Mangroves: Significance & Protection

Context - Residents and activists are protesting against infrastructure projects in Mumbai and its surrounding areas citing disregard for environmental regulations and lack of inclusive planning. Depletion of mangroves and dwindling fishing spots have sparked concerns among fisherfolk, who fear displacement and feel their livelihoods are being threatened.

Mangroves are salt-tolerant plant communities found in the intertidal zones in tropical and subtropical zones of the world. 

Ecological adaptations of Mangroves

• Pneumatophores are lateral roots that grow upward out of the mud and water to function as the site of oxygen intake for the submerged primary root system.
• Buttress roots also known as plank roots/ stilt roots are large, wide roots on all sides of a shallowly rooted tree. Typically, they are found in nutrient-poor tropical forest soils that may not be very deep. They prevent the tree from falling over (hence the name buttress) while also gathering more nutrients.
• Adaptations to low oxygen: By propping themselves above the water level with stilt roots and can then absorb air through pores in their bark (lenticels).
• Nutrient uptake: Pneumatophores (aerial roots) allow mangroves to absorb gases directly from the atmosphere.
• Limiting salt intake: Mangroves exclude salt by having significantly impermeable roots.
• Limiting water loss: They can restrict the opening of their stomata (pores on the leaf surfaces, which exchange carbon dioxide gas and water vapor during photosynthesis).
• Increasing survival of offspring: Mangrove seeds are buoyant and are therefore suited to water dispersal. 

Global distribution of Mangroves

• According to Global Forest Resource Assessment, 113 countries have Mangrove forests covering estimated 14.79 million hectares.
• The largest Mangrove area is in Asia (5.55 million hectares), followed by Africa (3.24 million hectares), North and Central America (2.57 million hectares) and South America (2.13 million hectares) and Oceania (1.30 million hectares).
• Country wise: About 40% of global mangrove cover is in just four countries: Indonesia > Brazil > Nigeria > Mexico.

Distribution of Mangroves in India

• According to India State of Forest Report, Mangrove cover in India is 4,992 sq. km constituting 0.15% of total area of India.
• State-wise Mangrove Cover: West Bengal > Gujarat > Andaman & Nicobar Islands > Andhra Pradesh > Maharashtra > Odisha > Tamil Nadu > Goa > Karnataka > Kerala > Daman & Diu & Dadra & Nagar Haveli > Puducherry.

About Sundarbans

• Located within the largest mangrove forest in the world. Located in the delta of Rivers Ganges and Brahmaputra on the Bay of Bengal in India & Bangladesh.
• Sundarbans Tiger Reserve is situated within the Site and part of it has been declared a “critical tiger habitat” under national law and also a “Tiger Conservation Landscape” of global importance.
• The Site is also home to a large number of rare and globally threatened species such as the critically endangered northern river terrapin (Batagurbaska), the endangered Irrawaddy dolphin, and the vulnerable fishing cat .
• It is listed as World Heritage Site and also in UNESCO Biosphere Reserve.

Importance of Mangroves

1. Important refuges of coastal biodiversity: Mangroves provide breeding grounds for marine biodiversity.
   • Under water the root system provides nesting and feeding grounds for juvenile fish, oysters, mussels, and sharks. Above ground mangroves provide homes for cranes, eagles and monkeys. 
   • Broad and towering canopies provide nesting and resting ground for migratory and sea birds and other wildlife. 
   • Stable and resilient mangrove ecosystems support the associated ecosystems such as seagrass beds and coral reefs thus maintaining their health, functioning and integrity.
2. Act as bio-shields: Mangroves acts as natural barriers against rising tides and storm-surges. Mangrove ecosystems prevent property damages and reduce flood risk in coastal areas. The dense root systems help stabilize shorelines by trapping sediments and reducing the impact of waves and tides. They are an effective check against Cyclones and Tsunamis in the coastal regions. 

3. Mangrove wood is a source of a wide variety of biomass and forest products. Communities along the coast depend on it for fuel, construction, fish traps, boat building and non-wood products such as traditional medicine.
4. Acts carbon sinks: Mangroves capture carbon from atmosphere for growth. Part of this carbon is stored in living biomass and part is sequestered in the soil. Dead mangrove material decomposes very slowly due to waterlogging of the soils with tides. It is believed that mangroves hold up to four times the amount of carbon as compared to forested ecosystems like temperate and boreal forests. 

5. Improve water quality: Mangroves act as natural water filters, trapping sediments and pollutants from runoff before they reach the open sea, thus improving water quality. 
6. Tourism and recreation: Mangroves have high aesthetic value and are important sites for ecotourism, bird-watching and other recreation activities. 

Challenges to Mangroves

1. Increasing human population in coastal areas and rising demand for land, timber, fodder, fuel-wood and other non-wood forest products. 
2. Growing land reclamation for agriculture and industrialization
3. Discharge of untreated domestic sewage and industrial effluents
4. Damming of rivers, which curbs the flow of sediments to coastal areas. The silt flow is essential for the regeneration and growth of mangroves.

Initiatives for promoting Mangrove.

1. Mangrove Alliance for Climate (MAC)
   • This initiative, launched by the UAE in partnership with Indonesia, promotes Mangroves as a nature-based solution to climate change. 
   • It was launched during COP 27 of UNFCCC. 
   • Membership has 17 member countries. India is also a member. 

2. Mangrove Initiative for Shoreline Habitats and Tangible Incomes (MISHTI) 
   • Envisages to comprehensively explore the possible area for development of Mangroves covering approximately 540 Sq. Kms. spreading across 11 States and 2 Union Territories during five years commencing FY 2023-24 onwards. 
   • The sharing of best practices on plantation techniques, conservation measures, management practices and resources mobilization through Public Private Partnership are objectives of the MISHTI scheme.

3. Planting of over 5 crore Mangroves under MGNREGA by West Bengal Government.
4. Mangroves for Future Initiative (MFF) 

Mangroves for the Future (MFF) is a unique partner-led initiative to promote investment in coastal ecosystem conservation for sustainable development. Co-chaired by IUCN and UNDP, MFF provides a platform for collaboration among the many different agencies, sectors and countries which are addressing challenges to coastal ecosystem and livelihood issues. 

Steps to promote mangrove forests.

1. Natural regeneration
2. Promotion of plantation activities in suitable land on the banks of rivers near estuary and on inter-tidal mudflats associated with the areas that are inundated by sea water on a daily cycle.
3. Regeneration of Mangrove forests in areas where it has been degraded.
4. Sharing of best practices.
5. Conservation of existing mangroves.
6. Notification of protected areas in mangroves.
7. Ensuring ecological flows in rivers.
8. Effective implementation of Coastal Regulation Zone Guidelines.