Water clarity refers to how clear or transparent water is, which can be influenced by various factors such as sediment, algae, and pollutants. Clear water allows sunlight to penetrate, supporting aquatic life and ecosystems. Measuring water clarity often involves using a tool called a Secchi disk, which is a black-and-white disk lowered into the water until it is no longer visible. The depth at which it disappears indicates the clarity level. High clarity is essential for the health of aquatic habitats, while low clarity can signal environmental issues.