What is a Secchi disc?
A Secchi disk is a circular metal plate attached to a calibrated rope. It is probable the easiest and less expensive tool to use in water quality monitoring. One of the best aspects of a Secchi disk is that the information can be easily interpreted by volunteers and can be used to detect water quality trends. What does a Secchi disc measure? Water clarity is a quick and easy measurement that tells a lot about lake water quality. First, it indicates the amount of light penetration into a lake. Second, Secchi transparency provides an indirect measure of the amount of suspended material in the water, which in many cases is an indication of the amount of algae in the water. How do I take a Secchi disc reading? First, anchor your boat over the deepest part of the lake. Lower your secchi disc into the water over the shady side of the boat (do not wear sunglasses). Keep lowering the disc until you can no longer see the white of the disc (eg. 3.0m). Note this depth and then raise the disc slig
