Stress of urban pollution on largest natural wetland ecosystem in East Kolkata-causes, consequences and improvement

The traditional practice of utilizing wastewater into fish pond is a unique example of sustainable socio-economic development pertaining to resource recovery in the Eastern Kolkata wetlands, a Ramsar site in India. This paper revealed the stress of urban pollution and poor land use planning on the world’s largest natural wetland. This is the first time to critically evaluate dynamics of oxygen demanding substances, nutrients and solids in waste water canal and fish ponds. This paper sheds some lights on absorbance of oxygen demanding substances on TSS and their adverse impact on fish ponds. Based on this concern, barriers to maintain water quality of wastewater canal and fish ponds; and opportunities to improve resource recovery efficiency have been explored. This study also explored that the radical technological change for fish pond management would not be effective in the prevailing socio-economic condition. But incremental changes and proper coordination between the concerned authority and fish farmers can easily accelerate the fish yield, functionality of pond ecosystem and reduction of pollutants.