oligotrophic

This term is primarily used in limnology and oceanography to describe bodies of water that are nutrient-poor. It carries a neutral scientific connotation, though in environmental contexts, it is often contrasted with eutrophic states, which describe nutrient-rich waters prone to algal blooms.

Because it is a technical descriptor of a chemical state, it is almost exclusively found in academic papers, ecological reports, and textbooks. It is rarely used in casual conversation unless the speaker is discussing specific aquatic ecosystems or water quality management.