Which of the following is a common consequence of eutrophication in aquatic systems?

Eutrophication refers to the excessive enrichment of water bodies with nutrients, particularly nitrogen and phosphorus, often due to runoff from agricultural or urban areas. This nutrient overload stimulates the rapid growth of algae, leading to algal blooms. One of the most significant consequences of this phenomenon is the depletion of oxygen levels in the water. As algae die and decompose, the decomposition process consumes oxygen in the water, which can lead to hypoxic (low oxygen) conditions. These conditions are detrimental to aquatic life, as many species, including fish and invertebrates, require sufficient oxygen to survive. Thus, decreased oxygen levels is a direct and common consequence of eutrophication in aquatic systems.

In contrast, increased biodiversity and enhanced fish populations are generally not outcomes associated with eutrophication; rather, the opposite tends to occur, as low oxygen levels can lead to fish kills and a decline in species diversity. Improved water clarity is also unlikely because algal blooms typically decrease visibility in the water rather than enhance it.