Why in the News?

Bihar’s only wetland of international importance under the Ramsar Convention lies neglected and is on the brink of drying up, even as the state is pitching other waterbodies for classification.

About Kanwar Lake:

• Kanwar Taal, known as Kabar Taal or Kabartal Wetland, is an oxbow lake in Begusarai district, Bihar, India.
• It is the largest freshwater oxbow lake in Asia, covering an area of 67.5 km².
• The lake was established as a bird sanctuary in 1987 and is now a designated Ramsar site since 2020.
• Covering the majority of the Indo-Gangetic plains in northern Bihar, this lake was declared a Ramsar site in 2020, making it the first wetland in Bihar to be included in the Ramsar convention.
• Kanwar Taal is a significant wetland in Bihar and is an essential stopover for migratory waterbirds along the Central Asian Flyway.
• The lake provides vital flood absorption during the monsoon season and supports agriculture during the dry season.
• It also houses five critically endangered species and over 50 fish species.
• Biodiversity: Kanwar Taal is rich in biodiversity.
• It is home to a wide range of plant and animal species.
• It supports 165 plant species and 394 animal species, including 221 species of birds.
• These bird species include both resident and migratory birds, with the lake serving as an important stopover point for migratory waterbirds travelling along the Central Asian Flyway.
• Flood Absorption: The wetland plays a crucial role in flood absorption during the monsoon season.
• It helps in reducing the impact of floods in the region by absorbing excess water, which is important for flood control and the protection of nearby areas.
• Agricultural Support: During the dry season, Kanwar Taal supports agriculture in the surrounding areas.
• The water from the lake is used for irrigation, benefiting local farmers and contributing to the region's agricultural productivity.
• Endangered Species: The wetland is home to five critically endangered species, highlighting its significance in conserving rare and threatened wildlife.
• Additionally, it hosts over 50 fish species, contributing to the aquatic biodiversity of the region.

What are Oxbow Lakes?

• Oxbow 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.
• 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.
• Eventually, 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.