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

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Ghissu Editorial · Accepted Answer

Mangroves are being depleted by aquaculture, urban and port reclamation, reduced freshwater and silt from upstream barrages, and climate and pollution stress, yet they shield the coast, nurture fisheries and store blue carbon. Villages behind the Pichavaram mangroves suffered far less damage in the 2004 tsunami.

**Introduction**

Mangroves are salt-tolerant inter-tidal forests with stilt and breathing roots. The Sundarbans, a UNESCO World Heritage Site, is India's largest stand, yet mangroves on both coasts are shrinking.

**Causes of Depletion of Mangroves**

1. **Aquaculture conversion**: Shrimp ponds have replaced mangroves in the Godavari-Krishna delta and the Indian Sundarbans.
2. **Urban and port reclamation**: Mumbai's creeks were filled for housing and roads, prompting the Bombay High Court in 2018 to ban mangrove destruction across Maharashtra.
3. **Less freshwater and silt**: Barrages such as Farakka raise salinity in the Sundarbans, while dams trap the silt deltas need.
4. **Climate and pollution**: Sea-level rise, cyclones such as Amphan (2020), oil and plastic waste, and fuelwood cutting all thin the cover.

**Importance of Mangroves for Coastal Ecology**

SKETCH: flow | How Mangroves Shield the Coast
- Storm surge arrives
- Dense roots absorb waves
- Silt trapped, shore built
- Erosion and flooding cut
- Villages behind protected

1. **Bio-shield**: Villages behind the Pichavaram mangroves suffered far less damage in the 2004 tsunami, and Kendrapara villages fronted by mangroves saw fewer deaths in the 1999 Odisha super cyclone.
2. **Fish nursery**: Roots shelter young fish, prawns and crabs, and leaf litter feeds a detritus food chain.
3. **Blue carbon**: Their soils store far more carbon per hectare than most dry-land forests; India joined the Mangrove Alliance for Climate at COP27 (2022).
4. **Filter and habitat**: They trap sediment that would smother coral reefs and host the Royal Bengal tiger of the Sundarbans and the saltwater crocodile of Bhitarkanika.

**Conclusion**

Mangroves guard the coast and feed its fisheries, so their loss is an ecological and economic loss together. CRZ enforcement and MISHTI (2023-24 Budget) can make them a lasting shield of climate resilience.

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

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