What is a common characteristic of algal blooms related to eutrophication?

Algal blooms, particularly those associated with eutrophication, are characterized by the rapid growth of algae in response to nutrient enrichment, often from fertilizers or other nutrient sources. A common outcome of these blooms is that they significantly decrease the availability of light in the water. As the algae proliferate, they form dense mats on the surface of the water. This dense growth blocks sunlight from penetrating deeper into the water column, which can inhibit the growth of submerged aquatic plants that rely on light for photosynthesis.

The reduction of light availability can have cascading effects on the aquatic ecosystem. For example, lower light conditions can lead to decreased growth of beneficial aquatic plants, which serve as habitats and food sources for various aquatic organisms. Additionally, when algae eventually die off, their decomposition consumes oxygen in the water, potentially leading to hypoxic or anoxic conditions that can be harmful or fatal for fish and other aquatic life.

The other options do not accurately reflect the consequences of algal blooms. While enhancing biodiversity and creating stable ecosystems may sound positive, algal blooms typically disrupt these processes instead. Moreover, algal blooms are not always beneficial for aquatic life; in fact, they can lead to detrimental conditions that affect many organisms in freshwater and marine environments.