Sea erosion shrinking Sundarbans forests

Sundarbans being monitored with a drone

The Sundarbans, the world's largest mangrove forest and a UNESCO World Heritage Site, is facing an alarming threat as relentless sea erosion steadily devours its landmass, displacing communities, destroying infrastructure and shrinking the forest..

Spanning the delta region of the Padma, Meghna and Brahmaputra river basins, the Sundarbans is a crucial ecological zone shared between Bangladesh and India.

It is home to rich biodiversity, including the endangered Royal Bengal tiger. But continuous erosion is rapidly reshaping the landscape, with islands and coastal land disappearing into the sea.

Vanishing Land and Lost Infrastructure

Jetties, Forest Department offices and other vital infrastructure are being washed away, forcing officials to abandon their posts.

In September last year, the East Sundarbans Division sought assistance from the Bangladesh Water Development Board (BWDB) to curb erosion at nine vulnerable locations.

Although sand-filled geo bags were placed in front of the Forest Office to mitigate the damage, the measure has largely proven ineffective.

According to sources in the Forest Department, the situation has worsened over the years, swallowing entire forested areas along with their trees.

The jetty at the Dubla Forest Office, several drinking water ponds, cyclone shelters and freshwater reservoirs at Meherali Char have already been lost to the rising tides.

Meanwhile, the old rest house and jetty at Katka have disappeared, and the two-storey Bogi Forest Office building is on the brink of collapse into the river.

“The forest land is continuously being destroyed, and many trees have already vanished. The old rest house at Katka has gone into the sea, and numerous areas deeper into the Sundarbans have been submerged,” said Soyebur Rahman Suman, in charge of the Katka Sanctuary Centre, a popular tourist spot in the Sundarbans.

A Sabur, an officer at Bogi Forest Station, echoed similar concerns. “Our office-cum-barracks are also at risk of being submerged. Staff have been forced to move to alternative shelters to avoid further danger.”

Despite efforts to control the damage, the situation has not improved. “The Water Development Board placed sandbags in September and October last year to prevent erosion, but they have not been effective,” added Sabur.

Nine Critical Zones Under Threat

Forest officials have identified nine key locations that are severely affected by erosion: Kachikhali Sanctuary Centre, Katka Sanctuary Centre, Chandeshwar Patrol Outpost,        Jelepalli Dubla Patrol Outpost, Bogi Forest Station, Jhapsi Patrol Outpost, Jongra Patrol Outpost, Karamjal Wildlife Breeding Centre and Shuarmara Patrol Outpost.

Rana Deb, Sharankhola Range Officer of the Eastern Sundarbans Division, noted that while some forest areas are eroding, new chars (sandbanks) are forming in other river regions. But this offers little consolation given the immense destruction already suffered by the Forest Department, particularly after Cyclone Remal.

Funding Shortages Hindering Protection Efforts

Abu Raihan Md. Albunni, Executive Engineer of BWDB in Bagerhat, admitted that financial constraints have hindered further erosion prevention efforts. “Sand-filled geo bags were placed in front of Bogi Forest Station, but due to budget limitations, no action has been taken in other erosion-affected areas,” he said.

Divisional Forest Officer of the East Sundarbans Division, Kazi Muhammad Nurul Karim, expressed grave concern over the worsening crisis, attributing it in part to climate change.

“We sent a letter to the Executive Engineer of BWDB in September last year, requesting urgent intervention at nine locations. Although some geo bags were placed in Bogi, they were ineffective in halting the erosion,” he said.

Alarming Shrinkage of the Sundarbans

A World Bank report, Coping with Climate Change in the Sundarbans: Lessons from Multidisciplinary Studies (2020), presents alarming evidence of the forest's shrinking footprint. The total area of the Sundarbans (including both Bangladesh and India) measured 11,904 sq km between 1904 and 1924. By 1967, it had reduced to 11,663 sq km, and in 2016, it further declined to 11,506 sq km.

According to various sources, the Sundarbans is crisscrossed by approximately 450 rivers and canals, stretching about 350 km in total length. Natural tidal activity continuously reshapes these waterways, causing both erosion and deposition. However, the extent of land loss in the last century has far outpaced natural recovery, posing an existential threat to the forest and its inhabitants.

Need for Urgent Action

The relentless erosion of the Sundarbans demands immediate intervention from policymakers, conservationists and international stakeholders. Without robust mitigation strategies and sustainable erosion control measures, the continued loss of land will exacerbate climate vulnerability, displace more communities, and push the region’s fragile ecosystem further towards collapse. - UNB