What does excessive nutrient richness in a water body, often caused by runoff, lead to?

Excessive nutrient richness in a water body, primarily due to runoff containing fertilizers and other nutrient-rich substances, leads to a process known as eutrophication. This phenomenon is characterized by the rapid growth of algae (algal blooms) that thrive on the abundant nutrients, particularly phosphorus and nitrogen.

As algae proliferate, they can block sunlight from penetrating the water, disrupting the photosynthesis process of aquatic plants. When the algae eventually die and decompose, this decomposition process consumes significant amounts of dissolved oxygen in the water, which can lead to hypoxic or anoxic conditions detrimental to aquatic life. Eutrophication not only affects oxygen levels but also alters the overall ecological balance of the water body, potentially resulting in the loss of biodiversity.

In contrast, while acidification and deoxygenation may occur as a consequence of certain types of pollution, they aren’t directly related to the specific event of excessive nutrient enrichment. Pollution is a broader term that encompasses a variety of contaminants and does not specifically describe the process triggered by nutrient overload. Therefore, eutrophication is the most accurate term to describe the consequence of excessive nutrient richness.