Artificial Reefs Fight Back Against Island Erosion

The islands of the Gulf of Mannar, crucial for coastal protection and marine biodiversity, face an existential threat as two of the 23 have vanished. Kariyachalli, an island vital to the region's marine biosphere reserve, has shrunk dramatically, losing 71.37% of its landmass since 1969 and projected to disappear by 2036. To counteract this severe erosion, a significant intervention has commenced, involving the deployment of approximately 8,500 artificial reef modules.

These artificial reefs, constructed from ferro-cement and steel, are strategically designed based on local bathymetry to dampen wave forces and arrest land loss. Complementing the reefs, seagrass beds will be planted to further slow ocean currents and enhance biodiversity, benefiting endangered species like dugongs. The entire restoration process, including reef placement and seagrass planting, is anticipated to take about 18 months, with continuous monitoring planned for at least five years post-completion.

A budget of ₹50 crore has been allocated for Kariyachalli's preservation, highlighting the critical need for such measures amidst climate change. The government of Tamil Nadu emphasizes that the cost of these conservation efforts is minimal compared to the essential role these islands play in safeguarding coastal communities from natural disasters, such as cyclones and tsunamis.