Eutrophication and Its Effects

Producers

• Definition: Organisms that carry out photosynthesis (e.g., plants, algae).
• Requirements: Carbon dioxide, sunlight, water, and minerals (nitrogen, phosphorus, potassium).
  • Essential for growth: The more resources available, the better they grow.
  • Limiting factor: Growth can be limited if any requirement is in short supply.

Importance of Fertilizers

• Purpose: To supplement minerals that may be limiting factors.
• Benefit: Increases crop production to meet global food demands.
• Problem: Excess fertilizers can be washed away into water bodies.

Eutrophication

• Definition: The process by which a body of water becomes enriched in dissolved nutrients ("well-nourished").
• Causes: Runoff of fertilizers from farmland into lakes and oceans.
• Effects on Algae:
  • Algae thrive with increased nutrients, growing rapidly on the water surface.
  • Extensive algal growth can cover the surface of water bodies.

Consequences of Algal Blooms

• Light Blockage: The algal layer prevents sunlight from reaching deeper water levels.
  • Result: Death of plants at the bottom due to lack of sunlight.
• Organic Matter Increase: Decomposing algae provide organic matter for microorganisms.
  • Microorganisms:
    • Use aerobic respiration, requiring oxygen.
    • Proliferate due to abundant dead organic material.
    • Deplete oxygen levels in water.

Impact on Aquatic Life

• Oxygen Depletion:
  • Reduces available oxygen for fish and other aquatic organisms.
• Biodiversity Loss:
  • Leads to death of various species and a decrease in biodiversity.