Context: Kawar Lake, Bihar’s only wetland of international importance under the Ramsar Convention lies neglected and is on the brink of drying up.

About Kawar Lake

• Also known as Kabartal wetland, it is Asia’s largest oxbow lake situated in the Begusarai district of Bihar.

• It draws water from the confluence of the Gandak, Bia and Kareh river and is a residual oxbow lake, formed due to meandering of Gandak river, a tributary of Ganga.

• It covers majority of the Indo-Gangetic plains in northern Bihar and was declared the first and only Ramsar site of Bihar in 2020.

• Ramsar sites are internationally recognized wetlands that are crucial for biodiversity and environmental conservation, 75 out of them are in India.

• Fauna: More than 40 different species of fishes, over 106 species of birds and about 60 species of migratory birds from Central Asia including Oriental white-backed vulture, greater adjutant, Crested Serpent Eagle, etc.

Threats & Challenges

• Kawar Lake's water level is significantly low due to deficit rainfall.

• The lake has been drying up since 2010.

• Migratory bird hunting, agriculture around wetland areas, and government policies are major obstacles.

• Urbanization and land acquisition threaten the wetlands.

• Conflicts between farmers and fisherfolk are common around the lake.

• Silt accumulation is increasing, reducing the depth of the lake.

About Ox-bow Lakes

• Ox-bow lakes are crescent-like water bodies formed due to erosion and deposition in meanders of rivers.

• Meanders are loops or curved structures formed in the course of a river due to friction or tectonic activity.

How Ox-bow lakes are formed?

• The speed of water flow in the outer section of this meander is more than the inner part causing its neck to become narrower over time.

• The size of this loop increases making it harder for the river to flow through it so it opts for a straight path.

• Finally the ends of this meandered loop are separated by deposition of sediments or silt separating the river and a horseshoe-like structure called oxbow lake.

Wetlands in Bihar

• India has 75 Ramsar sites.

• Bihar has about 4.4% wetlands of its total geographical area. (Survey by the Indian Space Research Organisation in 2006-07)

• Proposed Ramsar Sites: The Bihar State Wetland Authority identified wetlands for inclusion as Ramsar sites including Kusheshwarsthan, Barela, Goga Bil, Nagi, Nakti dams, Udaipur lake, Vikramshila Gangetic Dolphin Sanctuary, and Gokul reservoir.