Question

With the help of a flow chart, show the phenomenon of biomagnification of DDT in an aquatic food chain.

Answer 1

• DDT is the most commonly known pesticide which kills pests like mosquitoes, fleas, house flies and bugs.

• On a long run, DDT has proven to be harmful to both man and environment.
  
• DDT sprayed in farms get settled in the soil. It gets percolated into the deep layers of the soil with water used in irrigating the field. Slowly, it reaches ground water.
  
• When the agriculture waste is dumped into water bodies, DDT enters water resources.
  
• It is a non-biodegradable substance that gets accumulated in the food chains. DDT being toxic and interrupting the food chain by accumulation causes biomagnification.
  
• It is absorbed by aquatic organisms like small planktons.
  
• When these planktons are consumed by fish, DDT gets accumulated in the body of fishes that feed on them.
  
• Fishes in turn pass on DDT to the birds that prey on it. In birds, DDT prevents formation of egg shell, leading to breaking of eggs even before they can hatch. Ultimately, the organisms which occupy the highest trophic level suffer the most.