The use of pesticides and fertilisers leads to soil pollution. These are often not easily biodegradable and so they accumulate in the soil and kill soil organisms. Rain water run-off may carry such chemicals into streams,rivers and lakes. These toxic chemicals can eventually find their way into the tissues of different organisms associated with aquatic ecosystem.
The accumulation of silt due to poor cultivation along the river banks and the destruction of riverine leads to soil erosion. The deposition of silt near the mouth of river makes the water turbid and so impedes the penetration of sunlight. This affects the aquatic organisms and pollute the water.
