Florida Wastewater Practice Test

What role does phosphorus play in aquatic environments?

1. It acts as a toxic agent

2. It contributes to organic sediment

3. It is a key nutrient for plant growth

4. It promotes mineral deposition

The correct answer is: It is a key nutrient for plant growth

Phosphorus is recognized as a key nutrient that supports the growth of aquatic plants, including algae and macrophytes. In aquatic ecosystems, phosphorus is essential for various biological processes, particularly photosynthesis and energy transfer. When phosphorus is present in sufficient quantities, it can stimulate plant growth and increase productivity within the water body. However, an excess of phosphorus can lead to eutrophication, where nutrient over-enrichment results in rapid algal blooms. As these blooms die off and decompose, they can deplete oxygen levels in the water, harming fish and other aquatic organisms. Thus, while phosphorus plays a critical role as a nutrient for plant growth, its concentration must be monitored to maintain a balanced and healthy aquatic environment. Other options do not align with phosphorus's function; it is not inherently a toxic agent or primarily responsible for organic sediment or mineral deposition but rather plays a fundamental role in nutrient cycling and the support of aquatic biodiversity.