UPSC Mains 2019 GS Paper 1 Q5: model answer
Discuss the causes of depletion of mangroves and explain their importance in maintaining coastal ecology.
What the question wants
Discuss why mangroves are being depleted and explain their role in coastal ecology.
How to structure it
Discuss ... explain: two parts, causes then importance.
- Status
- Causes of depletion
- Importance
- Conservation
How to think it through
Odisha learnt this the hard way. In the 1999 super cyclone, villages behind mangroves suffered far fewer deaths than those without. That one study makes this answer.
Model answer
India has about 4,992 sq km of mangroves (ISFR 2021), nearly 40% in West Bengal's Sundarbans.
Causes of depletion
- Aquaculture: shrimp farms on the Andhra and Tamil Nadu coasts.
- Urbanisation and ports: Mumbai's mangroves lost to housing and roads.
- Agriculture and salt pans.
- Pollution from industry and oil spills.
- Reduced freshwater flow from upstream dams makes water too salty.
- Sea-level rise and cyclones (Amphan 2020 damaged the Sundarbans).
- Firewood and fodder use by poor coastal households.
Importance for coastal ecology
- Natural barrier against cyclones, storm surges and tsunamis; 1999 Odisha cyclone studies showed fewer deaths behind mangroves.
- Nursery for fish, crabs and prawns; supports fisheries.
- Blue carbon: store up to four times more carbon than land forests.
- Prevent erosion by trapping sediment.
- Filter pollutants and protect coral reefs and seagrass.
- Habitat for tigers, crocodiles and birds.
Conservation
MISHTI (2023) aims to plant mangroves on 540 sq km; CRZ rules; community-run mangroves like those in Pichavaram in Tamil Nadu. Protecting mangroves is cheaper than building sea walls, and it works better.
Draw: Coastal cross-section: sea, mangroves, village, with storm surge being absorbed.
Keywords, cases and data to drop in
ISFR 2021, Sundarbans, blue carbon, storm surge buffer, MISHTI 2023, CRZ, Pichavaram.
Where most answers lose marks
- Only listing importance and missing causes.
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Question text as printed in the official UPSC Civil Services (Main) question paper. The model answer is original Battle IAS work; use it to learn structure, not to memorise.
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