Question

A farmer was using pesticides on his farm. He used the produce of his farm as food for rearing fish. He was told that fishes were not fit for human consumption because large amounts of pesticides had accumulated in the tissues of fishes. Explain how this happened?

Answer 1

Pesticides are synthetic toxic chemicals with ecological consequences. Most pesticides are organic toxins, non-biodegradable and water-insoluble.

They are transferred from the lower trophic level to the higher trophic level because they are highly persistent. They enter into the food chain and hence possess potential harms for human consumption.

Pesticides from the soil are transferred into the crops, from the crops these are transferred into rearing fish food. Pesticides entered into the water through rearing fish food and finally entered into the bodies of the fishes.

Therefore, pesticides are transferred from lower trophic levels to higher trophic levels through the food chain. Over time, the concentration of pesticides in fishes reach a level which causes the serious metabolic and physiological disorder.