What effect do nutrients typically have when they enter a body of water?

Nutrients entering a body of water, particularly nitrogen and phosphorus, can significantly impact aquatic ecosystems. When these nutrients are abundant, they create a situation conducive to the rapid growth of algae, which can lead to harmful algal blooms. These blooms can produce toxins that are detrimental to aquatic life, wildlife, and even humans, disrupting entire ecosystems.

In contrast to this, while some nutrients might enhance photosynthesis in beneficial plants, too much nutrient input tends to favor algal growth over that of more desirable submerged aquatic vegetation. Additionally, high nutrient levels often lead to turbidity and reduced water clarity rather than promoting clear water, and they do not actively affect water temperature. Therefore, the primary concern when discussing the entry of nutrients into water bodies is the potential for harmful algal blooms, which can have severe ecological and health implications.