What impact does eutrophication have on aquatic ecosystems?

Eutrophication refers to the process whereby water bodies receive excess nutrients, primarily nitrogen and phosphorus, leading to an overgrowth of algae and aquatic plants. This phenomenon significantly impacts aquatic ecosystems by promoting the rapid growth of certain organisms, particularly algae, a situation often referred to as an algal bloom.

When eutrophication occurs, the increased nutrient levels encourage the proliferation of algae and aquatic pests, which can overshadow or outcompete other species for sunlight and resources. As the algae die and decompose, a process called hypoxia occurs, where oxygen levels in the water decrease, potentially leading to dead zones. This decrease in oxygen can severely affect fish and other aquatic organisms, leading to reductions in their populations.

Thus, the correct answer highlights how eutrophication fosters the growth of aquatic pests, which can disrupt the balance of the ecosystem and lead to further ecological consequences. Understanding this relationship is crucial for effectively managing aquatic ecosystems and mitigating the negative impacts associated with nutrient pollution.