Eutrophic systems are depicted as ponds with lots of algae grown and a high oxygen content. Oligotrophic systems have less oxygen and very little algae growth. In water quality tests, Eutrophic systems often have higher amounts of oxygen, high amounts of nutrients and low levels of clhlorine. Where as in an oligotrophic system the water will have lower amounts of oxygen and nutrients but will not always have a greater amount of chlorine.
A eutrophic system, notice the high amount of algae.
A oligotrophic system, notice the lack of algae