Shallow (0.5-3.0 m) saline lake (freshwater in the past) with vast Phragmites, Typha and Scirpus beds, open-water areas linked by channels through reeds, together with saltmarsh fringes and semi-desert islands with Salsola, etc., lying between the Kura and Aras rivers. Surrounding Mil steppe is slightly undulating alluvial plain with semi-desert and desert vegetation. The wetland area has recently decreased in size, having previously increased from 4,400 ha to 10,000 ha as a result of receiving water from irrigation systems. This wetland, together with lakes Boz Koba (IBA 010) and Sarysu (IBA 032), forms the water-body system of the Mil steppe.
At least 115 species have been recorded and at least 87 breed, including a colony of Pelecaniformes and Ciconiiformes (20,000-25,000 pairs), also Cygnus olor, Anser anser, Netta rufina, Francolinus francolinus (a few broods each year), Himantopus himantopus, Recurvirostra avosetta, Glareola nordmanni, and Chettusia leucura. Species of global conservation concern that do not meet IBA criteria: Haliaeetus albicilla (winter visitor in small numbers). About 300,000 birds (presumably mainly waterbirdsmostly wildfowl) formerly wintered at the site, with a lower count of 110,000 in January 1991 (50,000-60,000 ducks).
Non-bird biodiversity: There are more than 20 species of fish were noted in the lake. There is Pelobates syriacus B. (Red Data Book of Azerbaijan) from amphibians, Sus scrofa, Felis chaus, Canis lupus, Canis aureus, Vulpes vulpes, Lepus europeus, Myocastor coypus etc. from mammals also occur on this site.
BirdLife International (2020) Important Bird Areas factsheet: Aggyol. Downloaded from http://www.birdlife.org on 08/04/2020.