Why In News?

• An artificial lake in MP’s Shivpuri district – Sankhya Sagar, has virtually disappeared under a thick layer of an invasive aquatic plant (hyacinth), threatening the biodiversity of the water body.
• Sankhya Sagar – a Ramsar site (declared in 2022), is a wetland site designated internationally important by UNESCO.

About the lake and the invasive species:

=> The lake spreads across 248 hectares (612.82 acres) and helps maintain the ecological balance of the Madhav National Park.

=> The lake is home to marsh crocodiles aka ‘Mugger’ (Crocodylus palustris), which is a Schedule I reptilian species protected under the Indian Wildlife (Protection) Act, 1972.

=> Water hyacinth (Pontederia crassipes) is an invasive plant species (macrophytes) native to South Africa.

=> Although the plant has some uses (acts as a water purifier by removing heavy metals), it poses a threat to aquatic biodiversity when it covers the entire surface of a water body.

Ramsar convention/The Convention on Wetlands of International Importance:

=> It is an international treaty for the conservation and wise use of wetlands.

=> It is named after the Iranian city of Ramsar (on the Caspian Sea), where the treaty was signed on 2 February 1971.

=> It came into force in 1975. India has 75 sites (as of August 2022) recognised under the convention.

Montreux Record:

• Montreux Record under the Convention is a register of wetland sites where changes in ecological character have occurred, are occurring, or are likely to occur as a result of technological developments, pollution or other human interference.
• It is maintained as part of the Ramsar List.