This site, which was listed as an IBA by Evans (1994) is a large reservoir of about 25,000 ha that is fed by the Lesser (Little) Zab River from the northeast and the Hizop stream from the northwest. The lake is formed by the Dukan dam, built in 1959 upstream of the town of the same name. The rivers are fed by rainfall and snowmelt, leading to peak discharge in spring and low water in summer and early fall. The lake itself is divided into two parts; a larger lake to the north and a smaller lake to the south separated by a winding gorge.
The Rania Plain, where the lake is located, is the largest valley in the Lesser Zab basin. Most tributaries join the Lesser Zab upstream of Dukan, the largest being the Baneh River and Qala Chwalan. A number of smaller streams join the Lesser Zab in the Rania Plain, which is now partly inundated by Dukan Lake. More than 65 villages and six towns are located around the lake, including Rania, Chwar Qurna, and Qala Dza. Much of the land around the lake is used for agriculture and grazing is practiced extensively. There are some small mineral ponds between Rania and the lake on the north side, close to Qurago and Bemushen villages
Additional Important Bird Observations: During the surveys, 181 species were recorded. In addition to those in the table the following were observed at levels that did not meet the IBA criteria: in winter Marbled Duck Marmaronetta angustirostris (Vulnerable), Ferruginous Duck Aythya nyroca (Near Threatened), Eastern Imperial Eagle Aquila heliaca (Vulnerable), Pallid Harrier Circus macrourus (Near Threatened) and Little Bustard Tetrax tetrax (Near Threatened); breeding European Roller Coracias garrulus (Near Threatened). The site held breeding populations of four Mediterranean and one Sahara-Sindian Desert biome-restricted species (Appendix xx). In winter the site also held up to 1500 (over 2%) of the armenicus race of Yellow-legged Gull Larus michahellis
Other Important Fauna: Data on mammals are only for 2008-2010, with more specific information collected in 2010. Local fishermen reported observations of two globally Near Threatened species: Eurasian Otter Lutra lutra and Striped Hyaena Hyaena hyaena. One local reported the hunting of an Otter in the year 1996. There also have been reports of wolf attacks on local animal herds.
Fish: Data were collected for the years 2007 and 2008 only, during which 21 species were reported. According to Coad’s (2010) criteria, the significant species observed were: Acanthobrama marmid, Alburnus mossulensis, Luciobarbus subquincunciatus, Carassius auraatus, Cyprinion macrostomum, Cyprinus carpio, Hypophthalmichthys molitrix, Heteropneustes fossilis, Gambusia holbrooki, Luciobarbus esocinus, Luciobarbus xanthopterus, Squalius cephalus, Silurus triostegus and Tor grypus. The following species are of no economic importance but their conservation status in Iraq is unknown: Alburnus caeruleus, Barbus lacerta, Capoeta damascina, Mastacembelus mastacembelus, Mystus pelusius, and Squalius lepidus.
Additional Plant & Habitat Information: This site contain a good population of Anchusa italica and Gundelia tournefortii, which are important as a traditional food; as well as a good population of Linum usitatissimum, which is important as a genetic resource.
Habitat and land use
The main habitat was mountain riverine forest with, in some areas cliff habitat around the reservoirs edge. The site is located in the foothills of Zagros range, where the geology is sedimentary limestone, and the soil type is sandy clay. About 60% of the area was non-vegetated.
The Zagros Mountains, in which the basin is situated, have been occupied since at least the Lower Paleolithic, and an early archaeological site in the Lesser Zab basin, Barda Balkha, dates to the Middle Paleolithic. The lake is surrounded by mountains (Sara and Qarasird to the southeast, Assos to the northeast, Kosrat to the southwest, and Barda Rash to the northwest), rolling hills, and lowland areas characterized by oak forests and steppe ecosystems.
Pressure/threats to key biodiversity
Hunting and fishing constitute a very significant threat to the area. Hunters were observed during winter in Dukan, especially in the northern part of the lake near the place where the Lesser White-Fronted Goose Anser erythropus was observed. In Rania district, several pools have been constructed with bird hides to attract water birds. As hunting is a popular activity in the area, its practitioners need to be educated to prevent them from killing globally threatened bird species (Ararat et al., 2009). To protect fish spawning in the area the Kurdistan Ministry of Agriculture prohibits fishing from mid-May to the end of July. When the team visited the site in summer it relied on interviews with local fisherman to gather information on fish species in the lake, such as Leuciscus vorax. Coad (2010) noted that this fish was commonly caught by American soldiers throughout Iraqi waters as evidenced by photos he received for identification in 2004. Fishing, when allowed, is usually done with nets whose mesh size ranges from 30 mm to 80 mm. Individual anglers have also been observed.
Dukan is one of the most popular picnic sites in the area, particularly during spring and summe and parts of this site are heavily impacted by picnickers and tourist activities and the trash they generate. Regulations for development and trash collection are limited, so the volume of visitors presents a significant threat.
The road to the lake from the town of Dukan was widened in 2010/2011, which caused a high level of erosion into the lake itself. The dam continues to raise environmental concerns downstream due to fluctuating water levels, the entrapment of sediments and creation of almost zero sediments downstream, which increases the erosion potential and decreases biodiversity below the dam.
Pollution from industry and agriculture is another very significant threat. Farmers in the northeastern part of the site near Rania were observed using poison to kill mice in their fields. In 2009, just in the Rania district alone (which contains part of the site and contains an important bird area especially for raptors) farmers were provided with 120 kg of bromadioline a rodenticide, and 997 liter of malathion, another pesticide (both are slightly to moderately toxic to many birds).
There are many gravel mines along the Lesser Zab River above and one below the lake within the delineated area that negatively affect the ecosystem of the river and cause destruction to the riparian zone. The mines collect gravel from the river banks or the river bed, which has significant effects on the river morphology, sediment loads, and water speed in addition to habitat destruction and direct pollution caused by these activities. Other human impacts at this site include animal grazing, urban planning and the expansion of surrounding cities, garbage and sewage from various towns that affect the lake and the Lesser Zab.