Which term describes lakes or waters with low nutrients, low productivity, clear water, and little life?

• A. Oligotrophic
• B. Mesotrophic
• C. Eutrophic
• D. Highly productive

Answer: (A)

Nutrient availability drives how productive a lake is and how clear the water stays. Lakes with low nutrients have limited plant growth, so the water remains clear and there isn’t much life present. This is the oligotrophic state: very low concentrations of nutrients like phosphorus and nitrogen, low primary production, clear water, and often deep, cold conditions with high dissolved oxygen throughout the water column.

That matches the description given. In contrast, mesotrophic lakes have moderate nutrients and productivity, eutrophic lakes are rich in nutrients and very productive with murkier water, and “highly productive” isn’t a standard classification but would imply a situation like eutrophic or hypertrophic.