Sundarbans: Pollution and Resultant Vulnerabilities


The Sundarbans – the largest contiguous mangrove forest in the world – is an area which has reached critical levels of exploitation and exhaustion through human activity, similar to something like Western Ghats and Himalayas in northern parts of India.

Source: IUCN 2017

Let us proceed step by step to better understand what is going on in this marshy swamp which spans from the Hooghly river in West Bengal to Baleswar river in Bangladesh. We shall first look into the internal processes of the Sundarban ecosystem – both in-situ and ex-situ – and their corresponding outcomes. Secondly, we will highlight incidents of polluting businesses operating in this freshwater swamp and how this pollution is deteriorating the site and its intrinsic value. Thereafter, we would explore few lethal vulnerabilities arising specifically due to these polluting-industries in and around Sundarbans and try to find a convincing way out to manage the same. Lastly, we will delve into the relationship between cyclones and these mangroves, to highlight the critical role played the latter in mitigating damage.

Causes of Degradation

Before entering into the environmental processes present in the ecosystem of this mangrove forest, let us take a cursory look at its geography. Sundarbans is a marshy delta with an area of around 10,000 sq. km2, with 60% of it in Bangladesh and the rest falling in India. Rivers like Ganga, Brahmaputra and Meghana drain and deposit all of its silt into this marsh. The ecosystem is unique in the sense that the freshwater rivers and saltwater from the Bay of Bengal confluence and have developed an endemic and enriching biosphere.

[Indigenous Tribes] are one of the internal causes of degradation, but they know and have practised the concept of ‘sustainability / inter-generational equity’ since ages.

Internal Threats

Indigenous Communities

Let us look into the processes of this ecosystem. These processes are multiple, on-going and pose a high threat to the ecosystem of Sundarban. Firstly, there are indigenous communities habituated in the heart of Sundarbans since the last 200 years. Bluntly put, they were forced here from the neighbouring parts like Jharkhand, Chhattisgarh and Odisha by the British government to bring more land under cultivation and taxation. After many generations, they have come to terms with life here, using the mangroves for firewood, fuel, food, fodder and fibre needs of their daily lives. This is one of the internal causes of degradation, but tribes know and have practised the concept of ‘sustainability / inter-generational equity’ since ages. Yet one still cannot discount its role in contributing to degradation.

Deterioration from Non-Human Sources

Firstly, the mangroves have a specific type of root-system developed naturally to adapt to the highly saline water and anaerobic conditions present in the swampland. This exposes the roots to diseases and makes it not only susceptible to damage from other organisms, but also drying out as unlike other plants their roots are not protected by the soil around it.

Secondly, the Himalayan rivers which drain into the Sundarbans mentioned earlier run a long path, and hence are utilised by a lot of people, settlements, and states in the upper-riparian areas. Even with their perennial flow, the river regime drastically fluctuates in the lean-summer seasons, adversely impacting the freshwater requirement of the mangroves downstream.

The third threat which is not caused exclusively by humans is from seawater entering Sundarbans from the Bay of Bengal. As this is a Bay, the water gushes in with large force. They are geographically known as tidal surges, distinct from the daily ebb and flow of high and low tide. These surges are intense during seasonal monsoons and annual cyclonic conditions, and exacerbate already on-going coastal erosion.

The aforementioned represent prominent and persistent internal natural causes of degradation. There have been at play since ages, being documented in historical literature dating back to 2nd century AD.

Knowing that so many high polluting factories of such huge scale operate in the locality, it is an easy guess where all this pollution load is going to end up.

External Threats

There are also processes that are external to the Sundarbans, these were not fully known till India and Bangladesh both started exploiting it beyond the natural handling capacity of the swamp.


Mongla Port, located strategically in the south-west part of Bangladesh, is the reason for inconsiderate industrialisation in the Bangladesh-governed part of Sundarban. There are several cement manufacturing units, one oil & gas refinery plant, huge leather processing plant, and a controversial Thermal Power Plant to be built with expert mentoring from the Indian Government. Due to all such big-ticket projects located in this ‘Ecologically Critical Area’ (ECA) – a status accorded by the Bangladesh – the port is buzzing with activity and cargo movement. To make the point clearer, let us look at the finding of the 2015 Feasibility Study for Mongla-Special Economic Zone (SEZ) outsourced to PricewaterhouseCoopers which stated the situation as ‘potentially alarming’. The reasons for this were stated to be the absence of an effluent treatment plant, a drainage system and waste water treatment plant. Knowing that so many high polluting factories of such huge scale operate in the locality, it is an easy guess where all this pollution load is going to end up.

Tiger Prawn Fishing

Recently, there were studies conducted by environmental groups on both sides of Sundarbans. One of the Marine Scientists involved in one such study by Jadavpur University, Mr. Abhijit Mitra, said,

the low salinity and intense Industrialisation in the Hooghly Estuarine stretch is responsible for the high concentration of heavy metals in the muscles of life under water like Shrimps. This was found in the samples collected from stations in and around western side of Sundarbans.

If this is the case with the relatively lesser industrialised portion of Sundarbans, what will be the status of wildlife in and around Mongla?

Now, shrimp farming is an activity which is natural to the region, but it has hidden costs on the forest life. People have been traditionally farming the famed Tiger Prawns in Sundarbans without creating an imbalance in the ecosystem of Sundarbans. However, as the marine product started to receive concentrated market attention domestically and in South East Asia, many big business houses like TATA, ITC, Britannia & Hindustan Lever entered the Sundarbans around late 1990s. For improving the exports in volumes – a priority during the liberalisation of the Indian economy – these giants were given a free pass to do as they fit necessary. This resulted in indigenous shrimp farmers substituting traditional techniques for intensive machinery. Everyone won but nature. The consequence was rampant erosion of mud-dykes and weakening of the mangrove root system which ultimately affected the fish population and dependant food-chain. One guesstimate says that fishing will not be a viable vocation in the Sundarbans after 5-7 years (ICSF 2014).


The waters around this forest has been used for shipping since the days of British Raj. But things have changed in magnitude and intensity with corresponding developments in technology. Constant shipping has been a threat, the carelessness of which was represented by the oil spills in 2014 and in 2015. Around 500 tonnes of heavy fuel leaked into the river waters. This, fortunately for the polluters, happened in the Bangla waters, letting them escape from Indian scrutiny. Shocking pictures of dead animals, oil-soaked plants and thick layers of oil floating over water rocked the newspapers and other media. No independent study of the damage caused to this sensitive mangrove forest was ever conducted.

Let us ascertain the outcome of all such spoiling of the beautiful forest. We shall make it simpler here to understand through tabulating the causes and results. For time being, we only enlist the anthropogenic one, as they are the real culprits that need timely and adequate regulation.

1.Rampant Industrialization & Rapid UrbanizationHeavy Metal Pollution
2.Chemicals used by Agri & Aqua-culturistArtificial Eutrophication
3.Tourism & EntertainmentSolid Waste/Plastic Pollution
4.Senseless ShippingOil Spills

Cause and Result of Anthropogenic Activities in the Sundarbans

All the above-mentioned results have made a huge impact on the ecology. These are nothing but adverse and unwanted by-products of the senseless push for indiscriminate economic development. This has made the place and its people very vulnerable in the following dimensions.

As pollution crossed a manageable threshold, vulnerabilities rise up in scale or scope. Thus, disturbing the systems internal mechanics.

  1. Ecological
    • Rising Sea-levels, Salinity & Habitat Loss.
    • Drop in Primary Productivity, Biomass Production & Death of Endemic Species.
    • Bioaccumulation & Biomagnification in the food web.
    • Declining Mangrove Diversity, both in size and quality causing serious threat to Carbon Sequestration Potential.
  2. Meteorological
    • Extreme & Severe Weather Events like the recent Amphan cyclone.
  3. Economic
    • Uncertain Livelihood & Outmigration due to negative spillover effects on fishing, boat-making, fish marketing, honey harvesters etc.
  4. Human – Social
    • More stress on the already strained quality of life.
  5. Political
    • West Bengal Politics has already drifted away from the mainstream and with mismanagement of disasters, the people & elite might feel more estranged.
  6. Strategic
    • What if China enters with ‘Environment Aid’ for Bangladesh and stirs tension in our backyard?

Amidst these multi-dimensional vulnerabilities, we can explore and explain most of them. But recent events coinciding with the topic attains highest weightage in terms of importance –the Amphan cyclone. This would be juxtaposed with the 2019 Bulbul cyclone along with others to project its impact.

Cyclones and the Sundarbans

The super cyclone Amphan which gusted across Sundarbans, caught national attention and opened up the islander’s suffering from recurring-extreme-intense natural disasters. A cyclone impacts everyone indiscriminately, but not everyone can withstand and recover at the same time and at the same pace, and the slowest of all is the natural geographic entities. As pollution crossed a manageable threshold, vulnerabilities rise up in scale or scope. Thus, disturbing the systems internal mechanics.

Mangroves are the real game-changer when it comes to direct emergency response to cyclonic winds and storm waters. Last year, many such mangrove-lands faced the cyclone, sacrificed themselves and saved the crowded cities.

Below is some data to highlight the destruction of mangroves over the years by different causes which allows us to see the losses and immaterial toll on Sundarbans and surrounding areas caused by cyclones.

  • A 2012 study by the Zoological Society of London (ZSL) found out that the Sundarban coastline was retreating about 200 metres every year.
  • Agricultural & allied activities have destroyed up to 42,450 acres of mangrove land from 1975 – 2010.
  • Shrimp cultivation & Hatcheries business have destroyed over 18,670 acres.
  • Rising sea-levels have submerged around 19,000 acres of forest land.
CyclonesDeathsDamage ($USD)Environmental
Sidr 20073447 – 15000~2.3 billion40% of Sundarbans was damaged. Mangrove Recovery could take 40 years to pre-Sidr levels.
Aila 2009~ 339~1 billionSundarbans flooded with 6m of water height. Endangered tigers along with crocodiles and deer drowned.
Bulbul 2019~ 413.3 billionMangroves reduced wind-speed (~20kmph) & broke waves, protecting the Delta and the city of Kolkata from devastation anticipated to be high. Parts with less mangrove density were badly affected. Mangroves themselves suffered widespread damage.
Amphan 2020~ 128>13 billionSundarbans affected as follows: Storm Surge of ~5 metresFlooding extended 15km inland
Profile of damage from past cyclones in the Sundarbans and adjacent areas

We see that the number of lives lost relative to property damage has decreased over the years, indicating how we have not yet forged a way to protect property – the loss of which has quadrupled in the same span. One inference which green activists and experts have been shouting out loud for many years, the knowledgeable words of whom have fallen against purposely-deaf administration and the least-interested media. The inference has finally been acknowledged since the Bulbul cyclone i.e. Mangroves are the real game-changer when it comes to direct emergency response to cyclonic winds and storm waters. Last year, many such mangrove-lands faced the cyclone, sacrificed themselves and saved the crowded cities.

In disaster management studies, a disaster management cycle is used to address any such emergency. The first, and the most important stage in that cycle, is ‘Response’. This stage is vital because it is operational at the time when damage is occurring, when natural forces interact and effects are underway. Mangroves face what man cannot! They slow-down the gushing force of air and die out in the process. They are the first line of action before any humans come into the scene. It is time we collectively realise their importance and plan to develop their mitigating capability.


We must be aware that people are differently placed in terms of vulnerabilities, resources, and resilience. Thus, our action should focus on helping equitably the weakest more than the ones who are better-situated, with the time of grassroots action being in-between two cyclones or other disasters. The indigenous communities, business groups, local officials, state-level policy and trans-national cooperation must work in concert to ensure that the Sundarbans remains as a lively ecosystem, with each one of them acting consciously and responsibly for greater good.

(Akshay is a researcher by inclination and chemist by training, who has spent the last decade knowing ‘what’ of life and plans to experience the ‘how’ and ‘why’ in upcoming ones. He is interested in Waste2wealth ideas. You can reach him at


ICSF. 2014. “The Sundarbans Fisheries: Coping in an Overly Stressed Mangrove Estuary.” Disha Earth. December. Accessed July 24, 2020.

IUCN. 2017. IUCN World Heritage Outlook. November 09. Accessed July 24, 2020.

Schwartzstein, Peter. 2019. “This vanishing forest protects the coasts—and lives—of two countries.” National Geographic Magazine, July.

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