Mangroves anchor the edges of the world, but they are slipping away, thanks to coastal development, pollution, over-harvesting, nutrient loading, overuse of freshwater, and climate change.
The world’s largest intact halophytic (salt-tolerating) mangrove forest is the Sundarbans, a UNESCO World Heritage Site that straddles India and Bangladesh. It forms the transition zone between the Ganges and the Bay of Bengal, and is a stronghold for the endangered Bengal tiger, as well as many other species, from monkeys to crocodiles.
However, as a recent report by Dr. Md. Mizanur Rahman warns, these mangroves are in trouble. They face rising temperature, rising seas, silt and pollution washing down from deforested areas in the Himalaya, and pressures from aquaculture activities around the Sundarbans.
They are also being assaulted by rising salinity, brought by the formerly fresh rivers and streams that feed them. As agriculture increases in the region, water levels drop, minerals accumulate, and salinity rises. Brackish water is also expanding underground.
The fate of the Sundarbans mangroves lies both in how they can be protected locally, and in the health of the whole Ganges system. What happens upstream affects what comes down the pike.