Disque Secchi - Secchi disk

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The Secchi Disk is a tool used by scientists to measure water clarity in oceans, lakes and rivers worldwide. It's simple yet effective method of measuring transparency has become an essential component in aquatic research. To use the Secchi Disk, researchers will first need to locate the depth at which the disk disappears from view underwater. The depth is then recorded and the process is repeated until the disk can no longer be seen.