Explain biomagnification with the help of DDT in water i.e. in the food chain

   phytoplankton→zooplankton→small fish→big fish→human

Asked by sajal2402 | 23rd Feb, 2019, 06:30: PM

Expert Answer:

Biomagnification is a cumulative increase in the concentration of a persistent substance in successively higher trophic levels of the food chain. For example, if an organism is eaten by another organism, these substances move up the food chain and become more concentrated at each step.

Biomagnification of a toxic substance has the potential to cause harm to organisms, particularly to those at the top of the food chain.

 When the DDT consumption is through phytoplankton to the human, the concentration goes on increasing as the food chain goes on. 
1. The concentration of toxic chemicals and pollutants seem to be very low when released in different environments.
2. Phytoplankton are small plants that float in the seas that normally absorb these toxins.
3. Zooplankton consume the phytoplankton and thus take in the toxins, which stay locked inside them.
4. Whenever the small fish feed on the zooplanktons, they take up the toxins, which get absorbed in their fatty tissues. The accumulation occurs and the concentrations build up to about 20 parts per billion
5. When the large fish consume the smaller fish for food, they consume the toxins that accumulate in their fatty tissues. The concentrations become higher up to ranges of 80 to 100 parts per billion. 
6. The levels of concentrations in the top level organisms such as big fish or humans increase to the highest ranges of 10,000 to 15,000 parts per billion. Humans become more susceptible to cancers, liver and kidney failure, respiratory disorders, etc.

Answered by Sivanand Patnaik | 24th Feb, 2019, 12:07: AM