Mangroves: Nature's Coastal Defence

How mangrove forests protect coasts from storms, support fisheries and store carbon, and why their economic value is often overlooked.

Mangroves are forests that grow in salty coastal waters, with tangled roots rising above the mud. India has some of the world’s most important mangroves, including the Sundarbans in West Bengal, shared with Bangladesh, and Bhitarkanika in Odisha.

What mangroves provide

Storm protection: roots and trees reduce the force of waves and storm surges.
Fisheries: mangroves are nurseries for fish, crabs and shrimp, supporting coastal livelihoods.
Carbon storage: mangroves store large amounts of carbon in their soils, called blue carbon.
Erosion control: roots hold soil and stabilise shorelines.
Wood, honey and tourism.

Evidence from Odisha

After the 1999 super cyclone in Odisha, economists Saudamini Das and Jeffrey Vincent studied villages along the coast. They found that villages with wider mangrove belts between them and the sea suffered fewer deaths, even after accounting for other factors.

Why mangroves are lost

Shrimp farming and aquaculture ponds.
Urban expansion, ports and industry.
Pollution and changes in freshwater flows.

These uses produce visible income, while mangroves’ benefits, such as storm protection, are spread across many people and not paid for, a classic externality problem.

Valuing mangroves

Economists use methods like avoided damages and fisheries value to estimate mangroves’ economic value. Studies often find their value per hectare exceeds that of converting them to other uses, especially when storm protection is included.

Protection and restoration

India’s Coastal Regulation Zone rules restrict development in mangrove areas.
The MISHTI scheme, launched in 2023, supports mangrove plantation along India’s coasts.
Community-based restoration involves local people in planting and protecting mangroves.

Mumbai’s mangroves

Mumbai still has significant mangrove areas, often under pressure from development. Courts have ordered their protection.

Two villages

Two coastal villages face the same cyclone. One has a wide mangrove forest in front of it; the other cleared its mangroves for shrimp ponds years earlier. The first suffers less flooding and damage. The shrimp ponds earned money, but their hidden cost appeared in the storm.

Thinking mangroves are wasteland

Mangroves provide valuable protection, fisheries and carbon storage, often worth more than the uses that replace them.

Key takeaways

Mangroves protect coasts, support fisheries and store blue carbon.
Odisha villages with wider mangroves had fewer deaths in the 1999 cyclone.
Mangroves are lost to aquaculture and development because their benefits are unpriced.
CRZ rules and the MISHTI scheme aim to protect and restore them.