Declared a wildlife sanctuary in October 1972 under Section 14 of the Sind Wildlife Protection Ordinance, 1972. Designated a Wetland of Interna- tional Importance at the time of Pakistan’s ratification of the Ramsar Convention on 23 July 1976.

Fauna Drigh is a breeding area for a variety of resident waterfowl, a very important roosting site for night heron Nycticorax nycticorax, and formerly a very important wintering area for ducks and common coot Fulica atra. Over 32,000 ducks and coots were present in January 1973, but numbers then declined rapidly as the area of open water diminished. Less than 7,000 ducks and coots were present in 1975 and 1976, and only 820 were recorded in January 1987.
However, large numbers of ducks were again present in the winter of 1987/88. Over 17,400 waterfowl were recorded in mid- January 1988, including: 6,500 common teaMnay crecca, 2,750 common pochard Aythyaferina, and 3,560 tufted duck A . fuligula. Very large numbers of night heron have roosted in the marshes for many years. About 1,500 were present in January 1987, and over 2,750 in January 1988. Details of other waterfowl known to occur in the sanctuary are
given by Scott, 1989. The sanctuary is rich in birds of prey such as osprey Pandion haliaetus, Eurasian marsh harrier Circus aeruginosus, greater spotted eagle Aquila clanga, tawny eagle A. rapax and imperial eagle A. heliaca. Little is known about the other fauna of the sanctuary.