Salt Marshes: Nature’s Living Defence Against Coastal Erosion

Salt Marshes: Nature’s Living Defence Against Coastal Erosion

• Recent scientific research has renewed attention to salt marshes as nature-based solutions for coastal erosion, rising sea levels and storm-related hazards. Research published in Communications Earth & Environment examined the protective and economic benefits of restoring marshes in front of seawalls. 
• The Global Wetland Outlook also highlighted extensive wetland degradation, underlining the urgency of ecological coastal adaptation.

What are Salt Marshes?

• Salt marshes are intertidal coastal wetlands dominated by salt-tolerant grasses, herbs and other halophytes. They develop especially along sheltered shorelines, lagoons, estuaries and tidal creeks where fine sediments accumulate. 
• Unlike mangroves, which mainly comprise woody plants, salt-marsh vegetation is typically herbaceous. Periodic tidal flooding, saline soils and sediment supply shape these dynamic landforms.

Coastal Geomorphology and Wave Attenuation

• Salt marshes form natural buffers between the sea and settlements. Plant stems and leaves exert drag on moving water, lowering wave energy; roots and rhizomes bind soil and help stabilise the shoreline. Slower currents permit sediment deposition and may enable marsh surfaces to rise. 
• Yet their effectiveness depends on vegetation cover, incoming wave height, tidal depth and sediment availability. During powerful storms, vegetation may become damaged, so salt marshes are not universal substitutes for engineered barriers.

Data and Indian Context

• The National Centre for Coastal Research (NCCR) assessed India’s mainland shoreline over 1990–2018: 33.6% experienced erosion, 26.9% accretion and about 39.5% remained stable. These figures describe that historical assessment period, not an annual erosion rate. The Global Wetland Outlook 2025 estimated that at least 400 million hectares of wetlands worldwide have been lost since 1970; this refers to all wetlands, not salt marshes alone.

Constitutional and Legal Background

• Article 48A directs the State to protect the environment and Article 51A(g) places an environmental duty on citizens. Judicial interpretation of Article 21 also connects a healthy environment with the right to life. 
• The Environment (Protection) Act, 1986, and the Coastal Regulation Zone (CRZ) Notification, 2019, underpin coastal regulation. Salt marshes are identified as ecologically sensitive coastal features, while the Wetlands (Conservation and Management) Rules, 2017, apply to wetlands within their defined scope.

Significance and Multidimensional Analysis

• Salt marshes provide coastal defence, fisheries nurseries, bird-feeding grounds and nutrient cycling. Waterlogged sediments can retain organic carbon over long periods, making tidal marshes part of the blue-carbon landscape. 
• Their ecological services connect disaster-risk reduction with biodiversity, climate mitigation and livelihoods. Salt marsh restoration in front of seawalls exemplifies a hybrid approach: nature absorbs some wave action while infrastructure addresses residual risk.

Causes, Issues and Challenges

• Land reclamation, port construction, aquaculture, pollution, altered freshwater and sediment flows, and coastal engineering fragment marshes. Accelerating sea-level rise poses a further challenge where marsh elevation cannot keep pace. 
• Hard structures may prevent landward migration, causing “coastal squeeze”. Planting vegetation without restoring appropriate tidal exchange, salinity and sediment dynamics can produce poor results. Benefits also vary between sheltered and high-energy coastlines.

Government Initiatives and Examples

• India’s CRZ framework, Coastal Zone Management Plans, National Coastal Mission and NCCR shoreline assessments support coastal ecosystem governance. Launched in June 2023, MISHTI is specifically a mangrove-restoration initiative; it should not be mistaken for a dedicated salt-marsh programme. 
• International living-shoreline designs use marsh planting, sediment management and sometimes low-profile structures to protect vulnerable shores.

Way Forward

• India should systematically map salt marshes, integrate them into district-level coastal hazard planning and protect natural tidal connectivity. Site-specific restoration should focus on native halophytes, sediment budgets and room for landward migration. 
• Satellite monitoring and field-based evaluation should measure ecological recovery and actual hazard reduction. Community participation, dedicated financing and carefully designed hybrid defences can align protection with local livelihoods.

MCQ — ENGLISH

Q. With reference to salt marshes and coastal protection, consider the following statements:

1. Salt marshes predominantly occur in sheltered intertidal environments where sediment deposition supports salt-tolerant vegetation.

2. Salt-marsh vegetation can reduce wave energy, but effectiveness depends on local hydrodynamic conditions.

3. MISHTI specifically targets salt-marsh restoration rather than mangrove restoration.

4. India’s CRZ framework recognises salt marshes among ecologically sensitive coastal features.

Code

(A) 1, 2 and 4 only   

(B) 1 and 3 only   

(C) 2, 3 and 4 only   

(D) 1, 2, 3 and 4

Answer: (A)

Explanation: Statements 1, 2 and 4 are correct. Marsh vegetation may attenuate waves and encourage sediment accumulation, subject to local conditions; the CRZ framework recognises salt marshes. 

Statement 3 is incorrect because MISHTI is intended for mangrove restoration.