Turbidity can harm aquatic plants by doing what?

• A. Increasing light penetration
• B. Decreasing nutrient availability
• C. Reducing light penetration and slowing photosynthesis
• D. Increasing water clarity

Answer: (C)

Turbidity lowers light penetration in water because suspended particles scatter and absorb sunlight. Aquatic plants rely on light to drive photosynthesis, so when light cannot reach their tissues effectively, the photosynthetic rate drops. With less photosynthesis, plant growth slows or declines, making turbidity harmful to aquatic vegetation. The key idea is that the main damage from turbidity is light limitation, not an increase in nutrients or clearer water. Increasing light or water clarity would help plants, while turbidity—by clouding the water—reduces light. Nutrient availability matters too, but turbidity’s direct effect on plants is through reduced light and slower photosynthesis.