UPSC Mains Answer: Discuss the causes of depletion of mangroves and explain their importance in maintaining coastal ecology.

Difficulty Level: Medium

Sub-category: Geography (Ecology and Environment)

Introduction

Mangroves, the salt-tolerant coastal forests, are vital ecosystems facing rapid depletion. Their degradation stems from anthropogenic and natural causes, jeopardizing coastal ecology and livelihoods.

Body

Causes of Depletion:

Urbanization and Infrastructure

Coastal cities expand into mangrove areas for ports, industries, and real estate, fragmenting habitats (e.g., Mumbai’s mangroves reduced by 40% since 1990).

Aquaculture

Shrimp farming, particularly in Southeast Asia and India’s Sundarbans, converts mangroves into ponds, releasing stored carbon and disrupting sediment flow.

Pollution

Industrial effluents, plastic waste, and oil spills (e.g., 2017 Ennore spill) suffocate mangrove roots and reduce biodiversity.

Climate Change

Rising sea levels and cyclones (e.g., 2020 Amphan) erode mangrove soils, while altered salinity levels hinder regeneration.

Deforestation

Fuelwood and timber extraction, especially in Sundarbans and Andaman, deplete mangrove cover faster than natural regrowth rates.

Ecological Importance

Biodiversity Hotspots

Mangroves host 75% of tropical fish species, migratory birds (e.g., Bengal florican), and endangered species like Royal Bengal tigers.

Coastal Protection

Their dense roots act as natural barriers, reducing storm surge impacts by 66% (IPCC) and preventing erosion (e.g., Odisha’s mangroves saved 1,500 lives during 1999 super cyclone).

Carbon Sequestration

Mangroves store 4x more carbon per hectare than rainforests, mitigating climate change (Blue Carbon Initiative).

Water Filtration

Roots trap pollutants and sediments, improving water quality for coral reefs and seagrass beds downstream.

Livelihoods

Support fisheries (100 million people globally) and eco-tourism, providing income for coastal communities.

Conclusion

Reversing mangrove depletion demands integrated policies: strict coastal regulation (CRZ norms), community-led restoration (e.g., Gujarat’s ‘Mangrove Cell’), and global climate action. Their ecological services are irreplaceable, making conservation a non-negotiable priority for sustainable coastal development.