If the concentration of DDT in zooplankton measures 0.04 parts per million, what is the approximate concentration of DDT at each other trophic level shown?

If the concentration of DDT in zooplankton measures 0.04 parts per million so the concentration of DDT in the next trophic level is 0.004 parts per million.

Explanation:

The concentration of DDT in the next trophic level is 0.004 parts per million because we know that in the ecosystem only 10% of the energy is passed from one trophic level to another while the 90% of the energy is lost in the form of heat energy. So if the DDT concentration in zooplankton is 0.04 ppm so the next trophic level has 0.004 ppm DDT.

the peaceful equids (horses, donkeys and zebras) were enslaved by the human race to do our bidding -- sorry, domesticated -- several thousand years ago, and since that time they've been an invaluable resource for transportation, agriculture, warfare, companionship and sometimes-horrifying entertainment.