Kariyachalli Island | 04 Jul 2025

Source: DTE  

Tamil Nadu, under the TNSHORE (Tamil Nadu Sustainably Harnessing Ocean Resources) project, is working to protect the ecologically vital Kariyachalli Island in the Gulf of Mannar, which has shrunk by over 70% since 1969 and may be submerged by 2036. 

Kariyachalli Island 

• About: Kariyachalli Island, located within the Gulf of Mannar Marine National Park, is part of one of India’s four major coral reef regions (others: Gulf of Kutch, Lakshadweep, and Andaman & Nicobar Islands). 
  • It serves as a vital habitat for endangered species like dugongs (sea cows, IUCN: Vulnerable), which rely on seagrass ecosystems. 
• Threats: The island has lost 70% of its landmass since 1969, and due to climate change, 30% of its coral has already bleached. 
• Conservation: The TNSHORE project plans to install 8,500 artificial reef modules that are trapezoidal structures made of ferrocement and steel with perforations for nutrient flow along with seagrass plantation and coral habitat restoration, to help reduce wave energy and stabilize the shoreline. 

Gulf of Mannar 

• About: The Gulf of Mannar, an extended part of the Laccadive Sea, contains 21 islands and is bordered by Rameswaram, Ram Setu bridge, and Mannar Island.  
  • It receives rivers like the Tambraparni and Aruvi, and hosts the Tuticorin port.  

• Biodiversity: Home to the Gulf of Mannar Marine National Park—South Asia’s first Marine Biosphere Reserve—it supports corals, fishes, and endangered species like dugongs, whale sharks, and sea turtles. 
  • The gulf is noted for its pearl banks and sacred chank (a gastropod mollusk). 
• Gulf of Mannar Marine National Park: Established in 1982, it features coral reefs, mangroves, mudflats, creeks, seagrass beds, seaweeds, estuaries, sandy shores, saline grasslands, marshes, and rocky coastlines.