The ecologically subsidised city

The ecologically subsidised city

Context:

•  Kolkata’s wetland conservation and ecological importance

Rural ecological reference:

•  A renowned environmentalist discovered that kolkatas waste water is detained in shallow water bodies which serve as oxidation ponds because of the presence of algae.

Under the open tropical sun

• Ghosh discovered that water undergoes change, getting comprehensively treated and cleaned as the bacteria disintegrate and the algae proliferate, serving as food for fish.
• The treated water is used by villagers in the area to grow vegetables and paddy.

Significance of discovery:

•  It is considered a remarkable ecological wisdom on the part of largely illiterate villagers, based on knowledge of local conditions and wetland hydrology.

Ramsar site:

•  The 125 sq km area of the wetlands were recognised internationally in 2002 as a ‘Ramsar site due to the efforts of Ghosh.

World’s largest organic sewage treatment plant:

• Kolkata is fortunate to be home to the world’s largest organic ‘sewage treatment plant’, the wetlands.
•  Unobserved by the rest of the world, sun-fed algae and the bacteria in the sewage perform this wondrous function.
• The capacity to treat 750 million litres of wastewater per day. In monetary terms it would be over $25 billion (Rs. 162,500 crore) annually.
• These wetlands are also home to a wide variety of aquatic life, vegetation, and hundreds of species of birds

UN Millennium Ecosystem Assessment

• In 2005, the UN Millennium Ecosystem Assessment found ecological degradation to be more prominent within wetlands than any other ecosystem on Earth.