Recovery of Sundarbans through Mangrove plantation

In 2009, Cyclone Alia unleashed a devastating wave of destruction along the Eastern coastal belt of India, with West Bengal and Odisha bearing the brunt of the impact. Subsequently, the region, especially the Sundarbans, has endured the wrath of several cyclones, including Amphaan, Yaas, and Fani.

Moved by the devastating aftermath of these natural disasters, the West Bengal State Forest Department, in collaboration with experts and numerous NGOs, embarked on an innovative and proactive journey to restore ecological equilibrium and sustainability. Their method of choice: extensive mangrove plantation initiatives.

The name Sundarban finds its origin in the lush Sundari trees, scientifically recognized as Heritiera Littoralis, which once thrived in the region. These trees are part of the mangrove plant family and once dominated the landscape. However, human intervention, especially in the form of tourism infrastructure development by government and private entities, has taken a toll on the delicate ecosystem of the Sundarbans. This disruption has unfortunately led to the gradual decline of the beloved Sundari species. Nevertheless, the Sundarban Delta continues to host around 90 other mangrove species, showcasing its resilience and rich biodiversity.

Effect of deforestation on Mangroves

Over the years, deforestation has had a range of detrimental effects, notably including increased soil erosion. This can be attributed to the absence of mangroves, which are equipped with deep roots that effectively anchor the soil and prevent erosion during high tides in rivers. The removal of these mangroves has resulted in the loss of these crucial root systems, depriving the soil of its stabilizing support.

One of the consequences of mangrove deforestation is the elevated release of carbon dioxide into the atmosphere. This occurs because mangroves serve as essential natural carbon sinks, absorbing four times more carbon than typical tropical forests. We are now planting certain types of mangroves, such as the Keora and Chak Keora, along with three other mangrove species, in the Hooghly River.

In an interview with Ground Report, Dr Swati Nandi Chakrabarty, the Head of Life Sciences at GuruNanak Institute of Pharmaceutical Science & Technology, explained that these plantations are expected to significantly reduce carbon levels in the air, and an estimated reduction of 37% is anticipated.

She further added, "It is projected that these positive impacts will become noticeable within four years, assuming that everything progresses according to plan. The benefits of these plantations will extend to the citizens of Kolkata, functioning as carbon sinks, effectively mitigating pollution and reducing the frequency of heatwaves. Additionally, they will play a crucial role in facilitating adaptation to climate change."

Carbon Sequestration through Photosynthesis

In an interview with Ground Report, Professor Dr Ashish Kumar Paul, from the Geography Department at Vidyasagar University, elucidated the role of mangroves as carbon sinks. He described how mangroves absorb carbon through photosynthesis and store it in their submerged roots, referred to as "blue carbon."

He added, that the previous tidal flatlands and mangrove forests covered an expansive area of approximately 9,600 square kilometres, but this region has now dwindled to a mere 2,200 square kilometers.

Dr. Paul also mentioned the collaborative endeavours aimed at rejuvenating this lost forest land and natural habitat. The West Bengal State Forest Department partnered with numerous NGOs and actively participated in World Environment Day on June 5, 2023. One noteworthy NGO deeply involved in these efforts is the Purbasha Eco Helpline Society, which has been actively engaged since 2010, with support from international organizations like the World Wildlife Fund. The society is under the capable leadership of Mr. Umashankar Mandal, affectionately known as the "Mangrove Man."

He further elaborated on the Sundarbans Delta, encompassing the National Park, housing the tiger core area, and the Biosphere Reserve, where people reside. Researchers, in collaboration with NGOs and local villagers, conduct field visits to collect crucial information about the region and the well-being of mangroves and other species. All these endeavours are diligently supervised by the State Forest Department.

Tiger conservation and Habitat goals

The department had two primary goals: animal conservation and habitat preservation. Animal conservation primarily focuses on tiger preservation and securing their habitat. Each tiger necessitates its corridor area, a food source, and space for various activities.

By calculating the required space for a tiger to thrive comfortably in its natural habitat and expanding the corridor area, we aim to mitigate the frequent incidents of tigers venturing into villages and becoming man-eaters. This habitat restoration project commenced in 2020 and is still ongoing, with substantial support from the Central government.

The Professor highlighted the collaboration between the West Bengal Government and researchers in planting mangroves within the Sundarbans Tiger Reserve. The government distributed mangrove seeds and employed locally cultivated saplings. This initiative not only provided a sustainable income source for the locals but also offered ecological benefits.

The project's goal is to afforest approximately 2.74 square kilometres of land within the Tiger Reserve over three years. Plantations were thoughtfully situated in areas with favourable environmental conditions, particularly in mudflat regions. The government identified potential plantation sites using satellite imagery, while researchers conducted fieldwork.

Various experiments, including chlorophyll analysis, affirmed the project's success in enhancing plant health. Consequently, this afforestation effort expanded the core area of the Tiger Reserve and introduced two additional beats in 2022-23, showcasing its positive outcomes.

Importance of the Ecological Buffer Zone

Rural residents in the biosphere reserve have rights to natural resources. Educating them about the benefits of mangrove plantations can foster a sustainable community.

The ecological buffer zone, the land area situated between the National Park and residential areas, plays a vital role. It spans the southeastern regions of various blocks, from North 24 Paraganas to South 24 Paraganas districts, and encompasses the tributaries and distributaries of the Ganga, primarily the Hoogly, Saptamukhi, Matla river, Jamila river, Thakuran river, Gosaba river, Haribhanga river, Raimangal river, which are essential for silt deposition and freshwater supply. These factors create tidal flatlands where mangroves thrive.

However, due to human interference, the freshwater supply and silt deposition have dwindled from 90% in past decades to just 10% today, posing a severe threat to the mangroves. This is a pressing issue that requires immediate attention. Researchers and NGOs are actively engaged in addressing this matter and working toward a solution.

To tackle this issue, establishing buffer zones along the boundaries of these block islands, with a minimum width of 500 meters, can significantly reduce the impact of tidal surges during cyclones and thunderstorms.

Community participation is essential for their welfare, safeguarding their agricultural lands and the telecommunications infrastructure in the main areas. When executed effectively, this approach can temporarily alleviate human migration resulting from climate change, offering additional time for relocation.

Mangrove plantations provide locals with an income source by cultivating saplings alongside their agricultural activities. The government and NGOs play a pivotal role by purchasing mangrove saplings and seeds from them, establishing sustainable income sources.

Bay of Bengal's Climate Signs

In recent times, nature has displayed signs of climate change in the Bay of Bengal, particularly through an increased frequency of deadly cyclones. Favourable conditions for mangrove growth are now evident along the Hooghly River near Kolkata, a phenomenon not observed a few years ago. This is nature's way of illustrating its attempt to adapt to climate change. We must take this as a lesson and adapt promptly.

Initiating these efforts, several NGOs, in collaboration with researchers, schools, and colleges, have united to plant various types of mangroves known for their effectiveness in mitigating air and water pollution, reducing heatwaves, and sequestering carbon.

"Among the most suitable species for the metro city and its surrounding suburban areas are Chak Keora, Ora, and Keira mangroves. Nurseries in the Sundarbans raise saplings of these species and later transplant them here.

We have already established plantations along the banks of the Hooghly River in Chandannagar and Outram Ghat in Kolkata, and we are currently planning to disperse seeds in the canals of Khidderpur, Baranagar, and Alipur.

Research has identified these favourable conditions. However, it's essential to regulate and monitor their growth in the coming years," concluded Prof. Dr. Ashish Kumar Paul of Vidyasagar University.

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