Introduction
Mangroves are specialized halophytic intertidal wetland ecosystems located along tropical and subtropical coastlines. According to the India State of Forest Report (ISFR) 2021, India's mangrove cover stands at 4,992 sq km, constituting about 0.15% of the nation's total geographical area.
Current Status and Distribution of Mangroves in India
India's mangrove ecosystem exhibits notable geographical concentration alongside qualitative conservation challenges:
- Spatial Distribution: West Bengal accounts for the largest share at 42.3% (dominated by the Sundarbans), followed by Gujarat at 23.5% (Kachchh and Gulf of Khambhat), Andaman and Nicobar Islands at 12.3%, and Odisha (Bhitarkanika).
- Net Growth vs. Qualitative Stress: While ISFR 2021 recorded an incremental net increase of 17 sq km in total cover, dense mangrove stands face degradation due to expanding commercial aquaculture, infrastructure development such as ports, and reduced upstream freshwater flow resulting from dams and barrages.
Function of Mangroves as a Bioshield
Mangrove vegetation serves as a critical nature-based infrastructure barrier along dynamic coastlines through distinct mechanisms:
- Cyclone and Storm Surge Dissipation: The complex aerial root architectures, including stilt roots and pneumatophores, generate hydraulic drag that rapidly dissipates wave kinetic energy and reduces storm surge heights. Example: The Sundarbans and Bhitarkanika mangrove systems significantly attenuated coastal inundation and buffered inland habitations during the 1999 Odisha Super Cyclone and Cyclone Amphan (2020).
- Tsunami Wave Dampening: Dense mangal thickets act as physical shock absorbers against extreme hydrodynamic surges, reducing wave velocity and run-up heights. Example: The Pichavaram mangrove forest in Tamil Nadu effectively shielded adjoining villages such as Parangipettai from severe devastation during the 2004 Indian Ocean Tsunami.
- Shoreline Stabilization and Saltwater Intrusion Control: Interlocking root matrices trap deltaic sediments and bind coastal soils, counteracting coastal erosion while buffering coastal aquifers against saltwater ingress. Example: Mangroves in the Krishna-Godavari deltas play a pivotal role in checking coastline retreat and limiting marine salinisation of inland agricultural lands.
Conclusion
To sustain this ecological bioshield, targeted initiatives like the Mangrove Initiative for Shoreline Habitats & Tangible Incomes (MISHTI) should be converged with MGNREGS and CAMPA funds, alongside rigorous enforcement of Coastal Regulation Zone (CRZ-I) norms to ensure resilient coastal ecosystems.