Why talk about mangroves?
Today, 26 July, celebrated as World Mangrove Day, is a great time to learn about these distinct forests, what they do for us, the threats they face because of us, and what we can do to help!

Occupying a unique space on the Earth’s coastlines, mangroves are tropical groups of trees, characterized by their location at the interface between marine and freshwater, serving an enormous range of benefits and functions.

What is extremely unique to mangrove vegetation is their ability to withstand ever-changing, saline environments, with their highly specialized root systems undergoing periodic flooding, driven by tides. The extreme environmental conditions at river mouths (of which these forests form an important part) results in the fact that there are only a few types of mangrove flora, with just over 90 species known worldwide.

Do they exist in India?
In India, we have over 4750 square kilometers found along our coastline. This alone accounts for around 3% of the world’s total mangrove cover!  This is largely due to the fact that half of India’s mangrove cover is within the Sundarbans, one of the largest continuous blocks of mangroves in the world. Almost 80% of India’s mangroves are found in West Bengal, Gujarat, and the Andaman and Nicobar Islands. Additionally, Maharashtra and Andhra Pradesh also hold decent stretches of mangroves.

Why do we need forests on coastlines?
The strong, entangled roots of mangrove trees protect our coastal areas from strong waves, cyclone damage and storm surges! Additionally, these roots also trap sediments and particles, which result in clear, rich waters, favoring photosynthesis and driving the nutrient cycle.

This is why strong mangrove patches positively influence conditions that drive healthy fisheries, and the robust existence of other marine life, such as coral reefs and sea grass beds! 

Do mangroves support marine life?
Innumerable fish species spend a significant part of their early lives in mangroves, protected by the shelter provided by roots and the nutrients trapped from freshwater sources. Many species important to us as sources of food and livelihood shelter and grow in such habitats! 

Are Mangroves useful to communities?
Coastal communities benefit from healthy mangroves in more ways than just food and livelihood! Shorelines are protected, sheltering communities occupying sea shores from extreme weather events. Healthy mangroves also provide opportunities for harvesting medicinal products, in addition to other forest produce!

 An understated but essential role played by mangroves is serving as carbon sinks. Their rich, peaty soils hold large amounts of carbon, in addition to the dissolved carbon at greater depths, offsetting to some extent the impacts of climate change.

So…what’s the problem?
Unfortunately, the problems are many!

• Human activities:   Large patches have been cleared in Andhra Pradesh for the construction of aquaculture facilities for shrimp farming. Additionally, many wetlands harboring mangrove stands are also cleared for other agriculture, such as the growing coconuts, rice paddy, and pasture for grazing!
• Over Consumption:  Population  rise and an increased dependence on forest products have resulted in over-exploitation, degrading the condition of previously pristine mangrove stands.
• Infrastructure: The construction of dams and channels to divert water interferes with the supply of water to mangroves. As a result, salinity levels are heightened, stressing the biodiversity of such regions.
• Climate Change: Similar to most marine habitats, mangroves are also under threat from climate change. Sea level fluctuations will alter the spread of mangroves, with such vegetation dependent on staying submerged for a certain period of time, over somewhat consistent tidal influences. 

What are we doing to change this?
In India, much work is already underway. On realizing that much of India’s mangrove cover has been lost over time, restoration efforts were put in place, encouraging the planting of new mangrove stands.

Since 1939, Gujarat has almost doubled its mangrove cover through restoration efforts. However, this cover is largely represented by one species, Avicennia marina. While this has resulted in a greater cover, the lack of diversity in mangrove species has resulted in the limited recovery of ecosystem functions, shown by low success rates of restoration efforts.

Yet, despite the fact that India has shown a marginal increase in mangrove cover recently; much work is needed to ensure that such efforts result in healthy, functional ecosystems. The reliance of certain coastal ecosystems on healthy, functioning mangroves is extremely strong, and efforts to respect and nourish our mangroves must be corresponding.

Ultimately, the benefits of mangroves will positively influence not only the environment, but all coastal communities and all stakeholders either directly or indirectly reliant on marine resources. This includes all of us in one way or the other, from those who live alongside turbulent oceans, to those who eat seafood, and those who enjoy visiting beaches. Mangroves in one way or the other are a part of all the processes that go about crafting the coast into how it is as we know it.

Photo © Chiranjit Chakraborty, Pankaj Kumar Sarkar, Ratul Saha, Shuvarthi Guha