What is one major environmental impact of increased nitrogen loading in water bodies?

Increased nitrogen loading in water bodies is primarily associated with the deterioration of water quality. When excessive nitrogen, often from agricultural runoff or wastewater, enters aquatic ecosystems, it leads to nutrient pollution. This results in an overabundance of nutrients, particularly nitrogen, which fuels the growth of algae.

This rapid increase in algae, often referred to as algal blooms, can deplete oxygen levels in the water as the algae decay, leading to hypoxic or anoxic conditions, which are detrimental to aquatic life. Additionally, algal blooms can produce toxins that harm fish, other aquatic organisms, and potentially humans. This cascade of effects deteriorates the overall quality of the water, making it unsafe for consumption, recreation, and damaging the habitat for various species.

In contrast, other options suggest outcomes that do not align with the negative consequences associated with excessive nitrogen loading. Improved aquatic plant growth can occur initially but may not be sustainable and can lead to imbalances. While a reduction in algal blooms and an increase in biodiversity are typically linked to better water quality, they would not be valid outcomes of increased nitrogen levels.