Why mangroves are the need of the hour for our coastal communities
By: Suhas S
Tags: Global Warming, India, Data Science, Climate Adaptation, Climate Change

Why mangroves are the need of the hour for our coastal communities Suhas S Follow May 17 · 4 min read

Sea level rise has been an issue that the world has been forced to deal with over the past two decades. Since the start of the satellite record in 1993, it has been observed that global warming has caused in some ocean basins across the world a sea level rise as much as 6–8 inches (15–20 centimetres). The mean sea level rise between 2006 and 2015 has been 2.5 times the average rate per year. By the end of the century, the global sea level is likely to rise at least one foot (0.3 meters) when compared to the levels of the 2000s.

With the Decade of the Oceans (2021 -2030) on the horizon, now is the time to gather the science that is necessary for a safe ocean where people are protected from ocean hazards. One of the key actions that should be taken to ensure a safer ocean is to find ways to mitigate and adapt to the rising threat of global warming to the world’s communities based in and around the oceans.

The coasts of India get heavy rain in monsoons and this has in recent times caused massive issues (flooding, soil erosion, saline water inland). The coastal communities also face threats from the rise of sea levels and the projected increase over the next thirty years. Sea level rise causes erosion and pushes salty water upstream in coastal areas. Coastal flooding will grow more frequent and damaging. Low-lying islands will be at the risk of getting submerged completely and storms can get powerful. All these can ultimately lead to displacement of thousands of people and loss of livelihood. Even as storms become more intense due to climate change, walls along many of India’s vulnerable shore are insufficient to protect the thickly populated coastal areas.

Karnataka has lost about 22% of its coastline due to erosion, according to a 2018 study. Image — Times of India

Karnataka, one of the 4 southern states of India has a coastline of approximately 320 kilometres. With the IPCC (Intergovernmental panel on climate change) forecasting that sea levels in India will rise at the rate of 2.4mm a year and by 2050 to a total increase of 38cm, the forecast is grim. Karnataka with the major port of Mangalore and the fishing villages along the length of its coastline will be affected immensely by rising sea levels. If the rise is not managed and the risk mitigated by scientific solutions, the coming decades will see massive damages to coastal infrastructure, ecosystems and biodiversity. A 14.60cm rise in sea level is predicted for Mangalore which can cause large parts of its busy port to go underwater.

So what is the solution? How can the problems that global warming has brought to the forefront be addressed?

It must be kept in mind that well intended solutions can turn worst when interventions are carried out haphazardly. Data driven scientific approaches combined with natural solutions are the need of the hour to address these issues. Such solutions need to be prioritised to address the issues of rising sea levels in coastal regions as well as the issues of sustainable development and biodiversity management.

One of the important nature solutions we can look at are mangrove ecosystems.

While mangroves were previously dismissed as swampy forests with little to offer, the global consensus on these important ecosystem has changed. Preserving and restoring mangrove forests can be an extremely economically effective strategy for protecting coasts from tropical storm damage, research has shown. As older mangroves trees and ecosystems have been cut down, it is necessary to replant mangroves to regenerate the ecosystem.

A typical Mangrove ecosystem in a delta. Image — Pixabay

Mangroves can be a key contributor in turning the tide on these issues of global warming and oceans that we have mentioned previously. Cyclones which are common in the Bay of Bengal and in the Arabian Sea, which also lead to heavy rainfall and property destruction on the Indian coasts will benefit from having mangrove ecosystems which can protect against storm surges and high waves that can be destructive.

Villages protected by mangroves and other coastal vegetation in Tamil Nadu survived the impact of the 2004 tsunami better than those that did not have the same protection. Mangroves also provide protection against sea level rise because the soil platform under the mangroves plants continues to rise in height. The leaves from the mangrove plants fall into silt trapped from the water, and together the platform continues to rise. This can keep pace with the projected sea level rise and prevent inundation.

At the Blue Carbon Company, we specialise in using data driven AI solutions to map coastal regions which are most at risk due to rising sea levels. Identifying and quantifying areas that are at most risk helps to drive action plans to mitigate and adapt to them. We also look into data for coastal natural ecosystems such as Mangroves to provide solutions to address the most pressing issues faced by coastal communities and regions. We also use data to create value to other aspects of livelihood, biodiversity and other important ecosystem services provided by these coastal ecosystems.

While we are certain that data driven natural solutions are the way ahead to mitigate and adapt to the issue of global warming, we also strongly believe that for such measures to succeed, regeneration and replanting of mangrove ecosystems must be a community driven effort. A long term involvement of the local community of fishermen, farmers and coastal communities, coupled with short-term incentives can see such projects succeed and provide huge benefits for the community.