Secchi Disk Reading
(monitoring water quality & clarity)
There are many opportunities to contribute to making Big Sauk Lake the best it can be. One way is to participate in the Volunteer Water Monitoring program. Two of your Big Sauk Lake Association board members are helping with this and have been doing so for a number of years.
Jeff Mayer and Vern Beckermann take periodic readings at the locations specified on the map below. Under the map, you can see some good information that explains what a secchi disk is, where it came from, and some variations.
The links below will bring you to the MPCA data summary for the main bays of Sauk Lake. It looks like secchi disk data collection on Sauk Lake started in 1972 in one bay and 1980 in the other.
https://cf.pca.state.mn.us/water/watershedweb/wdip/details.cfm?wid=77-0150-02
https://cf.pca.state.mn.us/water/watershedweb/wdip/details.cfm?wid=77-0150-01
Jeff Mayer and Vern Beckermann take periodic readings at the locations specified on the map below. Under the map, you can see some good information that explains what a secchi disk is, where it came from, and some variations.
The links below will bring you to the MPCA data summary for the main bays of Sauk Lake. It looks like secchi disk data collection on Sauk Lake started in 1972 in one bay and 1980 in the other.
https://cf.pca.state.mn.us/water/watershedweb/wdip/details.cfm?wid=77-0150-02
https://cf.pca.state.mn.us/water/watershedweb/wdip/details.cfm?wid=77-0150-01
A Secchi disk is a circular metal plate attached to a calibrated rope. It is probably the most inexpensive and easy to use tool in water quality monitoring. One of the best aspects of the Secchi disk is that the information provided by the Secchi disk is easily interpreted by volunteers and can be used to detect water quality trends in lakes.
The Secchi disk is named after Fr. Pietro Angelo Secchi, scientific advisor to the Pope and astrophysicist. Secchi was asked by Commander Cialdi, head of the Papal Navy, to measure the transparency in the Mediterranean Sea. The first disk was lowered from the papal yacht, l'immacolata Concezion (Immaculate Conception), on April 20, 1865 (Carlson and Simpson, 1996).
Secchi disk color and style varieties
There have been many revisions to the first disks used by Secchi in terms of size and color. The two most common colors variations in use today are the all-white disk and black-and-white-quadrant version. In Minnesota, we use an all-white, 8-inch-diameter metal disk with notched sides for rope storage when the disk is not in use.
The Secchi disk is named after Fr. Pietro Angelo Secchi, scientific advisor to the Pope and astrophysicist. Secchi was asked by Commander Cialdi, head of the Papal Navy, to measure the transparency in the Mediterranean Sea. The first disk was lowered from the papal yacht, l'immacolata Concezion (Immaculate Conception), on April 20, 1865 (Carlson and Simpson, 1996).
Secchi disk color and style varieties
There have been many revisions to the first disks used by Secchi in terms of size and color. The two most common colors variations in use today are the all-white disk and black-and-white-quadrant version. In Minnesota, we use an all-white, 8-inch-diameter metal disk with notched sides for rope storage when the disk is not in use.
