The pollution level of heavy metals in surface waters of Bangladesh is
increasing rapidly due to unplanned urbanization, industrialization and
uncontrolled use of agrochemicals. The insufficiently treated waste
disposed from various industries into the river water makes serious
problem to aquatic flora and fauna. Photosynthetic activity is inhibited in
polluted water due to reduced light penetration. The elevated pollution
level is a great threat to human and animals all over the country. Fish
production and availability is badly reduced in polluted water