Tamil Nadu's Marine Restoration Efforts for Kariyachalli Island

TAMIL NADU’S MARINE RESTORATION MISSION TO SAVE KARIYACHALLI ISLAND

The Tamil Nadu government has launched a marine restoration mission under the TNSHORE (Tamil Nadu Sustainably Harnessing Ocean Resources) project to protect the rapidly eroding Kariyachalli Island in the Gulf of Mannar. Over 70% of the island’s landmass has disappeared since 1969 due to rising sea levels, coral reef degradation, and coastal erosion.

The project involves the installation of 8,500 artificial reef modules and the planting of native seagrass to stabilise the island and restore marine biodiversity. Without immediate intervention, the island could completely vanish by 2036.

FAQs

1. Where is Kariyachalli Island and why is it ecologically significant?
Located in the Gulf of Mannar Marine National Park between Rameshwaram and Thoothukudi, Kariyachalli is part of a crucial coral reef ecosystem. It supports rich marine biodiversity, including endangered species such as dugongs (sea cows).

2. What are the main threats causing the island to shrink?
The island is losing land due to a combination of rising sea levels, strong wave action, coastal erosion, and the degradation of coral reefs and seagrass beds. As of 2024, its area had reduced to just over 3 hectares during high tide.

3. What is Tamil Nadu’s response under the TNSHORE project?
The state government will deploy 8,500 specially designed artificial reef modules to absorb wave energy, prevent further erosion, and promote sediment accumulation. In addition, native seagrass will be replanted to restore marine habitats and reduce underwater current strength.

4. What do the artificial reef modules look like and how do they work?
These trapezoidal structures are made of ferrocement and steel, measuring 2–3 metres in height and weighing up to 3 tonnes. Their perforated design allows water and nutrients to circulate freely while reducing the impact of waves on the coastline.

5. How will seagrass planting help in this effort?
Seagrass beds play a critical role in trapping sediments, reducing erosion, and supporting biodiversity. They serve as feeding grounds for species like dugongs and help protect the seabed from wave-induced damage.

6. What is the timeline and cost of the restoration project?
The mission is budgeted at ₹50 crore. The deployment of reef modules will begin in August 2025 and take around 45 days to complete. Noticeable ecological improvements are expected within a year of implementation.

7. Which species of corals will be restored and why?
Only native coral species known for their resistance to bleaching and temperature stress will be used. This approach enhances the reef’s long-term resilience to climate change.

8. What broader environmental lessons does this project offer?
The Kariyachalli Island initiative demonstrates how science-driven marine restoration can protect vulnerable coastal ecosystems. It underlines the urgency of climate adaptation and the need for sustainable ocean resource management in India’s coastal regions.

“Restoring an island is not just an act of conservation—it’s an act of preservation for future generations.”