What frequently causes eutrophication in lakes?

• A. A diminished supply of nitrates and phosphates
• B. Industrial poisons
• C. An increase in primary consumers
• D. None of the listed responses is correct.
• E. Nutrient enrichment such as nitrate and phosphate runoffs from land

Answer: (E)

Verified step by step guidance

1. Understand the concept of eutrophication: Eutrophication is the process by which a body of water becomes overly enriched with minerals and nutrients, leading to excessive growth of algae and other aquatic plants.
2. Identify the primary nutrients involved: The nutrients most commonly associated with eutrophication are nitrates (NO₃⁻) and phosphates (PO₄³⁻). These compounds are essential for plant growth and can lead to algal blooms when present in high concentrations.
3. Recognize the sources of these nutrients: Nitrate and phosphate runoffs typically originate from agricultural activities, where fertilizers are used, and from urban areas where wastewater and sewage can contribute to nutrient levels in nearby water bodies.
4. Consider the impact of nutrient enrichment: When lakes receive an excess of these nutrients, it can lead to rapid algae growth, which depletes oxygen levels in the water as the algae die and decompose, affecting aquatic life.
5. Evaluate the options given in the problem: The correct answer is nutrient enrichment, specifically nitrate and phosphate runoffs, which are not listed among the options provided. This highlights the importance of understanding the underlying causes of eutrophication.