The power of mangroves over seawalls

Why in the News?

Cyclone Dana highlighted how Odisha’s mangroves protected coastal communities, strengthening the case for nature-based coastal defence over seawalls. This has renewed attention on India’s continued preference for spending ₹2,641 crore on hard infrastructure despite evidence that mangroves and other coastal ecosystems provide long-term, cost-effective protection to nearly 250 million coastal residents.

Why Are India’s Coastal Regions Becoming Increasingly Vulnerable to Climate Change?

1. Rising sea levels: The Arabian Sea and Bay of Bengal are experiencing accelerating sea-level rise, threatening low-lying coastal districts, deltas, and island territories.
2. Intensifying cyclones: Climate change is increasing both the frequency and intensity of cyclones along India’s coast, the eastern seaboard (Odisha, Andhra Pradesh, West Bengal) is particularly exposed.
3. Saline intrusion: Saltwater intrusion into freshwater aquifers and agricultural land is degrading livelihoods. This directly affects food security and drinking water in coastal communities.
4. Storm surges: Storm surges linked to cyclonic events are intensifying. These cause disproportionate damage to ecologically fragile coastal landscapes and displacing communities.
5. Compound risk: These interacting hazards do not operate independently. They multiply threats along India’s coastline, making the fragile coastal landscape both physically and economically vulnerable.
6. Large Population Exposure: Nearly 250 million people living along India’s coastline face direct impacts of climate-related coastal risks.
7. Extensive Coastline: India’s 11,000-km coastline increases exposure to multiple climate hazards simultaneously.

Why Are Mangroves, Seagrasses and Coral Reefs Considered Natural Coastal Defences?

1. Coral Reefs: The First Line of Defense
   1. Natural Breakwaters: Coral reefs sit furthest out in the ocean and absorb up to 97% of incoming wave energy before it can reach the shore.
   2. Friction and Depth: The jagged, complex structures of coral skeletons create immense bottom friction, forcing waves to break early and lose their destructive power
2. Seagrass Meadows(The Middle Buffer): Reduce coastal erosion, trap sediments and support marine biodiversity.
   1. Erosion Control: Located in the shallow waters between reefs and the shore, seagrasses act as underwater carpets that anchor the seabed with their roots.
   2. Sediment Trapping: Their long blades slow down water currents, forcing suspended sand and organic particles to drop to the seafloor, which actively builds up the underwater terrain.
3. Mangroves: The Intertidal Shield
   1. Storm Surge Mitigation: Mangrove forests act as the final, dense barrier against extreme weather, capable of reducing storm surge heights by up to 66%. 
   2. Energy Dissipation: Their massive networks of tangled prop roots and thick trunks create a dense obstacle course that rapidly saps the remaining power of waves and incoming floods.

How Does Ecosystem-based Adaptation (EbA) Strengthen Climate Resilience?

EbA uses biodiversity and ecosystem services to help people adapt to climate change. This reduces climate impacts while sustaining ecosystems that support fisheries, agriculture, and tourism.

1. Climate Risk Reduction: Uses biodiversity and ecosystem services to help people adapt to climate change.
2. Livelihood Protection: Supports fisheries, agriculture and tourism-dependent communities.
3. Long-Term Sustainability: Maintains ecosystem functions while reducing climate vulnerabilities.
4. Cost Effectiveness: Avoids repeated expenditure on expensive hard infrastructure maintenance.
5. Disaster Risk Reduction: Reduces losses from cyclones, flooding and coastal erosion.
6. Nature-based Solutions: Integrates conservation and restoration into adaptation planning.

What Evidence Demonstrates the Effectiveness of Ecosystem-based Adaptation?

Bhitarkanika Mangroves During Cyclone Dana

1. Cyclone Protection: Mangroves in Odisha’s Bhitarkanika quietly protected communities from cyclone impacts.
2. Natural Buffer: Reduced climate impacts while strengthening ecosystem health and livelihoods.

Global Evidence

1. Protection Capacity: A healthy hectare of coastal habitat protects more people per hectare than almost any other natural asset.

Sundarbans Example

1. Mangrove Restoration: Around 18,000 women restored 4,600 hectares of mangroves.
2. Cyclone Mitigation: Restoration reduced impacts of Cyclones Amphan and Yaas.
3. Livelihood Benefits: Strengthened local economic opportunities and social outcomes.

Kerala Example

1. Seawall Consequences: Armouring and erosion-control measures protected specific sites.
2. Adjacent Damage: Accelerated erosion in neighbouring areas, illustrating unintended consequences of hard infrastructure.

Why Does India Continue to Prefer Seawalls and Embankments?

Seawalls are massive, heavy-duty structures built directly parallel to the shoreline where the sea meets the land. They are designed as a last line of defence to protect high-value coastal areas, like cities and roads, from intense wave action. Embankments are raised earthen ridges or mounds constructed along rivers, lakes, or low-lying coastlines. They focus on holding back water from flat, expansive areas rather than fighting heavy, crashing ocean waves.

1. Engineering Bias: Adaptation planning strongly favours hard infrastructure such as seawalls, groynes, embankments and tetrapods.
2. Political Visibility: Seawalls and embankments provide visible and immediate outputs, making them attractive for governments.
3. Institutional Preference: Existing planning, procurement and budgeting systems are designed around construction-based projects.
4. Administrative Familiarity: Engineers and local authorities are more experienced with hard infrastructure than ecosystem restoration.
5. Perceived Certainty: Seawalls provide tangible and measurable protection, whereas ecosystem benefits are often viewed as less predictable.

What does India’s coastal adaptation spending pattern reveal about institutional bias toward hard infrastructure?

1. Hard protection dominance: Coastal States spent ₹2,641 crore on hard protection measures over the last decade. This reflects a stark preference for engineered measures such as seawalls, groynes, embankments, and tetrapods.
2. National Coastal Mission decline: Budget fell from ₹195 crore in 2022-23 to just ₹50 crore in 2024-25.
3. PSL and visibility bias: Fragile institutional mandates, weak monitoring, and a preference for visible infrastructure often leave ecosystem-based interventions buried within broader sectoral programmes rather than recognised as adaptation in their own right.
4. Reporting gap: Adaptation benefits of coastal ecosystems are rarely assessed or recorded separately, making India’s coastal EbA portfolio appear much weaker than it is.

What Prevents Ecosystem-based Adaptation from Becoming Mainstream Policy?

1. Fragmented Terminology: EbA overlaps with Nature-based Solutions (NbS), Coastal Adaptation (EbCA), Ecosystem-based Disaster Risk Reduction (Eco-DRR) and related concepts.
2. Classification Challenges: Similar interventions are recorded under conservation, restoration or management categories instead of adaptation.
3. Weak Monitoring: Limited mechanisms exist to measure adaptation outcomes.
4. Institutional Fragmentation: EbA interventions remain dispersed across multiple schemes and sectors.
5. Inadequate Recognition: Policymakers often fail to identify adaptation benefits generated by ecosystem restoration.
6. Limited Financing: Absence of dedicated adaptation financing restricts scale and replication.

Why Does Classification of Ecosystem-based Adaptation Matter?

1. Policy Recognition: Enables clear identification of adaptation actions.
2. Monitoring Frameworks: Facilitates tracking and evaluation of adaptation outcomes.
3. Financing Access: Strengthens eligibility for climate adaptation funding.
4. Evidence Generation: Supports measurement of climate resilience benefits.
5. Policy Integration: Ensures ecosystem restoration becomes part of mainstream adaptation planning.

How Does the Mangrove Initiative for Shoreline Habitats and Tangible Incomes (MISHTI) Reflect the Potential of EbA?

MISHTI is a dedicated central government scheme in India aimed at reviving and expanding the country’s mangrove cover while generating sustainable livelihoods for coastal communities. Announced during the Union Budget 2023-24 and officially launched on World Environment Day (5 June 2023), it serves as a core part of India’s strategy to build a nature-based “bio-shield” against climate change.

1. Programme Objective: Targets restoration of 540 sq km of mangroves across nine States.
2. Climate Resilience: Enhances natural protection against coastal hazards.
3. Livelihood Support: Generates economic opportunities linked to ecosystem restoration.
4. Current Limitation: Primarily framed as a restoration programme rather than a climate adaptation initiative.

What Policy Reforms Are Needed to Mainstream Ecosystem-based Adaptation?

1. Policy Integration: Embeds EbA within coastal planning and adaptation frameworks.
2. Dedicated Financing: Expands budgetary support for ecosystem-based interventions.
3. Outcome Monitoring: Develops indicators for adaptation benefits.
4. Institutional Coordination: Harmonises fragmented schemes and programmes.
5. Climate Accounting: Recognises ecosystem restoration as an adaptation investment.
6. Natural Capital Approach: Treats ecosystems as strategic climate-resilience assets.

Conclusion

The choice before India is not merely between two adaptation techniques but between two development pathways. While seawalls offer localised and short-term protection, mangroves and other coastal ecosystems provide durable climate resilience, biodiversity conservation and livelihood security. Mainstreaming Ecosystem-based Adaptation will be critical for protecting India’s 250 million coastal residents in an era of accelerating climate change.

Value Addition

Nature-based Solutions (NbS)

Definition: Nature-based Solutions (NbS) is an umbrella concept defined by the International Union for Conservation of Nature (IUCN) as actions to protect, sustainably manage, and restore natural or modified ecosystems. These actions address societal challenges, such as climate change, food security, water security, human health, and disaster risk, while simultaneously providing human well-being and biodiversity benefits.

1. India’s NDC 2022 references NbS for carbon sequestration through forests.

Ecosystem-based Adaptation (EbA)

Definition: Use of biodiversity and ecosystem services to help people adapt to adverse impacts of climate change.

Key Features

1. Ecosystem conservation
2. Ecosystem restoration
3. Climate risk reduction
4. Community participation
5. Livelihood enhancement
6. Disaster resilience

Ecosystem-based Coastal Adaptation (EbCA)

EbCA is a subset of Ecosystem-based Adaptation (EbA). It focuses specifically on helping coastal communities adapt to the long-term, gradual changes brought by climate change.

1. The Core Strategy: It uses coastal biodiversity and ecosystem services to help human societies adapt to climate pressures.
2. Primary Targets: Sea-level rise, coastal erosion, saltwater intrusion into agricultural land, and changing ocean temperatures.
3. Example: Dynamically planting salt-tolerant mangrove species along an eroding coastline. As sea levels rise, the mangroves naturally trap sediment, raising the land.

Ecosystem-based Disaster Risk Reduction (Eco-DRR)

Eco-DRR focuses on using ecosystems to reduce the immediate impact, frequency, and severity of sudden natural disasters.

1. The Core Strategy: It manages and restores ecosystems to act as physical shock absorbers against extreme physical hazards.
2. Primary Targets: Sudden disasters like cyclones, tsunamis, massive storm surges, and flash floods.
3. Example: Protecting an offshore coral reef. When a cyclone strikes, the reef acts as a natural breakwater, absorbing up to 97% of the wave energy before it crashes into coastal towns, directly reducing casualties and property destruction.

Ecological Bio-Shields:

1. A bio-shield is a dense strip of vegetation planted along a coast to act as a barrier against natural hazards. 
2. Casuarina trees, mangroves, and coastal palms are frequently used together to create multi-tiered, living walls that trap flying debris and slow down incoming water.If

Integrated Coastal Zone Management (ICZM): 

1. India’s ICZM project (World Bank-assisted) aimed to address coastal erosion, pollution, and habitat loss through integrated planning. 
2. EbA mainstreaming is its natural evolution.

PYQ Relevance

[UPSC 2022] Explain the causes and effects of coastal erosion in India. What are the available coastal management techniques for combating the hazard?

Linkage: The PYQ examines coastal vulnerability and compares different coastal protection approaches, including structural and ecosystem-based measures. The article extends the PYQ by assessing whether ecosystem-based solutions such as mangroves can provide more sustainable and cost-effective coastal protection than conventional seawalls and embankments.