What Steps Is India Taking to Prevent Coastal Erosion?

October 1, Kariyachalli (India) (RASAS/AFP) — As sea levels rise, India is employing artificial rocks, transplanted coral, and seagrass to protect the Kariyachalli Island located off its southern coast. This conservation effort aims to slow the pace of coastal erosion and shield the island and mainland from encroaching seawater. Kariyachalli, part of a chain of 21 islands in southern Tamil Nadu, has lost over 80% of its landmass in the last half-century. According to government estimates, the island’s area shrank from 20.85 hectares in 1969 to just 3.14 hectares last year. Without effective control, it is anticipated that the island could be completely submerged underwater by 2036.

Senior state official Supriya Sahu explained that diminished natural resilience heightens the risks posed by storms, cyclones, rising sea levels, and coastal erosion. Marine scientists note that the coral reefs, seagrass beds, and small islets in the Gulf of Mannar act as natural barriers by absorbing wave impact. However, decades of human activities, pollution, overfishing, and increasing ocean temperatures have weakened these coral reefs. Around Kariyachalli, coral coverage declined from approximately 500 hectares in 2005 to 197 hectares by 2021.

Under a conservation program costing about 4.79 million USD, 8,500 artificial rock structures are being installed around Kariyachalli. These structures, designed based on studies of sea level, currents, and waves, are expected to reduce wave energy and provide a substrate for new coral growth. Seagrass helps stabilize soil and sand as well as offering breeding and nursery grounds for marine life. Nonetheless, rising sea temperatures pose additional challenges to coral restoration. In 2024, severe coral bleaching in this region led to significant coral mortality.

Scientists are also searching for heat-resistant coral species capable of withstanding future marine heatwaves. Encouraging results from restoration efforts on other islands in the Gulf of Mannar provide hope. On Van Island, the placement of around 10,000 artificial rock units has facilitated partial recovery of lost land. Coral transplanted on Singal Island also endured the 2024 bleaching better than older coral formations. Wildlife warden Akhil Thampi noted that due to the positive outcomes seen on Van Island, similar restoration initiatives have been launched on Kariyachalli. Martina, a 29-year-old involved in seagrass conservation, highlighted that increased seagrass growth supports fish reproduction, preserves marine ecosystems, and improves the livelihoods of local communities.