Vaan Island Reef Restoration Yields Rs61.67 Crore Benefits

Artificial Reef Project Demonstrates Coastal Recovery Success

A decade-long artificial reef restoration programme at Vaan Island has generated socio-ecological benefits valued at ₹61.67 crore, significantly exceeding its inflation-adjusted cost. A technical evaluation conducted by the Tamil Nadu Coastal Restoration Mission, Suganthi Devadason Marine Research Foundation, and Indian Institute of Technology Madras reported a benefit-cost ratio (BCR) of 2.34, confirming the economic viability of nature-based coastal interventions.

Reversing Extensive Coastal Degradation

Vaan Island, one of 21 coral islands in the Gulf of Mannar , had experienced severe erosion, shrinking by over 90% between 1969 and 2015. Factors such as coral mining, reef degradation, and sea-level rise contributed to the decline.

To stabilise the island, researchers deployed approximately 10,600 engineered artificial reef modules beginning in 2015. Geomorphic monitoring indicates measurable recovery, with the island’s area expanding from 1.53 hectares to more than 2.3 hectares.

Ecological Recovery and Habitat Regeneration

The reef structures facilitated rapid marine colonisation. Studies recorded dense coral settlement across modules, alongside substantial increases in reef-associated fish populations. Enhanced coral cover and fish density reflect improved habitat quality and ecosystem resilience.

Native vegetation diversity has also been preserved, reinforcing the island’s ecological stability.

Economic and Coastal Protection Gains

Economic valuation identified coastal protection as the largest benefit component. Artificial reefs reduced wave energy, stabilised sediments, and supported fisheries productivity. With an inflation-adjusted project cost of ₹26.37 crore, the initiative produced a strong net present value.

Replicable Restoration Framework

Authorities consider the Vaan Island model a blueprint for safeguarding other vulnerable islands. Restoration efforts have already expanded to Kariyachalli Island , signalling broader climate-resilient coastal management strategies.

Exam-Focused Key Points

• Gulf of Mannar contains 21 coral islands.

• Artificial reefs mimic natural reef functions.

• BCR above 1 indicates economic feasibility.

• Coral reefs protect coastlines from erosion.

• Reef restoration supports biodiversity and fisheries.