Which of the following best describes the condition of a eutrophic lake?

A eutrophic lake is characterized by having a high concentration of nutrients, particularly nitrogen and phosphorus. These nutrients promote the overgrowth of algae and aquatic plants, leading to increased organic matter within the lake. This high nutrient load often results in a condition known as algal blooms, which can deplete oxygen levels in the water as the algae decay, harming aquatic life.

In contrast, the other descriptions do not align with the definition of a eutrophic lake. A lake that is predominantly clean and low in nutrients would actually be termed oligotrophic, indicating a lack of organic matter and a clearer water column. The reference to stability with low variability does not accurately depict the dynamic nature of nutrient fluctuations and biological activity in a eutrophic lake. Lastly, a description of a clear lake with limited fish activity does not apply to eutrophic conditions, as the presence of high nutrients leads to abundant biological productivity, which typically supports a greater diversity of fish and aquatic life, albeit potentially leading to oxygen deficits.