Observe figure and answer the following questions.

(i) The ecological term used to describe the DDT accumulation at different troohic levels ?
(ii) List any one effect of DDT accumulation on birds.
(iii) Will DDT accumulation lead to eutrophication ?
(iv) Does it affect the BOD?
(v) Name disease caused by accumulation of any heavy metal.

Explanation

(i) The ecological term used to describe the DDT accumulation at different trophic levels is called biomagnification.
(ii) High concentrations of DDT distueb calcium metabolism birds , which causes thinning of egg shell and their premature breaking, eventually causing decline in dird populations.
(iii) Yes, DDT accumulation can lead to eutrophication.
(iv) It increases the BOD, resulting in a decrease in dissolved oxygen in the water body.
(v) Eating fish that has accumulated mercury, a heavy metal , causesa a disease called Minamata . It is characterised by diarrhoea , heamolysis , numbness , deafness, mental derangement, meningitis and death.