lands to the west and south, and semi-arid steppe and hills to the north and east. There are villages on the shore, with small steamer ferries operating between them. The lake has little value for conventional outdoor recreation because of its extremely high salinity, but has exceptionally high values for eco-tourism because of its great scenic beauty and spectacular concentrations of waterbirds.
See box for key species. The lake is extremely important for breeding Pelecanus onocrotalus, Plegadis falcinellus, Platalea leucorodia, Phoenicopterus ruber, Tadorna ferruginea, T. tadorna, Himantopus himantopus, Recurvirostra avosetta, Larus armenicus, L. genei and many other species. The pelicans, spoonbills, Egretta garzetta and many of the gulls breed on a group of small islands (Dowguzlar Islands) near the south end of the lake, feeding on the extensive brackish and freshwater wetlands on the plain to the south. Flamingos are known to have bred in large numbers every year since at least the early 1960s, and appear to be increasing steadily; in some years there are several large colonies. After hatching, the chicks form large creches and swim to the south end of the lake to feed in the extensive shallows. Most other species of waterfowl breed on the mudflats round the lake or in the extensive fresh to brackish marshes at the main river mouths. The vast mudflats surrounding the lake are the most important autumn staging area for migratory shorebirds and Anas querquedula in Iran, while the open waters of the lake occasionally support huge numbers of passage Podiceps nigricollis. An estimated 146,000 small shorebirds (probably mostly Calidris minuta and C. ferruginea) were located on the mudflats during an aerial survey on 29-31 August 1973, along with over 21,000 A. querquedula and 13,600 Recurvirostra avosetta. The lake appears to be an important moulting area for Tadorna tadorna (with up to 35,000 in August), and in mild winters may support large numbers of wintering waterfowl. Alectoris chukar is a common resident. At least 187 species have been recorded in the reserve.
Non-bird biodiversity: Mammals: Ovis ammon of the western red race have been introduced to Kabudan Island (estimated 1,150 in 1973/74), and Dama mesopotamica (E) to Ashk Island. Panthera pardus (rare) was introduced to Kabudan in about 1970 in an attempt to control Ovis numbers; it is known to have bred there, but is believed to have died out towards the end of the decade.
Pressure/threats to key biodiversity
Kabudan Island was established as a Protected Region in February 1960. This was enlarged to cover the entire lake and all its islands (483,000 ha) in 1967. The Protected Region was reduced in size to 465,000 ha and given National Park status in the early 1970s; it has since been reduced to its present size of 463,600 ha. The entire lake was designated a Ramsar Site in 1975, and 462,600 ha of the National Park were designated a Biosphere Reserve in 1976. Cornwallis (1976) recommended that the boundaries of the National Park be extended to the upper limit of the inundation zone of the lake. This would involve no conflict with agricultural interests, and would incorporate the Gordeh Git and Mamiyand marshes (see site 008), the Talab-e-Garrous marshes, and Ghopi Bob Haydar (a small lake and freshwater marsh c.4 km south-east of Talab-e-Garrous). Freshwater discharge into the marshes at the south end of the lake was reduced in the early 1970s following the construction of a dam on the Mahabad river, but this was partially compensated for by discharge from the irrigation scheme through two main drains emptying into one of the marshes (Talab-e-Garrous). These drains provide water to the marsh through the summer and have improved its value for nesting birds (Cornwallis 1976). The most serious threat is likely to be water-borne pollution from towns in the catchment area, especially the large city of Tabriz to the north-east and the town of Uromiyeh to the west, and pollution with toxic chemicals used in the surrounding agricultural land.
BirdLife International (2019) Important Bird Areas factsheet: Lake Uromiyeh. Downloaded from
http://www.birdlife.org on 12/12/2019.