What is a primary concern of eutrophication in water bodies?

Eutrophication is primarily characterized by the excessive growth of aquatic plants and algae in water bodies, which is mainly triggered by an overabundance of nutrients, particularly nitrogen and phosphorus. These nutrients often originate from agricultural runoff, wastewater discharge, and other human activities. When these nutrients enter a water body, they stimulate the rapid growth of algae, leading to phenomena such as algal blooms.

This excessive plant and algae growth can have significant ecological impacts, including the shading of submerged aquatic plants, which diminishes their growth and disrupts the habitat for fish and other aquatic organisms. Furthermore, when the algae die and decompose, the process consumes dissolved oxygen in the water, leading to hypoxia or anoxia, which can result in dead zones where aquatic life cannot survive.

Other options like increased levels of dissolved oxygen, reduction of water surface temperature, and decrease in water salinity do not represent primary concerns associated with eutrophication. In fact, eutrophication typically leads to lower oxygen levels, higher temperatures due to reduced light penetration, and can affect salinity, but these are secondary consequences rather than primary concerns. Thus, the growth of aquatic plants, marked by this uncontrolled proliferation caused by nutrient overload, is the central issue at the heart of eut