How does eutrophication affect aquatic ecosystems?

Eutrophication significantly impacts aquatic ecosystems by promoting excessive plant growth, particularly algae. This phenomenon typically occurs when an overabundance of nutrients, especially nitrogen and phosphorus, enters water bodies, often from agricultural runoff or sewage discharge. The excess nutrients stimulate rapid algal blooms, which can cover the surface of the water and deprive other aquatic organisms of sunlight necessary for photosynthesis.

As the algal blooms die off, they sink to the bottom, where they are decomposed by bacteria. This decomposition process consumes large amounts of oxygen from the water, leading to hypoxic or anoxic conditions—meaning there is insufficient oxygen available for fish and other aquatic organisms to survive. The resultant oxygen depletion can cause significant die-offs of these organisms, disrupt the balance of the ecosystem, and lead to dead zones where life cannot be sustained.

Understanding the consequences of eutrophication is crucial for effective water management and conservation strategies aimed at protecting aquatic ecosystems from nutrient overload and its associated effects.