Author: Shikhita Gupta
Taking care of the habitat that surrounds and sustains us has become even more crucial as the world is dealing with the pandemic and the floods caused by the heavy rainfalls have left almost no corner of the world! Every year 26 July is celebrated as ‘The International Day for the Conservation of the Mangrove Ecosystem’ to raise awareness about the importance of mangroves as a unique, special, self-sustaining but now threatened ecosystem that is in dire need of protection and conservation.
But before we understand how we can protect our wonderful mangrove systems, let’s look at all we should know about them.
What are mangroves?
Mangroves are tropical species, surviving at temperatures above 66° F (19° C), not tolerating fluctuations exceeding 18° F (10° C) or temperatures below freezing for any length of time. They grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate, and only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures (Florida Museum, 2018). Mangroves do not require saltwater to survive and are capable of growing in freshwater habitats, although most do not due to competition from other plants (NOAA, 2018).
Image Source: Mangrove and its ecology, Wall Street International Magazine
Where can you find Mangroves across the Globe?
The SAS (South Asia Sea) region mangroves are one of the most crucial mangrove ecosystem hotspots. It covers about 47 % of the world’s mangrove area, containing 85 % of the world’s mangrove species, and occurring in a variety of habitats. The total area of mangroves in the Indian Ocean region is 84,984.56 sq.km which includes Myanmar (6,950 sq.km), India (4,871 sq.km), Bangladesh (4,500 sq.km), Pakistan (2,600 sq.km), Sri Lanka (1,200 sq.km). Fourteen species are endemic to this region. (Kandasamy and Rajendran, 2005).
In this region, Sundarbans is the world’s largest contiguous mangrove patch covering an area of 10,000 sq.km and is part of the progradation delta of Ganga-Brahmaputra-Meghna River systems that comprises an area of 80,000 sq.km and is recognized internationally as the UNESCO (United Nations Educational, Scientific and Cultural Organization) World-Heritage site.
The mangrove ecosystem plays a vital role in the coastal biodiversity of 30 countries bordering the Indian Ocean. The intricacy of the roots of mangroves allows fishes and other organisms to thrive. They offer critical nursing environments for juveniles of thousands of fish species, from 1-inch gobies to 10-foot sharks. They also conserve biological diversity — including several endangered mammals [the Royal Bengal tiger (Panthera tigris tigris) deer, otters, manatees, and dolphins], reptiles (e.g., crocodiles, iguanas, and snakes), amphibians, and birds (herons, egrets, pelicans, and eagles) (Sandilyan and Kathiresan, 2012). They protect coral reefs, seagrass beds, and shipping lanes against siltation while providing habitat, spawning grounds, and nutrients for a variety of fish and shellfish (Conservation.Org, 2021).
Image Source: Carylsue, National Geographic
…and also, local livelihoods!
Mangroves are commonly found along sheltered coastlines in the tropics and sub-tropics where they support biodiversity and provide crucial socio-economic and environmental functions. They provide a variety of wood and non-wood forest products and protect coastlines from wind, waves, and water currents. Mangroves are identified as a primary nursery area for commercially important fish and shrimp species. Globally, 80 % of the fish catches are directly or indirectly dependent on mangroves. Mangrove plants are traditionally used to cure diseases and provide livelihoods to locals who sell them for medicinal value. (Sandilyan and Kathiresan, 2012).
Role of Mangroves in the Fight against Climate Change
Mangroves are magical when it comes to their role in fighting climate change, they not only help in mitigation due to their ability to store vast amounts of carbon, but also stabilize the coastline, reducing erosion from storm surges, currents, waves, and tides. They also play an integral role in maintaining the coastal ecosystem; they actively absorb the pollutants released by human settlements (Conservation.Org, 2021).
Mangroves account for only approximately 1% (13.5 Gt year-1) of carbon sequestration by the world’s forests, but as coastal habitats, they account for 14% of carbon sequestration by the global ocean. (Taylor and Francis, 2014).
Threat to Mangroves
Mangroves are very crucial in our fight against climate change but the sad reality is these beautiful ecosystems are often used for dumping waste, including plastics that do not biodegrade, harming both — these ecosystems and the species living there. There are three major threats to Mangroves-destructive fishing practices, nutrient pollution caused by agriculture and tourism, and deforestation caused by coastal development (Amnh, 2021).
India has lost 40% of its mangrove area during the last century. A 2013 study on the effect of waste on mangrove functionality indicates that there may also be a potential link between mangrove pollution and carbon sequestration, as salinity stress can lead to mangrove mortality and less productive mangrove ecosystems (UNEP, 2017).
Mangrove forests are harvested for wood chips, pulp, and charcoal production. That’s why they are now becoming one of the world’s most threatened tropical ecosystems. The decline in its number and quality is already at an alarming rate. Verified reports show that over 35% of the world’s mangroves have disappeared. The figure is even higher at 50% in Asian countries like the Philippines, Vietnam, and India. While in the Americas, mangroves are being cleared at a faster rate than tropical rainforests (IUCN, 2021).
The need to save Mangroves
It is highly crucial to conserve mangroves as, if the mangrove carbon stocks are disturbed, resultant gas emissions may be very high (IPCC AR5). Also, mangrove has got definite role against pollution because of their natural ability to act as a sink of anthropogenic and industrial pollutants. Mangrove ecosystems are specific in numerous aspects (e.g., carbon and nutrients cycles, sediment characteristics, tidal conditions) therefore once damaged, then it will affect speciation, an evolutionary process that helps to create new endemic species. It can also arrest and bioremediate certain pollutants (like fluoride) in the local environment.
Now that we know about the wonders of nature’s one of most productive ecosystems, we need to conserve and protect them.
To conserve mangroves, we need community-based solutions which will engage the community in the conservation initiatives as well as provide the locals with socio-economic benefits. Mangrove restoration will offer the possibility to reverse patterns of mangrove decline and rebuild lost biodiversity and ecosystem services. Appropriate and more specific national laws, regulations, and enacted and enforced policies are key to improved mangrove management. Reducing plastic waste at an individual level will also be a key step that an individual can take to stop these wonderful trees from vanishing off the face of the earth.
So, it’s time now for us to take a stand against climate change and protect mangroves because if not now, then when?
Blog Credits: Shikhita Gupta
Florida Museum. 2019. Habitat Requirements. [ONLINE] Available at: https://www.floridamuseum.ufl.edu/southflorida/habitats/mangroves/requirements/
NOAA. 2018. What is a “mangrove” forest? [ONLINE] Available at: https://oceanservice.noaa.gov/facts/mangroves.html
Kandasamy & Rajendran. 2005. Coastal mangrove forests mitigated tsunami. [ONLINE] Available at: https://www.researchgate.net/publication/222661244_Coastal_Mangrove_forests_mitigated_tsunami
Sandilyan and Kathiresan. 2012. Mangrove conservation: a global perspective. [ONLINE] Available at: https://link.springer.com/article/10.1007/s10531-012-0388-x
Taylor & Francis Online. 2014. Carbon sequestration in mangrove forests. [ONLINE] Available at: https://www.tandfonline.com/doi/abs/10.4155/cmt.12.20?journalCode=tcmt20
AMNH. 2021. Mangrove Threats and Solutions. [ONLINE] Available at: https://www.amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/mangrove-threats-and-solutions
Conservation.Org. 2021. MANGROVES:11 FACTS YOU NEED TO KNOW [ONLINE] Available at: https://www.conservation.org/stories/11-facts-you-need-to-know-about-mangroves
UNEP. 2017. Coastal crisis: Mangroves at risk. [ONLINE] Available at: https://www.unenvironment.org/news-and-stories/story/coastal-crisis-mangroves-risk
IUCN. 2021. Mangrove Restoration. [ONLINE] Available at: https://www.iucn.org/theme/forests/our-work/forest-landscape-restoration/mangrove-restoration
IPCC AR5. 2014. [ONLINE] Available at: https://www.ipcc.ch/assessment-report/ar5/