The East Kolkata Wetlands (22024-22036' N latitude to 88023'-88032' E longitude) which is having the area of approximately 125 square kilometers consist of several fish farms. A large amount of fishes are grown in these farms and their growth depends upon the sewage water which is highly enriched in nutrient. And at the same time sewage water is also treated naturally. The wetlands have been designated as a RAMSAR site because of its important ecological significance. But the problem is that the fish ponds are decreasing their depth because of sedimentation which needs to be removed to keep the farms alive. The present study is to analysis the sediment quality in terms of the concentration of harmful heavy metals like Pb, Cd, Zn etc. and nutrients present in it. The research work actually justifies whether the soil has any harmful effect on fishes or not as eventually those are consumed by thousands of people. Study also finds the appropriate places where the excess soil is to be utilized. For the study three fish ponds were selected and 30 soil samples from each pond were collected randomly and tested carefully after required processing. The result shows that the soil contains very high amount of available primary nutrients like nitrogen (varies from 161 to 298.2 ppm), phosphorus (varies from 87.5 ppm to 158.5 ppm) and potassium (varies from 275.9 to 351.35 ppm) which is more and more high than most of the agricultural land and can be used for agricultural field preparation. The study also reveals that the heavy metals do not affect the quality of fishes grown in the farms.
Keywords: sediment yield, primary nutrients, heavy metals, quality analysis.