| /

The Secchi Stick is a simple analytical device to determine optical density of a liquid.  The depth at which the disk is no longer visible is taken as a measure of the transparency of the water. This measure is known as the Secchi depth and is related to water turbidity.  We have a video on it's operation on youtube.



PLOT: Nannochloropsis: Dry Weight and Cell count as a Function of Secchi Stick Depth.