Temperature and Secchi Disk Readings
The weekly testing of water temperature and clarity using a Secchi disk provides a valuable indication of the productivity of the lake. The more productive a lake is, the higher the algal growth and, therefore, the less clear the water becomes. The Secchi disk (left) is used to measure the depth of light penetration.
While natural processes affect the productivity and the “age” of a lake, man-made activities can hasten the process. Nutrients (primarily nitrogen and phosphorous) are required for plant growth (algae, weeds ...). These nutrients can enter the lake as a result of runoff from livestock areas, faulty septic systems, or commercial fertilizers applied to fields, lawns and gardens. Secchi disk data is used to identify trends which can indicate problems with nutrient loading in the lake.
This information was most recently used in the BC Lake Stewardship Society pamphlet “The Importance of Bridge Lake and its Watershed”. To read the PDF-File ( 8 pages, 2.2 MByte) click here. A hardcopy of this report can also be obtained if you send an email to firstname.lastname@example.org