Stunted mangroves too short to protect city
20 April 2008
KOLKATA, April 20: A recent study conducted on the stunted growth of mangrove vegetation in the Sundarbans spells doom for Kolkata and parts of south Bengal in the event of a major storm like hurricane Sidr.
The study comprising compilation of data regarding salinity, tidal amplitude, turbidity coupled with quantum of dissolved oxygen in the local river water points a warning finger towards the city and the unsuspecting inhabitants living in and around it.
The increasing siltation of the Hooghly river mouth is cutting down the amount of fresh water inflow in the rivers crisscrossing Sundarbans. This increases the proportion of salinity in the river water, the study conducted by Nature Environment and Wildlife Society (NEWS) said.
The rise in the salinity is adversely affecting the mangroves which act as buffers in case of storms. In fact, the presence of the mangroves had a considerable role in cutting down the wind speed of hurricane Sidr from 240 km per hour to 100 km per hour, decreasing the loss of life and property in Bangladesh.
But the rise in salinity on the Indian Sundarbans is already making its presence felt. Mangroves of the Sundari variety from which the area derives its name are becoming extinct, the NEWS study funded by the British Deputy High Commission, Kolkata said.
The more salt-tolerant mangroves like baine, garjan, kankra, hental are facing a different problem from the emerging situation. Stunted growth stares them in the face.
As a fallout of the increased salinity, they are no longer growing to the heights they once commanded. Once a strong storm lashes out, it is feared it would pass unchecked over the short trees, no longer acting as high green ramparts resisting the passage of the invading hurricane.
Some tall but not so strongly rooted mangrove clumps may stand in the way of the oncoming storm. But their once solid phallanx would be as good as “broken reeds” leading to devastating losses in terms of men and materials, the study said. But mangroves of Bangladesh Sundarbans stand thick and tall as the presence of greater fresh water inflow owing to lesser siltation does not affect its mangrove population. Unless the water quality changes in the Indian Sundarbans, a major ecological disaster awaits Kolkatans.
Source: Statesman News Service