Holt Modern Biology 1st Edition by John Postlethwait ,Janet Hopson

Exercise 5

Ecologists recognize the following ecological zones in the ocean: photic , aphotic , intertidal , neritic , oceanic , pelagic , and benthic.
Part A Describe the factors used as a basis for distinguishing the zones.
Part B Relate these factors to the types of organisms that inhabit each zone.