Define turbidity and explain why high turbidity can be harmful to aquatic ecosystems.

• A. Turbidity is the measure of water temperature.
• B. Turbidity is the color of water due to dissolved minerals.
• C. Turbidity is cloudiness from suspended particles; high turbidity reduces light, harms photosynthesis, and can clog fish gills.
• D. Turbidity is the presence of chlorine in water.

Answer: (C)

Turbidity is the cloudiness of water caused by suspended particles like sediment, silt, and organic matter. When turbidity is high, these particles scatter and absorb light, reducing how far light can penetrate the water. That shaded light limits photosynthesis by aquatic plants and algae, which can lower oxygen production and disrupt the base of the aquatic food web. The suspended particles can also settle on the bottom, smother habitats, and physically irritate or clog the gills of fish and other aquatic animals, making respiration and feeding more difficult. Plus, the particles can carry pollutants and nutrients that promote problems like eutrophication, stressing ecosystems further. So the description of turbidity as cloudiness from suspended particles, with the resulting reduction in light and potential harm to organisms, is the best explanation. It’s not about water temperature, it’s not about color from dissolved minerals, and it’s not about chlorine presence.