Due to increasing concentrations of ddt as one moves up the food chain, cormorants and mergansers have about times as much ddt residue as the background concentration in the water.

1 million 

Toxins will be accumulated in the higher level pyramid, this phenomenon is called biomagnification. The rate of biomagnification from water to producer approximately 1000 times, while the rate for every level above producer around 10 times. Assuming the bird is a tertiary consumer, the rate would be 1000* 10^3= 10^6= 1 million times

Competition. interaction among organisms that compete for the same natural resource (food, shelter, water, space) in an ecosystem. predation. an interaction in which one organism kills another for food. predator. prey. symbiosis. mutualisum. commensalisum. parasitisum.

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