This blog is a continuation of the previous blog: “ECOSYSTEM RESTORATION”. Here,we focus on a singular ecosystem: the mangroves. To refer to the previous blog ,click here!
TABLE OF CONTENTS
|2||DEGRADATION OF MANGROVES:|
2.1) TIMBER AND TANNIN.
2.3) AGRICULTURAL USE.
2.4) CLIMATE CHANGE & POLLUTION.
|3||RESTORATION OF MANGROVES:|
3.1) FAILED ATTEMPTS.
3.2) SUCCESSFUL ATTEMPTS.
|4||WHY SHOULD WE RESTORE MANGROVES/ IMPORTANCE OF MANGROVES:|
4.1) CARBON SEQUESTRATION.
4.2) PREVENT FLOODS, TSUNAMIS, SOIL EROSION.
4.4) LIVELIHOOD FOR COMMUNITIES.
Mangroves, the first line of defence for the coastal communities are highly productive ecosystems. They are distinguished by a dense tangle of prop roots that gives the trees the appearance of standing on stilts above the water. They are the world’s only tall forests where land, freshwater, and saltwater mix. Oh, did you know, they occupy less than 1% of the world’s surface and are found in the tropical and subtropical tidal areas. India is blessed to have about 4,921 square kilometres of mangrove forests. These forests have provided shelter to countless species, protected the citizens from cyclones, floods and soil erosion while also sequestering huge amounts of carbon!
Despite all this, the mangroves are the most threatened ecosystem in the world.Our country in particular has lost about 40% of its mangrove forest in the last century. Why is it that we continue to destroy something that is so vital to us?This blog dives into all the factors that affect the ecosystem, its importance and methods to restore mangroves.
DEGRADATION OF MANGROVES:
Well since ages now we have developed this pattern of destroying ecosystems for our needs (timber, salt pans, etc) and under the claim of “development” we slowly proceed to exploit the already limited resource.
1) TIMBER AND TANNIN:
The Mangrove wood has high industrial value because it is resistant to rot and insects apart from that it can be also used as construction material or for fuel and charcoal. Tannin is also extracted from the bark from some mangrove species to form a compound known as “feather” for its ability to bind with certain types of proteins to form a strong, flexible,resistant insoluble substance.
Mangroves are known to provide a safe nursing ground for a wide range of fish larvae as they enhance the survival rate of these species in their early life stages. In India, brackish water aquaculture is restricted to shrimp farming because of the high export value of thePenaeid shrimp. At times whole patches of mangroves are destroyed for aquaculture expansion. Localized water pollution and eutrophication caused due to aquaculture have led to detrimental effects on the forest.
3) AGRICULTURAL USE:
In the 1960s and 70s the ecological and economic benefits of mangroves were unknown to man, so they used the close proximity of mangroves to the ocean to their benefit, for farming.Mangroves were converted into agricultural lands to cultivate rice paddies, coconuts and salt pans. This turned into a custom practice for the farmers
which is now controlled by implying certain laws. However, the damage caused is almost irreversible.
4) CLIMATE CHANGE & POLLUTION:
The impact of climate change is extremely fatal. Climate change has led to gradual rise in sea levels, because of which mangroves tend to move landward, but human
encroachment prevents it and, as a result, the width of the mangroves decreases. Solid waste pollution is a major threat to mangroves: in urban cities like Kolkata and Mumbai where clusters of garbage are seen floating near the coasts. Studies have found trace amounts of heavy metals & toxins in mangrove roots, they have a direct effect on the salinity of water.Garbage piles also hinder the growth of mangrove tillers.
RESTORATION OF MANGROVES:
Mangrove restoration may sound similar to reforestation on land but it is tougher than one could imagine. This ecosystem is very complex and attains a balance from the different species of plants and wildlife along with the appropriate amount of salt, oxygen and pH in the water. It is also regulated by tidal waters. Since the 1990s, international organizations and NGOs have tried various methods to save and restore the mangrove ecosystem. Some suggest leaving it up to mother nature to rehabilitate while others have come up with various innovative ideas to recover the mangrove forest.
1) FAILED ATTEMPTS:
Some tackle the issue by first planting seedlings in a greenhouse (a controlled safe environment) and then transferring it to its natural habitat. This hasn’t been effective in many cases. Take for example, the infamous Sri Lankan mangrove rehabilitation project, they planted mangrove seedlings in 2000 hectares of land which cost them 13 million USD yet more than 80% of the plants died in the early stage. The reason for this, was simple human negligence! The communities responsible for looking after the seedlings were not provided with enough tactical information about the requirements of the forest. Some groups inadvertently chose unsuitable restoration sites while others planted non-native species, or even planted seedlings incorrectly. A few were even eaten by grazing animals.
2) SUCCESSFUL ATTEMPTS:
Robin Lewis (a wetland scientist) has restored several mangrove ecosystems around the globe. He observed that mangroves do restore themselves, they also transform sand into rich mangrove peat in a few years but controlling the water flow is where the complications begin. The roots of mangrove trees require 70% dryness and 30% wetness i.e, when the water flows in it wets the roots and when it flows out the roots are dry. The factor may slightly vary in different areas but the ratio remains the same. His theory has been successfully implemented in 25 countries around the world including the USA, Thailand and Indonesia.
WHY SHOULD WE RESTORE MANGROVES/ IMPORTANCE OF MANGROVES?
1) CARBON SEQUESTRATION:
Mangroves form a “blue carbon ecosystem,” storing three to four times more carbon than terrestrial forests.During their growth period, mangroves can store and stockpile carbon from the atmosphere. The majority of this carbon is trapped in the soil beneath mangrove trees.
2) PREVENT FLOODS, TSUNAMIS, SOIL EROSION:
Mangroves aid in flood mitigation by acting as barriers through factors such as bottom friction, tree density, and shape which reduces the force of flood waves passing through mangrove forests. For instance, according to research, mangrove forests helped curb shoreline damage during the 2004 Indian Ocean tsunami.A mangrove forest’s aerial roots retain sediments, stabilising the soil of intertidal areas and reducing erosion. Storm surge and waves are dissipated by the roots, trunk, and canopy.
Indian mangrove ecosystems are rich in floral and faunal diversity, with over 1600 plant and 3700 animal species. Many commercially important fish species have their larvae in mangroves. Fishes are also confinedto the mangrove habitat because it provides them with both food and shelter.The muddy floors are home to amphibious mud-skipper fishes. Avifauna love mangrove forests because they provide a safe haven for them. They use mangroves for roosting, breeding, and food. These ecosystems are home to a variety of birds, including the little cormorant, grey heron, egrets, and grey pelicans.
4) LIVELIHOOD FOR COMMUNITIES:
The rural communities that live close to the mangroves depend on it for various commodities required to survive. Wood is a popular resource; the rural communities use to make handicrafts out of it or even as fire-wood. Many people use it for dyes, honey, wax, gums, resins etc. The leaves of Golpata (Nypa fruticans) and Hental (Phoenix paludosa) were once widely used in the Sunderbans for thatching hut roofs, making ropes, and making handicrafts.
To sum up, mangroves protect us from natural calamities like hurricane winds and cyclones, its home to millions of species and they also reduce carbon emission. This saves the government millions of dollars which would’ve been required in case of a natural disaster or to reduce carbon emissions. Restoration is possible and a must! In 2021, we have a plethora of alternatives to almost every problem, the issues related to mangrove deforestation are solvable, for instance, aquaculture can be done in a controlled manner without farming the mangroves, timber can be replaced by recycled wood/plastic and much more. Scientist have been warning us about the catastrophic events that may happen in the future due to global warming. If we start rehabilitating now, we might have a chance at maintaining our ecosystem.