How do soluble phosphorus and nitrogen affect water quality?

• A. They can lead to spikes in nutrient concentrations, adversely impacting aquatic ecosystems.
• B. They remove nutrients from water.
• C. They decrease algal growth.
• D. They stabilize temperatures.

Answer: (A)

Soluble phosphorus and nitrogen act as readily available nutrients in water, so when they enter a body of water, they can quickly boost the level of nutrients that algae and aquatic plants can use. This often leads to rapid growth or blooms of algae. When these blooms explode, they disrupt the ecosystem: shading and outcompeting other plants, altering food webs, and, as the blooms decompose, consuming oxygen in the water. That drop in dissolved oxygen can create dead zones and stress or kill fish and invertebrates, degrading overall water quality.

So, the best description is that soluble phosphorus and nitrogen can lead to spikes in nutrient concentrations, adversely impacting aquatic ecosystems. They do not remove nutrients, nor do they decrease algal growth or stabilize temperatures—their primary impact is fueling nutrient-driven growth and the associated ecological problems.