Trophic state of a lake is determined by the amount of biologically useful nutrients dissolved in the waters of the lake.
A lake or a water body may be oligotrophic, eutrophic, mesotrophic and hypereutrophic.
An oligotrophic lake is a type of lake that has a low productivity due to low nutrient content in the lake. Waters in these types of lakes are clear due to a limited growth of algae in the lake.
