What is the limiting nutrient typically found in lakes that affects their ecological balance?

Phosphorus is often the limiting nutrient in freshwater ecosystems, such as lakes, and plays a crucial role in maintaining their ecological balance. In these environments, the availability of phosphorus typically controls the growth of algae and aquatic plants. When phosphorus is present in adequate amounts, it can stimulate algal blooms, which can lead to eutrophication—a process that depletes oxygen in the water and can negatively affect fish and other aquatic organisms.

The reason phosphorus is commonly limiting is due to its low concentration in most freshwater systems compared to other nutrients like nitrogen. While nitrogen can also influence algal growth, it is usually much more abundant in these ecosystems than phosphorus. As a result, managing phosphorus levels is essential to preventing excessive nutrient loading and maintaining the health and balance of aquatic environments. This understanding is fundamental for environmental engineering and management practices aimed at protecting water quality.