If a water body is healthy and supports no significant biological activity, then its condition is called:

A healthy water body low in nutrients and biological activity is called oligotrophic.

Its clear, well-oxygenated water supports only sparse plant and algal growth.

Hypotrophic is not a standard term for this trophic condition.

Mesotrophic describes a body with a moderate, intermediate level of nutrients.

Eutrophic describes the opposite state, rich in nutrients and choked with algal growth.

As nutrient enrichment proceeds, an oligotrophic lake can gradually turn eutrophic.