While the world’s supply of wetlands and intertidal zones continues to shrink, there are still some large examples of this vital habitat. If you want a big wetland, it helps to have a big river mouth. And it really helps to have three big river mouths together, so the region where the Ganges (Padma), Brahmaputra and Meghna rivers all converge and empty into the sea is sort of a mega-delta. This enormous feature is shared by coastal Bangladesh and India. Mudflats, and low elevation farming cover vast stretches of the region. One part of this huge wetland is called the Sundarbans. It is defined by its forest of mangrove and other salt-tolerant trees such as the sundari. The name itself means “beautiful forests,” and it covers around 3,900 square miles, making it the world’s largest mangrove forest. A labyrinthine network of rivers and streams course between innumerable islands in a landscape providing a huge wealth of aquatic habitat. Indeed, it is so special and valuable that it has been declared a UNESCO World Heritage Site, and India has preserved part of it as a national park.
Mangrove forests, as longtime Geo-Joint readers will recall, are coastal forests growing in salty or brackish water. The root systems on some species look like long spider legs, keeping their trunks above water. These interlocking “legs” create safe zones for fish and anchor the easily eroded soil. Another 300-plus species of trees, shrubs and epiphytes grow there on marshy or solid ground, depending on their adaptations. In its totality, the forest acts as a habitat for a rich variety of animals on water, land, and air which include primates, deer, abundant bird life, otters, crocodiles, pythons, two rare species of freshwater dolphins, and the region’s most famous inhabitants, tigers.
The tigers in the Sundarbans are Royal Bengal tigers and though their numbers there have fallen to 100, the region is still the site of their greatest concentration. Feared as man-eaters by the local population, an average of 50 people a year die in tiger encounters; in some years it has gone as high as 170. Despite the danger, the area’s residents believe the tigers are protectors of the forest and so respect and appreciate their presence. Indeed the tigers are the long-term losers in this game as their habitat increasingly shrinks due to deforestation and other land-use pressures. The Sundarbans tigers are different in habit from their brethren who are mostly scattered across the vastness of India. Living as they do in such a saturated world, these tigers have become fully accustomed to spending a lot of time in the water, and are excellent swimmers.
The Sundarbans provide more than natural resources and wildlife viewing possibilities. As with any large body of vegetation growing in a low coastal environment, the biomass alone acts as a shield against wave damage from the sea. Root structures help hold precious silt and mud in place against the erosive forces of water. Bangladesh has no shortage of water-themed disasters. Its many rivers can deliver floods of epic proportions, and the Bay of Bengal, south of the Sundarbans, acts as a funnel for typhoons that roar northward out of the Indian Ocean. High waves, storm surge, and increased river flow from monsoonal rains can inundate thousands of square miles, wreaking havoc on coastal communities. The forests and swamp vegetation at least mitigate the destruction, and such biomes are designed by nature to bounce back from harsh weather events. Whether that will continue to be the case as sea level quickly rises and climate change brings more powerful storms remains to be seen.
Threats to the Sundarbans and its denizens are not limited to natural disasters. Logging, draining swampy areas for buildable land, and the development of coastal shrimp farms eat away at the habitat. In 2014, a tanker wreck spilled nearly 100,000 gallons of fuel oil into the waters at the north end of the Sundarbans, meaning its damage could flow south creating a long, oily path. Though fears of widespread destruction were not realized, the accident underscored the need for more stringent vessel traffic standards in and around the Sundarbans. Not much progress in that regard has been made, and in 2015 an overloaded cargo ship capsized and spilled its load of potash fertilizer. Increasing ship traffic and other human pressures will test the environment’s ability to absorb such abuse. It’s another reminder that paper proclamations of special status don’t protect nature’s treasures as much as does the dedicated stewardship of those who have a stake in its survival.