A water body with extremely low nutrient content is called:

Concept

The trophic state of a water body is classified by its nutrient supply and the biological productivity that supply can support. Low nutrient supply generally produces low algal biomass, whereas increasing enrichment supports progressively greater productivity.

Application

The stem specifies an extremely nutrient-poor water body. In the trophic sequence, that description corresponds to the oligotrophic state.

Contrast

• Dystrophic describes brown-coloured water dominated by humic substances, often acidic and low in light penetration.

• Oligotrophic describes clear water, sparse algal biomass, and high dissolved oxygen at depth.

• Mesotrophic describes intermediate algal biomass and moderate productivity between nutrient-poor and nutrient-rich states.

• Eutrophic describes dense algal growth and a greater risk of oxygen depletion as organic matter decomposes.

Cross-check

The associated clear-water, low-biomass profile is consistent with an oligotrophic system and contrasts with the greater productivity of mesotrophic and eutrophic systems.

Therefore, the water body is oligotrophic.