Discuss the causes of depletion of mangroves and explain their importance in maintaining coastal ecology.

Mangroves are salt-tolerant intertidal forests at the land-sea interface that act as natural bioshields; India held about 4,992 sq km of mangrove cover according to the India State of Forest Report 2021.

Causes of depletion

• Aquaculture and agriculture: clearing for shrimp ponds and paddy is the largest driver.
• Coastal development: ports, industry, tourism and urban expansion.
• Altered water and sediment flows: upstream dams reduce freshwater and silt, while pollution and effluents degrade the habitat.
• Overexploitation and climate stress: fuelwood cutting, cyclones and sea-level rise with saline ingress.

Importance in coastal ecology

• Storm and tsunami buffer: mangrove belts absorbed wave energy during the 2004 Indian Ocean tsunami and blunt cyclonic surges.
• Nurseries: they are breeding and nursery grounds for fish, prawns and crabs, sustaining coastal fisheries.
• Blue carbon: mangroves sequester carbon in waterlogged soils far more efficiently than most terrestrial forests.
• Biodiversity and livelihoods: the Sundarbans shelter the Royal Bengal Tiger and countless waterbirds and reptiles, while mangroves check shoreline erosion and saline intrusion into farmland and groundwater, and support fishing communities.

Protecting them through community-based conservation, regulated aquaculture, mangrove afforestation and strict Coastal Regulation Zone enforcement is essential for coastal resilience in a warming, storm-prone climate.