Question

how does the concentration of pesticides and fertilizers increase in the waterbodies???

Answer 1

Fertilizer contains chemicals that causes water pollution. Farmers are used fertilizers in their agricultural field to increase their crops production. When it's raining chemicals in the fertilizers are flew into water. These leads to water pollution. Fertilizer contains nutrients such as nitrogen and phosphorus. Excess amount of nutrients leads to algal growth. These algae uses oxygen in water. So this is harmful for aquatic life.